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Seaweed as a Superfood - Vitamins, Minerals, Fiber and Protein Prperties Brown seaweeds Natural digestion remedies excellent sources of Angioxidant molecules with a wide range of seaaweed effects, whose content can vary depending on several og, Cognitive function enhancers the origin and nAtioxidant environment in which seawfed algae grow. Cognitive function enhancers This Antioxidant properties of seaweed and algae aimed to estimate proeprties compounds regarding primary and secondary metabolites of eight brown macroalgal species from a clean Egyptian Red Sea coast. A proximate analysis, pigment, phenolic compounds, and vitamin contents were determined. Results: Based on the chemical composition, Polycladia myrica was the most valuable species, with a comparatively high protein content of This species also acts as a great source of vitamin C, flavonoids, tannins, phenol content and total antioxidant capacity. Discussion: The antioxidant activity of the selected algae indicated that its phenol, vitamin and pigment contents were powerful antioxidant compounds based on the structure—activity relationships.Antioxidant properties of seaweed and algae -
The assay was carried out with the caspase-3, caspase-8 and caspase-9 Colorimetric Assay Kit BioVision Inc. Treated cells were counted and pelleted 1 × 10 6 cells. Cell pellets were resuspended in 50 μL of chilled lysis buffer from the kit: mM sodium chloride, 1.
The suspensions were incubated in ice for 10 min and subsequently centrifuged at 10, × g for 1 min. Protein concentrations were quantified using the Bradford assay. A total of 50 μg of protein as estimated by the Bradford assay was diluted with 50 μL of cell lysis buffer. Dithiothreitol DTT 10 μL was added to 1 mL of 2X reaction buffer from the kit.
Samples were diluted with dilution buffer and the absorbance taken at nm. MCF-7 cells were treated with the most potent fraction of each sample for 24 and 48 h. The DNA of the cultured cells was then extracted with Tri Reagent. Samples were electrophoresed at 80 V for 2 h by 0.
A p -value of less than 0. SPSS, version The seaweeds were extracted in five different solvents, i. The cytotoxic activity of each extract on MCF-7 cells was determined. As shown in Table 1 , the methanolic extracts of C.
ornata had the lowest IC 50 values. For P. tetrastromatica , only the hexane extract showed an IC 50 value. Among all samples tested, T. ornata showed cytotoxic activity with most of the solvents, compared with P. tetrastromatica and C. Thus, the hexane extract of P. tetrastromatica and methanolic extracts of C.
ornata were chosen for partial purification through column chromatography. No cytotoxicity was observed in extract-treated B5 cells. MCF-7 and B5 cells were treated with doxorubicin as a positive control. The drug showed IC 50 values at 0.
The hexane extract of P. tetrastromatica was the only extract that was able to achieve IC 50 among all the five solvents tested. Hence, it was postulated that MCF-7 cells were more susceptible to the effects of the hexane extracts of P.
tetrastromatica than the other solvents. However, in the case of C. ornate , the methanolic extracts of both seaweeds exhibited greater potency among the five solvents tested. Thus, it is suggested that MCF-7 cells are more susceptible to the effects of polar compound s from the methanolic extracts of C.
ornata as methanol is a polar solvent. The susceptibility and resistance of MCF-7 cells to different extracts vary as the compound s present in all the marine organisms have variable polarity and extractability [ 27 ].
From the results obtained, the seaweed extracts were more suited to be used as chemotherapeutic agents as compared with the standard drug, doxorubicin. This is because treatment with doxorubicin in normal breast cells B5 resulted in high toxicity to the cells. The cytotoxic activity of the extracts can be attributed to the presence of active phytochemicals such as quinine and alkaloids.
Quinine derivatives confer cytotoxic activity via interference of DNA and RNA replication and mitochondrial oxidative pathways, as well as through the formation of peroxide, superoxide and hydroxyl radicals in the cell. Cytotoxic activity of alkaloids, on the other hand, is due to the presence of microtubule interfering agents that can bind to beta tubulin, thus inhibiting the formation of the mitotic spindle fibre required for cell division [ 28 ].
The methanolic extract of P. terastromatica and C. racemosa ; and the DCM extract of T. ornata showed the highest percentage yield among all five solvents tested, with yields of 8. The lowest percentage yield of P. ornata was in hexane 0. However, the acetone extract of T. ornata had the highest TPC with a value of The methanolic extracts of P.
racemosa demonstrated the highest TPC among the five solvents used for each seaweed sample, with TPC values of The variations in the TPC values obtained in this study might be due to the dilution of phenolic concentration per g extract by extracted matter other than phenolic compounds.
This is because methanol is not only an effective solvent for the extraction of phenolics but also for the extraction of other compounds [ 29 ]. All three samples showed significantly higher TPC ranging from 6. Methanol is generally the most suitable solvent for the extraction of polyphenolic compounds due to its ability to inhibit the action of polyphenol oxidase that leads to the oxidation of polyphenols Yermilo et al.
Other studies have also reported methanolic extracts as having the highest TPC in edible Japanese brown seaweeds, three Nigerian plants and Tecoma stans , also known as yellow elder or small tree [ 29 ].
Methanolic extracts contain significantly high TPC as phenolic compounds are typically more polar compounds. Generally, the two brown seaweeds, P. tetrastromatica and T. ornate , had higher TPC compared to the green seaweed, C.
This might be attributed to the presence of phlorotannins, bi-polar polyphenols commonly found in brown seaweeds. Phlorotannins show antioxidative properties due to the presence of multiple phenolic groups that assist the algae to overcome oxidative stress arising from their environment [ 29 ].
The TFC of the different solvent extracts of the three samples are shown in Table 2. tetrastromatica had the highest TFC ornata had the lowest TFC of 4. The acetone extract of T. ornata , on the contrary, demonstrated a relatively low TFC 8. Flavonoids are the major subclass of polyphenols and antioxidants in plants.
Generally, flavonoids occur as glycosides, containing several phenolic hydroxyl groups on their ring structures. Flavonoids are effective ROS scavengers due in part to the presence of phenolic hydroxyl groups [ 32 ].
It was postulated that flavonoids may have direct contribution to antioxidative actions. Antioxidant activity depends on the number and position of hydroxyl groups, other substituents and glycosylation of flavonoid molecules [ 33 ].
ornata in this study showed relatively low TFC despite having a high TPC value, suggesting that flavonoids are not the most abundant polyphenols present in T. ornata , and the high TPC values might be due to the presence of other phytochemicals such as phenolic acids, stilbenes, lignans, alkaloids, essential oils, ascorbic acid, tocopherols, carotenoids and steroids [ 34 ].
The TFC values of the four marine organisms in the present study were higher than that of two seaweeds Ulva lactuca and Sargassum wightii with TFC values of 1.
As reported by Cox et al. Phenolic compounds act as antioxidants via several pathways. The most significant pathway is the scavenging of free radicals in which free radical chain reactions can be interrupted by phenolic compounds.
In addition, polyphenols demonstrate antioxidant activity by the inactivation of lipid radicals and by the prevention of degradation of hydroperoxides to free radicals.
Antioxidant activities are predominantly attributed to their redox properties, allowing them to act as reducing agents, singlet oxygen quenchers and hydrogen donors. The hexane extract of C. racemosa showed the lowest IC 50 value of ornata was the highest The free radical scavenging assay using the DPPH radical is a preliminary test for the analysis of the antioxidant potential of extracts.
The assay has been used extensively as it allows high throughput screening and it has high sensitivity for the detection of active ingredients even at low concentrations. Antioxidant activity is related to the presence of bioactive compounds such as phenolics, flavonols and flavonoids.
Polyphenols and anthocyanins scavenge DPPH via the donation of hydrogen, thus reducing DPPH DPPH-H. Since the DPPH radical scavenging activity of the seaweeds in our study is considerable, they could be used as substitutes to replace harmful synthetic antioxidants commonly used in processed food products, such as butylated hydrotoluene BHT and butylated hydroxyanisole BHA , which have been reported to be carcinogenic and tumorigenic at high doses [ 37 ].
In our study, all three samples demonstrated higher DPPH radical scavenging activity ranging from This might be attributed to the different extraction methods used. As reported by Luo et al. ornata , with the highest TPC, demonstrated the highest percentage of superoxide anion inhibition of ornata ranging from Only the ethyl acetate, acetone and methanolic extracts of T.
ornata demonstrated strong superoxide anion scavenging activity. The IC 50 values of these extracts were significantly lower than that of the positive controls, indicating their higher potency in scavenging superoxide anions. Therefore, the antioxidant mechanism of these extracts might be mainly due to their superoxide anion scavenging ability.
Superoxide anion is the reduced form of molecular oxygen produced from the mitochondrial electron transport system upon the acceptance of a single electron. Energy is generated from mitochondria using electron transport chain reactions.
Any loose electrons from the electron transport chain reactions will react directly with molecular oxygen, forming superoxide anion, which is the precursor for the formation of other ROS, including hydrogen peroxide, hydroxyl radicals and singlet oxygen [ 38 ].
ornata demonstrated stronger superoxide anion scavenging activity compared to the positive controls. This might be attributed to the presence of sulfated polysaccharides from T.
ornata which have been reported to be excellent antioxidants for the management of oxidative stress [ 39 ]. The methanolic extract of T. ornata exhibited the highest percentage of inhibition of The DCM and acetone extracts of T.
Nitric oxide NO is an important cellular messenger involved in numerous physiological functions of the body.
Nitric oxide is generated from L-arginine by vascular endothelial cells, certain brain cells and phagocytes. The damage brought about by nitric oxide and oxygen free radicals is further exacerbated as they react to produce peroxynitrites, which in turn lead to severe toxic reactions in nucleic acids, proteins and lipids [ 31 ].
The NO generated from sodium nitroprusside SNP reacts directly with oxygen to produce nitrite. The results shown in Table 2 indicate that the dichloromethane extract of C.
racemosa and the DCM and acetone extracts of T. ornata in SNP solution are capable of decreasing the levels of nitrite. The reduction in the nitrite level might be due to the direct competition between the extracts and oxygen in the reaction with NO.
The DCM extract of C. ornata had lower IC 50 than the IC 50 of ethyl acetate extract of Cassia auriculata leaves Hexane and acetone extracts of C. racemosa and the methanol extract of T. ornata showed similar IC 50 values The results in Table 2 show that all three samples exhibited strong hydroxyl radical scavenging activity, comparable to that of quercetin.
The hydroxyl radical is the most reactive radical and has the shortest half-life among other ROS due to its ability to induce severe damage to adjacent molecules. It can cause cell damage by reacting with lipids, saccaharides, polypeptides and nucleotides.
In this study, EDTA, which acts as an iron chelator, was not used. Hence, hydroxyl radicals are generated site-specifically whereby unchelated iron ions are weakly associated with deoxyribose. These iron ions then react with hydrogen peroxide through the Fenton reaction, forming hydroxyl radicals that launch an immediate attack on the deoxyribose.
When extracts are added to the reaction mixture, they remove the hydroxyl radicals from deoxyribose, thus directing the damage towards them and preventing the reaction [ 22 ]. The IC 50 values indicate that these extracts are better hydroxyl radical scavengers than rutin.
The three samples under study showed a higher percentage inhibition of hydroxyl radicals ranging from The TPC of P. ornata were found to be positively correlated with the DPPH radical scavenging activity with Pearson correlation coefficient r values of 0.
Brown seaweeds P. ornata had higher TPC values compared with that of C. The Pearson correlation coefficients for P. ornata were similar, indicating that their DPPH radical scavenging activity might be attributed to their similar antioxidant content [ 41 ].
The DPPH scavenging activity of these brown seaweeds might be due to the presence of phlorotannins, the major antioxidants in brown seaweeds [ 29 ]. The scavenging activity of the green seaweed, C.
racemosa , on the other hand, might be due to the presence of phytochemicals such as ascorbic acid, folic acid, Vitamin A and B1 [ 18 ]. All three enzymes exhibited a decrease in activity relative to the control in a time-dependent manner.
There was a sharp decrease in CAT activity within the first 8 h. Antioxidant enzyme activities of methanolic extracts of P.
ornate for 8, 16 and 24 h. a superoxide dismutase SOD , b catalase CAT , c glutathione reductase GR. Note the enzyme activity decreasing upon treatment.
Antioxidant enzymes are involved in the direct elimination of ROS in cells. SOD constitutes the first line of defence against ROS in living cells. SOD catalyzes the dismutation of superoxide radical, which is the precursor of hydroxyl radicals and other ROS, to hydrogen peroxide H 2 O 2 and water.
CAT, on the other hand catalyses the conversion of H 2 O 2 to oxygen and water. GR facilitates the removal of H 2 O 2 and organic peroxides [ 42 ]. Cancer cells generate excessive amounts of ROS, contributing to an altered redox status.
These ROS include H 2 O 2 and NO. An augmented level of ROS will lead to oxidative stress. One of the hallmarks of cancer cells as compared to normal cells is a persistent pro-oxidative state that can lead to intrinsic oxidative stress [ 43 ].
If the ROS produced could be removed immediately by free radical metabolizing enzymes SOD, CAT and GR , normal cells might be protected against the cancer and carcinogenesis. The activities of SOD, CAT and GR for all three samples were found to be reduced in comparison to the untreated cells.
The reduction in CAT activity is considered as a general response to stress. It has been suggested that the reduction in CAT activity is due to the inhibition of enzyme synthesis or alterations in the assembly of enzyme subunits under stress conditions [ 44 ].
A decrease in CAT and GR activities in treated MCF-7 cells might be due to increasing ROS. CAT can be downregulated by ROS while peroxides and hydroxyl radicals inactivate GR [ 45 ].
Accumulation of ROS due to the reduction in the enzyme activities might be the cause of cancer cell killing. The partially purified fractions obtained from column chromatographic separation were subjected to the MTT assay. The cytotoxic activity of the partially purified fractions of all samples in MCF-7 cells increased significantly Table 3.
The column chromatographic separation of whole extracts yielded purer compounds which resulted in more potent cytotoxic activity. As shown in Table 3 , there was significant enhancement of cytotoxic activity in the partially purified fractions of P.
ornata as compared to the crude extracts. A plausible explanation of this is because most unwanted components which are not bioactive, such as coloured pigments, resin or wax, were removed during sequential extraction, leaving only cytotoxic compounds or other bioactive phenolic compounds [ 46 ].
In addition, the existence of antagonistic interactions in the whole extracts could account for their weaker activities than those observed in the fractions [ 47 ]. Moreover, whole extracts may be inactive due to the fact that the active fractions or components may be present in minute quantities.
Hence, their effects could have been suppressed by other compounds. However, the aforementioned compounds became concentrated and therefore exhibited higher activities upon fractionation [ 48 ]. Following determination of cytotoxic activity, the pooled fractions P2 of P.
tetrastromatica , P1 of C. racemosa and P1 of T. ornata were subjected to LC-MS analysis. Pseudopelletierine eluted at The compounds detected are summarised in Fig. MS spectra of protonated and deprotonated molecules. b Compounds with pharmacological activity isolated and identified in P.
ornata fractions. Marine organisms such as fungi, bacteria, seaweeds and sponges are taxonomically diverse and biologically active, offering a wide array for the discovery of new anticancer drugs derived from bioactive compounds with medicinal properties such as terpenoid derivatives, flavonoids, flavones, alkaloids, glycosides, polyphenolics and steroids [ 49 ].
Alkaloids are widely present in natural products particularly in ethnobotanically important plants and marine organisms.
Furthermore, alkaloids have been of specific interest due to their physiological activities including anticancer, antiviral and antimalarial activities [ 50 ]. LC-MS profiling revealed the presence of three important cytotoxic alkaloids in the seaweeds, which include camptothecin, lycodine and pseudopelletierine.
Camptothecin quinoline alkaloid is one of the most well-known examples of cytotoxic alkaloids and accounts for approximately one-third of the global anticancer drug market [ 51 ].
Orhan et al. Pseudopelletierine isolated from the stem bark and root of pomegranate was believed to have antimicrobial, anthelmintic and molluscicidal as well as antiuraemic activities [ 53 ]. Camptothecin, lycodine and pseudopelletierine had been reported to exhibit remarkable antioxidant activities such as DPPH, superoxide and hydroxyl radical scavenging activities [ 54 — 56 ].
Therefore, it is postulated that these compounds are the main contributors to the cytotoxic activity of the seaweeds in our study. The caspase-8 activity of P. tetrastromatica increased and peaked at 16 h treatment by 1.
ornata peaked at 8 h treatment by 1. Caspase-9 activities peaked at 8 h treatment by 1. ornata Fig. Caspase-3 activities of P. racemosa increased and peaked at 24 h treatment by 2. Caspase-3 activities of T.
ornata , on the other hand, peaked at 8 h treatment by 2. Caspase activities of MCF-7 cells treated with seaweed fractions. ornata column chromatographic fraction. Note caspase activity induction upon cell treatment.
It is hypothesized that the MCF-7 cells in this study died due to the cytotoxic effects exerted by the seaweed extracts. MCF-7 cell death might be induced by two mechanisms, necrosis and apoptosis. Necrosis is occasionally related to external damage, resulting in accidental cell death.
Consequently, mitochondrial and cytoplasmic swelling, followed by compromised membrane integrity which subsequently leads to cell burst and release of cytoplasmic contents will occur [ 57 , 58 ]. Apoptosis, on the other hand, involves a sequence of events, starting with the release of mitochondrial cytochrome c, activation of caspase cascades, degradation of poly- ADP -ribose polymerase PARP and eventually fragmentation of chromosomal DNA [ 59 — 61 ].
Caspase-3 plays a crucial role as early apoptosis biochemical markers in mammalian cells. The activity of the caspases studied suggests that the extracts inhibited the proliferation of MCF-7 cells by inducing apoptosis via both extrinsic ligand-receptor mediated pathway and intrinsic mitochondrial mediated pathways, since caspase-8, 9 and 3 were all activated.
The mechanism by which caspase-8 is activated is unclear. However, since autoactivation induced by oligomerization can lead to activation of caspase-8, it could be possible that the samples induced oligomerization of caspase In the extrinsic pathway, interaction of ligands, such as TNF or Fas, with their death receptors, Fas-associated death domain FADD , leads to activation of initiator caspase caspase Executioner caspase caspase-3 appears as a zymogen in cells and has no activity until it is cleaved by an initiator caspase caspase-8 or 9 after being stimulated by apoptotic stimuli.
Activated caspase-8 cleaves and activates caspase-3, which subsequently cleaves various substrates, leading to apoptosis [ 62 ]. In the intrinsic pathway, caspase-8 cleaves BID pro-apoptotic member of Bcl-2 family and causes the release of cytochrome c from the mitochondria.
Cytochrome c together with apoptotic protease activating factor 1 APAF1 , ATP and procaspase-9 form an apoptosome, which then activate caspase Caspase-9 in turn activates caspase-3, resulting in apoptosis [ 63 ].
Figure 4 shows DNA degradation in extract-treated MCF-7 cells whereas the untreated control cells showed intact genomic DNA when observed with a UV transilluminator. Smearing pattern was observed in lanes 2, 4, and 6 DNA from cells treated with P. ornata for 24 h , whereas a typical laddering pattern was observed in lanes 3, 5 and 7 treatment with the same samples for 48 h.
This is because caspase-3 was activated at 24 h for P. racemosa and activated at 8 h for T. DNA fragmentation in MCF-7 cells treated with seaweed fractions. ornata for 24 and 48 h, respectively. DNA fragmentation is one of the hallmarks of apoptosis. The activity of caspase-3 is closely related to the initiation of DNA fragmentation.
tenuistipitata , and the data were To determine the antioxidant ability of extracts, the phosphomolybdenum method is widely utilized. In this method, converting Mo VI to Mo V forms phosphomolybdenum V complex, a bluish-green colored compound in the presence of antioxidant-containing substances.
tenuistipitata A nm 3. However, in the context of water extract, G. In the crude methanolic extract, P. tetrastromatica had the highest antioxidant activity of tenuistipitata had Methanolic extracts of P.
tetrastromatica Extracts showed their activity in a concentration-dependent manner. When compared to all other crude extracts, the IC 50 value of the positive control i.
The antioxidant activity of crude extracts was evaluated using the nitric oxide scavenging assay. Here, methanolic extracts of P. The scavenging activity showed concentration-dependent manner for the all the crude extracts of both seaweed.
All antioxidant activities of crude seaweed extracts were positively correlated with one another, which evidently point out that phenolic compounds are primarily accountable for the antioxidant properties. Prospective studies show that total phenolic and flavonoid content are significant antioxidant activity determinants in different crude extracts of seaweed.
The physiological and mechanical capabilities of marine living beings that permit them to endure in multifaceted living forms give an extraordinary impending generation of secondary metabolites phytochemicals , which are not observed in earthborn circumstances.
Hence, crude extracts of seaweed are amongst the foremost excessive fountainheads of unique, exceptional, and identified bioactive compounds And the fact that only a few studies have been conducted on Bangladeshi seaweed assets emphasizing its bioactivity or secondary metabolites existences.
Hence, it becomes time demanding to be familiar with almost completely unexplored Bangladeshi seaweed assets for way more excellent knowledge of its bio-functional activity as the abundance and accessibility of bioactive compounds of seaweeds are to a significant extent changes concurring to geographic area, natural condition, season, development and fair as the profundity of inundation In Bangladesh, however, there is a lack of information on available secondary metabolites and antioxidant properties of seaweed.
However, other researchers explored Bangladeshi seaweeds, and a variety of phytochemicals and promising antioxidant properties were discovered 16 , Hence, in the present study, we used a combination of qualitative and quantitative tests Phytochemical analysis and FTIR to screen out for functionally bioactive compounds and determine antioxidant activities using various in vitro spectroscopic assays of different crude extracts of two significant Bangladeshi seaweeds P.
Furthermore, a correlation between TPC, TFC, and antioxidant activity was investigated in order to well appreciative the role of phenols and flavonoids in antioxidant activity.
The presence of any phytoconstituents primarily influenced by the dissolvable solvent used for extraction and the seaweed physicochemical properties. The essential bioactive compounds in seaweed can be screened using various methods while keeping different solvents and situations in consideration In this study, we used methanol, ethanol, and water extracts having a dielectric constant of about 33, 25, and 80, respectively The phytochemical screening indicates active secondary metabolites such as saponin, terpenoid, cardiac glycoside, phlobatannin, phenolic, and flavonoid in various extracts at different concentrations Table 1.
Among them, terpenoids were absent in the aqueous extract in both seaweed because they are non-polar compounds and required non-polar solvents for extraction Besides these, all components showed positive results in the methanolic extract of both seaweeds.
Our present finding coincides with the findings of other authors; who also found several phytochemicals in case of altered solvents from brown seaweed P. tetrastromatica 20 , But in the case of G. tenuistipitata there has been no prior research on preliminary phytochemical screening was found in the literature.
However, some scholars also identify several phytoconstituents from red algae G. corticata and G. verrucosa respectively, which the current results validate 34 , As indicated by the relevant studies, several phytochemicals in red algae H.
musciformis collected in Bangladesh, linked to the current observation Fourier transformed infrared spectroscopy FTIR can be intended to qualitatively analyze different functional groups in seaweed crude extracts Fig.
Previous researcher also used FTIR to identify several phytochemicals from brown seaweed P. tetrastromatica , associated with our current observation 33 , They noticed a different category of compounds in other extracts, which may be attributed to differences in extraction methods and seaweed origin.
Also, some scholars identify different functional groups from red seaweed G. rubra and H. musciformis , respectively, which is almost similar to the present findings 16 , The incidence of specific fatty acids in various extracts has been observed, determining each extract's antioxidant activity.
The polarity of any solvent plays a significant role in the extraction of phenolic compounds from some plant or fruit Since it can suppress polyphenol oxidase activity, methanol is usually the most effective solvent for polyphenolic extraction Our present study found that methanolic extract contained a significant amount of phenolics, tetrastromatica and In contrast, ethanol and water extract contain fewer amounts Table 3.
Similar results in red and brown seaweed obtained from the Bangladeshi coast Some academics reported tetrastromatica , which is a more petite figure than the one we have now 43 , This wider variety of results may be attributed to environmental conditions, the origin of the seaweed, or the varietal extraction method.
Similarly, methanol extract has the most significant percentage of total flavonoid content for both seaweed species Table 3. Our results obtained are similar to the case of other researchers, who also found that methanolic extracts showed the maximum quantity of TFC compared to other solvents 16 , 21 , Flavonoids are natural phenolic compounds having a unique structural characteristic which leads them to a wide range of biofunctional properties, like free radical scavenging and antioxidant properties It is often difficult to quantify the antioxidant efficacy of any natural extracts as individual studies work through unique specific mechanisms More specifically, different methods such as PTIO and nitroprusside-Griess reagent are being used for performing NO scavenging assay In our present study, different in vitro antioxidant assays including DPPH, ABTS, reducing power assay, phosphomolybdenum, H 2 O 2 scavenging and NO scavenging assay were performed to evaluate antioxidative properties of the crude extracts of two seaweeds.
The antioxidant efficacy of altered crude extracts increased with increasing concentration, showing that these properties are dose dependent. The influence of the amount of bioactive phytochemicals might be responsible for higher antioxidant activity with the increase of concentration.
In the case of all antioxidant assays, it was observed that brown seaweed P. tetrastromatica showed higher activity compared with the red seaweed G. An approach similar to ours has been presented earlier 28 , The antioxidant capacity of the crude extracts ordered in the rank methanol, ethanol and water extract Fig.
This is due to the fact that methanol extracts can have an H-donating property, allowing them to stop the oxidation process by transforming free radicals to stable compounds. However, the highest effect was observed for ethyl acetate fraction in the case of P. pavonica 52 , ethyl acetate and petroleum ether fraction in the case of G.
verrucosa 53 and aqueous extract in the case of P. boergesenii 54 which are contradictory to the present findings. These differences might be due to the variation in solvent used for analysis and the differences in the analytical method. Here, TPC and various antioxidant assays of seaweed extracts shown a strong positive linear correlation.
Other scholars also documented a similar positive linear correlation amongst TPC and various antioxidant activities of seaweed extract 16 , 28 , Though, other researcher observed a negative correlation between TPC and antioxidant activity activity of lipid peroxidation inhibition in the case of red seaweed which test was not performed in our current research Furthermore, total phenolics and flavonoid content of various seaweed extracts had a similar positive correlation which is in agreement with the results of other researchers 28 , Our present finding evidently recommends the existence of phenolic or flavonoid compounds in methanolic extracts may be primarily responsible for the result of the highest antioxidant activity in the crude extracts.
Mature G. tenuistipitata and P. Saint Martin's Island is still considered a biologically diverse ecosystem free of external pollutants, with a dense growth of various seaweeds. Permission of sample collection was gained from the local government before harvesting seaweed following local and national regulations.
In this experiment, samples of two different species of seaweeds one red and one brown were commonly found in the rocky surfaces during low tide.
The entire plant was collected from the exposed rock to ensure that the holdfast would not be left out. The collected thallus was washed thoroughly with clean seawater to remove dirt, sand, and other impurities.
Fresh samples were then washed thoroughly with distilled water for further removal of any other remaining impurities. Dried seaweed sample was grounded to make fine powder as the finer the powder, the more efficient the extraction would be.
Four gram of seaweed fine powder was soaked in mL of solvent water, methanol and ethanol by maceration for the preparation of an extract by solvent extraction.
The sample was kept in the dark for 24 h with intermittent shaking for better extraction. After incubation, the solution was filtered with Whatman filter paper No 4 20—25 µm retaining hygienic conditions. After filtration, the remaining wet powder was again extracted in their respective solvents for 12 h through sporadic shaking and filtered to get the maximum out of the sample powder.
Newly prepared all crude extracts of seaweed were subjected to qualitative assessments for the identification of various classes of active phytochemical constituents such as saponin 58 , terpenoid 59 , cardiac glycosides 60 and phlobatannin 16 following standard methods.
General reactions in these analyses exposed the presence or absence of these compounds in the crude extracts tested. Different crude extracts of P.
tenuistipitata were used to determine the presence of characteristic peaks and their functional groups using FTIR spectroscopy Perkin Elmer Spectrum 2 61 , 62 , FTIR spectra were recorded within the wavelengths of and cm —1. Analysis was done in triplicate and confirmed the spectrum in case of all extracts.
This parameter was carried out in the crude extracts using Folin-Ciocalteu Phenol reagents and external calibration with Gallic acid following by 41 with slight modification. Briefly, 0.
After 15 min, 2. The concentration of total phenolics was calculated as mg of Gallic acid equivalent per gram. The calibration equation for Gallic acid was.
This parameter was computed in the crude extracts using the aluminum chloride colorimetric method with minor modifications Briefly, 1 mL extract solution was mixed with 3 mL methanol, 0.
The solution was then incubated at RT for 30 min and absorbance was measured at nm. The concentration of total flavonoids was calculated as mg of quercetin equivalent per gram.
The calibration equation for Quercetin was. The DPPH free-radical scavenging assay was carried out in triplicate with negligible modification Ascorbic acid was used as a positive control.
The percent radical scavenging activity of the crude extracts was calculated using the following formula:. The antioxidant activities of different extracts were evaluated through the ABTS radical scavenging by the extracts ability to scavenge ABTS with slight modification IC 50 values were tested for each sample at each concentration.
The percentage of inhibition was calculated using the following formula,. Antioxidant activity of different crude extracts reducing power at various concentrations with insignificant modification Briefly, 1.
After incubation at 50 °C in a water bath for 20 min, 1. The supernatant was collected and mixed with 3 mL of DW and µL of ferric chloride solution 0. Here ascorbic acid was used as a positive control.
Antioxidant activity was also expressed as equivalents of ascorbic acid. The antioxidant activity of different extract solution water, ethanol and methanol was evaluated by the green phosphomolybdenum complex formation with slight modification A reagent solution was prepared with 0.
Further, 1. Blank was run same procedure just replacing the extract with the equivalent solvent. Extracts antioxidant activities were evaluated by the hydrogen peroxide scavenging activity with slight modification Briefly, aliquot extracts at various concentrations was added 0.
Different concentrations were tested for each sample to get IC 50 value. The percentage of inhibition of the crude extracts was calculated using the following formula:.
where: A 0 is the Absorbance of control and A 1 is the Absorbance of sample solution. Different crude extracts antioxidant activity was evaluated by the NO scavenging ability with slight modification Briefly, 50 µL of extracts was mixed with µL of sodium nitroprusside SNP, 10 mM and incubated the mixture at room temperature for 4 h.
Further, µL of griess reagent was added to the mixtures. The obtained experimental data was analyzed through the standard statistical procedure. Data were analyzed using SPSS software IBM Co.
All analyses were performed in triplicate. Herzberg, G. The Spectra and Structure of Simple Free Radicals Cornell University Press, Google Scholar. Han, D. Mitochondrial respiratory chain-dependent generation of superoxide anion and its release into the intermembrane space.
Article CAS PubMed PubMed Central Google Scholar. Machlin, L. Free radical tissue damage: Protective role of antioxidant nutrients 1. FASEB J. Article CAS PubMed Google Scholar. Fang, Y. Free radicals, antioxidants, and nutrition.
Nutrition 18 , — Joseph, N. Oxidative stress and ADHD: A meta-analysis. Article PubMed Google Scholar. James, S. et al. Metabolic biomarkers of increased oxidative stress and impaired methylation capacity in children with autism.
Halliwell, B. Oxidative stress and cancer: Have we moved forward?. Article CAS Google Scholar. Valko, M. Free radicals and antioxidants in normal physiological functions and human disease.
Cell Biol. Hwang, O. Article PubMed PubMed Central Google Scholar. Forsberg, L. Oxidative stress, human genetic variation, and disease.
Vertuani, S. The antioxidants and pro-antioxidants network: An overview. Liu, R. Synthetic phenolic antioxidants: A review of environmental occurrence, fate, human exposure, and toxicity.
Article ADS CAS PubMed Google Scholar. Kim, E. Antioxidant and DNA protection activities of a glycoprotein isolated from a seaweed, Saccharina japonica. In addition, some of the polyphenols contained in marine algae are metabolites not found in terrestrial plants, which makes their contribution through algae complementary to that of terrestrial vegetables Brown seaweeds are characterized by the production of phenols and flavonoids In this study, three phenolic compounds were evaluated, including phenol, flavonoids, and tannins Figure 5.
spiralis contained the highest total phenolic content TPC However, S. trinodis had the lowest TPC Several studies have reported comparable phenol levels The phenolic concentration in the tested algal methanolic extracts exceeded that reported by Elkhateeb et al. subrepandum collected from Hurghada 2.
This variation in total phenol content might be related to the types of algal species and the solvent used for extraction. The DPPH activity was evidenced in the present work by an equation that seems to depend mainly on the phenol content. Figure 5. Phytochemical contents of phenols, flavonoids, and tannins in the tested seaweeds.
Flavonoids consist of a large group of polyphenolic compounds with a benzo-𝛾-pyrone structure and antioxidant activity, which depends on the number and position of the free OH groups 59 , Flavonoids stabilize the ROS by reacting with reactive radical compounds.
The hydroxyl group of flavonoids had the high reactivity to convert free radicals to inactive form as shown in the following equation 55 :. The present study achieved a total flavonoid content TFC of the tested seaweeds ranging from The inhibition of lipid peroxidation by tannin constituents can act via the inhibition of cyclooxygenase The highest and lowest contents of tannins were found in D.
spiralis euryphyllum 9. The results obtained were smaller than those detected by Shobier et al. sinuosa fluctuated from 0. Moreover, Ismail et al. The antioxidant activity of seaweeds arises from their chemical compositions, including their phenolic compounds, pigments, polysaccharides, vitamins, and precursor contents such as AsA , micro- and macroelements, and proteins Among the different types of algae, it is a well-known fact that brown algae usually have the highest antioxidant activity, followed by red and green algae Three simple methods were used to evaluate the antioxidant capacity of the methanolic extract of the brown species, including the DPPH free-radical scavenging activity, total antioxidant capacity and hydrogen peroxide assay Figure 6 ; Table 2.
The maximum DPPH scavenging activity of spiralis, and the minimum of These results are better than the AsA standard These findings are consistent with those of Farghl et al. In contrast, the TAC approach may be broadly classified as ET, which was used to assess and evaluate the antioxidant activity of various seaweed components electron donors.
TAC showed that the scavenging value fluctuated from 6. euryphyllum to The other six species exceeded that reported by Farghl et al. The highest and lowest H 2 O 2 scavenging activities among the studied seaweeds were observed in D.
Ismail et al. aquifolium and S. euryphyllum collected from the Red Sea may be related to their polysaccharide content. Table 3 shows the statistically significant correlation between the three antioxidant activities of the selected species and 19 estimated parameters.
This statistical analysis confirmed the vital role of different estimated antioxidants with different antioxidant mechanisms as previously illustrated. Table 3. Seaweeds contain a variety of bioactive compounds that have nutritional and therapeutic attributes, making them an intriguing potential resource.
They contain low-calorie content and a variety of important nutrients, such as proteins, vitamins, and fiber, as well as the presence of bioactive substances with functional qualities that provide further benefits for health, such as phenolic compounds.
There is a growing trend to use Phaeophyta in functional food production around the world and holds great promise for the future. Seaweeds are high in a variety of nutritious compounds as well as unique metabolic chemicals phlorotannins, fucoxanthin, and sulfated polysaccharides with intriguing bioactivities, making them excellent candidates for nutraceutical applications with higher value-added.
So, this study has an innovative approach to evaluating the value of the studied brown seaweed as a substitute food source. Applying inexpensive and simple laboratory techniques for analyzing seventeen components is very encouraging. Based on energy and calorie contents, integrating a considerable amount of seaweeds into the diet can reduce the appetite for further eating.
In particular, the phenolic compounds are effective antioxidants in marine algae. Moreover, algal vitamins can be used as safe nutraceutical substances. The production of seaweed-based functional food at an industrial scale could address the limitations and challenges faced by the manufacturer.
Unfortunately, there remain considerable challenges in quantifying these benefits, as well as possible adverse effects. First, there is a limited understanding of the nutritional content of various algal species, geographical regions, and seasons, all of which can substantially affect their dietary value.
The second issue is quantifying which fractions of algal foods are bioavailable to humans and which factors influence how food constituents are released, ranging from food preparation through effects in the gut microbiome.
The third understands how algal nutritional and functional constituents interact in human metabolism. Recently, research has been done on a wide range of food products with incorporated macroalgae, as well as some marketed macroalgae-based food products commercially available today, like food ingredients, nutraceuticals, food supplements, and food hydrocolloids.
MI: conceptualization, collection, identification of seaweed, data processing, writing original draft, and writing review. GE: conceptualization, methodology, data processing, formal analysis, writing original draft, and writing review.
JM: formal analysis, reviewing original draft, and formatting. All authors contributed to the article and approved the submitted version. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
The authors acknowledge the financial assistance provided by the Universidad de Santiago de Compostela, for recovering the publishing fee. Also, the authors are grateful to Madiha Helmy Mostafa Master student, geophysics and geology department Faculty of Science, Alexandria University for her kind help in preparing the maps.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers.
Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
Duarte, CM, Marbá, N, and Holmer, M. Rapid domestication of marine species. doi: PubMed Abstract CrossRef Full Text Google Scholar. Sultana, F, Abdul Wahad, M, Nahiduzzaman, M, Mohiuddin, M, Zafar Iqbal, M, Shakil, A, et al.
Seaweed farming for food and nutritional security, climate change mitigation and adaptation, and women empowerment: a review. Aquac Fish. CrossRef Full Text Google Scholar. Ismail, MM, El Zokm, GM, and El-Sayed, AAM. Variation in biochemical constituents and master elements in common seaweeds from Alexandria coast, Egypt, with special reference to their antioxidant activity and potential food uses: prospective equations.
Environ Monit Assess. Choudhary, B, Chauhan, OP, and Mishra, A. Edible seaweeds: a potential novel source of bioactive metabolites and nutraceuticals with human health benefits.
Front Mar Sci. Pajot, A, Huynh, GH, Picot, L, Marchal, L, and Nicolau, E. Fucoxanthin from algae to human, an extraordinary bioresource: insights and advances in up and downstream processes. Mar Drugs. Lopez-Santamarina, A, Miranda, JM, Mondragon, AC, Lamas, A, Cardelle-Cobas, A, Franco, CM, et al.
Potential use of marine seaweeds as prebiotics: a review. Tagliaprieta, BL, and Pedrosa, MT. Brown algae and their multiple applications as functional ingredientes in food production. Food Res Int. Shannon, E, and Abu-Ghannam, N.
Seaweeds as nutraceuticals for health and nutrition. Ismail, MM, Gheda, SF, and Pereira, L. Variation in bioactive compounds in some seaweeds from abo Qir bay, Alexandria. Egypt Rend Fis Acc Lincei.
Ismail, GA, and Ismail, MM. Variation in oxidative stress indices of two green seaweeds growing under different heavy metal stresses. Michalak, I, Tiwari, R, Dhawan, M, Alagawany, M, Farag, MR, Sharun, K, et al. Antioxidant effects of seaweeds and their active compounds on animal health and production—a review.
Vet Q. Oza, RM. A revised checklist of Indian marine algae , vol. Bhavnagar: CSMCR Institute Google Scholar. Aleem, AA. A preliminary list of algae from Sierra Leone. Bot Mar. Guiry, MD, and Guiry, GM, Algae base. World-wide electronic publication.
Galway, Ireland: National University of Ireland Dubois, M, Gilles, KA, Hamilton, JK, Rebers, PA, and Smith, F. Colorimetric method for determination of sugars and related substances.
Anal Chem. Lowry, OH, Rosebrough, NJ, Farr, AL, and Randall, RJ. Protein measurement with the Folin phenol reagent.
J Biol Chem. Association of Official Analytical Chemists AOAC. Official methods of analysis. Gaithersburg, MD: The Association of Official Analytical Chemists Connan, S. Spectrophotometric assays of major compounds extracted from algae.
Methods Mol Biol. Osório, C, Machado, S, Peixoto, J, Bessada, S, Pimentel, FB, Alves, RC, et al. Pigments content chlorophylls, fucoxanthin and phycobiliproteins of different commercial dried algae.
Nagata, M, and Yamashita, I. Simple method for simultaneous determination of chlorophyll and carotenoids in tomato fruit. Nippon Shokuhin Kogyo Gakkaishi. Pantelidis, GE, Vasilakakis, M, Manganaris, GA, and Diamantidis, G. Antioxidant capacity, phenol, anthocyanin and ascorbic acid contents in raspberries, blackberries, red currants, gooseberries and cornelian cherries.
Food Chem. Prieto, P, Pineda, M, and Aguilar, M. Spectrophotometric quantitation of antioxidant capacity through the formation of a phosphomolybdenum complex: specific application to the determination of vitamin E. Anal Biochem. Taga, MS, Miller, EE, and Pratt, DE. Chia seeds as a source of natural lipid antioxidants.
J Am Oil Chem Soc. Yan, X, Chuda, Y, Suzuki, M, and Nagata, T. Fucoxanthin as the major antioxidant in hijikia fusiformis, a common edible seaweed. Biosci Biotechnol Biochem. Tambe, VD, and Bhambar, RS.
Estimation of total phenol, tannin, alkaloid and flavonoid in Hibiscus tiliaceus Linn. Wood extracts. J Pharmacogn Phytochem. Yepez, B, Espinosa, M, López, S, and Bolaos, G. Producing antioxidant fractions from herbaceous matrices by supercritical fluid extraction.
Fluid Phase Equilib. Gülçin, I, Sat, IG, Beydemir, S, and Küfrevioglo, ÖI. Evaluation of the in vitro antioxidant properties of broccoli extracts Brassica oleracea L. Ital J Food Sci. Michel, G, Tonon, T, Scornet, D, Cock, JM, and Kloareg, B. Central and storage carbon metabolism of the brown alga Ectocarpus siliculosus : insights into the origin and evolution of storage carbohydrates in eukaryotes.
New Phytol. Fouda, WA, Ibrahim, WM, Ellamie, AM, and Ramadan, G.
The antioxidant Antioxidant properties of seaweed and algae and Antioxidant properties of seaweed and algae contents of total seaweeed and flavonoids were quantified in Antiozidant methanolic extracts of four Chaetomorpha species including C. aerea, C. crassa, C. linum and C. Eight samples of Chaetomorpha plants were collected from five locations along the northern coasts of the Persian Gulf in south of Iran from December until October
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