POTENTIAL HEALTH BENEFITS FROM ALGAE: WOMEN HEALTH, LONGEVITY AND BEAUTY

ANTIOXIDANT ACTIVITY

Antioxidants produce positive effects on health care by acting as a shield to our bodies. They stabilize free radicals (reactive oxygen species), which react with large molecules such as lipids, proteins, DNA that cause diseases, e.g., mellitus, diabetes, aging, cancer, and neurodegenerative disorders [105]. Due to the number of health benefits produced by the antioxidants, they are commercially synthesized and deliberately added to the food and pharmaceutical items. TBHQ (tert-butylhydroquinone), BHA (butylated hydroxyl anisole), BHT (butylated hydroxyl toluene), and PG (propylene glycol) are a few examples of commercially available synthetic antioxidants. These synthetic antioxidants are also used to overcome the oxidation process and different peroxidation reactions.

They have the potential to cause different health risks, therefore, proper knowledge and strict regulatory limits regarding their best usage should be followed [117]. However, natural antioxidants are safe, cheaper, and fittest alternatives in food production and processing [120]. Currently, pharmaceutical industries are conducting extensive research to develop natural antioxidants based on plants and marine sources. Among marine flora, marine algae are abundant sources having safe and natural antioxidants [91, 135].

Sulfated polysaccharides (SPs) produced by marine algae are considered a good source of dietary fiber (Table 6.3), at the same time different research works also explored the great antioxidant potential of SPs. Fucoidan, laminaran, and alginic acid are a few main classes of SPs which showed antioxidant activity [132,170]. Antioxidant potential of SPs can be analyzed through different analyses like DPPH (2-diphenyl- 1-picrylhydrazyl), FRAP (ferric reducing antioxidant power), NO (nitric oxide) scavenging, ABTS assays [2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)], hydroxyl radical scavenging, and lipid peroxide inhibition methods. Kim et al. [70] demonstrated as compared to commercially available antioxidants (BHA, a-tocophorol), Sargassitm fulvellum having SPs, is a comparatively more effective scavenger. Different structural properties of SPs are directly related to their antioxidant activities like sulfating degree, molecular mass, categories of the mam sugar and glycosidic bonding [123, 188].

SPs having lower molecular mass have revealed as more effective antioxidants as compared to SPs of higher molecular mass [152]. Various types of ulvans (Ulva pertusua) having different molecular mass, varied in their ability of Н,О_л degradation and antioxidant activities [123]. Qi et al. [123] also stated high antioxidant potential of lower molecular mass ulvans. It was explained that lower molecular weight ulvans may easily and efficiently integrate into the cells; therefore, they are more effective in proton donation. Among fucoidan, alginate, and laminaran from Turbinaria conoides, fucoidan revealed maximum antioxidant activity [20].

TABLE 6.2 Antioxidant Compounds Derived from Marine Algae

Marine algae-based natural pigments (fucoxanthin, phycoerythrobilin, chlorophyll) can also contribute to antioxidative functions (Tables 6.2-6.4). Yan et al. [182] investigated that mam antioxidant compound (fucoxanthin) from Hizikia ftsiformis showed maximum radical scavenging activity due to double allenic bonds at C-70 position. Sachindra et al. [136] isolated fucoxanthin from Undaria pimiatifida and further synthesized two metabolites known as fucoxanthinol and halocynthiaxanthin. Antioxidant potential of these formulated metabolites was assessed through DPPH assay, scavenging of hydr oxyl radicals, and quenching of singlet oxygen. Fucoxanthin showed the highest scavenging activity followed by fucoxanthinol and halocynthiaxanthin [136].

Phycobiliproteins in marine algae are extensively applied as natural dye in foods and cosmetic industry. Extensively used compounds as dyes in food and cosmetic industry are C-phycocyanin, C-phycocyanin, and

R-phycoerythrin [144]. Compared to ardenia and indigo to give bright blue color in food items, phycobili proteins (despite their decreased stability under heat and light) are approved for multipurpose use in foods. Antioxidant functions of phycoerythrobilin isolated from Porphyra sp. were also explored [180]. Based on research studies on biocompounds from marine organisms, natural pigments are more effective and non-poisonous having the highest antioxidant activity.

TABLE 6.3 Marine Algae-Based Soluble, Insoluble, and Total Dietary Fiber