Biochemical and nutritional analysis of seaweed (Iyengaria stellata) and its therapeutic significance, using antioxidant, antimicrobial, and hypoglycemic activities

Abstract

Seaweeds have gained significant attention for their bioactive compounds and extensive use in pharmaceuticals, nutraceuticals and cosmeceuticals. Therefore, comprehensive analysis was conducted to investigate the nutritional composition, identify and quantify the Phyco-chemicals and to evaluate the pharmacological potential using hypoglycemic, antimicrobial and antioxidant activities of Iyengaria stellata extract. The results of nutritional analysis revealed 39.72±2.60 % total ash, 14.54±0.44 % crude fat, 9.61±0.60 % proteins, 5.29±0.52 % crude fibers, 10.49±1.00 % moisture content, and total energy was 108.26±2.01 Kcal 100 g−1 of dry powder. Approximately, 15 compounds were tentatively detected in ethyl acetate extract with major compounds being Pentadecanoic acid, 14-methyl-, easter (31.62 %), (Z) -9- stearic acid, methyl easter (13.36 %), Elaidic acid, methyl easter (11.46 %), Phytol (6.31 %), n-Hexadecanoic acid (7.47 %), Linolelaidic acid, methyl ester (5.64 %) and 1-octadecyne (5.34 %). Similarly, n-butanol extract contained 16 compounds with primary compounds being Hexadecanoic acid, methyl ester (25.96 %), Elaidic acid methyl ester (21.39 %), Linolelaidic acid methyl ester (11.53 %), Octadecanoic acid, methyl ester (5.89 %), and Hexanedioic acid, dioctyl ester (5.26 %). FT-IR analysis revealed the presence of similar groups of compounds i.e. alcohols, phenols, lipids, carboxylic acids, amines, aromatics, ketones and halogens. Total phenolic contents (TPC) in ethyl acetate and n-butanol extract were measured as 2.982±0.876 mg GAEg−1 and 1.538±0.711 mg GAE g−1, whereas Total Flavonoids contents (TFC) were 2.058 ± 0.121 mg QE g−1 and 1.614 ± 0.643 mg QE g−1, respectively. Ethyl acetate extract exhibited more antioxidant potential with an IC50 (2.59±1.34) compared to n-butanol extract (2.75±1.60). Moreover, n-butanol extract exhibited strong antimicrobial activity. The most susceptible strains were E. coli, S. aureus and P. aeruginosa. In terms of in-vivo hypoglycemic activity, the n-butanol extract proved to be more effective which significantly reduced the blood glucose level up to 226.17±3.43, 201.33±4.63 and 265.17±3.92 at 300, 200 and 100 mg kg−1 doses respectively after 24 h. In conclusion, the seaweed I. stellata exhibited significant potential in terms of its antioxidant, antimicrobial, and hypoglycemic properties.