Phytochemical Evaluation and Bioactivity of Polysiphonia subtilissima Montagne

The chemical profile and bioactivity of Polysiphonia subtilissima, a marine bioactive red alga from the east coast region of Odisha state of India is investigated. Qualitative tests of the extracts confirmed the presence of various primary and secondary metabolites. Moreover, the agar, carrageenan, fatty acids, flavonoids and polyphenols, employed DPPH scavenging, HRBC and optimized critical dilution to test the extracts for antioxidant, anti-inflammatory, antibacterial and anticoagulant effects were investigated. The methanolic extract showed total phenolic (3.14 mg), flavonoid (2.72 mg) and fatty acid (0.12 mg in ethylacetate and 0.1 mg in chloroform) and highest antioxidant activity (95%), at 515.5 nm. At 100 and 200 µg/mL doses, the aqueous extract had the highest anti-inflammatory activity (72.13% and 89.61%). Maximum bactericidal inhibitions of 73.7%, 77.6% and 58% were detected in the ethanolic fraction at 500 µg/mL. Water extract showed anticoagulant action with activated partial thrombo-plastin time (APTT) clotting durations of 139 s, prothrombin time (PT) of 70 s and thrombin time (TT) of 60 s.