In Vitro Antioxidant and Anti-Inflammatory Activities of Seaweeds From the Bay of Bengal Coastal Region in Lipopolysaccharide-Induced RAW264.7 Cells.

Seaweeds are marine macroalgae that are rich in various secondary metabolites known to exhibit different biological activities such as anti-diabetic, anti-inflammatory, antioxidant, etc. This study aimed to determine the bioactive metabolites, as well as the antioxidant and anti-inflammatory activities of two red algae (Ceramium virgatum and Gracilaria corticata) and two green algae (Enteromorpha flexuosa and Ulva fasciata), which are prevalent in the coastal region of the Bay of Bengal. The total phenolic and flavonoid contents were determined using the Folin-Ciocalteu and aluminium chloride methods. Antioxidant and anti-inflammatory activities were evaluated using the ABTS assay and protein denaturation, LPS-induced RAW264.7 cells, respectively. The highest total phenolic (5.73 ± 0.06 mg GAE/g dry extract) and flavonoid (5.25 ± 01.6 mg QE/g dry extract) contents were found in C. virgatum, and it also shows good antioxidant activity with an IC50 value of 258.66 µg/mL. The protein denaturation assay and NO production inhibition assay of C. virgatum showed the lowest IC50 value (65.39 µg/mL) and lower NO level. Analysis of secondary metabolites using HR-LCMS reveals the presence of 12 phytoconstituents in C. virgatum extract. From these results, it is evident that C. virgatum can contribute to the development of antioxidant and anti-inflammatory agents.