Chemical Composition of Ethanolic Extracts from some Seaweed Species of the South Indian Coastal Zone, their Antibacterial and Membrane-Stabilizing Activity

The present study was intended to investigate the presence of major chemical components in seaweed extracts by using of Fourier-transform infrared spectroscopy (FTIR) and to explore the antibacterial and in vitro anti-inflammatory (membrane stability) properties of ethanolic extracts of nine different seaweeds collected from the Ramewaram coastal region. Total flavonoid content (TFC) and total tannin content (TTC) of ethanolic extracts were determined using spectrometric method. Antimicrobial activity of ethanolic extracts was tested against six bacterial strains using the disc diffusion method. Study of the preliminary anti-inflammatory activity of seaweed extracts was performed by the HRBC membrane stabilization method. Turbinaria ornata shows the highest TFC and TTC among all the studied seaweed species. Significant differences were observed in anti-inflammatory activity of ethanolic extracts from various seaweeds investigated using the human red blood cell (HRBC) membrane stabilization method. HRBC membrane stabilization activity of ethanolic extracts of seaweeds exhibited dose dependency and increased with increasing concentration of the extract. Ethanolic extract of T. ornata had the strongest growth inhibition against Proteusmirabilis. FTIR spectroscopy analysis of three seaweeds provided a detailed report of major functional constituents and chemical components. It can be concluded that seaweeds are rich in polyphenols to which acquire potent antimicrobial and anti-inflammatory activity. Seaweed extracts are a major breakthrough for pharmaceutical application.