Biomedical Potential and Preliminary Phytochemistry of the Brown Seaweed Sargassum wightii Greville ex J. Agardh 1848

The brown seaweed Sargassum wightii Greville ex J. Agardh 1848 was collected from Pamban (south east coast of Tamilnadu, India; Latitude 9o18’N and Longitude 79o12’ E) and extracted with different solvents such as acetone, ethanol, benzene and chloroform in a soxhlet apparatus. The antibacterial activity of the extracts were tested against natural pathogens isolated from housefly (Musca domestica Linnaeus 1758), such as Staphylococcus aureus, Enterococcus faecalis, Bacillus cereus, Micrococcus luteus, Pseudomonas aeruginosa and Escherichia coli respectively. The extracts were also subjected to alpha amylase inhibitory, anti-inflammatory and antioxidant activities following standard protocols. Ethanol extract exerted high inhibitory effect on all the microbes and was assertive against B. cereus (14.2 mm). Potential and significant (p<0.05) alpha amylase inhibition was observed in the chloroform extract (81.24±8.063%). The benzene extract had significantly (p<0.05) higher antioxidant activity (74.44±3.27%) and the antiinflammatory activity was comparatively higher in the acetone extract (65.5±1.21%). However, the control drugs exhibited better activity than all the tested extracts. The qualitative phytochemistry showed the presence of flavonoids, pholobatannins, phenolic compounds, aromatic acids and xanthoproteins. The Fourier transform infra-red (FT-IR) spectrum contained eight major peaks which confirmed the presence of amino, keto, fluoro alkane group and aromatic compounds in the extracts which could be responsible for the bioactivity.