In vitro antioxidant activities of selected seaweeds from Southeast coast of India

Objective:In vitro antioxidant activities of three selected Indian seaweeds viz.,Halimeda tuna(H.tuna),Turbinaria conoides(T.conoides) and Gracilaria foliifera(G.foliifera) were evaluated.Methods:Total antioxidant activity,total phenolic content,and reducing power of crude methanol and diethyl ether extracts were determined.Results:Total phenolic content and total antioxidant activity were higher(1.231±0.173 mg GAE/g,1.675±0.361 mg GAE/g) in T.conoides respectively.Reducing power of crude methanol extract increased with concentrations of the extract.The Fourier transform-infra red spectrum analysis revealed the presence of polyphenolic signals.The seaweed extracts displayed moderate antioxidant activity compared to gallic acid standard.Conclusions:The seaweeds could be considered for curing diseases from oxidative deteriorations.

Evaluation of antibacterial potential of seaweeds occurring along the coast of Mandapam,India against human pathogenic bacteria

Objective:To investigate the antibacterial activity of six seaweeds against twelve human bacterial pathogens using seven different solvents.Methods:Antibacterial activity was evaluated using the disc diffusion technique on Mueller Hinton agar.Broth dilution assays are standard method used to compare the inhibition efficiency of the antimicrobial agents.Results:Among the six seaweeds tested,the antibacterial activity was higher in the brown seaweeds when compared to red and green seaweeds.Padina gymnospora was found exerting a strong antibacterial activity with a high range inhibition[(6.00±0.82)to(22.67±1.25)mm].Broth dilution assay was conducted against Salmonella sp.with the chloroform extract of Padina gymnospora and the growth inhibition was found in the range of 74.26%to 82.56%.Conclusions:Further research studies are being carried out on other species of seaweeds of different habitats in order to provide complete data of the antimicrobial potential of these algae.It is also essential to study the principle compound present in the seaweeds which is responsible for antimicrobial activity.It can be achieved by using advanced separation techniques.