Protective role of edible clam Paphia malabarica (Chemnitz) against lipid peroxidation and free radicals

Objective: To investigate in vitro inhibition of lipid peroxidation and free radical scavenging properties of a seafood Paphia malabarica (Chemnitz) as a natural source of antioxidants. Methods: Antioxidant activities of Paphia malabarica extracts were tested spectrophotometrically against 2,2-diphenyl-2-picryl-hydrazyl, hydroxyl radical scavenging, in vitro inhibitions of lipid peroxidation and results were presented as percentage relative activities by comparing with standard synthetic antioxidant compounds. In addition, reducing potentials and presence of antioxidant compound in sample extract was tested with exponential increase in absorbance and ferric reducing antioxidant power values respectively. Results: The scavenging potential of 2,2-diphenyl-2-picryl-hydrazyl radical and reducing action increased in a dose dependent manner. Inhibition of lipid peroxidation shown by methanol extract and its significant correlation with center dot OH scavenging activity implies its potential to protect the cell damage against reactive oxygen species. Increasing antioxidant equivalents of ascorbic acid in ferric reducing antioxidant power assay further supported its role in reducing reactions. Conclusion: Dose dependant antioxidant responses by methanolic extracts of clam P. malabarica and their role in breaking chain reactions of lipid peroxidation highlights its potentials against reactive oxygen species mediated radical reactions. Present investigation forms a first comprehensive report on the nutraceutical property of a seafood P. malabarica as a natural source of antioxidants.