Comparative analysis of phytochemical profile, antioxidant activities and foam prevention abilities of whole fruit, pulp and seeds of Emblica officinalis

Emblica officinalis fruit is commonly used in Ayurvedic formulations for its role in prevention of various diseases. Its seeds have been found to enhance the antioxidant defences of the body in diabetic rats and its pulp methanolic extract is known for its antioxidant potential. However the antioxidant activity of the seed in comparison to pulp needs to be studied. A comparative study of the antioxidant potential of the whole fruit, seeds and pulp, respectively, is needed to identify which part of the fruit could be exploited for pharmaceutical or nutraceutical purposes. We compared the free radical scavenging capacity of the methanol extract of seed, pulp and whole fruit extract and also identified major flavonoids and phenolics by HPLC profiling. We also assessed the oxidized LDL- induced foam cell prevention and nitrite scavenging activity after LPS stimulation of RAW 264.7 macrophages. Pulp showed the highest antioxidant activity compared to seeds with IC50 values of 6 mu g/ml and 13 mu g/ml for DPPH radical scavenging assay and 41 and 70 mu g/ml for nitric oxide scavenging activity, respectively. After 5 h incubation, among the three extracts studied, pulp showed the highest activity-88.89 % prevention of LDL oxidation, higher than that of the standard, ascorbic acid. Phytochemical analysis showed that phenolic content was highest in pulp and total tannins highest in seeds. HPLC profiling documented the presence of caffeic acid, coumaric acid, syringic acid and myricetin in both pulp and seeds with gallic acid present in pulp and tannic acid in seeds and whole fruit extract.