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 μg/ml and 13 μg/ml for
DPPH radical scavenging assay and 41 and 70 μg/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.