Objectives: The synthetic antioxidants produce numerous adverse effects to overcome these adverse effects and the use of natural products is the alternative. In this study, the evaluation of total phenolics, flavonoid contents, and antioxidant properties of Punica granatum, Psidium guajava, and Vitis vinifera seed extracts was done. Methods: The total phenolic content was estimated with gallic acid equivalent and the total flavonoid contents were estimated on quercetin equivalent. For the antioxidant properties of selected seed extracts, the 2,2-diphenyl-1-picrylhydrazyl radical scavenging, ferrous reducing power, and hydrogen peroxide radical scavenging assays were followed to find the free radical scavenging ability of the selected seed extracts. Results: The ethyl acetate extract of P. granatum seed contains higher phenolic content (70.25±1.25 μg/ml) and flavonoid content (58.15±1.85 μg/ml) and possesses a high free radical scavenging ability. Based on the inhibitory effects of fruit seeds against synthetic radicals, they can be ranked as P. granatum>P. guajava>V. vinifera. Conclusion: According to overall observations of the study, the pomegranate seed extract contains a higher level of phenolic and flavonoid contents and shows a higher scavenging effect against free radicals among the others seeds. Phytochemical screening showed that the ethyl acetate extract of pomegranate fruit seed possesses more secondary metabolites compared to other seed extracts.

A novel molecule PG-1, tri-O –punicyl glycerol was isolated and characterized from the seed extract of Punica granatum which was found to possess ant proliferative effect against lung cancer cell lines (A549) without any harmful effects on fibroblast cell line. The IC50 value determined by MTT assay is 25±8.5µg/ml for PG-1 and that of L- ascorbic acid is 22±7.4. Comet assay showed the damage of DNA at a concentration of 250µg/ml and Flow cytometry indicated a cell cycle arrest at G0 phase at a concentration of 12µg/ml. PG-1 also possesses an effective antioxidant activity which was determined through in vitro DPPH and ABTS assay methods. In DPPH assay the IC50 value was 26±5.7 µg/ml, 24±6.8 µg/ml and in ABTS assay the IC50 value was 26±0.62 µg/ml and 23±0.65µg/ml, for PG-1 and L-ascorbic acid respectively. PG-1 can be considered as a lead molecule from a natural plant P. granatum with lower side effects against lung cancer cell line (A549). Further the GC-MS analysis of ethyl acetate extract from P. granatum led to the identification of twelve compounds out of which octadecatrienoic acid which constitutes 19.88% of the whole extract is the major compound.