Phytochemical and Biological Characterization of Phyllanthus emblica Seed Extract

Background: Plant-derived compounds play a vital role in the development of several therapeutic agents. Phyllanthus emblica, Indian gooseberry has both dietary and medicinal uses. Its fruit is health beneficial, and the seeds are eliminated during consumption which may have biological activity hence the seed of P. emblica has to be investigated. Our study aims to evaluate the antioxidant, antibacterial activity, in vitro cytotoxic potential and to determine the presence of various bioactive compounds of P. emblica seed extract. The ethanolic P. emblica seed extract was subjected to phytochemical screening and antibacterial activity was evaluated using the well diffusion method against Streptococcus mutans and Enterococcus faecalis. Antioxidant ability was determined by DPPH, ABTS and phosphomolybdenum reduction assay. Further, Gas chromatography-mass spectrometry (GC-MS) was used for the identification of bioactive compounds.  Results: The phytochemical screening identified the presence of secondary metabolites such as terpenoids, phytosterols, phenols, flavonoids, tannins, glycosides, carbohydrates, saponins, and quinines in P. emblica seed extract. The total tannin and flavonoid contents were 514.24 mg TAE/g and 861.9 mg QE/g respectively. The seed extract exhibited antibacterial activity against S. mutans and E. faecalis. The ethanolic seed extract showed high scavenging activity in DPPH (96.38%), ABTS (98.88%) assay and had a potent reductive ability (81.92%) in phosphomolybdate assay. The MTT assay revealed the extract exhibited maximum cytotoxicity against SCC25 cells at a concentration of 200 μg/ml. The GC-MS analysis of the P. emblica seed extract showed the presence of 17 bioactive compounds and the major compounds were cyclotrisiloxane, hexamethyl, di-n-octyl phthalate, 1,2-dihydro-1,4-dimethoxy-2-oxoquinazoline, calycotomine, methyl, phenol, 2,4-bis (1,1-dimethyl ethyl) and 1-dodecanol, 3,7,11-trimethyl. Hence, the presence of these compounds in seed extract may be responsible for therapeutic intervention.  Conclusions: The study analysed the biological activity of the seed, and the identified bioactive phytochemicals could be selected in the pharmaceutical industry for drug discovery.