Phytochemical Analysis, Antioxidant, Antimicrobial and Anticancer Activity of Nigella sativa and Oroxylum indicum

Medicinal plants are traditionally being used by various communities for curing several ailments. Two plants namely Nigella sativa and Oroxylum indicum were selected for the study based on their traditional use. The seed extract of Nigella sativa and stem bark extract of Oroxylum indicum were subjected to phytochemical analysis and tested for antimicrobial, anticancer and antioxidant activities. Various phytochemicals like alkaloids, steroids, terpenes, phenol, flavonoids and glycosides were reported in both the samples. The total phenol content was found to be 2.018 ± 0.051 mg/g and 16.012 ± 0.005 mg/g in Nigella sativa and Oroxylum indicum, respectively, and total flavonoid content was found to be 0.39 ± 0.018 mg/g and 3.065 ± 0.023 mg/g, respectively. Antioxidant potential was investigated by DPPH method, and IC₅₀ was found to be 64.0 ± 3.59 µg/ml and 110.36 ± 0.50 µg/ml for Nigella sativa and Oroxylum indicum respectively. The methanolic extract of Nigella sativa did not showed any inhibitory action against E. coli but showed significant inhibition against S. aureus, while Oroxylum indicum exhibited mild antimicrobial activity against both the microbes. HCT 116 and HEPA 16 cell lines were used for testing cytotoxic activity of the plant extracts. The results showed that Oroxylum indicum significantly inhibited the growth of HEPA 16 cells whereas Nigella sativa extract significantly inhibited the growth of HCT 116 cells. From the present study, it can be concluded that both the plants are rich in phytochemicals and possess potential antioxidant, anticancer and antibacterial activities.