Chemical composition, antioxidant, antimicrobial, and anticancer activities of Mahonia napaulensis DC. bark from Nepal.

Background: Cancer is one of the major health problems worldwide and medicinal plants constitute a common alternative for cancer treatment having no or fewer side effects. This study aimed to assess total phenolic (TPC) and flavonoid (TFC) contents, antioxidant, biological activities (especially antibacterial, antifungal, and anticancer), and chemical composition of methanol extract of M. napaulensis DC. bark (MNBM). This is the first study evaluating its anticancer activity and chemical composition by LC-MS/MS analysis.

Methods: TPC, TFC, antioxidant, antimicrobial, and anticancer activities were determined by Folin-Ciocalteu, AlCl₃, DPPH, Resazurin, and MTT assays, respectively. Its metabolite profiling was done by LC-MS/MS analysis. The statistical significance of differences between test groups was analyzed by a one-way ANOVA.

Results: The preliminary phytochemical screening revealed the presence of various phytochemicals viz. alkaloids, steroids, glycosides, polyphenols, tannins, flavonoids, coumarins, terpenoids, and quinone. MNBM showed 38.00 ± 1.50 mg GAE g^-1 dry sample as TPC, 35.04 ± 4.87 mg QE g^-1 dry sample as TFC, and 212.97 μg/mL IC₅₀ value (P < 0.05) as moderate antioxidant activity. MNBM showed minimal inhibitory concentration (MIC) values of 100.22 mg/mL, 50.15 mg/mL, and 25.08 mg/mL against S. aureus, E. coli, and C. albicans, respectively as weak antimicrobial activity. It showed no antibacterial effect against B. cereus and P. aeruginosa at 120 mg/mL. The anticancer activity of MNBM was moderate against human lung cancer cells A549 (228.97 μg/mL IC₅₀ value) and human cervical cancer cells HeLa (367.72 µg/mL IC₅₀ value) (P < 0.05). The LC-MS/MS analysis reported the presence of different anticancer compounds viz. dihydroberberine, d-berbamine, (S)-glaucine, protopine, grosheimin, mycophenolic acid, berberine, alpha-linolenic acid, etc. CONCLUSIONS: MNBM showed dose-dependent moderate antioxidant, weak antibacterial, weak antifungal, and moderate anticancer activity due to the synergistic effect of different phytochemicals and anticancer compounds.