Assessment of antioxidant, anticancer, and antibacterial activities of the rhizome of ginger (Zingiber officinale)

Background Zingiber officinale rhizome is rich in phenolic and flavonoids contributing antioxidant and anticancer activity. Methods This study was designed to assess the in vitro antioxidant, anticancer, and antibacterial activities of Z. officinale rhizome. Ethanol extract of Z. officinale rhizome was tested for total phenolic and flavonoid content. The antioxidant activity was analyzed by DPPH scavenging and ABTS assay methods. The cytotoxic potential of ethanolic rhizome extract was tested against MCF-7 cell lines and anti-apoptotic genes were determined. Results Ethanol extract of Z. officinale rhizome exhibited phenols (266.57 +/- 4.09 mg GAE/g dry weight of the dry extract) and flavonoid (114.04 +/- 2.46 mg QE/g mg dry weight of the dry extract). The ethanol extract significantly affected the generation of free radicals and the IC50 values were 107.19 +/- 1.7 mu g/mL (DPPH method) and 121.94 +/- 0.32 mu g/mL (ABTS method) (p < 0.05). The rhizome extract showed statistically significant cytotoxic activity compared to the control (p < 0.05) with an IC50 value of 92.49 +/- 3.14 mu g/mL. It also showed bactericidal activity against Gram-positive and Gram-negative bacteria. The MIC values ranged from 3.12 +/- 0.44 mu g/mL to 25 +/- 5.33 mu g/mL. The most susceptible strain was S. epidermidis (MTCC 12228) the MIC value was 3.12 +/- 0.44 mu g/mL and the MBC value was 6.25 +/- 3.23 mu g/mL. The rhizome extract increased the mRNA levels of caspase-9, 8, and -3, Bax mRNA and subsequently reduced anti-apoptotic genes (Bcl-xL and Bcl-2) than control (P < 0.05). The MCF-7 cells, treated with rhizome extract showed upregulation of p21 and p53 mRNA than untreated control cells (p < 0.05). Conclusion The present finding revealed the antioxidant, anticancer, and antibacterial properties of Z. officinale rhizome.