Synergistic impacts of rifampicin and doxorubicin against thioacetamide-induced hepatocellular carcinoma in rats

Background and aims

Combination therapy is a promising new strategy that has been proposed to increase the efficacy of cancer treatment. We aimed to investigate the anti-cancer activity of rifampicin monotherapy and its combination with doxorubicin against hepatocellular carcinoma (HCC).

Materials and methods

The in vitro half maximal inhibitory concentration (IC₅₀) and selectivity index (SI) of the drugs under investigation against HepG2 and human lung fibroblast (WI38) cell lines were determined. For the in vivo experiment, male Sprague-Dawley albino rats were injected with thioacetamide at 200 mg/kg twice a week for 90 days; HCC development was confirmed histopathologically. Following HCC induction, the rats were treated with intraperitoneal doxorubicin, rifampicin, or their combination for 45 or 90 days. After sacrifice, the livers were examined histopathologically. The levels of aminotransferases, albumin, bilirubin, malondialdehyde, superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC), and nitric oxide were measured by spectrophotometry. Alpha-fetoprotein, cancer antigen 19-9, tumor necrosis factor-alpha, interleukin-6, Bcl-2-associated X protein, caspase 3, caspase 8, and p53 were estimated using ELISA.

Results

In vitro, the combination of doxorubicin and rifampicin showed the highest SI of 3.43. In vivo, among the measured markers, the levels of TAC, CAT, SOD, and p53 decreased (P < 0.001) and the rest of the measured marker levels increased (P < 0.001) in the HCC-bearing rats; after treatment in all groups, all these changes improved toward normal in a time-dependent manner. The combination of doxorubicin and rifampicin optimized the effects of the two individual drugs and exerted the best antioxidant effects.

Conclusions

In general, compared with rifampicin or doxorubicin alone, combination therapy has favorable outcomes. Based on our results, the combination of rifampicin and doxorubicin might be applicable for HCC chemotherapy.