Standardized aqueous stem bark extract of Gmelina arborea roxb. possesses nephroprotection against adriamycin-induced nephrotoxicity in Wistar rats

Nephrotoxicity is a major limitation of adriamycin (ADR) chemotherapy. We hypothesized that administration of standardized aqueous bark extract of Gmelina arborea Roxb. (GA) (Family; Verbenaceae), a traditional therapeutic agent, may reduce the nephrotoxicity caused by ADR in Wistar rats. The dose-dependent nephroprotective activity of the standardized GA extract was investigated in ADR-induced (20 mg/kg, ip) nephrotoxicity in male Wistar rats (n = 6/group). The lyophilized powder of the aqueous refluxed (4 h) GA extract was administered at 100, 300 and 500 mg/kg doses orally for three consecutive days. Fosinopril sodium (0.09 mg/kg) was used as the positive control. Assessment of biochemical parameters on serum, urine and histopathology on H and E stained kidney sections were done at the end of the intervention. The treatment with GA and fosinopril decreased the elevation of serum creatinine, blood urea nitrogen, cystatin C, β₂-microglobulin and loss of total protein in urine in nephrotoxic rats in a dose-dependent manner (p < 0.05). In contrast, serum concentrations of albumin and total protein were increased significantly (p < 0.05). H and E stained kidney sections showed an attenuation of renal parenchymal injury following the treatment. The aqueous extract of GA demonstrated antioxidant potential in vitro. Present findings conclude that the standardized aqueous extract of GA stem bark exerted a dose-dependent protection against ADR-induced nephrotoxicity in vivo and may be a promising adjunct in ADR chemotherapy.

Keywords: in vitro antioxidant activity; Adriamycin; chemical standardization; nephroprotective activity; nephrotoxicity; phytochemistry.