Ameliorative effect of a standardized polyherbal combination in methotrexate-induced nephrotoxicity in the rat

Abstract

Context Nephrotoxicity is a renal dysfunction that arises from direct exposure to environmental chemicals or as a side effect of therapeutic drugs. Boerhaavia diffusa Linn. (Nyctaginaceae), Rheum emodi Wall. Ex. Meissn. (Polygonaceae), Nelumbo nucifera Gaertn. (Nelumbonaceae) and Crataeva nurvala Buch-Ham. (Capparidaceae) are well-recognized medicinal plants of Indian traditional system of medicine used for kidney disorders. Objectives The present investigation was undertaken to develop a chromatographically characterized polyherbal combination and to evaluate its nephroprotective activity. Materials and methods Roots of B. diffusa and R. emodi, flowers of N. nucifera and stem bark of C. nurvala were extracted by decoction using 70% ethanol. Response surface methodology (RSM) was used for the optimization of extraction parameters. Polyherbal combinations with different doses (150–300 mg/kg) were tested against methotrexate-induced nephrotoxicity in Wistar rats. Results The optimized extract contained 27% phenols and 15% flavonoids, which showed 75% 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging potential. Based on the retention time of high-performance liquid chromatography (HPLC) analysis, 17 out of 122 constituents were found common in all extracts and combinations. Two combinations showed significantly higher (p ≤ 0.05) DPPH scavenging potential and xanthine oxidase inhibition. The half maximal inhibitory concentration (IC50) of the best combination for DPPH scavenging and xanthine oxidase inhibition were 80 and 74 µg/mL, respectively. Treatment of methotrexate-induced nephrotoxic rats with polyherbal combination significantly (p ≤ 0.05) improved the kidney function markers, oxidative stress markers and histological parameters. Discussion and conclusion The developed combination was found to be effective in nephrotoxicity; it can be explored further for the management of drug-induced nephrotoxicity and other chronic kidney diseases.