Antioxidant Potentials and Nephroprotective Effects of Methanol Extract and Dichloromethane Fraction of Root Bark of Garcinia kola (Heckel) on Gentamicin-Induced Nephrotoxic Rats

Abstract

This study investigated the nephroprotective and antioxidant effects of methanol extract (ME) and dichloromethane fraction (DCMF) from the root bark of Garcinia kola against gentamicin-induced nephrotoxicity in rats. The root bark was collected from Iperindo, Osun State, Nigeria, and dried for eight weeks. After grinding into a powder, the root bark was extracted using 80% methanol. The extract was filtered, centrifuged, and concentrated to obtain ME. A portion of ME was fractionated using n-hexane and dichloromethane to obtain DCMF. The phenolics and flavonoid contents of ME and DMCF were analyzed. Gentamicin, ME, and DCMF were administered to forty Wistar rats for a total of fourteen days, both prior to and following therapy. The rats were split up into groups. Levels of endogenous antioxidant molecules and enzymatic antioxidant activity were measured. Phytochemical analysis revealed that the ME and DCMF contained significant amounts of phenolics (ME: 409.17 ± 16.38 mg/g TAE; DCMF: 623.98 ± 14.32 mg/g TAE) and flavonoids (ME: 377.82 ± 8.29 mg/g RE; DCMF: 192.33 ± 7.26 mg/g RE). The animal experiment results showed that both ME and DCMF significantly reduced elevated levels of non-enzymatic antioxidants caused by gentamicin. Furthermore, ME and DCMF corrected the changes in antioxidant enzyme activities caused by gentamicin exposure. These findings suggest that the ME and DCMF of G. kola contain bioactive phytoconstituents with protective effects against gentamicin-induced nephrotoxicity. The extracts were effective in restoring antioxidant balance by normalizing endogenous antioxidant levels and antioxidant enzyme activities. This highlights the therapeutic potential of G. kola in protecting kidney function against drug-induced toxicity.