Hepatoprotective activity of Picrorhiza kurroa and Berberis lycium is mediated by inhibition of COX-2 and TGF-β expression in lantadenes-induced sub-chronic toxicity in guinea pigs

Abstract

BackgroundThe toxicity of Lantana camara weed is common in grazing livestock throughout the world. Specific treatment for the toxicity is lacking. However, herbal plants could be investigated for their effectiveness in inhibiting hepatic damage caused by lantadenes of L. camara. Therefore, the extracts Berberis lycium and Picrorhiza kurroa, which are known to exhibit multiple useful effects were assessed for their hepatoprotective action in sub-chronic lantadene toxicity. PurposeThe focus of the study was to investigate the molecular pathogenesis of sub-chronic lantadene toxicity and, the mechanism of hepatoprotection by freeze-dried methanolic extracts of the Berberis lycium root bark and Picrorhiza kurroa rhizome in lantadenes-induced sub-chronic hepatopathy in guinea pig laboratory animal model. MethodsIsolation of lantadenes from L. camara leaves, followed by its characterization and quantification by UPLC-MS method was done. The methanolic extracts of ameliorating plant parts (root bark of B. lycium, rhizome of P. kurroa) were prepared and quantification of berberine and picroside was carried out. The in vivo sub-chronic toxicity and amelioration experiment in guinea pigs was conducted for 90 days by distributing them into 7 groups with 6 animals in each group. At the end of the experiment, serum biochemical analysis, oxidation stress levels in the liver and kidneys were determined. Gross pathology and microscopic observations in different organs, Masson’s trichome staining for fibrous collagenous tissue deposition assessment, and immunohistochemical expression of the TGF-β antigen in the liver of animals were done. The effect of lantadenes on pro-inflammatory cytokines and the level of α-smooth muscle actin in the liver was estimated by real-time RT-PCR and ELISA, respectively. ResultsSub-chronic lantadene intoxication increased serum ALT, AST, ALP, bilirubin, creatinine, total proteins and lipid peroxidation in liver tissue; decreased catalase, superoxide dismutase and reduced glutathione activity in liver tissue; caused hepatic necrosis with bile duct proliferation and TGF-β antigen expression in the periportal regions; upregulated the IL-1β, IL-6, TGF-β, and COX-2 pro-inflammatory cytokine gene expression and increased the titre of α-SMA in the liver. The P. kurroa extract at 200 mg/kg bw and B. lycium extract at 200 mg/kg bw produced favourable effects against lantadenes-induced hepatic toxicity and significantly reversed these changes to near normal. ConclusionsP. kurroa and B. lycium extracts at 200 mg/kg bw can be used to ameliorate the hepatotoxicity produced by sub-chronic exposure to lantadenes. The findings of the molecular pathogenesis of sub-chronic lantadene toxicity and its amelioration in guinea pig laboratory animal model are novel. Further investigations are needed to study the in-depth mechanism of hepatoprotection of P. kurroa and B. lycium in lantana intoxicated grazing (host) animals.