Hepatoprotective effects of green Capsicum annum against ethanol induced oxidative stress, inflammation and apoptosis in rats

Abstract

Ethnopharmacological relevance: Capsicum annum L. (CA) is used extensively as a spice and is a rich source of antioxidant vitamins. It has long been used in Indian, Native American, and Chinese traditional medicine as a carminative and an appetizer that normalizes liver function. However, its hepato-protective activity has so far not been studied.

Aim of the study: The present study was undertaken to evaluate the efficacy of aqueous extract of CA at two different doses (125 mg/kg body weight and 250 mg/kg body weight), against ethanol induced oxidative stress and apoptosis in liver tissue.

Materials and methods: Adult male Wistar rats, weighing 150-200 g, were randomly grouped (n = 6) and treated with ethanol (2 g/kg bw, i.p.), CA₁₂₅ (125 mg/kg bw, i.p.), CA₂₅₀ (250 mg/kg bw, i.p.), ethanol with CA (similar doses), and control (0.5 ml normal saline, i.p.) for 30 days. Lipid peroxidation (LPO) and reduced glutathione content (GSH) in tissue homogenate, along with catalase (CAT), superoxide dismutase (Cu-Zn-SOD & Mn-SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-s-transferase (GST) and glucose-6-phosphate dehydrogenase (G-6-P-D) activity were evaluated. Serum levels of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphate (ALP), triglyceride (TG), total cholesterol (CHLS), high density lipoprotein (HDL), low density lipoprotein (LDL) very low density lipoprotein (VLDL), tumour necrotic factor alpha (TNF-α) and interleukin 6 (IL-6) were also measured using ELISA kits. Histopathological evaluation of the hepatic tissue was performed by hematoxylin and eosin (H&E) and periodic acid-schiff (PAS) staining. TUNEL assay was performed for apoptosis detection.

Results: Ethanol significantly (p < 0.001) increased ALT, AST, ALP, TNF-α, IL-6, LPO, Cu-Zn-SOD, GST, GPx, TG, CHLS, LDL, VLDL levels, along with significant (p < 0.001) decrease in HDL, Mn-SOD, CAT, GSH, GR and G6PD activity. Co-administration of CA along with ethanol alleviated changes in the above parameters (p < 0.001) in a dose-dependent manner and also reduced the number of apoptotic death cells. Histo-pathological and histo-chemical studies of liver sections also ascertained the outcomes of this study.

Conclusion: Thus, it can be concluded that the aqueous extract of green CA can exert a protective effect against ethanol induced hepato-toxicity. The possible mechanism may be by acting as an antioxidant; preventing ethanol induced apoptosis and reducing pro-inflammatory cytokine levels.

Keywords: Antioxidant; Apoptosis; Capsicum annum; Hepato-protective; Interleukin 6; Tumour necrotic factor alpha.