Ameliorative effects of Orlistat and metformin either alone or in combination on liver functions, structure, immunoreactivity and antioxidant enzymes in experimentally induced obesity in male rats

BACKGROUND: Prevalence of obesity is increasing worldwide. Obesity is associated with incidences of metabolic disorders and cardiovascular diseases and the risk of having it rose sharply during the COVID-19 pandemic. Obesity is associated with oxidative stress, inflammatory markers and hepatic disorders and has become one of the silent killer diseases affecting global health. METHODS: This study examined the effects of obesity on liver functions (ALT, AST and LDH), lipid profile (TG, TC, HDL-c, LDL-c and vLDL-c), tumour necrosis factor alpha (TNF-α), inflammatory marker, C-reactive protein (CRP), leptin hormone and antioxidant enzymes (CAT, SOD and GPx) and lipid peroxidation marker (MDA) in liver homogenates besides histological structure of the liver tissues and assessment of DNA damage. Fifty male Wistar rats were used and they were divided into five treatment groups: I-Control group, II-high-fat diet (HFD) treated group (Obesity) group, III-HFD plus Orlistat (ORL), IV-HFD plus metformin (Met) and V- HFD plus ORL plus Met. RESULTS: Experimentally-induced obesity caused a significant increase in liver enzymes including lipid markers (triglycerides and total cholesterol), inflammatory markers, tumour markers and lipid peroxidation markers and a concurrent decline in antioxidant enzymes and damage of liver main structures characterised by presence of congestion and accumulation of mononuclear inflammatory cells in blood sinusoids. In contrast, groups treated with either ORL or Met or both group, we recorded restoration of normal hepatic structures and a decline in DNA damage, liver enzymes and antioxidant levels. The best restoration and amelioration were observed in the group treated with a combination of ORL and Met. CONCLUSION: Our findings indicated the synergistic effect of ORL and Met in ameliorating hepatic functions and lipid profile, alleviating inflammation, genotoxicity and side effects of experimentally-induced obesity.