Combined effects of metformin and honey on lipid metabolism in diet-induced hyperlipidemic rats

Abstract

The study was designed to evaluate the combined effect of metformin and honey treatments on lipid metabolism in diet-induced hyperlipidemic rats. Eighty-five male Wistar rats (80-100g): twenty normal and sixty-five hyperlipidemic rats were used. Sixty-five rats were fed with high fat diet for 30 days to induce hyperlipidemia. Five rats each from control and hyperlipidemic were randomly selected to evaluate fasting blood glucose (FBG) level and hyperlipidemic state. Fifteen normal rats (control) formed Group 1(received 0.3ml/100g b.w distilled water) and the hyperlipidemic rats were divided into 4 groups of fifteen rats. Group 2 (hyperlipidemic control), Group 3 (hyperlipidemic plus metformin 100mg/kg), Group 4 (hyperlipidemic plus honey-1ml/100g); Group 5 (hyperlipidemic plus metformin-100mg/kg) and honey(1ml/100g). All treatments were administered orally, once daily for 28 days and animals were weighed weekly throughout the study. Blood was obtained from 5 rats in each group weekly post treatments through retro-orbital plexus, FBG was assessed using glucometer(Acucheck) and serum from remaining blood sample was used for assessing total cholesterol (TC), triglycerides (TG), high density lipoprotein (HDL), spectrophotometrically using Agape Biochemical kits. Low density lipoprotein (LDL), Very low density lipoprotein (VLDL), atherogenic index and HDL/LDL ratio were mathematically calculated. Histology of the liver was done using H&E stain. The FBG was significantly reduced in all treatment groups (3, 4 and 5) compared with Groups 1 and 2 (the controls). Group 5 animals showed significant reduction in TC, TG, LDL, VLDL and significant increase in HDL level by day 28 of treatment compared with controls. Histopathological results showed severe diffuse fatty infiltration of the hepatocytes and extensive periportal vacuolar degeneration of hepatocytes at day 28 in hyperlipidemic group while group 5 showed very mild diffuse periportal cellular infiltration of the hepatic parenchyma with no visible lesion. It was concluded that the combination of both metformin and honey treatments significantly reduced blood glucose level, serum total cholesterol, triglycerides, low density lipoprotein and fatty infiltration of hepatic parenchyma and increase high density lipoprotein level which was not achieved with administration of either metformin or honey alone in hyperlipidemic rats.

Keywords: hyperlipidemia, Metformin, Honey, Lipid profile, Fasting blood glucose