International Journal of Advanced Scientific Research 4 International Journal of Advanced Scientific Research ISSN: 2456-0421; Impact Factor: RJIF 5.32 Received: 02-06-2020; Accepted: 17-06-2020; Published: 03-07-2020 www.allscientificjournal.com Volume 5; Issue 4; 2020; Page No. 04-10 Hypolipidemic effect of the crude ethanolic extract of thymus vulgaris in rats fed with lipid David Christopher Bando 1* , Hannah Nuhu Tubasen 2 , Imbasire Nuhu 3 , Emmanuel Odiba Ogu 4 , Sylvia Ozioma Madukwe 5 1, 2, 3, 4 Bioresources Development Centre, National Biotechnology Development Agency, Jalingo, Taraba, Nigeria 5 Department of Medical Laboratory Science, Faculty of Health sciences and Technology, College of Medicine, University of Nigeria Abstract This study was designed to evaluate the hypocholesterolemic effect of crude ethanolic extract of Thymus vulgaris in cholesterol fed rats. Acute toxicity test and preliminary quantitative screening were performed. Twenty-five (25) adult female Albino Wistar rats weighting 120-150g were used for this study. The animals were divided into five (5) groups (A-E) according to their body weights (w±20g). Group A and B, were set as the test groups and received 150mg/kg and 300mg/kg ethanolic extract of Thymus vulgaris (EETV) respectively. Group C received 20mg/kg Atorvastatin (positive control) and group D received 2000mg/kg cholesterols in coconut oil only (negative control) and group E received feeds and water (normal control). The administration was by oral route. Group E served as normal control. The administration of the EETV and cholesterol was for a period of twenty one (21) days. After an overnight fast all the animals (group A to E) were bled (5-8ml) through the retro-orbital vein into labeled plain tubes with the aid of heparinized capillary tubes for lipid profile. The Acute toxicity study revealed that the extract has an oral LD 50 of >3000mg/kg. The phytochemical screening on the extract revealed the abundance of oils, saponins, polyphenols, flavonoids and tannins. There were no alkaloids, glycosides and high dose (300mg/kg/bw of EETV) lowered the levels of these cholesterol parameters in the rats significantly when compared with those of the negative control group. There was significant increase in the mean triglycerides (TG) levels of group C and D with mean TG levels of 1.18±0.09 mmol/L respectively when compared with the normal control group (0.22±0.02mmol/L; p<0.001). Furthermore, rats in groups A and group B had mean total cholesterol levels of 3.65±0.20mmol/L and 3.05±028mmol/L respectively and these were significantly lowered when compared with the negative control group with mean total cholesterol level of 5.15±0.11mmol/L (p<0.001). The atorvastatin group (positive control), had also significantly lowered mean total cholesterol level when compared with the negative control group. From the result of this study it could be concluded that Thymus vulgaris has a hypolipidemic effect in lipid fed rats. Keywords: hypolipidemic; thymus vulgaris; hdl; vldl; ethanolic extraction; eetv 1. Introduction Cholesterol is one important biological molecule that plays vital roles in membrane structure as well as a key precursor for the synthesis of the steroid hormones, the bile acids and vitamin D [1] cholesterol is found in every cell of the body and has important natural functions. Although cholesterol is being manufactured by the body but also, is taken in from food. It has a waxy and fat-like nature or appearance. Cholesterol being an oil-based substance does not mix with the blood, because it is water based substance; it is therefore carried around the body in the blood by lipoproteins [2] . The parcels of cholesterol are carried by two types of lipoproteins: Low-Density lipoprotein (LDL-cholesterol carried by this type is known as ‘bad’ cholesterol) and High- Density lipoprotein (HDL –cholesterol carried by this type is known as ‘bad’ cholesterol). There are four main functions of the cholesterol, without which we could not live; consequently it contributes to the structure of cell walls, makes up digestive bile acid in the intestine, allows the body to produce vitamin D and enable the body to make certain hormones. Cholesterol synthesis and utilization is tightly regulated in order to prevent over accumulation and abnormal deposition within the body of particular clinical importance in the abnormal deposition of cholesterol and cholesterol-rich lipoproteins in the coronary arteries [3] . The transportation of Cholesterol in the plasma predominantly takes place as cholesteryl esters associated with lipoproteins. Cholesterol from diet gets conveyed from the small intestine to the liver within chylomicrons. All synthesized Cholesterol by the liver, as well as any dietary cholesterol in the liver that exceeds hepatic needs, is transported in serum within LDLs. In the liver VLDLs are synthesized and invariably converts it into LDLs through the action of endothelial cell- associated lipoprotein lipase. Cholesterol that are found in living organisms plasma membranes can be extracted by HDLs and it is esterified by the HDLs associated enzyme Lecithin: cholesterol acyltransferase (LCAT). The cholesterol acquired from peripheral tissues by HDLs can then be transferred to VLDLs and LDLs via the action of cholesteryl ester transfer protein (apo-D) which is associated with HDLs. Peripheral cholesterol are allowed to be returned to the liver in LDLs by reverse cholesterol transport process. Ultimately, cholesterol is excreted in the bile as free cholesterol or as bile salts following conversion to bile acids in the liver. [4] . Animal’s fats are basically complex mixtures of triglyceride which possess lesser amounts of phospholipids and cholesterol. Consequently, it is deduced that all foods containing animal fat contain cholesterol to varying extents