Study of Mustard Oil (Brassica nigra L.) As A Hypolipidemic 7102 285 Study of Mustard Oil (Brassica nigra L.) As A Hypolipidemic Khalid G. Al-Fartosi Department of Biology, College of Science, University of Thi-Qar Ali B. Roomi Saad H. Al-Badry General Directorate for Education in Thi-Qar/Iraq ABSTRACT Background: The present study investigated the effect of mustard oil on body weight and lipid profile in normal and hyperlipidimic mice was studied. The work involved the following studies. Materials and methods: Twenty-four female mice are divided into four groups each group contain six animals. The normal control group (A) treated with (0.1 mL) distilled water (D.W) for 30 days, group (B) treated with daily high cholesterol diet (5% cholesterol) for 30 days, and the group C treated with (0.1 mL/ 25 kg) for mustard oil besides high cholesterol diet (5% cholesterol) for 30 days. The group D treated with (0.1 mL/ 25 kg) for mustard oil besides standard diet. Results: Group (B) showed a significant increase (P < 0.01) in the body weight compared with normal control group(A). Mustard oil is significantly decreased the body weight in groups (C & D) compared with group(B). Lipid profile measured: Group (B) rats showed a significant increase (P < 0.01) in serum TC, TG, LDL and VLDL levels compared with normal control group(A). Serum HDL levels are a significant decrease in group (B) (P < 0.01) compared with normal control group(A). Mustard oil is significantly decreased the levels of TC and LDL in groups (C & D) compared with group(B) (P < 0.01). While, there was non-significant reduction in TG and VLDL of group (C) compared with group (B) (P < 0.01). Conclusions: Mustard oil has effect on reduce body weight and serum lipid profile and atherogenic index. Keywords: Mustard oil, hypolipidemic INTRODUCTION The major lipids are fatty acids, triglycerides (TG), cholesterol (free and esterified cholesterol) and phospholipids (PL). They are important in maintaining the structure of cell membrane (cholesterol and phospholipids), steroid hormone synthesis (cholesterol), and energy metabolism (TG and fatty acid) (Liu ,2002). Plasma lipoproteins are typically classified into five major subclasses on the basis of their densities (Betteridge,2000) .