Evaluation of Omega-3, Omega-6 and Lipid Contents of Wistar Rats Treated with Frequently Used Cooking Oil in Nigeria

Abstract

Many studies suggest a connection between the consumption of vegetable oils and cardiovascular diseases (CVD). This research investigated the effects of various cooking oils on the lipid profiles of Wistar rats. The study involved forty-two Wistar rats, approximately 3 months old, with an average weight of 140 ± 2.45 g. The oils examined included palm oil, Emperor oil, Golden Penny oil, Mamador oil, King's oil, and Power oil, sourced from different Port Harcourt, Nigeria markets. Each rat in the respective oil group received 1.0 ml of their assigned oil orally for 30 days, while the control group received no oil. On the 31st day, after a night of fasting, the rats were anaesthetised, and blood samples were collected via cardiac puncture into labelled plain bottles. These samples underwent lipid profile analysis using enzymatic methods and GC-MS, which identified components of omega- 3 and omega- 6 fatty acids. Examining various cooking oil brands uncovered several essential fatty acids, including EPA, DHA, and DPA. The findings indicated a significant increase in overall cholesterol levels (p < 0.05) in all groups except the palm oil group (1.20 ± 0.11 mmol/l), which was similar to the control group (1.26 ± 0.24 mmol/l). HDL- C levels were notably higher in groups consuming Golden Penny oil (1. 48 ± 0. 17 mmol/l), King's oil (1. 90 ± 0. 31 mmol/l), Mamador oil (1. 66 ± 0. 34 mmol/l), and Power oil (1. 29 ± 0. 69 mmol/l) compared to the control group (0. 70 ± 0. 23 mmol/l). Additionally, LDL-C levels significantly decreased in the King's oil group (0.15 ± 0.14 mmol/l) but increased dramatically in the Power oil group (0.86 ± 0.77 mmol/l) compared to the control group (0.27 ± 0.15 mmol/l). Triglyceride levels decreased significantly in the Emperor and Golden Penny oil groups, yet increased in the Power oil group (1.19 ± 0.72 mmol/l) compared to the control group (0.59 ± 0.15 mmol/l). In conclusion, the impact of different cooking oils on lipid levels in Wistar rats varies by brand, with palm oil displaying lower total cholesterol levels than the others. Palm, Golden Penny, and Emperor oils are particularly high in omega- 3, while Emperor and Golden Penny oils are abundant in omega- 6. Cooking oils containing omega- 3 and omega- 6 and lower total cholesterol levels may offer cardiovascular protection.