The present study aimed at evaluating the effects of domestic culinary treatment on phytochemical contents (phenolic content and dietary fiber), and the antidiabetic potential of Vernonia amygdalina in type 2 diabetic rats. The culinary forms implied boiling leaves of V. amygdalina directly and eliminating the leaves’ bitterness before boiling. Seventy wistar rats were artificially induced with type 2 diabetes using streptozotocin and high‐fat diet. They then received by oral intubation powders of different culinary forms of leaves extract or suspensions of V. amygdalina at a dose of 500 mg /kg for a period of 4 weeks. The crude fiber, total phenol contents and the DPPH scavenging ability of these culinary forms were also measured and the results showed that values of these parameters were higher in the unwashed form than the washed form. The washed and unwashed forms of V. amygdalina significantly reduced (p < 0.05) the blood glucose, the total cholesterol, triglyceride, transaminases, urea and creatine levels. Aqueous extract has the highest ability to reduce the blood glucose level (75.76%) followed by the unwashed form (61.17%) which was greater than that of the washed form. Also, these forms significantly increased serum HDL cholesterol and total protein level, with the highest activity obtained with the unwashed form. Washing the V. amygdalina leaves (that consists of multiple trituration of leaves with water) contributes to the reduction of antidiabetic and antioxidant properties.

Background: Hyperlipidemia is a major risk factor for cardiovascular diseases. Cucumeropsis mannii and Citrullus lanatus commonly called pumpkin seeds or egussi, the oil-rich seeds, have already demonstrated hypolipidemic activity. In Africa, these seeds are popularly used in the preparation of local foods. During that thermal process, the fatty acid content of pumpkin seeds’ oils may be altered in their functionality. Thus, this work aims at studying the effect of stifled cooking on the quality and the lipid-lowering potential of oils’ extracts from Citrullus lanatus (CL) and Cucumeropsis mannii (CM). Methods: The oils were extracted from the pumpkin seeds (raw and cooked) by a mixture of chloroform and methanol (2/1). The acid, iodine, peroxide and thiobarbituric acid value of the oils were assessed. For 28 days, the oils were subsequently administered by oral intubation to high-fat diet induced hyperlipidemic rats. At the end of the experimentation, the lipid profile, the markers of the hepatic and kidney function were determined. Results: The oils extracted from raw CL and CM significantly reduced (p˂0,05) serum triglyceride, total cholesterol, Low Density Lipoprotein (LDL) cholesterol, uric acid, serum transaminases, creatinine, urea and increases the serum High Density Lipoprotein (HDL)cholesterol level relative to the oils extracted from cooked CM and CL. Moreover, the oil from cooked CL significantly (p<0.05) reduced some lipid profile and toxicity parameters (triglycerides and Alanine animotransferase) while increasing the serum HDL compared to the oil extracted from cooked CM. On the other hand, all the quality parameters of the raw materials followed the limits for vegetable oils, as opposed to cooked samples. Conclusion: Stifled cooking affects the lipid-lowering potential of CM oil compared to that of CL oil. Keywords: Citrullus lanatus; Cucumeropsis mannii; Cucurbitaceae, Hyperlipidemia, Stifled cooking.