Portulaca oleracea Reduces Lipemia, Glycemia, and Oxidative Stress in Streptozotocin-induced Diabetic Rats Fed Cholesterol-enriched Diet

Aims: In this study, the effects of Portulaca oleracea (Po) in the treatment of hypercholesterolemia combined with diabetes in rats were investigated.

Place and Duration of Study: Laboratory of Clinical and Metabolic Nutrition, Department of Biology, Nature and Life Sciences Faculty, University of Oran1, Algeria, between September and July 2017.

Study Design: The effects of an aqueous extract from the leaves of Po were studied on glucose homeostasis, lipid parameters, and oxidative stress markers, in streptozotocin (STZ) induced diabetic rats on a cholesterol-enriched diet.

Methodology: Experimental hypercholesterolemia was induced by feeding rats with 1% cholesterol-enriched diet for 15 days. Hypercholesterolemic male Wistar rats (n=28) were rendered diabetic by a single intraperitoneal injection dose (55 mg/kg BW) of STZ. Hypercholesterolemic diabetic rats were divided into two groups (n=10): Hypercholesterolemic diabetic group (HC-D), and hypercholesterolemic-diabetic group supplemented with 1% of Po aqueous extract (HC-DPo) during 28 days. Assessed parameters were blood glucose, insulinemia, glycosylated haemoglobin (HbA1c), liver and plasma lipids, lipid peroxidation, and antioxidant enzymes in plasma, red blood cells (RBCs), and tissues.

Results: A significant increase in final body weight was found between both groups. In HC-DPo vs HC-D group, glycemic parameters were improved by decreasing glucose, HbA1C levels, and by enhancing insulinemia. Low plasma values of total cholesterol (TC) (-42%), triacylglycerols (TG) (-63%), very low and low density lipoprotein cholesterol (VLDL-C, LDL-C) (-66% and -80%), and increase of high density lipoprotein cholesterol (HDL-C) (-26%), leading to decreased atherogenic indices TC/HDL-C (-57%) and LDL-C/HDL-C (-85%) were noted in rats treated by Po compared to untreated group. In the liver, heart and aorta, lipid peroxidation was lowered, and inversely, antioxidant enzymes activities were increased after treatment with Po.

Conclusion: On the basis of these finding, it can be concluded that the Po aqueous extract is an interesting natural product to prevent hypercholesterolemia in diabetic rats. Protocols in hypercholesterolemia diabetic patients are needed to verify and validate these results.