Antidiabetic effect of flax and pumpkin seed mixture powder: effect on hyperlipidemia and antioxidant status in alloxan diabetic rats
Antidiabetic effect of flax and pumpkin seed mixture powder: effect on hyperlipidemia and antioxidant status in alloxan diabetic rats
Year: 2010
Authors: Makni, M. Fetoui, H. Gargouri, N.K. Garoui, E.M. Zeghal, N.
Publication Name: Journal of Diabetes and Its Complications
Publication Details: doi:10.1016/j.jdiacomp.2010.09.001
Abstract:
Reactive oxygen species play a crucial role in the pathogenesis of diabetes and its complications. This study aims to examine the effects of flax and pumpkin powder seed mixture on alloxan induced diabetes in Wistar rats. Animals were allocated into three groups of six rats each: a control group (CD), diabetic group (DD) and diabetic rats fed with flax and pumpkin seed mixture (DMS) group. The diabetic rats (DD) presented a significant increase in glycemia, plasma and liver lipid parameters such as total lipid, total cholesterol and triglycerides compared to the control group (CD). In addition, plasma and liver malonaldialdehyde levels (MDA, an index of lipid peroxidation) significantly increased compared to (CD). Antioxidant enzymes activities such as catalase, superoxide dismutase, and reduced glutathione (GSH) levels significantly decreased in the plasma and liver of diabetic rats compared to controls. Diet supplemented with flax and pumpkin seed mixture in the DMS group ameliorated antioxidant enzymes activities and level of GSH in diabetic rats and significantly decreased MDA levels. The present study revealed a significant increase in the activities of aspartate aminotransferase and alanine aminotransferase on diabetic status, indicating considerable hepatocellular injury. The administration of flax and pumpkin seed mixture attenuated the increased levels of the plasma enzymes produced by the induction of diabetes and caused a subsequent recovery towards normalization comparable to the control group animals. Our results thus suggest that flax and pumpkin seed mixture supplemented to diet may be helpful in preventing diabetic complications in adult rats. (Authors abstract)Although the underlying mechanisms of diabetes complications remain unclear, clinical and preclinical evidence suggests that diabetes is associated with oxidative stress, leading to an increased production of reactive oxygen species (ROS), including superoxide radical (O2−), hydrogen peroxide (H2O 2) and hydroxyl radical (OH_) or a reduction in the antioxidant defense system. Various dietary sources are presently receiving considerable attention. In a previosu study by this group, a flax and pumpkin seed mixture supplemented to diet of hypercholesterolemic rats had a significant anti-atherogenic, hypolipidemic and antioxidant potency. The present study was carried out in order to evaluate both the problems induced by diabetes and the protective effects of flax and pumpkin seed mixture. The most important result of the present study was that rats, fed a flax and pumpkin seed-enriched diet, were able to partly recover from alloxan-induced diabetes within a short time compared with rats fed control diet, an effect related to the partial regeneration or preservation of pancreaticβ-cell mass after alloxan treatment. At the end of the experiment, pancreaticβ-cell mass in the DMS group was similar to that of the CD group. The results obtained showed that flax and pumpkin seed mixture increased hepatic glycogen content. This suggests that the preservation of hepatic glycogen was maintained and the gluconeogenesis rate was depressed. In parallel, plasma insulin level significantly decreased in the DD group compared with the DMS animals. This indicated that changes in insulin may bring about changes in hepatic glycogen content and lead to the regulatory effect of flax and pumpkin seed mixture on glucose metabolism in alloxan-induced diabetic rats and confirmed a defect in pancreatic β-cell function and/or a decreased β-cell mass, as shown in the histological examination of different diabetes pancreatic sections. The antiatherogenic effect of flax and pumpkin seed mixture found in our studies might be due to the presence of PUFAs, phytosterols, tocopherols and β-carotene. The authors postulated that the supplementation of the diet with flax and pumpkin seed mixture had a protective or regenerative effect on the endocrine pancreas. It is possible that the mechanism of hepato-protection may be due to the antioxidant activity of flax and pumpkin seed mixture which contain flavonoids and phenolics as major compounds. Plasma enzymes including AST and ALT are used in the evaluation of hepatic disorders. An increase in enzyme activities reflects active liver damage. The present study revealed a significant increase in the activities of AST and ALT on diabetic status. The administration of flax and pumpkin seed mixture attenuated the increased levels of the plasma enzymes produced by induction of diabetes and caused a subsequent recovery towards normalization comparable to the control group animals. (Editors comments)
