Investigation of antioxidant defense mechanisms of Citrullus Colocynthis fruits and N-acetylcysteine in the diabetes mellitus model on rats

Abstract

The aim of study: to investigate the presence and mechanisms of antioxidant activity in dry extract of Citrullus Colocynthis fruits and N-acetylcysteine.Materials and methods. MDA, SOD, catalase, glutathione were studied in liver homogenate of streptozotocin-induced diabetic rats (group model, groups X1 and X2 - rats with diabetes who were given a plant extract per os at a dose of 200 mg / kg and 400 mg / kg respectively, X3 - rats with diabetes who were given NAC per os at a dose of1.5 g / kg) and healthy rats (group Control).Fatty acid composition of erythrocyte and heart homogenate was determined by a gas chromatography.Results. In Model the growth of MDA, reduction of SOD and catalase were observed. In X1 and X2 groups MDA concentration and SOD activity decreased in relative to Model and Control and catalase activity, on the contrary, increased reaching the level of Control and even higher (X2). Glutathione concentration also decreased and this negative effect was increasing with increasing of plant extract dose. NAC caused a decrease of MDA in relative to Model, normalized levels of SOD and catalase and effectively increased the concentration of glutathione compared with Model. 9 fatty acids (FA), 4 of which belong to the unsaturated one (oleic, linoleic, linolenic, arachidonic) and 5 - to saturated one (myristic, pentadecanoic, palmitic, margarine (heptadecanoic), stearic) were identified in heart homogenate and erythrocytes of rats.The plant extract significantly changes the ratio of fatty acids in the myocardium (increases the level of stearic and linoleic FA and decreases the level of pentadecanoic and arachidonic FA) and in erythrocytes (decreases the level of linoleic and linolenic FA and increases the level of saturated FA), practically without disturbing the balance between saturated and unsaturated FA. The quantitative composition of saturated FA doesn’t change statistically in the group X3 in relative to Control. NAC helps to reduce the level of arachidonic FA and increase the level of linoleic FA.Conclusion. Membrane protection is the main mechanism of AOA of plant extract: saturated fatty acids quantity increase helps to protect the membranes from lipid peroxidation, and raising of the level of FA from omega-3 group provides flexibility of erythrocyte membrane and increases the ability of red blood cells to filtration.NAC acts with increasing the levels of antioxidant enzymes and glutathione.