P 11: Role of herbal extracts in the prevention of oxidative stress and modulation of atherogenic risk factors in experimentally-induced DM

Abstract

Background and aims Complementary and alternative medicine modalities of treating diabetes mellitus and cardiovascular diseases (D&CVD) have been used in various parts of the world. Chemoprevention and chemotherapies using the naturally occurring nontoxic natural compounds has been advanced as a feasible strategy for D&CVD management. Diabetes and cardiovascular diseases are currently the leading cause of death globally. Diabetes has a distinctive association with CVD. Diabetes is well known to induce physiological stress response that involves activation of inflammatory, metabolic, and immunological mediators. Considerable data indicate that reactive oxygen species (ROS) and oxidative stress are important features of CVD including atherosclerosis, hypertension, and congestive heart failure. Clinical research has confirmed the efficacy of phytotherapy in the modulation of oxidative stress-induced CVDs associated with DM. Increasing number of studies reported that an increase in plasma total antioxidant capacity (TAC) is associated with intake of herbs, fruits and vegetables which are rich in antioxidants. This is based on findings that Leaf extract components, especially flavonoids have the free radical scavenging activity, showing the potential of antioxidant properties. Consequently, the present study was designed to investigate the hypoglycemic, hypolipidemic and antioxidtive effects of crude extract from leaves of Zizyphus spina-christi (ZS), Morus alba (MA) and Olea europeaea (OE) in experimentally induced DM. Materials and Methods Fresh leaves were dried, extracted by methanol, and then vacuum evaporated. Crude extracts from leaves of Zizyphus spina-christi (ZS), Morus alba (MA) and Olea europeaea (OE) were freshly dissolved in distilled water just before oral administration. Experimental rat model of T2DM was induced in male rats by a single ip injection of 50 mg/kg streptozotocin. All experimental groups received herbal extracts orally and individually at a dose of 0.1g/kg/day for 5 weeks. The body weight and fasting blood glucose level of all rats were measured before and after 5 weeks of treatment. In addition, HBA1c, serum insulin, lipid profile, and cardiac antioxidants as well as lipid and protein oxidation were evaluated. Results After a period of 5 weeks, the body weight of diabetic rats was significantly (p Conclusion Our data indicate that experimental diabetes led to alteration in the atherogenic parameters, with an increasing incidence of oxidative stress in the heart, and the effects of the extract might be attributed to the hypoglycaemic and antioxidative potential of flavonoids, the major components of the plant extract. These results provide the first evidence for the efficacy of ZS, MA or OE in restoring lipid profile in the diabetic rats, the mechanism of which may associate with the alleviation of oxidative stress. Consequently, we suggest that these extracts could be used as antidiabetic complement in case of DM. In future, more studies would be urgently required in order to confirm these results in human and to adjust the correct bio-available dose for better therapeutic effects.