Effects of a soybean protein diet on ovariectomised female albino rats subjected to myocardial infarction.

INTRODUCTION: Cardiovascular disease is the leading cause of death among menopausal women in developed countries, mostly due to the loss of endogenous oestrogen protection. Soybean protein (SP) is rich in isoflavone phytoestrogens. This study aimed to determine the effect of SP on ovariectomised rats subjected to myocardial infarction and its possible cardio-protection. METHODS: The study was conducted on 30 adult female albino rats, which were divided into three groups: Group I comprised the sham-operated rats; Group II, the ovariectomised (OVX) rats fed a standard diet; and Group III, OVX rats fed a standard diet supplemented with SP (OVX plus SP). The rats were anaesthetised, and electrocardiograms were conducted. The rats were then sacrificed, after which their hearts and livers were removed, weighed and subjected to histopathological examination. Blood was collected to determine the lipid profile, and the levels of total triiodothyronine, tetraiodothyronine (T4), thyroid-stimulating hormone (TSH), creatinine phosphokinase (CPK), lactate dehydrogenase, superoxide dismutase (SOD) and malonedialdehyde (MDA). RESULTS: The biochemical studies showed a significant increase in plasma CPK (Group II), MDA and triacylglycerol (Groups II and III) levels compared to Group I. The plasma SOD showed a significant decrease in Group II compared to Group I. Total cholesterol, low and very low density lipoprotein cholesterol levels showed a significant increase in Group II, and a significant decrease compared to Group I. Significant increases in T4 and TSH were found in Group III compared to Group II. CONCLUSION: SP intake can be valuable in protecting the heart against an attack of acute myocardial infarction.

Blood lipid peroxidation (superoxide dismutase, malondialdehyde, glutathione) levels in Egyptian type 2 diabetic patients.

INTRODUCTION: The existence of hyperglycaemia produces increased oxidative stress. The depletion of antioxidants as a defensive body mechanism may increase the risk of diabetic complications. Diabetes mellitus is associated with derangements in the serum levels of several biochemical parameters, and type 2 diabetes mellitus (or non-insulin-dependent diabetes mellitus) is a risk factor for cardiovascular diseases. METHODS: Data of 80 control subjects (male:female, 40:40) and 80 diabetic patients (male:female, 40:40), of similar age, gender, body mass index and duration of diabetes mellitus (for diabetic group), were collected from government and non-government organisations during the period, 2001-2004. Blood samples were also collected. Glucose, glucosylated haemoglobin, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDLC), TC/HDL-C, HDL-C/LDL-C, triacylglycerol, malondialdehyde, glutathione and superoxide dismutase levels were determined. RESULTS: Mean cholesterol, LDL-C, VLDL-C and triacylglycerol levels were significantly higher in patients with type 2 diabetes mellitus in comparison to the control subjects, while the mean value of HDL-C was significantly lower. A significant elevation in malondialdehyde level and decrease in glutathione content were observed in both male and female diabetic patients in comparison to the control subjects. CONCLUSION: The results suggest that the increase in lipid peroxidation, and the decline in antioxidant defences, may appear early in type 2 diabetic patients, before the development of secondary complications. This phenomenon might play an important role in the initiation and progression of diabetic complications. Our results also suggest that there seems to be an imbalance between plasma oxidant and antioxidant systems in patients with type 2 diabetes mellitus.