Does long term supplementation of vitamin E cause detrimental effects on the central nervous system? Morphological and histological study in experimental male Wistar rats.

AIM: Aging is attributed to neuronal loss associated with increased oxidative stress. Vitamin E, and in particular, tocotrienol are potent antioxidants, which have been shown to be neuroprotective. The main aim of the present study was to observe the effect of long term intake of vitamin E in the form of tocotrienol rich fraction (TRF) and refined, bleached, deodorized palm olein (RBDPO) on the brain of experimental rats. MATERIALS AND METHODS: Thirty male Wistar rats aged 3 months were either supplemented with TRF (dose of 200 mg/kg body weight), RBDPO (dose of 1 ml/kg body weight) or distilled water, continuously for 8 months. The animals were then examined in vivo for clinical magnetic resonance imaging (MRI) studies before being sacrificed. The brain was extracted, measured and studied for histological changes. RESULTS: The magnetic resonance imaging (MRI) scan of the lateral ventricle, cortical thickness of cingulate gyrus and hippocampus size did not show any significant changes in all three groups. The brain weight, length and width as well as histological sections of the brain showed no significant changes between the groups. CONCLUSION: It is thereby concluded that chronic consumption of vitamin E was not detrimental to the central nervous system.

Modulation of oxidative stress by Chlorella vulgaris in streptozotocin (STZ) induced diabetic Sprague-Dawley rats.

PURPOSE: Chlorella vulgaris (CV), a fresh water alga has been reported to have hypoglycemic effects. However, antioxidant and anti-inflammatory effects of CV in diabetic animals have not been investigated to date. The aim of the present study was to investigate the role of CV in inflammation and oxidative damage in STZ-induced diabetic rats. MATERIALS AND METHODS: Male Sprague-Dawley rats (300 - 400g) were divided into 4 groups: control, CV, STZ-induced diabetic rats, and STZ rats treated with CV (150mg/kg body wt). Blood samples were drawn from orbital sinus at 1 and 4 weeks for determination of oxidative cellular damage (DNA damage and lipid peroxidation [malondialdehyde, MDA]), inflammation (tumour necrosis factor alpha, TNF-α) and antioxidant status (catalase, CAT, and superoxide dismutase, SOD). RESULTS: CV did not have any effects on glucose levels in diabetic rats, over the 4 weeks of treatment. However, it reduced significantly DNA damage and blood MDA levels in STZ-induced diabetic rats compared to the control group. Plasma levels of TNF-α however did not show any significant changes in STZ-induced diabetic rats fed with CV. Antioxidant enzyme SOD showed no significant changes in all groups but CAT activity was reduced in STZ-induced diabetic rats compared to the control. CONCLUSIONS: CV did not have hypoglycaemic effect but it has a protective role in STZ-induced diabetic rats by reducing oxidative DNA damage, and lipid peroxidation.

Effect of Tai Chi exercise on DNA damage, antioxidant enzymes, and oxidative stress in middle-age adults.

BACKGROUND: The biochemical mechanisms involving oxidative stress to explain the relationship between exercise and healthy aging are still unclear. METHODS: Tai Chi participants and matched sedentary volunteers age 45 and above were enrolled. Glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities; levels of DNA damage using the comet assay; and malondialdehyde (MDA) and advanced glycation end products (AGE) were determined at 0, 6, and 12 months. RESULTS: Tai Chi subjects had decreased normal and increased mildly damaged DNA with elevated GPx activity after 6 months (n=25). Plasma MDA and AGE concentrations decreased significantly after 12 months (n=15) accompanied by increased SOD activity. This may be attributed to the hormesis effect, whereby mild induction of oxidative stress at the first 6 months of exercise resulted in stimulation of antioxidant defenses. These parameters were unchanged in the sedentary subjects in the first 6 months (n=27) except for elevated SOD activity. After 12 months, the sedentary subjects (n=17) had decreased normal DNA and increased severely damaged DNA with unaltered MDA and AGE levels while SOD and GPx activities were significantly elevated. CONCLUSION: Regular Tai Chi exercise stimulated endogenous antioxidant enzymes and reduced oxidative damage markers.

Long term Tai Chi exercise reduced DNA damage and increased lymphocyte apoptosis and proliferation in older adults.

Effect of Tai Chi exercise on the level of DNA damage using the comet assay, lymphocyte viability and frequency of sister chromatid exchange (SCE) were determined in adults aged above 45. Tai Chi participants of 7 years (n=35), showed higher level of normal DNA and lower level of mild and severely damaged DNA as compared to the sedentary subjects (n=35). The former are suggested to have effective DNA repair mechanism as their frequency of SCE was markedly lower. Higher lymphocyte apoptosis and proliferation found in the Tai Chi participants also indicated that the exercise promotes renewal and regeneration of lymphocytes.

Comparative effects of palm vitamin E and alpha-tocopherol on healing and wound tissue antioxidant enzyme levels in diabetic rats.

The effect of supplementing 200 mg/kg body weight palm vitamin E (PVE) and 200 mg/kg body weight alpha-tocopherol (alpha-Toc) on the healing of wounds in streptozotocin-induced diabetic rats was evaluated. The antioxidant potencies of these two preparations of vitamin E were also evaluated by determining the antioxidant enzyme activities, namely, glutathione peroxidase (GPx) and superoxide dismutase (SOD), and malondialdehyde (MDA) levels in the healing of dermal wounds. Healing was evaluated by measuring wound contractions and protein contents in the healing wounds. Cellular redistribution and collagen deposition were assessed morphologically using cross-sections of paraffin-embedded day-10 wounds stained according to the Van Gieson method. GPx and SOD activities as well as MDA levels were determined in homogenates of day-10 dermal wounds. Results showed that PVE had a greater potency to enhance wound repair and induce the increase in free radical-scavenging enzyme activities than alpha-Toc. Both PVE and alpha-Toc, however, were potent antioxidants and significantly reduced the lipid peroxidation levels in the wounds as measured by the reduction in MDA levels.

Effect of hemoglobin E on glycosylated hemoglobin determinations using different commercial kits.

The effect of HbE, a hemoglobin variant, on the determination of HbA1/HbA1c using 4 commercial kits based on cation-exchange resin, cation-exchange column chromatography and specific antibody techniques was studied. Fifty-eight normal and 63 HbE heterozygous subjects were tested for HbA1 and HbA1c using 4 commercial kits i.e. Eagles Diagnostics, Boehringer Mannehim (BM), Diastat and Ames DCA 2000. Analyses of the samples by the 4 kits were done within one week and samples were stored at 4 degrees C before analysis. The results showed that HbE affects the determination of glycosylated hemoglobin using cation-exchange based and not kits based on specific antibody techniques.

Diabetes mellitus and associated cardiovascular risk factors in north-east Malaysia.

Two thousand five hundred and eight subjects from the state of Kelantan in North-East Peninsular Malaysia were included in this study to determine the prevalence of diabetes mellitus and impaired glucose tolerance and their association with cardiovascular risk factors. The overall prevalence of diabetes mellitus was 10.5% and impaired glucose tolerance was 16.5%. There was no difference in the prevalence of diabetes mellitus between males and females but the prevalence of impaired glucose tolerance was higher in females (19.0%) than in males (11.5%). Subjects with diabetes mellitus were more obese (38.4%) than normal subjects (24.1%). They also had a higher prevalence of hypertension (12.9%) and hypercholesterolaemia (71.9%) than normal subjects. Subjects with impaired glucose tolerance also had a higher prevalence of obesity (35.5%), hypertension (9.0%) and hypercholesterolaemia (63.0%) than normal subjects. In conclusion, the prevalence of diabetes mellitus and impaired glucose tolerance was high and they were associated with a high prevalence of obesity, hypertension and hypercholesterolaemia.

Reduced red-cell folate in mania.

Forty-five hospitalised patients with DSM-III-R diagnosis of mania, were found to have a mean red-cell folate level of 193 nmol/l, as compared to 896 nmol/l in the control group (P < 0.00001). Assessment of serum folate in both groups showed no significant differences in the levels. Furthermore the manic patients and the controls were matched by the socio-economic status. This indicated that the reduced red-cell folate in mania is associated with the illness and not due to reduced absorption or dietary deficiency of folate. Considering previous studies that showed reduced red-cell folate in depression, our findings suggest that reduced red-cell folate occurred in both phases of bipolar disorders.

Prevalance of obesity and overweight in northeastern peninsular Malaysia and their relationship with cardiovascular risk factors.

Height and body weight were measured in 2,284 subjects over 20 years old. The subjects were chosen by cluster sampling in 9 districts of Kelantan. Blood was drawn after an overnight fast for measurement of cholesterol (chol), triglyceride (TG), VLDL and HDL-Chol. Oral glucose tolerance test was performed with 75 g glucose. The overall prevalence of overweight [BMI (kg/m2) > or = 25-< or = 30] and obesity (BMI > 30) was 21.3% and 4.5% respectively. The overweight and obese were significantly younger than the lean subjects. The prevalence of hypercholesterolemia (chol > 5.2 mmol/l) in lean, overweight and obese subjects was 65.3%, 70.2% and 74.7%, respectively. Impaired glucose tolerance was found in 16.6% of the lean, 21.6% of the overweight and 32.0% of the obese subjects. Diabetes mellitus was found in 7.9% of the lean, 10.5% of the overweight and 6.7 of the obese subjects. 10.1% of lean, 13.2% of overweight and 23.3% of obese individuals were hypertensive. In conclusion, the high prevalence of overweight and obesity in Malaysia was associated with adverse lipid and glucose metabolism as well as poor blood pressure control.

The effect of pravastatin in patients with primary hyperlipidaemia.

Thirty-four (34) subjects with primary hyperlipidaemia were enrolled for this study. After low fat dietary therapy for 6 weeks, subjects' whose serum total cholesterol fell to below 6.2 mmol/l (11 subjects) were excluded from the study and those whose serum total cholesterol were 6.2 mmol/l or more (23 subjects) were started on pravastatin 10 mg nocte. After 8 weeks of treatment, there was a significant decrease in the mean total cholesterol and LDL-cholesterol. However 13 of the subjects still had serum total cholesterol 6.2 mmol/l or more and their pravastatin dose was increased to 20 mg nocte. After 12 weeks, there was a significant reduction in triglyceride, total cholesterol and LDL-cholesterol. There was also a significant increase in HDL-cholesterol. The triglyceride fell by a mean of 15.7%, total cholesterol by a mean of 18.1% and LDL-cholesterol by a mean of 26.3%. HDL-cholesterol on the other hand, increased by 19.4%. The subjects whose total cholesterol fell below 6.2 mmol/l at week 8 had significantly lower total cholesterol to begin with than those whose total cholesterol failed to do so and hence were commenced on 20 mg pravastatin. This suggests that the optimum dose of the drug is dependent on the initial level of total cholesterol. We conclude that pravastatin is effective as a lipid lowering agent.

Urinary iodine excretion in the northeast of Peninsular Malaysia.

A total of 2,034 subjects aged 15 years and above from different parts of the State of Kelantan were studied to determine goiter size and urinary iodine excretion. The State was divided into 2 areas - area 1 consisting of localities in the districts near the coast and area 2 consisting of localities in the inland districts. There were 1,050 subjects in area 1 and 984 subjects in areas 2. The mean age (+/- SE) of subjects in areas 1 and 2 were 38.2 + 0.5 and 37.1 +/- 0.5 years, respectively. The prevalence of goiter was 31.4% in area 1 and 45.0% in area 2; the difference was statistically significant (p < 0.05). However, the prevalence of large and visible goiters (grades II and III) was only 2.0% in area 1 and 3.3% in area 2; the difference was not statistically significant. The mean (+/- SD) urinary iodine excretion in areas 1 and 2 was 57.1 +/- 2.1 and 56.8 +/- 2.1 micrograms I/g Cr, respectively. The values were below those recommended by WHO. There was no significant difference in urinary iodine excretion between those with and without goiters in both areas and also between the grades of goiters. There were significantly more females with goiters than males in both areas but there was no significant difference in the urinary iodine excretion between the 2 sexes. Thus based on urinary iodine excretion, the iodine intake of the population in this area, was suboptimal and this was associated with a high prevalence of goiter.

The prevalence of endemic goitre in Kelantan, Malaysia.

A large-scale study was undertaken in the state of Kelantan, to determine the prevalence of goitre. A total of 2,450 subjects above the age of 15 years were selected from 31 localities in the state and examination for goitre was done using the technique of Perez. The state was divided into 3 areas--coastal area (area 1), inland area (area 2) and the area in between the coast and the inland area (area 3). The overall prevalence of goitre was 36.8% and the prevalence in areas 1, 2 and 3 were 23.0%, 35.9% and 44.9% respectively and ranged from 6.9% in a locality in area 1 to 59.7% in a locality in area 3. In all areas, the prevalence was higher in females than in males. The prevalence of grades I, II and III goitres were 21.5%, 1.0% and 0.5% respectively in area 1, 33.6%, 1.5% and 0.7% respectively in area 2 and 41.7%, 2.2% and 1.0% respectively in area 3. Amongst age groups, goitre prevalence was highest in the 36 to 45 years age group in area 1 (33.9%), in the 15 to 25 years age group in area 2 (39.6%) and in the 26 to 35 years age group in area 3 (54.3%). In all the areas, goitre prevalence was lowest in the above 56 years age group. We concluded that the prevalence of goitre was high in Kelantan and there were regional differences in the prevalence rate within the state.