Effect of Tocotrienols enriched canola oil on glycemic control and oxidative status in patients with type 2 diabetes mellitus: A randomized double-blind placebo-controlled clinical trial.

BACKGROUND: Tocotrienols have been shown to improve glycemic control and redox balance in an animal study, but their effects on patients with diabetes are unknown. The study aimed to investigate whether tocotrienols improves glycemic control, insulin sensitivity, and oxidative stress in individuals with type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: This study was a double-blinded, placebo-controlled, randomized trial. A total of 50 patients, aged 35-60 years, with T2DM treated by noninsulin hypoglycemic drugs were randomly assigned to receive either 15 mL/day tocotrienols (200 mg) enriched canola oil (n = 25) or pure canola oil (n = 25) for 8 weeks. Fasting blood sugar (FBS), fasting insulin, total antioxidant capacity (TAC), malondialdehyde (MDA), and homeostatic model assessment for insulin resistance (HOMA-IR) were determined before and after the intervention. The data were compared between and within groups, before and after the intervention. RESULTS: Baseline characteristics of participants including age, sex, physical activity, disease duration, and type of drug consumption were not significantly different between the two groups. In tocotrienol enriched canola oil, FBS (mean percent change: -15.4% vs. 3.9%; P = 0.006) and MDA (median percent change: -35.6% vs. 16.3%; P = 0.003) were significantly reduced while TAC was significantly increased (median percent change: 21.4% vs. 2.3%; P = 0.001) compared to pure canola oil. At the end of the study, patients who treated with tocotrienols had lower FBS (P = 0.023) and MDA (P = 0.044) compared to the pure canola oil group. However, tocotrienols had no effect on insulin concentrations and HOMA-IR. CONCLUSION: Tocotrienols can improve FBS concentrations and modifies redox balance in T2DM patients with poor glycemic control and can be considered in combination with hypoglycemic drugs to better control of T2DM.

Effect of crocus sativus on gentamicin induced nephrotoxicity.

Crocus sativus, known as saffron, is used in folk medicine for treatment of different types of diseases, and its anti-inflammatory and free radical scavenging activities have been demonstrated. The present study evaluated gentamicin nephrotoxicity in saffron treated rats. Male Wistar rats (200-250 g) were treated with saffron (40 or 80 mg/k/d) for 10 days, or saffron (40 or 80 mg/ kg/d) for 10 days and gentamicin 80 mg/kg/d for five days, starting from day 6. At the end of treatment, blood samples were taken for measurement of serum creatinine (SCr) and BUN. The left kidney was prepared for histological evaluation and the right kidney for Malondialdehyde (MDA) measurement. Gentamicin 80 (mg/k/d) increased SCr, BUN and renal tissue levels of MDA and induced severe histological changes. Saffron at 40 mg/k/d significantly reduced gentamicin-induced increases in BUN and histological scores (p<0.05). Gentamicin-induced increases in BUN, SCr and MDA and histological injury were significantly reduced by treatment with saffron 80 mg/k/d (p<0.05, p<0.001, p<0.05, and p<0.001 respectively). In conclusion, our results suggest that saffron treatment reduces gentamicin-induced nephrotoxicity and this effect seems to be dose dependent.

The influence of calcium supplement on body composition, weight loss and insulin resistance in obese adults receiving low calorie diet.

BACKGROUND: Obesity and diabetes are the most important problems of public health. Evidence from molecular animal research and epidemiologic investigations indicate that calcium intake may have an influence on body composition, weight and insulin resistance. The objective of this study was to determine the effects of calcium supplementation on body composition, weight, insulin resistance and blood pressure in the face of calorie restriction in obese adults. METHODS: A double blind randomized placebo-controlled trial on 40 adults with Body Mass Index > 25kg/m(2) was conducted. Subjects were maintained for 24 weeks on a balanced deficit diet (-500 kcal/d deficit) and randomly assigned into two groups with 1000 mg ca/d as calcium carbonate or placebo. RESULTS: There were no significant differences in variables at the 12th and 24th week between the two groups. The lean mass showed no significant increase in the calcium group at the 12th week compared to baseline and in placebo group at the 24th week compared to the 12th week. The insulin concentration showed a significant decrease in the calcium group at the 12th week compared to the baseline (p < 0.05). The diastolic blood pressure had a significant decrease at the 24th week compared to the 12th week in both groups (p = 0.013-0.009). CONCLUSIONS: Results from this study suggest that 24 weeks of supplementation with 1000 mg ca/d did not have any effect on weight, body composition, insulin resistance and blood pressure beyond what can be achieved in an energy restricted diet in obese adults.

Effect of crocus sativus on gentamicin induced nephrotoxicity

Crocus sativus, known as saffron, is used in folk medicine for treatment of different types of diseases, and its anti-inflammatory and free radical scavenging activities have been demonstrated. The present study evaluated gentamicin nephrotoxicity in saffron treated rats. Male Wistar rats (200-250g) were treated with saffron (40 or 80 mg/k/d) for 10 days, or saffron (40 or 80 mg/ kg/d) for 10 days and gentamicin 80 mg/kg/d for five days, starting from day 6. At the end of treatment, blood samples were taken for measurement of serum creatinine (SCr) and BUN. The left kidney was prepared for histological evaluation and the right kidney for Malondialdehyde (MDA) measurement. Gentamicin 80 (mg/k/d) increased SCr, BUN and renal tissue levels of MDA and induced severe histological changes. Saffron at 40 mg/k/d significantly reduced gentamicin-induced increases in BUN and histological scores (p<0.05). Gentamicin-induced increases in BUN, SCr and MDA and histological injury were significantly reduced by treatment with saffron 80 mg/k/d (p<0.05, p<0.001, p<0.05, and p<0.001 respectively). In conclusion, our results suggest that saffron treatment reduces gentamicin-induced nephrotoxicity and this effect seems to be dose dependent.

Effect of vitamin C supplementation on oxidative stress and lipid profiles in hemodialysis patients.

BACKGROUND AND AIMS: The increase in oxidative stress is the main factor in acceleration of atherosclerosis, leading to death in hemodialysis patients. Vitamin C is one of the most important antioxidants that inhibits lipid peroxidation and improves endothelial function. This study aims to assess the effects of vitamin C supplementation on lipid profiles as well as markers of lipid peroxidation among hemodialysis patients. MATERIALS AND METHODS: In this double-blind, randomized, controlled clinical trial, a total of 42 patients were randomly assigned to vitamin C (n=21) or placebo groups (n=21). Patients in the vitamin C group consumed 250 mg vitamin C and those in the placebo group were given placebo every other day for 12 weeks. Fasting blood samples were collected at baseline and at the end of the study to measure serum concentrations of lipid profiles, as well as malondialdehyde (MDA) and vitamin C. RESULTS: After supplementation with vitamin C, serum vitamin C levels increased significantly in the vitamin C group as compared to baseline (p=0.033). There was also a significant difference in serum vitamin C levels between vitamin C and placebo groups (p=0.001). Serum MDA concentrations were marginally decreased in the vitamin C group after taking supplements (p=0.057). A significant difference was also seen in mean MDA changes between vitamin C and placebo groups (p=0.002). There was a significant difference in serum levels of total cholesterol (p=0.005), low-density lipoprotein (LDL-C) (p=0.012), and LDL-C/high-density lipoprotein (HDL-C) ratio (p=0.018) between the two groups; however, serum triglyceride and HDL-C levels were not significantly different between groups. CONCLUSION: Every other day supplementation with 250 mg vitamin C for 12 weeks increases serum vitamin C, decreases MDA levels, and improves lipid profiles in hemodialysis patients.

Development and validation of a short food-frequency questionnaire for screening women of childbearing age for vitamin A status in northwestern Iran.

A high percentage of women in their childbearing years suffer from subclinical vitamin A deficiency; 10% to 20% of pregnant women worldwide are vitamin A deficient. This study aimed to design and validate a short food-frequency questionnaire to serve as a simple screening tool for vitamin A status in women of childbearing age. The sample consisted of 187 healthy, nonpregnant, nonlactating women 15 to 49 years of age, from urban and rural areas of Marand district in East Azerbaijan. Dietary intake was evaluated by a face-to-face interview using a 24-hour dietary recall for two consecutive days and a 41-item qualitative food frequency questionnaire. Height, weight, and serum retinol were measured. Serum retinol values were less than 20 micrograms/dl for three subjects, while an additional 34 subjects (18%) had values between 21 and 30 micrograms/dl. Principal-component analysis performed on the food-frequency questionnaire identified five components that together defined 34.4% of the variance in estimated vitamin A intake and were used to derive a 20-item short food-frequency questionnaire. Internal consistency of the short instrument was acceptable (Cronbach's alpha = .59). Serum retinol was significantly correlated with total vitamin A intake and with intake of vitamin A from plant sources, as estimated by the short food-frequency questionnaire. Important sources of provitamin A in these women's diets included some not typical of other populations: nuts and green leaves of types used elsewhere in small quantities as herbs, but important in Iran because the amount and frequency of consumption are relatively high. We conclude that the questionnaire is relatively valid and potentially useful in identifying women at risk for vitamin A deficiency in this population.