Effects of nicotine and vitamin E on glucose 6-phosphate dehydrogenase activity in some rat tissuesin vivoandin vitro

Nicotine-mediated upregulation of microRNA-141 expression determines adipokine-intervened insulin resistance

MicroRNAs (miRNAs) are non-coding RNAs that are associated with adipokine homeostasis and insulin resistance. Whereas, smoking can disturb metabolic homeostasis. Present study was aimed to investigate the level of miRNA-141 in experimental animal model that were exposed with graded doses of nicotine. We further aimed to investigate the possible interplay of miRNA-141 expression change with adipokine homeostasis and occurrence of insulin resistance in nicotine-exposed experimental animals. Nicotine (0.5, 1.0, 3.0 and 6.0 mg/Kg) was administered to early adolescent; postnatal days ranging from 25 to 30 Wistar rats for one month. Serum was analyzed for leptin, adipokines, IL-6, MDA, HbA1c, insulin, G6PDH, hexokinase, and lipid profile. While miRNA-141 expression level was determined in plasma. Higher doses of nicotine were associated with higher glucose, HbA1c, leptin, IL-6, MDA and lipids levels, while, insulin, adiponectin, G6PDH, hexokinase and HDL levels were lower. Higher doses of nicotine also impaired glucose tolerance and exhibited significant increase in miR-141 expression signifying that nicotine exposure may influence adipokines regulation altering glycemic profile. This is accompanied with aggravated inflammatory responses where genetic expression of miRNA-141 can be an accessible biomarker for metabolic disturbances with insulin resistance and glucose intolerance.

Genistein improve nicotine toxicity on male mice pancreas

Nicotine is the most toxic factor of tobacco. Genistein is a phytoestrogen and antioxidant that has numerous health benefits. The aim of this study is to evaluate the effects of genistein against toxic properties of nicotine to the pancreas of mice. For this purpose, 48 male mice were randomly assigned into six groups (n=8): normal control, nicotine control (2.5 mg/kg), genistein (25 and 50 mg/kg), and nicotine+genistein (25 and 50 mg/kg) treated groups. Various doses of genistein and genistein+nicotine were administered intraperitoneally to animals for 4 weeks. The weight of pancreas, total antioxidant capacity and nitrite oxide of serum, insulin levels, and the number and diameter of islets of Langerhans were investigated. Nicotine administration reduced significantly total antioxidant capacity, insulin, pancreas weight, and the number and diameter of islets of Langerhans and increased nitrite oxide in serum compared to the control normal group (P<0.05). Conversely, genistein and genistein+nicotine increased significantly insulin, total antioxidant capacity, and the number and diameter islets of Langerhans and decreased serum nitrite oxide compared to the nicotine control group. It seems that the genistein can improve pancreas damage following the nicotine administration.

The effect of arsenic on some antioxidant enzyme activities and lipid peroxidation in various tissues of mirror carp (Cyprinus carpio carpio)

The effect of arsenic bioaccumulation in liver, kidney, skin, muscle, and intestinal tissues of mirror carp (Cyprinus carpio carpio) was investigated on lipid peroxidation and certain antioxidant enzyme activities. In this study, three aquarium groups were formed from mirror carp: control group, 0.5-, and 1-mg/L arsenic concentrations. The fish were dissected after 1 month. Arsenic bioaccumulation, malondialdehyde (MDA) levels, catalase (CAT), and superoxide dismutase (SOD) enzyme activities were determined in the tissues. Results showed that arsenic was accumulated in liver, kidney, muscle, skin, and intestinal tissues. As the final product of lipid peroxidation, MDA levels were determined to have increased in all tissues with the exception of muscle. On the other hand, CAT and SOD enzyme activities in the fish tissues were decreased as compared to the control group. In the muscle tissue, differences were observed in the enzyme activities depending on arsenic concentration. Considering the increases in enzyme inhibition and MDA levels, liver was observed to be the main tissue affected in response to the arsenic toxicity.

Effects of nicotine and vitamin E on glutathione reductase activity in some rat tissues in vivo and in vitro

Effects of nicotine, and nicotine+vitamin E on glutathione reductase (Glutathione: NADP(+) oxidoreductase, EC 1.8.1.7) activity in the muscle, heart, lungs, testicles, kidney, stomach, brain and liver tissues were investigated in vivo and also in vitro. The groups were: nicotine [0.5 mg/kg/day, intraperitoneal (i.p.)]; nicotine+vitamin E [75 mg/kg/day, intragastric (i.g.)]; and control group (receiving only vehicles). There were eight rats per group and supplementation period was 3 weeks. The results showed that nicotine (0.5 mg/kg, i.p.) inhibited glutathione reductase activity significantly in the liver, lungs, heart, stomach, kidney, and testicles by approximately 61.5%, approximately 65%, approximately 70.5%, approximately 72.5%, approximately 64% and approximately 71.5%, respectively, while it had activated glutathione reductase activity in the brain by approximately 11.8%, and had no effect on the muscle glutathione reductase activity. Vitamin E supplementation prevented this nicotine-induced decrease in glutathione reductase activity in liver, lungs, heart, stomach, and kidney. However, it did not prevent this nicotine-induced decrease in testicles. In vitro studies were also carried out to elucidate the effects of nicotine and vitamin E on glutathione reductase activity. In vitro results correlated well with in vivo experimental results in liver, lungs, heart, stomach, and testicular tissues. These results show that vitamin E administration generally restores the inactivation of glutathione reductase activity due to nicotine administration in various rat tissues in vivo, and also in vitro.

α-Tocopherol supplementation restores the reduction of erythrocyte glucose-6-phosphate dehydrogenase activity induced by forced training

BACKGROUND

Erythrocyte glucose-6-phosphate dehydrogenase (G6PD) activity is closely related to free radical production. alpha-Tocopherol (alpha-T) is implicated with the reduction of lipid peroxidation.

AIM

To investigate the effect of training and alpha-T supplementation on the erythrocyte G6PD activity.

METHODS

Blood was obtained from 10 basketball players pre-game (group A), post-game (group B) and after 30 days on alpha-T (dl-alpha-tocopheryl-acetate, 200mg 24h(-1) orally) supplementation pre- (group C) and post-training (group D). alpha-T and catecholamines were evaluated with HPLC methods and creatine kinase, lactate dehydrogenase, total antioxidant status (TAS) and G6PD activity with commercial kits.

RESULTS

TAS was increased in the groups with alpha-T addition (groups C and D). Post-exercise, TAS and G6PD activity were remarkably higher (2.10+/-0.13mmoll(-1), 7.92+/-1.5Ug(-1)Hb, respectively) in group D than those in group B (0.92+/-0.10mmoll(-1), 4.8+/-1.4Ug(-1)Hb, p<0.01, respectively). G6PD activity positively correlated with TAS (r=0.64, p<0.001) in all the studied groups.

CONCLUSIONS

Supplementation with alpha-T may protect G6PD activity from reduction induced by forced training.