Zinc Supplementation Restores Altered Biochemical Parameters in Stomach Tissue of STZ Diabetic Rats

Melatonin improves liver and pancreatic tissue injuries in diabetic rats: role on antioxidant enzymes

Purpose

Melatonin (Mel) is an indolamine mainly synthesized by the pineal gland and many other organs. It plays an important role in scavenging free radicals and stimulating antioxidant enzymes. The goal of this study was to investigate the effect of Mel and/or insulin treatment on oxidative liver and pancreas injuries in diabetic rats.

Methods

Male Wistar albino rats were assigned into 5 groups. Group I: control animals. Group II: diabetes was induced via a single dose of STZ (60 mg/kg) administered intraperitoneally. Group III: diabetic rats treated with Mel (10 mg/kg/day). Group IV: diabetic rats given insulin (6U/kg) subcutaneously. Group V: diabetic rats that received insulin and Mel at the same dose and time. After 12 weeks of the experiment, the animals were decapitated, liver and pancreas tissues were collected.

Results

The results indicated that reduced glutathione levels in liver and pancreatic tissue decreased, while protein carbonyl, advanced oxidized protein products and lipid peroxidation levels were elevated in diabetic group. Antioxidant enzyme activities decreased in liver tissues but increased in pancreatic tissues of the diabetic group. Administration of Mel, insulin or Mel + insulin reversed these biochemical changes in the diabetic animals.

Conclusion

This work shows that in long-term oxidative stress conditions caused by STZ-induced diabetes, either Mel or Mel + insulin administration may improve the deteriorated oxidant/antioxidant system in both the liver and pancreas tissues. These results suggested that Mel alone or Mel + insulin treatments might have a significant role in protecting against liver and pancreatic damage in STZ diabetic rats via different antioxidant effects.

Zinc Chloride Enhances the Antioxidant Status, Improving the Functional and Structural Organic Disturbances in Streptozotocin-Induced Diabetes in Rats

Background and Objectives: Diabetes mellitus (DM) is a complex disease affecting the whole metabolic balance of the body and resulting in multiple organ complications: cardiovascular, neuronal, renal, etc. Our study focuses on investigating the effect of zinc chloride (Zn) on certain blood parameters suggestive for assessing the metabolic disturbances, the liver and kidney function, the oxidative stress and the immune defense capacity in experimental-induced DM with streptozotocin (STZ) and cholesterol in rats. Materials and Methods: The animals were assigned to three groups, as follows: Group 1 (Control): buffer citrate solution 0.1 mL/100 g body; Group 2 (STZ): 20 mg/kg body STZ and fat diet (10 g cholesterol/100 g diet); Group 3 (STZ+Zn): 20 mg/kg body STZ + 5 mg/kg body Zn chloride and the same fat diet. DM was induced by administering STZ in a single take daily, for three consecutive days, Zn and citrate buffer were administered orally for a month. The protocol was approved by the Ethics Committee of the University 'Grigore T Popa' Iasi, in agreement with the International Regulations about the handling of laboratory animals. Results: The use of STZ in rats fed with cholesterol was correlated with important weight gain, hyperglycemia, the intensification of the transaminases activity and the increase in serum alkaline phosphatase, cholesterol, triglyceride, urea, creatinine and in malondialdehyde. Conclusions: The treatment with Zn resulted in weight loss and a decrease in blood sugar in diabetic rats. Supplementation with Zn notably reduced oxidative stress, preserved the pancreatic architecture and restored the liver and kidney function and structure in STZ-induced DM in rats.

Gastroprotective effect of vitamin U in D-galactosamine-induced hepatotoxicity

Galactosamine (GalN) is a well-known agent for inducing viral hepatitis models in rodents, but it can cause toxicity on different organs. Vitamin U (Vit U) has been proved as a powerful antioxidant on many toxicity models. The present study was designed to investigate the protective effects of Vit U on GalN-induced stomach injury. Rats were divided into four groups as follows: control (group I), Vit U given animals (50 mg/kg per day; group II), GalN administered animals (500 mg/kg at a single dose; group III), GalN + Vit U given animals (at the same dose and time, group IV). At the end of the 3rd day, animals were killed, and stomach tissues were taken. They were homogenized and centrifuged. In comparison to the control group, glutathione, total antioxidant capacity levels, catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and Na⁺ /K⁺ -ATPase activities of GalN group were found to be decreased. On the contrary, lipid peroxidation, advanced oxidized protein products, hexose-hexosamine, fucose, sialic acid, reactive oxygen species levels, as well as the activities of myeloperoxidase, xanthine oxidase, and lactate dehydrogenase were elevated. Administration of Vit U reversed these abnormalities in the GalN group. It can be concluded that Vit U exerts its unique antioxidant effect and prevents GalN-induced gastric damage.

Zinc Prevents Ethanol-Induced Oxidative Damage in Lingual Tissues of Rats

The current study was designed to investigate the effects of zinc sulfate on cell proliferation, metallothionein (MT) immunoreactivity and antioxidant system against acute ethanol-induced oxidative damage in tongue tissues of rats. Wistar albino male rats, 2.5 to 3.0 months, were divided into four groups: Group I (n = 8), intact control rats; group II (n = 8), control animals given only zinc sulfate (100 mg/kg/day, for 3 consecutive days); group III (n = 14), animals given 1 mL absolute ethanol; group IV (n = 11), animals given zinc sulfate and absolute ethanol at the same dose and time. Animals were sacrificed under anesthesia 2 h after ethanol administration or 4 h after the last zinc sulfate treatment. Ethanol administration caused a marked decrease in the number of MT immunopositive cells and the proliferating cells in the lingual epithelium. A statistically significant decline in reduced glutathione levels, catalase activity and superoxide dismutase activities was also observed, whereas a significant elevation of lipid peroxidation levels and lactate dehydrogenase activities was detected in the ethanol group. In contrast, these changes were reversed by administration of zinc sulfate to ethanol-treated rats. In conclusion, it shows that zinc sulfate has therapeutic effects on acute ethanol-induced oxidative damage in the tongue tissues of rats.