A combination of ascorbic acid and α-tocopherol or a combination of Mg and Zn are both able to reduce the adverse effects of lindane-poisoning on rat brain and liver

Gas formation and biological effects of biodegradable magnesium in a preclinical and clinical observation

Magnesium alloys are biodegradable metals receiving increasing attention, but the clinical applications of these materials are delayed by concerns over the rapid corrosion rate and gas formation. Unlike corrosion, which weakens mechanical properties, the gas formation issue has received little attention. Therefore, we evaluated the gas formation and biological effects for Mg implants through preclinical (immersed in Earle's balanced salt solution and in vivo) and clinical studies. The immersion test examined the gas volume and composition. The in vivo study also examined gas volume and histological analysis. The clinical study examined the gas volume and safety after Mg screw metatarsal fixation. Gas was mainly composed of H₂, CO and CO₂. Maximum volumes of gas formed after 5 days for in vivo and 7 days in clinical study. Within the clinical examination, two superficial wound complications healed with local wound care. Osteolytic lesions in the surrounding metaphysis of the Mg screw insertion developed in all cases and union occurred at 3 months. Mg implants released gas with variable volumes and composition (H₂, CO, and CO₂), with no long-term toxic effects on the surrounding tissue. The implants enabled bone healing, although complications of wound breakdown and osteolytic lesions developed.

In vivo antioxidant effect of aqueous root bark, stem bark and leaves extracts of Vitex doniana in CCl4 induced liver damage rats

OBJECTIVE

The antioxidant effects of aqueous root bark, stem bark and leaves of Vitex doniana (V. doniana) were evaluated in carbon tetrachloride (CCl4) induced liver damage and non induced liver damage albino rats.

METHODS

A total of 60 albino rats (36 induced liver damage and 24 non induced liver damage) were assigned into liver damage and non liver damage groups of 6 rats in a group. The animals in the CCl4 induced liver damage groups, were induced by intraperitoneal injection with a single dose of CCl4 (148 mg·ml(-1)·kg(-1) body weight) as a 1:1 (v/v) solution in olive oil and were fasted for 36 h before the subsequent treatment with aqueous root bark, stem bark and leaves extracts of V. doniana and vitamin E as standard drug (100 mg/kg body weighy per day) for 21 d, while the animals in the non induced groups were only treated with the daily oral administration of these extracts at the same dose. The administration of CCl4 was done once a week for a period of three weeks.

RESULTS

The liver of CCl4 induced not treated group showed that the induction with CCl4, significantly (P<0.05) increased thiobarbituric acid reactive substance (TBARS) and significantly (P<0.05) decreased superoxide dismutase (SOD) and catalase (CAT). However there was no significant (P>0.05) difference between TBARS, SOD and CAT in the liver of the induced treated groups and normal control group. In the kidney, TBARS showed no significant (P>0.05) difference between the normal and the induced groups, SOD was significantly (P<0.05) reduced in the CCl4 group compared to standard drug and normal control groups, CAT was significantly (P<0.05) increased in root and vitamin E groups when compared to induced not treated group. The studies also showed that when the extracts were administered to normal animals, there was no significant (P>0.05) change in the liver and kidney level of TBARS, SOD and CAT compared with the normal control except in the kidney of animals treated with stem extract where TBARS was significantly (P<0.05) lowered compared to control group.

CONCLUSION

The result of the present study suggests that application of V. doniana plant would play an important role in increasing the antioxidant effect and reducing the oxidative damage that formed both in liver and in kidney tissues. However stem bark has potential to improve renal function in normal rats.

Alpha-lipoic acid affects the oxidative stress in various brain structures in mice with methionine and choline deficiency

Deficiency in methionine or choline can induce oxidative stress in various organs such as liver, kidney, heart, and brain. This study was to examine the effects of alpha-lipoic acid (LA) on oxidative stress induced by methionine and choline deficiency (MCD) in several brain structures. Male mice C57BL/6 (n = 28) were divided into four groups: (1) control - continuously fed with standard chow; (2) LA - fed with standard chow and receiving LA; (3) MCD2 - fed with MCD diet for two weeks, and (4) MCD2+LA - fed with MCD diet for two weeks and receiving LA (100 mg/kg/day intraperitonealy [i.p.]). Brain tissue (cortex, hypothalamus, striatum and hippocampus) was taken for determination of oxidative stress parameters. MCD diet induced a significant increase in malondialdehyde and NOx concentration in all brain regions, while LA restored their content to normal values. Similar to this, in MCD2 group, activity of total SOD, MnSOD, and Cu/ZnSOD was reduced by MCD diet, while LA treatment improved their activities in all brain structures. Besides, in MCD2 group a decrease in catalase activity in cortex and GSH content in hypothalamus was evident, while LA treatment induced an increase in catalase activity in cortex and striatum and GSH content in hypothalamus. LA treatment can significantly reduce lipid peroxidation and nitrosative stress, caused by MCD diet, in all brain regions by restoring antioxidant enzymes activities, predominantly total SOD, MnSOD, and Cu/ZnSOD, and to a lesser extent by modulating catalase activity and GSH content. LA supplementation may be used in order to prevent brain oxidative injury induced by methionine and choline deficiency.

The effect of lipoic acid on cyanate toxicity in different structures of the rat brain

Cyanate is formed mostly during nonenzymatic urea biodegradation. Its active form isocyanate reacts with protein -NH2 and -SH groups, which changes their structure and function. The present studies aimed to investigate the effect of cyanate on activity of the enzymes, which possess -SH groups in the active centers and are implicated in anaerobic cysteine transformation and cyanide detoxification, as well as on glutathione level and peroxidative processes in different brain structures of the rat: cortex, striatum, hippocampus, and substantia nigra. In addition, we examined whether a concomitant treatment with lipoate, a dithiol that may act as a target of S-carbamoylation, can prevent these changes. Cyanate-inhibited sulfurtransferase activities and lowered sulfide level, which was accompanied by a decrease in glutathione concentration and elevation of reactive oxygen species level in almost all rat brain structures. Lipoate administered in combination with cyanate was able to prevent the above-mentioned negative cyanate-induced changes in a majority of the examined brain structures. These observations can be promising for chronic renal failure patients since lipoate can play a double role in these patients contributing to efficient antioxidant defense and protection against cyanate and cyanide toxicity.