Effect of Lecithin on <Emphasis Type="SmallCaps">d</Emphasis>-Galactosamine Induced Hepatotoxicity Through Mitochondrial Pathway Involving Bcl-2 and Bax

Twenty four Wistar strain albino rats were used for the investigations. Lecithin 50 and 100 mg/kg b wt was administered for 1 week by oral route. Liver damage was induced by intra peritoneal administration of 400 mg/kg b wt d-galactosamine on the last day. At the end of the study animals were sacrificed and liver enzyme levels, histopathology, mitochondrial integrity, expression of p53, Bax and Bcl-2 mRNA levels were studied. Increases in the liver enzyme levels by d-GalN were significantly inhibited by pretreatment with lecithin. Histopathological observation further confirmed the hepatoprotective effect of lecithin. In addition, the disruption of mitochondrial membrane, up regulation of Bax and down regulation of Bcl-2 mRNA levels in the liver of d-GalN intoxicated rats were effectively prevented by pretreatment with lecithin. The results of the present study validate our conviction that d-GalN causes hepatic damage via mitochondrial pathway involving Bax and Bcl-2.     

Prostaglandin,cortisol and catecholamines in angina pectoris

Plasma prostaglandin E₂ (PGE₂)-like activity, cortisol and catecholamines were estimated in twenty stable angina pectoris and thirty control cases. PGE₂ like activity was significantly decreased (0.7 ng/ml ± 0.44) in angina patients compared to control (1.6 ng/ml ± 0.7). The plasma catecholamines were only marginally elevated in angina patients (242.8 ng/100 ml ± 14.2) compared to healthy individuals (236.2 ng/100 ml ± 5.5). The changes in plasma cortisol levels were not significant in angina (18.4 μg%± 6.5) in comparison to control (16.9 μg% ± 3.2).     

A charged particle in perpendicular electric and magnetic fields

This section of Resonance presents thought-provoking questions, and discusses answers a few months later. Readers are invited to send new questions, solutions to old ones and comments, to ‘Think It Over’, Resonance, Indian Academy of Sciences, Bangalore 560 080. Items illustrating ideas and concepts will generally be chosen.     

Effect of chloride and diamide on sheep kidney,lung and serum angiotensin converting enzyme

The effect of chloride and diamide on angiotensin converting enzyme (ACE) activity from sheep kidney, lung and serum was investigated by using Hip-His-Leu as substrate. Optimum chloride concentrations were 400–1000 mM for kidney, 700 mM for lung and 1000 mM for serum. Optimum chloride concentration increased ACE activity of serum and lung 1.70 folds and 2.73 folds respectively of the activity at physiological chloride concentrations, suggesting that the effect of salt on blood pressure may be due to the chloride sensitivity of ACE. The difference in effect of chloride on lung, kidney and serum ACE suggest that each tissue ACE has unique three dimentional structure. Increased pulmonary and serum ACE activity on pretreatment with diamide indicates that tissue oxidation may alter blood pressure.     

Effect of Lecithin and silymarin on D-galactosamine induced toxicity in isolated hepatocytes and rats

To investigate Lecithin for its hepatoprotective activity against D-galactosamine (D-GalN) induced toxicity in freshly isolated rat hepatocytes and animal models. Freshly isolated rat hepatocytes were exposed to Dgalactosamine (30 mM) along with/without lecithin (100 μg/ml) and the levels of selected liver enzymes were measured. Thirty six Wistar strain albino rats were used for the in vivo investigations. Lecithin 50 and 100 mg/kg.b.wt were administered for one week by oral route. Liver damage was induced by intra peritoneal administration of 400 mg/kg b.wt D-galactosamine. The antihepatotoxic effect of lecithin was observed in freshly isolated rat hepatocytes at concentration 100 μg/ml and was found to be similar to that of the standard silymarin used. Its in vivo hepatoprotective effect at 100 mg/kg b.wt was comparable with that of the standard silymarin at 100 mg/kg body weight. Lecithin was able to normalise the biochemical levels which were altered due to D-galactosamine intoxication in freshly isolated rat hepatocytes and also in animal models.     

Altered antioxidant enzyme profile in wound healing

The effects of the alcoholic extract of the flowers ofIxora coccinea were studied on some of the antioxidant enzymes in dead space wounds created in rats. Increases in the tensile strength of the wound and in the level of lysyl oxidase, the crucial enzyme for collagen maturation, were observed indicating a definite prohealing action. In addition, a highly significant increase in the levels of catalase, glutathione peroxidase and glutathione reductase was observed in the drug-treated group. Thus, the gain in tensile strength may be attributed not only to the better cross-linking but also to the antioxidant properties of the drug.     

Protective Role of Catechin on <Emphasis Type="SmallCaps">d</Emphasis>-Galactosamine Induced Hepatotoxicity Through a p53 Dependent Pathway

Objective of this study was to obtain a better understanding of the mechanism responsible for the d-galactosamine (d-GalN) induced hepatotoxicity and to study the effect of catechin against d-GalN induced hepatotoxicity. Catechin 50 and 100 mg/kg b.wt was administered for 1 week by oral route. Liver damage was induced by intra-peritoneal administration of 400 mg/kg b.wt d-galactosamine on the last day of catechin treatment. At the end of treatment all animals were killed and liver enzyme levels were estimated. Dissected hepatic samples were used for histopathology, RNA isolation, expression studies of Bax, Bcl-2 and p53 mRNA levels and mitochondrial membrane potential studies. We found that increases in the liver enzyme activity and decrease in antioxidant enzyme activity by d-GalN were significantly restricted by oral pretreatment with catechin. Disruption of mitochondrial membrane potential, up regulation of p53, Bax and down regulation of Bcl-2 mRNA levels in the liver of d-GalN intoxicated rats were effectively prevented by pretreatment with catechin.