Melatonin Inhibits Benzene-Induced Lipid Peroxidation in Rat Liver

Histological Effect of Gemcitabine on the Liver and Kidney of Male Rat with and without Melatonin

Background: the aim of this study is to identify the toxic effect of gemcitabine on the kidney and liver tissues of rat and whether melatonin has any protective effect on these tissues. MATERIALS AND METHODS: 32 adults male Wistar rats were selected and divided into four groups. Group A was the control group that received normal saline. Group B received gemcitabine alone in a dose of 25mg/kg body weight intraperitoneally once per week for four successive weeks. Group C received gemcitabine intraperitoneally in a dose of 25mg/ kg and melatonin orally in a dose of 10mg/kg once per week for four successive weeks. Group D received only melatonin 10mg/kg once per week for four weeks. RESULTS: The histological changes of liver of group B showed disorganization of hepatic tissue with congestion in the portal area and chronic inflammatory cells infiltration in the periportal area. Nuclei of some hepatocytes were vesicular with steatosis. In group C liver sections showed inflammatory cell infiltration with mild pyknosis of some hepatocytes. Liver sections of group D were limited to degeneration of some hepatocyte. Renal sections of group B showed degeneration and necrosis of epithelial cells with thickening of blood vessel wall, congestion and thrombus formation with cystic appearance in the interstitial tissue were detected. While in group C the histological sections showed swelling of epithelial cells lining renal tubules with congestion of blood vessels. Renal sections of group D were more or less normal. CONCLUSION:   the present study concluded that gemcitabine induced toxic effect on liver and kidney of male rats and melatonin may play protective effect on the tissue of these organs. Key wards: gemcitabine, melatonin, liver, kidney, rat

Quantitative measurement of oxidative damage in erythrocytes as indicator in benzene intoxications

The metabolism of aromatic hydrocarbons by the organism forms products that cause cell death depending on the type of exposure. Benzene exposure has been linked to oxidative stress, hepatic damage, aplastic anemia, and hematopoietic cancer as lymphoid and myeloid leukemia. However, there are not fast methods to evaluate chronic benzene exposure in human blood. The objective of this work was the evaluation of the correlation between oxidative damage with benzene exposure and the level of cellular plasma membrane stability (CPMS) in erythrocytes to use it as a future indicator to determine the grade of benzene intoxications. CPMS in vitro assays were used to evaluate damage for benzene, toluene, and xylene. Erythrocytes CPMS assays in vitro shows a progressive reduction with benzene, toluene, and xylene suggesting that aromatic hydrocarbons complexity favors CPMS damage. Eight groups of Wistar rats (n = 5) were used to study the level of damage on CPMS by acute and chronic benzene administration. Enzymatic, metabolic, histological, and oxidative damage tests were performed. Acute administration (100 μL/100 g/single dose) showed a decrease of 66.7% in CPMS, while 63.6% for chronic administration (5 μL/100 g/every 2 days/3 months) showing a correlation with liver damage principally (transaminases activity increase, glycogen level decrease, and high oxidative damage). Tissue damage was observed in bone marrow, kidney, spleen, and lungs. Benzene produces damage on CPMS depending on the exposure time and dose. The CPMS technique could be used as an important aromatic hydrocarbons intoxication indicator.

Effects of Melatonin on Liver Injuries and Diseases

Liver injuries and diseases are serious health problems worldwide. Various factors, such as chemical pollutants, drugs, and alcohol, could induce liver injuries. Liver diseases involve a wide range of liver pathologies, including hepatic steatosis, fatty liver, hepatitis, fibrosis, cirrhosis, and hepatocarcinoma. Despite all the studies performed up to now, therapy choices for liver injuries and diseases are very few. Therefore, the search for a new treatment that could safely and effectively block or reverse liver injuries and diseases remains a priority. Melatonin is a well-known natural antioxidant, and has many bioactivities. There are numerous studies investigating the effects of melatonin on liver injuries and diseases, and melatonin could regulate various molecular pathways, such as inflammation, proliferation, apoptosis, metastasis, and autophagy in different pathophysiological situations. Melatonin could be used for preventing and treating liver injuries and diseases. Herein, we conduct a review summarizing the potential roles of melatonin in liver injuries and diseases, paying special attention to the mechanisms of action.

Melatonin reduces pancreatic tumor cell viability by altering mitochondrial physiology

Melatonin reduces proliferation in many different cancer cell lines. Thus, melatonin is considered a promising antitumor agent, promoting apoptosis in tumor cells while preserving viability of normal cells. Herein, we examined the effects of melatonin on the pancreatic AR42J tumor cell line. We have analyzed cytosolic-free Ca(2+) concentration ([Ca(2+) ](c) ), mitochondrial-free Ca(2+) concentration ([Ca(2+) ](m) ), mitochondrial membrane potential (Ψm), mitochondrial flavin adenine dinucleotide (FAD) oxidative state, cellular viability and caspase-3 activity. Our results show that melatonin induced transient changes in [Ca(2+) ](c) and [Ca(2+) ](m) . Melatonin also induced depolarization of Ψm and led to a reduction in the level of oxidized FAD. In addition, melatonin reduced AR42J cell viability. Finally, we found a Ca(2+) -dependent caspase-3 activation in response to melatonin. Collectively, these data support the likelihood that melatonin reduces viability of tumor AR42J cells via its action on mitochondrial activity and caspase-3 activation.