Protective effects of Syzygium cumini seed extract against methylmercury-induced sistemic toxicity in neonatal rats.

Syzygium cumini (L.) Skeels (Sc) belongs to the medicinal plants with an important source of phenolic compounds. Sc has been shown to possess antioxidant and anti-inflammatory properties. Methylmercury (MeHg), a highly toxic environmental pollutant, induces oxidative stress and dysfunction in many cell types. This study was aimed to evaluate the effect of aqueous seed extract of Sc (ASc) on MeHg-induced toxicity in rats. Two-day-old rats (P2) received a single dose of MeHg (10 mg/kg) and two doses of ASc (0.9 mg/kg) per os. After two days, the effects of the treatment were investigated in the cerebral cortex, hippocampus, kidney, liver and urine samples. Our results demonstrated that N-acetyl-ß-D: -glucosaminidase (NAG) activity in the kidney and urine, the lipid peroxidation levels in the liver and kidney samples, as well as the adenosine deaminase (ADA) activity in the hippocampus, kidney and liver were higher in MeHg-group when compared to the control group. The administration of ASc reverted the toxic effects of MeHg. It is noteworthy to observe that the main compounds present in the ASc, as gallic acid (the major component), chlorogenic acid and rutin, might be the responsible for such benefit, since they were found to display antioxidant properties.

Allium sativum L. extract prevents methyl mercury-induced cytotoxicity in peripheral blood leukocytes (LS).

Adenosine deaminase (ADA) is involved in purine metabolism and plays a significant role in the immune system. The focus of this investigation was to examine the effects of low concentrations of organic mercury on ADA activity in human leukocytes and to investigate the relationship between these effects and cell death. We have examined the protective potential effects of Allium sativum extract (GaE) against Methylmercury (MeHg)-induced cytotoxic effects on human leucocytes under in vitro conditions. MeHg (0.05-10 microM) significantly decreased leukocyte viability (58.97% for MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) and 51.67% for Alamar Blue (AB) and this decrease was positively correlated to the MeHg-induced inhibition of ADA activity. N-acetylcysteine (NAC) and GaE prevented both the MeHg-induced cytotoxic effects on leukocytes according to MTT and AB assays and the effects on the ADA activity. The present results suggest that the protective effects of GaE against MeHg-induced leukocyte damage is related to the removal of oxidant species generated in the presence of MeHg due to the antioxidant efficacy of garlic constituents. It is important to point out that the intense presence of ADA in Leukocyte suspension (LS) highlights the relevant effects in the immune system and in vitro cytotoxicity of MeHg exposure.