Comparative Evaluation of Adenosine Deaminase Activity in Cerebral Cortex and Hippocampus of Young and Adult Rats: Effect of Garlic Extract (Allium sativum L.) on Their Susceptibility to Heavy Metal Exposure

Abstract

Adenosine plays an important neuromodulatory role in the central nervous system, and adenosine deaminase is an important enzyme in the degradation of adenine nucleotides. Methylmercury is the most prevalent form of mercury found in the environment. Methylmercury neurotoxicity has been correlated to the production of reactive oxygen species. In this study, its potential pathogenic effects were investigated in vitro in cerebral cortex and hippocampus of rats. We first observed that adenosine deaminase activity was higher in young rat brains when compared to the 60-day-old rats and was higher in hippocampus when compared to the cortex. Methylmercury (0.1, 1.0, 20 μ M) inhibited adenosine deaminase activity in 7-and 60-day-old rats in a concentration-dependent manner. We have demonstrated that methylmercury-induced inhibition was antagonized by garlic alcoholic extract, but sodium selenate did not alter enzyme activity. In addition, glutathione and dithiothreitol restored the methylmercury-induced decrease of adenosine deaminase activity. These results demonstrated that there are age-related changes in adenosine deaminase activity and that thiol agents may contribute to the maintenance of adenosine deaminase activity and may be important in the neuromodulation of adenosine. Garlic alcoholic extract may be effective in reducing the effect of methylmercury-induced adenosine deaminase, which may be due to its sulphur-containing compounds.

<i>Syzygium cumini</i> Extract Decrease Adenosine Deaminase, 5′Nucleotidase Activities and Oxidative Damage in Platelets of Diabetic Patients

“…Recent studies have shown that ADA activity was higher in the brains of young rats, when compared to the 60-day-old adult rats [27]. Furthermore, observed an increase in the activity of ADA in the cerebral cortex of rats eight days after neonatal Hypoxia Ischemia [28] and the administration of Metothrexate (MTX) induced a significant decreased in the ADA activity in the cerebral cortex, kidney and liver tissues of young rats [29].…”

Does allicin combined with vitamin B-complex have superior potentials than alpha-tocopherol alone in ameliorating lead acetate-induced Purkinje cell alterations in rats? An immunohistochemical and ultrastructural study

“…Consequently, the determination of GFAP expression could possibly be a suitable marker for comprehending neurodegenerative alterations. Gliosis that develops in the lead acetate-treated groups could possibly be caused by the creation of free radicals [20]; antioxidants may minimise such a reactive gliosis, probably through reduction of the hazardous impact of ROS in the CNS [11]. An earlier work has described that allicin alters the GFAP content in various brain regions and has a principal neuroprotective influence in minimising neuroglia injury in the CNS [11].…”

“…Gliosis that develops in the lead acetate-treated groups could possibly be caused by the creation of free radicals [20]; antioxidants may minimise such a reactive gliosis, probably through reduction of the hazardous impact of ROS in the CNS [11]. An earlier work has described that allicin alters the GFAP content in various brain regions and has a principal neuroprotective influence in minimising neuroglia injury in the CNS [11]. On such a basis, the usage of either a-tocopherol or combined allicin and vitamin B-complex in the current research considerably diminished GFAP expression in rats' cerebellar cortices.…”

Decrease of adenosine deaminase activity and increase of the lipid peroxidation after acute methotrexate treatment in young rats: protective effects of grape seed extract

“…9 The tissues ADA activities were measured spectrophotometrically by the method of Giusti,18 which is based on the direct measurements of the formation of ammonia, produced when ADA acts in excess of adenosine. Protein concentration was measured by the method of Peterson 19 with bovine serum albumin used as a standard.…”

“…This may be related to the maintenance of adenosine levels and its role in the regulation of synaptic transmission, which is influenced by endogenous adenosine. 9 Grape seed extract (GSE) contains a number of polyphenols, including procyanidins and proanthocyanidins, which are powerful free radical scavengers. A number of studies have demonstrated the superior free radical scavenging ability of GSE as compared to vitamins C, E, and b-carotene.…”