Alteration in Glutathione and Its Metabolizing Enzymes in Cardiac Tissue Upon Oral Ingestion of Monosodium Glutamate to Hypercholestremic Adult Male Mice

Monosodium glutamate (MSG) was orally administered at dose levels of 4 and 8mg/g body weight to hypercholestremic adult male mice for 6 consecutive days and its effect was observed on 31st day after the last injection by evaluating the changes in total-sulfhydryl (TSH) group, Non-protein bound sulfhydryl (NPB-SH) group and protein bound sulfhydryl (PB-SH) and glutathione metabolising enzymes like glutathione reductase (GR) and glutathione peroxidase (GPx) enzymes in cardiac tissue of hypercholestremic adult male mice. The animals were divided in four groups each comprising 6 mice. Group-I: Control, Group-II: Hypercholestremic animals, Group-III: 4mgMSG/g body weight + hypercholestremic animals and Group-IV: 8mgMSG/g body weight + hypercholestremic animals. Animals were fasted overnight and sacrificed by decapitation. The 10 per cent homogenate was prepared in 100mM potassium phosphate buffer (pH7.5). The homogenate was centrifuged at 1,000g and supernatant was used for the estimation of TSH, NPB-SH, PB-SH, GR and GPx. The levels of TSH, PBSH and NPBSH groups were significantly decreased in cardiac tissue of all the study groups. The glutathione metabolising enzymes such as GR and GPx was significantly decreased in cardiac tissue of hypercholestremic adult male mice's without MSG (Group-2) and with MSG (Group-3 and group-4) ingestion. These observations suggested that ingestion of MSG at dose levels of 4 and 8mg/g body weight to hypercholestremic animals had no beneficial effect instead it further weakens the antioxidant status in the cardiac tissue by significantly lower the levels of glutathione and its metabolising enzymes and thereby being responsible for the initiation of coronary heart disease/atherosclerosis.