ஐ.எஸ்.எஸ்.என்: 2155-9899
Gayathri V and Mohanan PV
Toxicity occurs when cells develop inflammation due to exposure to several toxic substances. The study was aimed to assess the damage (toxicity) induced by kainic acid on splenic lymphocyte and enriched T lymphocyte under in vitro conditions and the protective role of exogenous melatonin against this damage (toxicity). The study included assessment of inflammatory mechanism by the expression of immune modulatory cytokine mediators using real time PCR. Oxidative stress (reactive oxygen species) and nitrosative stress (reactive nitrogen species) were also studied to determine the free radical production. Interestingly, kainic acid caused severe splenic lymphocytes and enriched T lymphocyte damage which was evident from deleterious alterations in various parameters. Kainic acid treatment (1 mM) resulted in increased mRNA expression of cytokines like tumour necrosis factor-beta, interleukin 6, interleukin 1, interferon gamma, mitogen-activated protein kinase gene-14, inducible nitric oxide synthase and decreased interleukin 10 mRNA expression. Tritiated (3H) Thymidine Incorporation study signifies that kainic acid treatment (1 mM) increased the proliferation of splenic and enriched T lymphocytes. These changes were normalized by exogenous administration of melatonin (0.25-1.0 mM) in combination with kainic acid. Flow Cytometry Analysis using Annexin V apoptosis assay kit revealed an increase in apoptotic and necrosis (double positive cells) in splenic lymphocytes treated with kainic acid alone. However, melatonin treated in combination with kainic acid, showed attenuation to apoptosis and necrosis on splenic lymphocytes. This study depicts that kainic acid induced inflammatory toxicity could be attenuated by exogenous melatonin treatment as evident by the decreased levels of the inflammatory cytokines, immune reactions and free radical production.