Nan-Hui Yu1,2, Haiping Pei2, Yong-Pan Huang3,4, Yu-Fei Li4. 1. Department of Pharmacy, Changsha Hospital for Maternal and Child Health Care, Changsha, China. 2. Department of Gastrointestinal Surgery, Xiangya Hospital, Central South University, Changsha, China. 3. Xiangya School of Medicine, Central South University, Changsha, China. 4. School of Medicine, Hunan Normal University, Changsha, China.
Abstract
BACKGROUND/AIMS: Exposure to arsenic in individuals has been found to be associated with various health-related problems including skin lesions, cancer, and cardiovascular and immunological disorders. (-)-Epigallocatechin-3-gallate (EGCG), the main and active polyphenolic catechin present in green tea, has shown potent antioxidant, anti-apoptotic and anti-inflammatory activity in vivo and in vitro. Thus, the present study was conducted to investigate the protective effects of EGCG against arsenic-induced inflammation and immunotoxicity in mice. METHODS: Serum IL-1β, IL-6 and TNF-α were determined by ELISA, tissue catalase (CAT), malonyldialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), nitric oxide and caspase 3 by commercial kits, mitochondrial membrane potential with Rh 123, mitochondrial ROS with 2',7'-dichlorofluorescin diacetate (DCFH-DA), apoptotic and necrotic cells and T-cell phenotyping with Flow cytometry analysis. RESULTS: The results showed that arsenic treatment significantly increased oxidative stress levels (as indicated by catalase, malonyldialdehyde, superoxide dismutase, glutathione and reactive oxygen species), increased levels of inflammatory cytokines and promoted apoptosis. Arsenic exposure increased the relative frequency of the CD8+(Tc) cell subpopulation (from 2.8 to 18.9%) and decreased the frequency of CD4+(Th) cells (from 5.2 to 2.7%). Arsenic exposure also significantly decreased the frequency of T(CD3) (from 32.5% to 19.2%) and B(CD19) cells (from 55.1 to 32.5%). All of these effects induced by NaAsO2 were attenuated by EGCG. CONCLUSIONS: The present in vitro findings indicate that EGCG attenuates not only NaAsO2-induced immunosuppression but also inflammation and apoptosis.
BACKGROUND/AIMS: Exposure to arsenic in individuals has been found to be associated with various health-related problems including skin lesions, cancer, and cardiovascular and immunological disorders. (-)-Epigallocatechin-3-gallate (EGCG), the main and active polyphenolic catechin present in green tea, has shown potent antioxidant, anti-apoptotic and anti-inflammatory activity in vivo and in vitro. Thus, the present study was conducted to investigate the protective effects of EGCG against arsenic-induced inflammation and immunotoxicity in mice. METHODS: Serum IL-1β, IL-6 and TNF-α were determined by ELISA, tissue catalase (CAT), malonyldialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), nitric oxide and caspase 3 by commercial kits, mitochondrial membrane potential with Rh 123, mitochondrial ROS with 2',7'-dichlorofluorescin diacetate (DCFH-DA), apoptotic and necrotic cells and T-cell phenotyping with Flow cytometry analysis. RESULTS: The results showed that arsenic treatment significantly increased oxidative stress levels (as indicated by catalase, malonyldialdehyde, superoxide dismutase, glutathione and reactive oxygen species), increased levels of inflammatory cytokines and promoted apoptosis. Arsenic exposure increased the relative frequency of the CD8+(Tc) cell subpopulation (from 2.8 to 18.9%) and decreased the frequency of CD4+(Th) cells (from 5.2 to 2.7%). Arsenic exposure also significantly decreased the frequency of T(CD3) (from 32.5% to 19.2%) and B(CD19) cells (from 55.1 to 32.5%). All of these effects induced by NaAsO2 were attenuated by EGCG. CONCLUSIONS: The present in vitro findings indicate that EGCG attenuates not only NaAsO2-induced immunosuppression but also inflammation and apoptosis.