title: Chronic pretreatment with American ginseng berry and its polyphenolic constituents attenuate oxidant stress in cardiomyocytes.
abstract: The acute anti-oxidant and protective effect of American ginseng berry extract (AGBE) has been demonstrated in cultured cardiomyocytes in our previous study. In the current study we evaluated if a chronic pretreatment of cultured cardiomyocytes with AGBE can alter the cellular antioxidant potential. Chick embryo cardiomyocytes were treated with AGBE (0.5-2.5 mg/ml) for up to 72 h. The treated cells were then exposed to exogenously added hydrogen peroxide (H(2)O(2); 500 microM). The oxidant-mediated injury was measured using a fluorescent probe 2',7'-dichlorofluorescin diacetate (DCFH/DA) while cell death was measured using propidium iodide (PI) staining. The non-treated (control) cells exposed to H(2)O(2) showed significant increase in DCF- and PI-mediated fluorescence suggesting significant oxidative injury and cell death. Pretreatment with AGBE demonstrated a significant attenuation of DCF fluorescence (p<0.005) with AGBE 0.5 mg/ml showing a 17% decrease, AGBE 1.0 mg/ml showing a 26% decrease, and AGBE 2.5 mg/ml showing a 49% decrease from control DCF fluorescence following a 72 h pretreatment. Cell death caused by H(2)O(2) was also significantly attenuated in AGBE-pretreated cells in a concentration- and time-dependent manner (p<0.005). We also demonstrated that active polyphenolic constituents in AGBE, caffeic acid and chlorogenic acid, appear to contribute significantly to AGBE's protective effects. Finally, catalase inhibition resulted in a significantly increased fluorescence in AGBE-treated cells compared to the control. The results suggest that pretreatment with AGBE upregulates peroxide detoxifying mechanisms, which could affect intracellular oxidant dynamics in cardiomyocytes.
authors.affiliation: Tang Center for Herbal Medicine Research, University of Chicago, Chicago, IL 60637, USA. smehendale@dacc.uchicago.edu
authors.forename: Sangeeta R
authors.initials: SR
authors.lastname: Mehendale
authors.forename: Chong-Zhi
authors.initials: CZ
authors.lastname: Wang
authors.forename: Zuo-Hui
authors.initials: ZH
authors.lastname: Shao
authors.forename: Chang-Qing
authors.initials: CQ
authors.lastname: Li
authors.forename: Jing-Tian
authors.initials: JT
authors.lastname: Xie
authors.forename: Han H
authors.initials: HH
authors.lastname: Aung
authors.forename: Chun-Su
authors.initials: CS
authors.lastname: Yuan
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002109:Caffeic Acids / Q000494:pharmacology; D002374:Catalase / Q000037:antagonists & inhibitors; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D002726:Chlorogenic Acid / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000494:pharmacology*; D005456:Fluorescent Dyes; D005638:Fruit / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000494:pharmacology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D005894:Panax / Q000737:chemistry*; D010636:Phenols / Q000494:pharmacology*; D059808:Polyphenols; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000975:Antioxidants; D002109:Caffeic Acids; D005419:Flavonoids; D005456:Fluorescent Dyes; D016877:Oxidants; D010636:Phenols; D059808:Polyphenols; D002726:Chlorogenic Acid; D006861:Hydrogen Peroxide; D002374:Catalase; C040048:caffeic acid