Protective effect of bioactive compounds from Lonicera japonica Thunb. against H۲O۲-induced cytotoxicity using neonatal rat cardiomyocytes

Objective(s):Pharmacological studies showed that the extracts of Jin Yin Hua and its active constituents have lipid lowering, antipyretic, hepatoprotective, cytoprotective, antimicrobial, antibiotic, antioxidative, antiviral, and anti-inflammatory effects. The purpose of the present study was to investigate the protective effects of caffeoylquinic acids (CQAs) from Jin Yin Hua against hydrogen peroxide (H۲O۲)-induced and hypoxia-induced cytotoxicity using neonatal rat cardiomyocytes. Materials and Methods:Seven CQAs (C۱ to C۷) isolated and identified from Jin Yin Hua were used to examine the effects of H۲O۲-induced and hypoxia-induced cytotoxicity. We studied C۴ and C۶ as preventative bioactive compounds of the reactive oxygen species (ROS) production, apoptotic pathway, and apoptosis-related gene expression. Results:C۴ and C۶ were screened as bioactive compounds to exert a cytoprotective effect against oxidative injury. Pretreatment with C۴ and C۶, dose-dependently attenuated hypoxia-induced ROS production and reduced the ratio of GSSG/GStotal. Western blot data revealed that the inhibitory effect of C۴ on H۲O۲-induced up and down-regulation of Bcl-۲, Bax, caspase-۳, and cleaved caspase-۳. Apoptosis was evaluated by detection of DNA fragmentation using TUNEL assay, and quantified with Annexin V/PI staining. Conclusion: In vitro experiments revealed that both C۴ and C۶ protect cardiomyocytes from necrosis and apoptosis during H۲O۲-induced injury, via inhibiting the generation of ROS and activation of caspase-۳ apoptotic pathway. These results demonstrated that CQAs might be a class of compounds which possess potent myocardial protective activity against the ischemic heart diseases related to oxidative stress.

Keywords:

Anti-apoptosis , Caffeoylquinic acids , Cardiomyocytes , Lonicera japonica Thunb , Oxidative stress