Protective effect of bioactive compounds from Lonicera japonica Thunb. against H2O2-induced cytotoxicity using neonatal rat cardiomyocytes

Abstract

<strong><em>Objective(s)</em><em>:</em></strong>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 (H₂O₂)-induced and hypoxia-induced cytotoxicity using neonatal rat cardiomyocytes. <br/><strong><em>Materials and Methods</em><em>:</em></strong>Seven CQAs (C1 to C7) isolated and identified from Jin Yin Hua were used to examine the effects of H₂O₂-induced and hypoxia-induced cytotoxicity. We studied C4 and C6 as preventative bioactive compounds of the reactive oxygen species (ROS) production, apoptotic pathway, and apoptosis-related gene expression. <br/><strong><em>Results:</em></strong>C4 and C6 were screened as bioactive compounds to exert a cytoprotective effect against oxidative injury. Pretreatment with C4 and C6, dose-dependently attenuated hypoxia-induced ROS production and reduced the ratio of GSSG/GStotal. Western blot data revealed that the inhibitory effect of C4 on H₂O₂-induced up and down-regulation of Bcl-2, Bax, caspase-3, and cleaved caspase-3. Apoptosis was evaluated by detection of DNA fragmentation using TUNEL assay, and quantified with Annexin V/PI staining. <br/><strong><em>Conclusion:</em></strong><em> In vitro</em> experiments revealed that both C4 and C6 protect cardiomyocytes from necrosis and apoptosis during H2O2-induced injury, via inhibiting the generation of ROS and activation of caspase-3 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.