Comparison of cardioprotective effects of labeled and unlabeled oleanoic acids with new BOPIM dye on primary neonatal rat cardiomyocytes following hypoxia/reoxygenation injury

BackgroundIt is well known that fluorescent labeling has recently become a major research tool in molecular and cellular biology for demonstrating therapeutic mechanisms and metabolic pathways. However, few studies have reported the use of fluorescent labeling of natural products.MethodsWe recently explored the boron 2-(2′-pyridyl) imidazole (BOPIM) derivative analogs, which are highly fluorescent, non-aggregated, and nontoxic. In the present study, the natural product oleanolic acid (OA) was functionalized and labeled with BOPIM, thus yielding a highly fluorescent probe, the comparison of cardioprotective effects of labeled and unlabeled OAs with BOPIM on primary neonatal rat cardiomyocytes with hypoxia/reoxygenation (H/R) injury were investigated.ResultsPretreatment with OA and BOPIM-OA significantly prevented the H/R induced cell death in primary neonatal rat cardiomyocytes. However, BOPIM exhibited no improvements on the H/R injury cardiomyocytes, and which were similar to those of the H/R group. The results of comparison of cardioprotective effects between labeled and unlabeled OAs with BOPIM showed that introducing the BOPIM chromophore did not make a difference with H/R injury cardiomyocytes.ConclusionBOPIM chromophore is a suitable probe for investigating the pharmacological mechanisms of natural products.