Phenolic composition, antioxidant, cytotoxic activities and cardioprotective effect of hydroalcoholic extract from aerial-parts of Hypericum attenuatum Fisch. ex Choisy.

This study investigated phenolic metabolites, antioxidant, cytotoxic and cardioprotective effects of the hydroalcoholic extract from the aerial parts of Hypericum attenuatum Fisch. ex Choisy. The total phenolic and flavonoid contents of the extract were 132.40 ± 2.06 mg GAE/g and 101.46 ± 1.47 mg QE/g respectively. The extract exhibited antioxidant activities with an EC₅₀ value against DPPH radical of 0.099 ± 0.03 mg/mL and a FRAP value of 1.22 ± 0.086 mmol/L Fe²⁺. The extract could protect H9c2 cardiomyoblasts from the injury of H₂O₂, while it restored the H9c2 cell viability to 82.69 ± 2.33% at 100 μg/mL. The extract possessed cytotoxicity on MGC803, C666-1 and SW620 cells with IC₅₀ values of 69.77 ± 2.43 μg/mL, 74.97 ± 1.08 μg/mL and 58.91 ± 1.81 μg/mL, respectively. Moreover, it could promote apoptosis of the tested cancer cells. This research provided useful information for the utilization of H. attenuatum as herbal medicine. [ABSTRACT FROM AUTHOR]