Steamed daylily flower (Hemerocallis fulva L.) protected cardiac and hepatic cells against ethanol induced apoptotic and oxidative damage.

Abstract

Our previous study examined the phytochemical composition and bio-activities of raw daylily flower (Hemerocallis fulva L.). However, this plant food is usually served via heat process such as cooking in a soup. This study aimed to investigate the phytochemical profile and biofunctions of steamed daylily flower (SDF). The content of total phenolic acids, total flavonoids, total carotenoids, total anthocyanins and total triterpenoids in SDF aqueous extract was assessed. Normal cardiac and hepatic cells, H9c2 and L-02 cells, were used to evaluate the protective effects of SDF against ethanol. SDF concentrations of 0.25%, 0.5%, and 1% were applied to treat H9c2 or L-02 cells for 48 h at 37 °C initially, followed by exposure to ethanol at 150 mM for 24 h at 37 °C. Results showed that the content of assessed phytochemicals was in the range of 1019-2045 mg/100 g dry weight. Flavonoids and triterpenoids were two major detected phytochemicals in SDF. SDF treatments at 0.5% and 1% increased the viability of H9c2 cells, but at three concentrations enhanced the survival of L-02 cells. SDF at 0.5% and 1% up-regulated Bcl-2 messenger RNA (mRNA) expression and down-regulated Bax mRNA expression. Ethanol increased reactive oxygen species production, decreased glutathione content, as well as lowered glutathione peroxidase and catalase activities. SDF treatments reversed these changes. SDF at 0.5% and 1% reduced the activity of cytochrome P450 2E1 and nicotinamide adenine dinucleotide phosphate oxidase, limited p47phox mRNA expression, as well as enhanced factor E2-related factor 2 and heme oxygenase-1 mRNA expression. SDF at three concentrations decreased gp91phox mRNA expression. In conclusion, these novel findings indicated that SDF aqueous extract was rich in phytochemicals and provided anti-apoptotic and anti-oxidative actions to protect cardiac and hepatic cells against ethanol. Thus, SDF might be considered as a functional food with multiple bio-activities.