Bài báo khoa học

Background: Leaves, flowers and young shoots of yellow Camellia species are often used as a substitute for green tea in Vietnam. Yellow Camellia species contain high levels of polyphenol compounds, and have shown activities such as antioxidant, anticancer, and cytotoxic. Objectives: We qualitatively screened phytochemicals, quantified total polyphenols of 70% ethanol (EtOH) extracts of leaves, young shoots, and flowers of Camellia vuquangensis and Camellia hatinhensis in Ha Tinh Province, Vietnam. Furthermore, these extracts have been evaluated for lipid peroxidation inhibitory activities at the in vivo level in the BALB/c mouse model, and in vitro cytotoxic activities. Materials and Methods: Chemical methods and thin-layer chromatographic (TLC) analysis were used for the qualitative screening of phytochemicals. High-performance liquid chromatography (HPLC) was used to determine total polyphenols. Cell survival was determined through optical density (OD) measured when the protein composition of the cells was stained with sulforhodamine B (SRB). Inhibition of lipid peroxidation was evaluated by determining the content of malondialdehyde (MDA), which is a product of membrane lipid peroxidation. Results: The total polyphenol contents of all parts of the two species were comparable to that of green tea with values between 319.3 and 342.6 mg gallic acid equivalents (GAE/g) dry weight. Extracts of leaves, flowers of C. vuquangensis and C. hatinhensis showed strong lipid peroxidation inhibitory activities (IC50: 7.92–17.45 μg/mL) and moderate cytotoxic activities against cell lines HepG2, A549, MCF7, SK-Mel-2, HT-29, and AGS (IC50: 34.73–80.58 μg/mL). Conclusion: These two tea species may be considered as herbal teas with various health benefits.