Optimization of extraction of flavonoid and polyphenol from Camellia megasepala leaves and their anticancer activity

Camellia megasepala Hung T. Chang & Trin Ninh, found in Na Hang district, Tuyen Quang province, contains a significant amount of flavonoids and polyphenols, which are important phenolic compounds known for their various biological activities beneficial to human health, including antibacterial and anti-inflammatory effects. This study applied the response surface methodology (RSM) to examine the influence of extraction factors on the polyphenol and flavonoid content in golden tea leaves. The optimal conditions for extracting polyphenols and flavonoids were temperature at 60°C, 70% ethanol concentration, extraction time of 80 minutes, and a material/solvent ratio of 1/20 (w/v). The experimental values were: flavonoid = 1.42 ± 0.0172 mgQE/g extract; polyphenol = 4.29 ± 0.0348 g/100g extract. The extract from golden tea leaves was evaluated for its cytotoxic activity against HepG2 liver cancer cells and A549 lung cancer cells. The inhibitory concentration (IC50) for the ethanol 70% extract was recorded as IC50 = 74.11 ± 1.37 µg/ml and IC50 = 67.11 ± 1.57 µg/ml for HepG2 and A549 cells, respectively. The results of this study suggest the potential application of golden tea leaf extract in inhibiting the growth of liver and lung cancer cells.