Abstract

• Tea leaves possess many useful biological activities and are consumed in the daily life of the Myanmar people which have been the reason for the selection of this plant for the present paper. Bioassay offers special advantages to know about the biological activity of plant extracts and provide information to isolate active compounds which is a preliminary key step for drug discovery system. Bioassays such as antimicrobial activity, antiproliferative and anti-inflammatory activities were determined. The main aim of the present research was to evaluate the biological properties of Camellia sinensis L. leaves. The antimicrobial activity of polar and non-polar extracts of the fermented tea leaves was screened by using agar well diffusion method. Among the tested extracts, flavonoid extract of fermented tea leaves possessed higher antimicrobial activity (30 mm- 35 mm) than the other extracts. In vitro antiproliferative activity of ethanol and watery extracts of the fermented tea leaves was investigated against human lung cancer and human cervix cancer by MTT assay. The IC50 values of ethanol and watery extracts for human lung cancer were observed 95.34 µg/mL and 123.44 µg/mL, respectively. In the case of human cervix cancer, the IC50 values for ethanol and watery extracts were found to be 116.26 µg/mL and 124.39 µg/mL, respectively. No antiinflammatory activity was found in both water and 70 % EtOH extracts by % NO inhibition assay and there was also no toxicity effect up to >100 µg/mL concentration. The fermented tea leaves were extracted with 70 % ethanol and followed by column chromatographic separation technique. Five compounds were isolated from the ethanol extract. The structures of isolated pure compounds were elucidated by 1H NMR, 13C NMR and ESI-MS spectroscopic methods. In conclusion, 70 % ethanol extracts of the fermented tea leaves possess significantly anticancer activity and antimicrobial activity. Therefore, fermented tea leaves (C. sinensis L.) may be used for preventing cancer and used as antimicrobial agent.