The Effects of Extraction Conditions on Extraction Yield and Syringin Content in Producing Standardized Tinospora crispa Aqueous Extract with High Antioxidant Activity

The herbal plant known as Tinospora crispa is reported to have many beneficial effects on health and has great potential in future to be developed as a health product either in the form of traditional medicine, food supplements or in pharmaceutical preparations. However, so far knowledge on processing procedures to produce quality standardized extracts of this plant to be used in product development has still not widely reported. Therefore, the objective of this study was to determine the optimal extraction conditions for producing a standardized T. crispa aqueos extract (STCAE) with high extraction yield and high syringin content. Experiments were conducted to determine the effects of various extraction conditions involving temperature (25–100 ° C), extraction time (0.5–6 hours) and liquid (water) to solid ratio (5: 1–25: 1 ml of solvent per g stem dry). Using optimized conditions obtained, the extract was standardized based on syringin and was further investigated on its antioxidant activity through DPPH, FRAP and TBA bioassays. Results revealed that the optimum extraction conditions were found to be 1 h extraction time and 15:1 ml g−1 liquid-to-solid ratio. For the extraction temperature, 60°C was found to be the best. STCAE was produced on the basis of the extract to contain with at least 0.4 wt% of syringin. STCAE was found to possess high antioxidant activities through DPPH, FRAP and TBA bioassays.