Antioxidant Activities and Total Phenolic Contents of Plook Fai Thatu Remedy

Abstract

Plook Fai Thatu Remedy (PT) is recorded in the Maha Chotirat scripture and has been used as an elixir. Currently, PT is a drug included in the National List of Essential Medicines (NLEM), according to the announcement of the National Drug System Development Committee in 2019.PT has not been studied for the biological activities. Therefore, the objectives of this study were to study the antioxidant activities and to determine the total phenolic contents. PT was extracted with 50% ethanol, 95% ethanol, and water. The antioxidant activity was performed by using DPPH and FRAP methods. The total phenolic content was determined by the Folin - Ciocalteu method. The results revealed that the antioxidant activity by DPPH and FRAP methods exhibited a similar trend. 95% ethanol extract exhibited the most potent antioxidant activity, followed by 50% ethanol extract and water extract with the EC50 values of83.59±0.58, 93.28±1.57 and 98.27±0.69 µg/mL, respectively. In addition the FRAP values of 95% ethanol, 50% ethanol, and water extracts are124.61±6.57, 117.47±2.98 and 74.78±2.31 mg Fe²⁺/g extract, respectively whereas the TEAC values are43.44±2.56, 40.65±1.16 and 24.00±0.90 mg Trolox/g extract, respectively. In addition,50% ethanol extract exhibited the highest total phenolic contents, followed by 95% ethanol extract and water extract (45.04±1.85, 36.85±1.96 and 23.09±1.70 mg GAE/g extract, respectively). In this study was found that the ethanol extract showed the strongest antioxidant activities and the highest total phenolic contents. Future research should be emphasized on the study of biological activity for the confirmation of the action of PT remedy.