Microscopic Characteristics, Total Phenolic Content and Antioxidant Activities of Root and Stem from Sida acuta Burm. F. extracts

Abstract

               Sida acuta (SA) belongs to the family Malvaceae. It is a medicinal plant that has long been used in Thai traditional and alternative medicine. It is used in the composition of various medicinal formulations such as anti-edema, analgesic and nourishing elements. The objectives for this study were to characterize microscopically, analyze the total phenolic content by Folin-Ciocalteu method and investigate antioxidant activities by DPPH and FRAP methods of roots and stems from SA extracts. SA were extracted using three methods as follows; maceration with 95% ethanol, maceration with 50% ethanol and decoction. The microscopical characteristics of SA powder have distinguishing features such as a large number of fibers and vascular bundles both in stems and roots. The most vascular bundle types are bordered pitted and reticulate vessels.             The result of total phenolic content found that the roots and stems extract from SA are in the range of 16.97±0.42 to 86.19±1.00 mg GAE/g extract. The 95% ethanolic extract from roots of (SARE95) showed the highest total phenolic content of 86.19±1.00 mg GAE/g extract. The DPPH method showed that the roots had better antioxidant activity than the stems compared to extraction with the same solvent. It was determined that 50% ethanolic extract of the root (SARE50) had the best antioxidant activity, followed by 95% ethanolic extract of the root (SARE95) with EC₅₀ values ​​of 48.05±1.23 and 55.38±0.56 µg/mL, respectively. The 95% ethanolic extract of roots (SARE95) contained the highest FRAP and TEAC (137.07±2.73 mg Fe(II)/g extract and 57.77±1.31 mg Trolox/g extract). The roots and stems extracts demonstrated good antioxidant activities. Therefore, future investigations of the active substances and other biological activities are warranted.