Comparative study on the phytochemical composition, amino acid profile, antioxidant, in vitro anti-inflammatory, and in vitro anti-diabetic activities on the leaf and stem bark of Acalypha indica

Herbal practitioners have long used Indian mercury (Acalypha indica) for therapeutic purposes. Research has proven that A. indica offers medicinal properties encompassing purgative, antifungal, and antibacterial action. This study aims to evaluate and compare the total phenolic and flavonoid content, amino acid profile, antioxidant, anti-diabetic, and anti-inflammatory activities of the A. indica leaf and stem. The quantitative phytochemical screening and amino acid profiling were carried out using standard methods. Antioxidant activities were investigated by the 1,1-diphenyl-2-picrylhydrazyl free radical scavenging method. Anti-inflammatory activities were obtained through the heat-induced hemoglobin denaturation inhibition method and the proteinase inhibition method. Anti-diabetic activities were assessed using an α-amylase inhibition assay. From the quantitative phytochemical screening, the total phenolic and total flavonoid contents were 100.5±0.01 and 93.48±0.40 for the leaf extract, and 92.2±0.26 and 139.0±0.28 for the stem respectively. The amino acid profiling for the stem showed concentration for the essential and non-essential amino acids with isoleucine and proline being the most abundant, and glysine having no concentration. The antioxidant potential at 1.0-200 µg/mL produced an IC50 of 4.16±0.04 µg/mL for the leaf extract, 5.57±0.06 µg/mL for the stem extract and 6.37±0.11 µg/mL for standard (ascorbic acid). Analysis for the anti-inflammatory studies revealed that the leaf extract of A. indica demonstrated better heat-induced hemoglobin denaturation protection when compared to the stem extract and for the anti-proteinase effects, the stem extract produced a more powerful dose-dependent outcome compared to the leaf extract. The anti-diabetic potential at 0.1-0.5 µg/mL produced an IC50 of 0.14±0.06 µg/mL for the leaf extract, 0.18±0.04 µg/mL for the stem extract, and 17.79±0.18 µg/mL for standard (acarbose). The study findings validate A. indica as a promising medicinal agent for managing inflammation, diabetes, and oxidative stress.