TLC-Densitometry Analysis Method of Asiaticoside Assay and Antioxidant Activity of Centella asiatica (L.) Urban Extract

Centella asiatica (L.) is a medicinal plant with anti-inflammatory, anti-asthmatic, anti-hemorrhoidal, wound healing, and antioxidant effects. Currently, the dry extract of Centella asiatica is widely produced by various industries. It is necessary to determine the quality of the extracts on the market. The aims of this study are to develop the asiaticoside assay method using TLC-densitometry, identification of the compound groups, and determination of the antioxidant activity of Centella asiatica dry extracts and Centella asiatica extract on-market products. The phytochemical content of Centella asiatica extracts was evaluated using the TLC–densitometry method. The validation of the analysis method for asiaticoside assay was subsequently carried out, as well as the determination of antioxidant activity using the DPPH method. The method validation results showed that the TLC–densitometry method met the validation parameter criteria. Asiaticoside assay of the dry extract, simplicia, and on-market extract products were 9.07, 0.10, 0.60, and 10.53%, respectively. Furthermore, the results of the antioxidant activity of the dry extract and on-market extract products showed an IC₅₀ value of 0.1166, 0.5783, and 1.9513 mg/mL, respectively. This study obtained a valid method for analyzing asiaticoside assay using the TLC-densitometry method. Asiaticoside content of dry extract was 9,07%, and extract products on-market were 0,60% and 10,53%, respectively. The IC₅₀ value of the dry extract of Centella asiatica was in the moderate antioxidant category, while the on-market extract products were in the very weak antioxidant category.