Phytochemical Screening, HPTLC Standardization and in-vitro Antioxidant Activity of Ethanolic Extract of Stachytarpheta Urticifolia Leaves

Abstract

The ethanolic leaf extract of Stachytarpheta urticifolia demonstrated significant in vitro antioxidant activity, which may be attributed to its rich phenolic and flavonoid content, particularly quercetin. The findings support the traditional use of the plant and suggest that it may serve as a promising natural source of antioxidant phytoconstituents for further pharmacological investigation. Phytochemical screening revealed the presence of flavonoids, polyphenols, alkaloids, tannins, triterpenoids, saponins, carbohydrates, and amino acids in the ethanolic extract. Among all extracts, the ethanolic extract showed the highest percentage yield (26.63% w/w) and the highest total phenolic content (254.66 ± 19.55 mg QE/g extract). HPTLC fingerprinting of the ethanolic extract revealed 11 peaks, with a major peak at Rf 0.429 corresponding to quercetin, confirming its presence in the extract. The quercetin content was estimated to be approximately 0.214 mg/g of extract. In antioxidant studies, the ethanolic extract exhibited concentration-dependent activity in all assays. At 50 µg/mL, the extract showed 89.11 ± 3.15% inhibition in the superoxide radical scavenging assay and 89.26 ± 2.17% inhibition in the hydroxyl radical scavenging assay. In the lipid peroxidation assay, the extract showed 94.69 ± 3.12% inhibition at 250 µg/mL, which was higher than the standard.