Evaluation of Bioactive Compounds and Free Radical Scavenging Potential of Curcuma longa L. Rhizomes

Abstract

The present investigation focuses on the phytochemical characterization and antioxidant potential of an ethanolic extract of Curcuma longa rhizomes. Standard qualitative phytochemical assays revealed the presence of carbohydrates, amino acids, saponins, alkaloids, tannins, phenols, flavonoids, glycosides, terpenoids, and phlobatannins. Quantitative estimations showed that the extract contains 75.6 ± 2.0 mg gallic acid equivalents (GAE)/g and 31.4 ± 3.2 mg rutin equivalents (RE)/g of phenols and flavonoids, respectively. Hydrogen peroxide scavenging activity increased proportionally up to 100 µg/ml, after which a steady plateau was observed, similar to the activity of the gallic acid standard. The EC₅₀ value of the extract was calculated as 41 ± 2.3 µg/ml, indicating a strong antioxidant capacity. The study reinforces the correlation between high phenolic and flavonoid content and the potent free radical scavenging properties of Curcuma longa.