Evaluation of the Antioxidant Activity of Pentachlaena latifolia H. Perrier (Sarcolaenaceae) Leaf Extracts

Abstract

Background: Pentachlaena latifolia (Sarcolaenaceae) is an endemic Malagasy species whose phytochemical composition and antioxidant potential remain insufficiently documented. This study characterised the phytochemical profile and evaluated the antioxidant activity of its leaf extracts. Materials and Methods: A crude hydroethanolic extract was obtained by maceration, followed by sequential extraction with solvents of increasing polarity using maceration and Soxhlet methods. Qualitative phytochemical screening was conducted on the crude ethanolic extract. Antioxidant activity was assessed using TLC-DPPH bioautography and a quantitative DPPH radical-scavenging assay, with L-ascorbic acid as the reference standard. Results: Hydroethanolic maceration yielded 7.76%, while the methanolic Soxhlet extract produced the highest yield among the sequential fractions at 9.10%. Screening detected tannins, flavanones, leucoanthocyanins, steroids, and triterpenes, whereas alkaloids, saponins, polysaccharides, and anthocyanins were not detected. All tested extracts produced antioxidant responses in the TLC-DPPH assay. The Soxhlet ethyl acetate extract showed the lowest IC₅₀ value (6.057 µg/mL), followed by the crude hydroethanolic extract (10.92 µg/mL), ascorbic acid (12.68 µg/mL), the methanolic Soxhlet extract (13.41 µg/mL), the macerated ethyl acetate extract (16.53 µg/mL), and the Soxhlet hexane extract (25.42 µg/mL). Conclusion: Solvent polarity and extraction technique influenced extraction yield and DPPH-scavenging activity. The semi-polar Soxhlet ethyl acetate fraction showed the greatest activity under the assay conditions and warrants further chemical characterisation and evaluation using complementary antioxidant methods.