Phytochemical and Antioxidant Investigations of Extracts from the Leaves of Macaranga heterophylla (Müll. Arg.) (Euphorbiaceae), A Medicinal Species used in Côte d'Ivoire

Aims: This work aims to investigate the phytochemical composition and antioxidant potential of the leaves of Macaranga heterophylla.

Methodology: For this purpose, phytochemical screening by detection tests and thin layer chromatography (TLC), determination of total phenols content, total flavonoids content and condensed tannins content, and assessment of antioxidant potential by DPPH and reducing power tests were carried out on aqueous crude extracts, ethanolic crude extracts and selective extracts of the leaves of M. heterophylla.

Results: The percentage yields obtained with ethanol (70%) (28.90 and 24.70% for the ethanolic decoction and ethanolic macerate respectively) are higher than those obtained with water (24.30 and 21.10% for the aqueous decoction and aqueous macerate respectively). The phytochemical screening highlighted the presence of several phytochemical families such as phenolic compounds (coumarins, flavones, tannins), quinones, sterols and polyterpenes, saponosides, glycosides, cardiotonic glycosides and oligosaccharides. Quantitative analysis of total phenolics, total flavonoids and proanthocyanidols showed that their respective levels in the leaves of M. heterophylla varied depending on the solvent and the extraction technique. Concerning total phenolics, the aqueous decoction and ethanolic macerate gave the best total phenol contents (129.04 ± 9.53 and 119.82 ± 2.63 mg EAG/g DM respectively); for total flavonoids, the aqueous decoction gave the best content (33.03 ± 1.61 mg EQ/g DM), while for condensed tannins, the aqueous macerate gave the best content (0.87 ± 0.02 mg ECT/g DM). With regard to DPPH antioxidant activity, the results showed that the ethanolic decoction has more pronounced antioxidant activity than the aqueous decoction, while the aqueous macerate showed better antioxidant activity than the ethanolic macerate. Concerning the reducing power test, the opposite trend was observed.

Conclusion: The present study demonstrated that M. heterophylla is a concentrate of secondary metabolites with antioxidant properties, which would explain its use in traditional medicinal practice.