Antiplasmodial Activity of <i>Vachellia xanthophloea</i> (Benth.) P.J.H. Hurter (African Fever Tree) and Its Constituents

• Main Authors: Nasir Tajuddeen (Author), Tarryn Swart (Author), Heinrich C. Hoppe (Author), Fanie R. van Heerden (Author)
• Format: Book
• Published: MDPI AG, 2022-04-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

<i>Vachellia xanthophloea</i> is used in Zulu traditional medicine as an antimalarial remedy. A moderate antiplasmodial activity was previously reported for extracts of the plant against D10 <i>Plasmodium falciparum</i>. This study aimed to identify the phytochemicals responsible for the antiplasmodial activity of the leaf extract. The compounds were isolated by chromatography and their structures were determined using spectroscopic and spectrometric methods. The antiplasmodial activity was evaluated using a parasite lactate dehydrogenase assay and cytotoxicity was determined using a resazurin assay. The ethyl acetate fraction inhibited <i>P</i>. <i>falciparum</i> with IC₅₀ = 10.6 µg/mL and showed minimal cytotoxicity (98% cell viability at 33 µg/mL). The chromatographic purification of this fraction afforded sixteen compounds, including two new flavonoids. A 1:1 mixture of phytol and lupeol was also isolated from the hexane fraction. All the compounds were reported from <i>V. xanthophloea</i> for the first time. Among the isolated metabolites, methyl gallate displayed the best activity against <i>P. falciparum</i> (IC₅₀ = 1.2 µg/mL), with a 68% viability of HeLa cells at 10 µg/mL. Therefore, methyl gallate was responsible for the antiplasmodial activity of the <i>V. xanthophloea</i> leaf extract and its presence in the leaf extract might account for the folkloric use of the plant as an antimalarial remedy.

Item Description

10.3390/ph15040470
1424-8247