In vitro antileishmanial, antiplasmodial and cytotoxic activities of a new ventiloquinone and five known triterpenes from Parinari excelsa

Abstract

Context: Parinari excelsa Sabine (Chrysobalanaceae) is an indigenous tree from West and Eastern Africa. This tree is used in Ivory Coast as an antimalaria remedy.

Objective: The in vitro antiplasmodial and antileishmanial activities of the stem bark, the leaf and the major compounds from the stem bark were investigated.

Materials and methods: The leaves and stem bark from P. excelsa were separately collected, air-dried and powdered. Two extracts (methylene chloride and methanol) were realized for both powders. Every extract was tested for its antiplasmodial and antileishmanial activities. Only the stem bark crude extracts were fractionated by column chromatography and their major components were analyzed by NMR, HRESIMS and IR methods. The compounds were tested for their antiplasmodial and antileishmanial activities.

Results: The comparison of the IC₅₀ values of the crude extracts were in this ordrer: 3.41 (IC₅₀ of PeBMc) <4.10 (IC₅₀ of PeBMc) <4.42 (IC₅₀ of PeLMe) against P. falciparum and 5.19 (IC₅₀ of PeBMc) <12.32 (IC₅₀ of PeBMe) <19.33 (IC₅₀ of PeLMc) <32.37 (IC₅₀ of PeLMe) against L. donovani. The stem bark crude extracts were the most active against both parasites. Their fractionation leaded to a new ventiloquinone, five triterpenes and one chlorogenic acid. All these compounds were isolated for the first time from P. excelsa. High activities were observed with (3β)-3-hydroxyolean-12-en-28-oic acid (IC₅₀ = 8.2 µM) and 3β-hydroxyolean-5,12-dien-28-oic acid (IC₅₀ = 7.7 µM) against L. donovani. With the antiplasmodial activity, the best activity was observed with 16β-hydroxylupane-1,20(29)-dien-3-one (IC₅₀ = 28.3 µM).

Discussion and conclusion: These findings demonstrated that the constituents of P. excelsa stem bark have in vitro antiplasmodial and antileishmanial activities.

Keywords::

• Medicine
• plant
• extraction
• isolation
• malaria
• leishmania

Acknowledgments

We are thankful to Patrick Wehrung (Université de Strasbourg) for NMR and MS analyses data, Aké A. L (Jardin botanique de l’Université de Cocody-Abidjan) for plant identification.

Declaration of interest

The authors are grateful to AUF (Agence Universitaire de la Francophonie) for financial support.