Antiplasmodial potential and GC-MS fingerprint of endophytic fungal extracts derived from Cameroonian Annona muricata

Rufin Marie Kouipou Toghueo; Eugénie Aimée Madiesse Kemgne; Pierre Eke; Michelle Ines Mbekou Kanko; Darline Dize; Dinkar Sahal; Fabrice Fekam Boyom

doi:10.1016/j.jep.2019.02.010

Antiplasmodial potential and GC-MS fingerprint of endophytic fungal extracts derived from Cameroonian Annona muricata

J Ethnopharmacol. 2019 May 10:235:111-121. doi: 10.1016/j.jep.2019.02.010. Epub 2019 Feb 6.

Authors

Rufin Marie Kouipou Toghueo¹, Eugénie Aimée Madiesse Kemgne¹, Pierre Eke¹, Michelle Ines Mbekou Kanko¹, Darline Dize¹, Dinkar Sahal², Fabrice Fekam Boyom³

Affiliations

¹ Antimicrobial & Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaoundé I, P.O. Box: 812, Yaoundé, Cameroon.
² Malaria Drug Discovery Laboratory, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
³ Antimicrobial & Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaoundé I, P.O. Box: 812, Yaoundé, Cameroon. Electronic address: fabrice.boyom@fulbrightmail.org.

PMID: 30738118
DOI: 10.1016/j.jep.2019.02.010

Abstract

Ethnopharmacological relevance: Annona muricata (Annonaceae) is a commonly used medicinal plants in Cameroonian traditional medicines to treat various diseases including malaria. Previous studies have shown that extracts from this plant have antiplasmodial activity.

Aim of the study: This study aimed to explore the endophyic fungi associated with some parts of this plant for their ability to produce antiplasmodial metabolites.

Materials and methods: One hundred and fifty-two endophytic fungi isolated from twelve different organs of A. muricata were cultured and the ethyl acetate extracts of conditioned media screened for antiplasmodial activity using the 96-well microtiter plate format SYBR green florescence assay against Chloroquine-sensitive Pf3D7 and Chloroquine-resistant PfINDO/PfDd2 strains of Plasmodium falciparum.

Results: Twenty-seven (17.76%) of fungi tested were found to completely inhibit the growth of Plasmodium parasites at 10 µg/mL. The 5.8S rDNA sequencing data revealed the strongly active (IC₅₀ < 2 µg/mL against at least 2 P. falciparum strains) isolates to be Trichoderma afroharzianum AMrb7, Penicillium citrinum AMrb11, Neocosmospora rubicola AMb22, Penicillium tropicum AMb3, Penicillium citrinum AMrb23, Aspergillus versicolor AMb7, and Fusarium sp AMst1. Of these, the extracts from Penicillium citrinum AMrb11 (IC₅₀ 0.84-0.93 μg/mL) and Neocosmospora rubicola AMb22 (IC₅₀ 0.39-1.92 μg/mL) showed the highest promise against all three plasmodial strains with selectivity indices ranging from 34.71 to 180.97. Dynamic head space GC-MS analysis of ethyl acetate extracts of promising fungi revealed broad-spectrum antimicrobial compounds such as Penicidin, Aromadendrene, Ethyl p-methoxycinnamate, 2-Coumaranone and 2-Methyl resorcinol.

Conclusion: These results have opened new avenues for discovery of novel antimalarial lead compounds from endophytic fungi associated with Annona muricata - a medicinally important plant.

Keywords: Annona muricata; Antiplasmodial activity; Endophytic fungi; GC-MS; Pf3D7; PfDd2; PfINDO; Selectivity index.

MeSH terms

Annona / microbiology*
Antimalarials / administration & dosage
Antimalarials / isolation & purification
Antimalarials / pharmacology*
Cameroon
Chloroquine / pharmacology
Drug Discovery / methods
Endophytes / isolation & purification
Fungi / isolation & purification*
Gas Chromatography-Mass Spectrometry / methods
Inhibitory Concentration 50
Medicine, African Traditional / methods
Plasmodium falciparum / drug effects*

Substances

Antimalarials
Chloroquine