Use of Essential Oils for the Treatment of Fusarium oxysporum f. sp. Albedinis: Chemical Profile, In Vitro Antifungal Activity, and In Silico Investigation by Molecular Docking Study
Authors: Diass Khaoula , Oualdi Imane , Benabbas Redouane , Zaki Hanane , Ouabane Mohamed , Hammouti Belkheir , Touzani Rachid , Bouachrine Mohammed 
Published: October 2024

Background:

Fusarium oxysporum f. sp. Albedinis a telluric fungal pathogen commonly
found in soils, is the causal agent of fungal vascular wilt of date palms in Moroccan oases. The infection
by the pathogen leads to the death of the date palm after six months to two years, which
causes enormous economic and environmental damage.

Objective:

The framework of this paper is to determine the chemical composition of six essential oils
using GC-MS and their antifungal activity on the mycelial growth of Fusarium oxysporum f. sp. Albedinis,
as well as the molecular docking study to evaluate the inhibitory potential of fungal trypsin.

Methods:

The essential oils were extracted from different parts of the plants (whole plant, flowers,
and leaves) by steam distillation, and were identified using gas chromatography-mass spectrometry
(GC/MS). The antifungal assay of the extracted essential oils and their main components was assessed
using the direct contact method with the fungus at different concentrations; the obtained results
were evaluated by calculating the minimum inhibitory concentration (MIC) of each essential
oil, followed by an in-silico study of the major identified compounds for better understanding of the
inhibitory potential against fungal trypsin activity.

Results:

The identification of the different bioactive compounds using GC-MS revealed that Rosmarinus
officinalis Eo was characterized by eucalyptol 46.26%, camphor 10.03%, and β-pinene 6.63%;
while Lavandula officinalis Eo was endowed by the presence of linalool 14.93%, camphor 14.11%,
and linalyl acetate 11.17%. Furthermore, Artemisia herba alba was rich in 1,3,5-cycloheptatriene, 1,6-
dimethyl- 36.44%, camphor 22.50%, and α-thujone 7.21%. While Eucalyptus globulus was rich in eucalyptol
74.32%, β-Cymene 11.41%, α-Pinene 6.96%. Finally, Mentha pepirita and Mentha pulegium
were both characterized by the presence of D-limonene 20.15%, trans-carveol 19.59%, D-Carvone
14.96%, and pulegone (42.40%), 3-cyclopentene-1-ethanol, 2,2,4-trimethyl- (11.28%), 1,3,4-
trimethyl-3-cyclohexenyl-1-carboxaldehyde (9.68%), respectively. Regarding the in vitro, all Eos from
different plants exhibited pronounced antifungal effect. The MIC values recorded for E. globulus were
MIC= 1.75 mg/L, M. pulegium and L. officinalis (MIC= 1.80 mg/L), and M. piperita (MIC= 1.90
mg/L). The strongest inhibition potential was associated with R. officinalis EO (MIC= 1.15 mg/L) and
A. herba alba EO (MIC= 1.60 mg/L). As for the computational study performed camphor one of the
bioactive compounds showed its ability to act against trypsin which could be considered a potential
candidate against Fusarium oxysporum f. sp. Albedinis.

Conclusion:

The studied essential oils from different medicinal and aromatic plants showed significant
antifungal activity, probably due to the Camphor which could have an inhibitory effect on the
Fusarium oxysporum f. sp. Albedinis trypsin. Further research should be conducted in vivo for
a better understanding of the mechanism of action of these essential oils.