Screening of Anti-Inflammatory Activity and Metabolomics Analysis of Endophytic Fungal Extracts; Identification and Characterization of Perylenequinones and Terpenoids from the Interesting Active Alternaria Endophyte

Rosella Spina; Armelle Ropars; Sihem Bouazzi; Safa Dadi; Pascal Lemiere; François Dupire; Afra Khiralla; Sakina Yagi; Jean-Pol Frippiat; Dominique Laurain-Mattar

doi:10.3390/molecules28186531

Screening of Anti-Inflammatory Activity and Metabolomics Analysis of Endophytic Fungal Extracts; Identification and Characterization of Perylenequinones and Terpenoids from the Interesting Active Alternaria Endophyte

Molecules. 2023 Sep 9;28(18):6531. doi: 10.3390/molecules28186531.

Authors

Affiliations

¹ Université de Lorraine, INRAE, LAE, F-54000 Nancy, France.
² Université de Lorraine, SIMPA, F-54000 Nancy, France.
³ Université de Lorraine, CNRS, L2CM, F-54000 Nancy, France.
⁴ Botany Department, Faculty of Sciences and Technologies, Shendi University, Shendi 11111, Sudan.
⁵ Department of Botany, Faculty of Science, University of Khartoum, Khartoum 11115, Sudan.

Abstract

Patients suffering from inflammatory chronic diseases are classically treated with anti-inflammatory drugs but unfortunately are highly susceptible to becoming resistant to their treatment. Finding new drugs is therefore crucial and urgent and research on endophytic fungi is a promising way forward. Endophytic fungi are microorganisms that colonize healthy plants and live within their intercellular tissues. They are able to produce a large variety of secondary metabolites while allowing their host to stay healthy. A number of these molecules are endowed with antioxidant or antimicrobial as well as cytotoxic properties, making them very interesting/promising in the field of human therapy. The aim of our study was to investigate whether extracts from five endophytic fungi isolated from plants are endowed with anti-inflammatory activity. Extracts of the endophytic fungi Alternaria alternata from Calotropis procera leaves and Aspergillus terreus from Trigonella foenum-graecum seeds were able to counteract the lipopolysaccharide (LPS) pro-inflammatory effect on THP-1 cells differentiated into macrophages. Moreover, they were able to induce an anti-inflammatory state, rendering them less sensitive to the LPS pro-inflammatory stimulus. Taken together, these results show that these both endophytic fungi could be interesting alternatives to conventional anti-inflammatory drugs. To gain more detailed knowledge of their chemical richness, phytochemical analysis of the ethyl acetate extracts of the five endophytic fungi studied was performed using HPTLC, GC-MS and LC-MS with the Global Natural Products Social (GNPS) platform and the MolNetEnhancer tool. A large family of metabolites (carboxylic acids and derivatives, steroid derivatives, alkaloids, hydroxyanthraquinones, valerolactones and perylenequinones) were detected. The purification of endophytic fungus extract of Alternaria alternate, which diminished TNF-α production of 66% at 20 µg/mL, incubated one hour before LPS addition, led to the characterization of eight pure compounds. These molecules are altertoxins I, II, III, tricycloalternarenes 3a, 1b, 2b, anthranilic acid, and o-acetamidobenzoic acid. In the future, all these pure compounds will be evaluated for their anti-inflammatory activity, while altertoxin II has been shown in the literature as the most active mycotoxin in terms of anti-inflammatory activity.

Keywords: Alternaria alternata; GNPS; anti-inflammatory activity; endophytic fungi; molecular network; perylenequinones.

Grants and funding

This work was supported by “Impact Biomolecules” project of the “Lorraine Université d’Excellence”, funded by the ANR “Investissements d’avenir” (ANR-15-IDEX-04-LUE) concerning E-info emerging project. The study was funded by project “Interdisciplinarité” (number: INTER-2019-029) of the University of Lorraine.