Flash Talk 4 “Harmine and Harmaline of Peganum harmala L. Seeds as Promising Hits Against Mycetoma: One of the Most Neglected Diseases”

Mycetoma, a chronic granulomatous infectious disease caused either by bacteria (actinomycetoma) or fungi (eumycetoma). It is one of the most neglected tropical diseases [1]. Both mycetoma types are treated using different antifungals or antibacterial combinations for extended periods. However, no efficient regimen is yet available for mycetoma treatment, especially eumycetoma [2]. Hence, physicians tend to resort to surgical amputations due to mycetoma deleterious outcomes. Peganum harmala L. seeds (Nitrariaceae) contains various secondary metabolites including β-carboline alkaloids. The current study aims to investigate the antimycetomal activity of P. harmala seeds with special reference to harmine and harmaline.

P. harmala ethanolic extract and fractions exhibited appreciable antimycetomal activity against two eumycetoma isolates and two actinomycetoma isolates belonging to Madurella mycetomatis, Actinomadura madurae, respectively. Harmine and harmaline were identified using thin layer chromatography in both extract and fractions ([Fig. 1]). Both of them exhibited considerable antimycetomal activity against both mycetoma types. Herewith, we intend to provide evidence that the harmine and harmaline are responsible for the antimycetomal activity of P. harmala seeds. The antifungal and antibacterial activity have been previously attributed by total harmala alkaloids and other pure β-carboline alkaloids including harmine and harmaline [3].

Fig. 1 Method of extraction and fractionation of Peganum harmala seeds along with the screening results of extract, fractions and pure compounds (chemical structures illustrated), represented as MIC in µg/mL. Key. PHCr: Crude extract, PHPE: Petroleum ether fraction, PHCH: Chloroform fraction, PHEA: Ethyl acetate fraction, PHnBut: n-butanol fraction and PHAR: Aqueous Residue.

In conclusion, the inhibitory properties of P. harmala seeds against mycetoma types renders it a promising hit for further optimization to lead molecules that could be further exploited as a treatment against mycetoma types. A discovery that would shorten the diagnosis and hence earlier initiation of treatment before disease progression result to further clinical manifestation requiring surgical intervention.

• References

• 1 Mahmoud A, Abd Algaffar S, van de Sande W. et al. Niclosamide Is Active In Vitro against Mycetoma Pathogens. Molecules 2021; 26
• 2 Abd Algaffar S, Verbon A, van de Sande W, Khalid S. Development and validation of an in vitro resazurin-based susceptibility assay against Madurella mycetomatis. Antimicrobial Agents and Chemotherapy 2021; 65
• 3 Nenaah G. Antibacterial and antifungal activities of (beta)-carboline alkaloids of Peganum harmala (L) seeds and their combination effects. Fitoterapia 2010; 81: 779-782

Publication History

Article published online:
12 December 2022