Planta Med 2015; 81 - PM_35
DOI: 10.1055/s-0035-1565412

Identification of the strictosamide isolated from Nauclea latifolia as the bioactive agent against Madurella mycetomatis

S AbdElGaffar 1, HA Ali 2, OM Khider 1, SA Khalid 1, 3
  • 1Faculty of Pharmacy, University of Science & Technology, P.O. Box 477 Omdurman, Sudan, Sudan
  • 2Commission for Biotechnology and Genetic Engineering, National Center for Research, Khartoum, Sudan, Sudan
  • 3Department of Pharmacognosy, Faculty of Pharmacy, University of Khartoum, P.O. Box 1996 Khartoum, Sudan, Sudan

The decoction of different parts of Nauclea latifolia Smith (Rubiaceae) is commonly employed in the African traditional medicine for the treatment of several diseases, such as malaria, gastrointestinal tract disorders, and as antimicrobial [1]. It has already been demonstrated that N. latifolia is very efficient in the biosynthesis of β-carboline alkaloids besides other secondary metabolites [2].

In our quest to identify a new antifungal agent from natural source we screened the crude extract of the fruits, root bark, leaves and stem bark of Nauclea latifolia in vitro against Madurella mycetomatis, the most common eumycetoma causative organism.

Following bioactivity guided fractionation while employing the newly developed resazurin assay in 96-microplate [3] a promising inhibitory activity emerged against M. mycetomatis ranging between 625 and 39.1 µg/mL. This attempt has eventually resulted in the isolation of the β-carboline alkaloid, strictosamide (1), which exhibited a MIC of 3.91 µg/mL while ketoconazole, the positive control showed MIC of 0.25 µg/mL. It is pertinent to note that strictosamide has already exhibited antiparasitic activity against a number of neglected diseases [2].

References:

[1] Anowi C.F, Cardinal N.C, Ezugwu C.O, Anastasia U, Utoh-Nedosa U.A, Antimicrobial properties of the chloroform extract of the stem bark of Nauclea latifolia, Int J Pharm Pharm Sci, 2012; 4: 744 – 750.

[2] Khalid SA. Natural product-based drug discovery against neglected diseases with special reference to African natural resources. In: Chibale K, Devis-Coleman M, Masimirembwa C, editors. Drug discovery in Africa. Berlin Heidelberg: Springer; 2012: 211 – 237.

[3] Khalid SA. Development of microtiter plate-based method for the determination of the MIC of antimycetomal agents against Madurella mycetomatis. II ResNet NPND workshop on natural products against neglected diseases, Nov. 25 – 28th, 2014, Rio de Janeiro, Brazil.