Antiplasmodial Activities Of The Stem Bark Extract And Compounds Of Zanthoxylum Gilletii (De Wild) P.G. Waterman

Abstract

Introduction: Multidrug resistance remains a major obstacle hindering successful antimalarial chemotherapy. In the current study, 50% metha - nol in dichloromethane extract and six compounds from the stem bark of Zanthoxylum gilletii were explored for their antiplasmodial potential against three strains of Plasmodium falciparum . Materials and Methods: The ex - tract was obtained by cold percolation using 50 % MeOH in CH 2 Cl 2 and the antiplasmodial activities were assayed using a non–radioactive Malaria SYBR Green I assay to determine a concentration that inhibits growth of 50% of parasites in culture (IC 50 ). Results and Discussion: Chromato - graphic separation of the crude extract yielded six known compounds including: one lignan, sesamin ( 1 ), an alkamide, fagaramide ( 2 ), three benzo [ c ] phenanthridine alkaloids, 8–acetonyldihydrochelerythrine ( 3 ), dihydro - chelerythine ( 4 ), norchelerythrine ( 5 ) and one pentacyclic triterpenoid, lupeol ( 6 ). The extract and sesamin ( 1 ) showed promising antiplasmodial activities against the chloroquine resistant (W2), chloroquine sensitive (D6) and 3D7 strains of P. falciparum , with IC 50 values of 2.52, 1.48 and 1.43 μg/mL and 5.4, 9.1 and 8.3 μM, respectively. To the best of our knowledge, this is the first report on antiplasmodial activities of the stem bark extract (50% MeOH in CH 2 Cl 2 ) and compound 1 – 3 and 6 . Furthermore, three of the isolated compounds; 1 , 3 , 6 are reported from this species for the first time. Conclusion: The good antiplasmodial activities exhibited by the stem bark of Z. gilletii against three different strains of P. falciparum may be attributed to the presence of 1 - 3 exhibiting good activities against all strains of P. falciparum .