Author:

Keywords:

Science & Technology, Life Sciences & Biomedicine, Chemistry, Medicinal, Pharmacology & Pharmacy, Antimalarial, Antiplasmodium falciparum activity, Apoptosis, Bischalcone, Chloroquine resistant, ANTIMALARIAL AGENTS, MALARIA, CHALCONES, DISCOVERY, CYTOTOXICITY, DERIVATIVES, HYBRIDS, DESIGN, Antimalarials, Artemisinins, Benzaldehydes, Cell Line, Tumor, Cell Survival, Chalcones, Chloroquine, Dose-Response Relationship, Drug, Drug Resistance, HeLa Cells, Humans, Molecular Structure, Parasitic Sensitivity Tests, Plasmodium falciparum, Structure-Activity Relationship, Hela Cells, 0304 Medicinal and Biomolecular Chemistry, 0305 Organic Chemistry, 1115 Pharmacology and Pharmaceutical Sciences, Medicinal & Biomolecular Chemistry, 3214 Pharmacology and pharmaceutical sciences, 3404 Medicinal and biomolecular chemistry, 3405 Organic chemistry

Abstract:

The inherent affinity of natural compounds for biological receptors has been comprehensively exploited with great success for the development of many drugs, including antimalarials. Here the natural flavoring compound vanillin has been used as an economical precursor for the synthesis of a series of novel bischalcones whose in vitro antiplasmodial activities have been evaluated against erythrocytic stages of Plasmodium falciparum. Bischalcones 9, 11 and 13 showed promising antiplasmodial activity {Chloroquine (CQ) sensitive Pf3D7 IC50 (μM): 2.0, 1.5 and 2.5 respectively}but only 13 displayed potent activities also against CQ resistant PfDd2 and PfIndo strains exhibiting resistance indices of 1.4 and 1.5 respectively. IC90 (8 μM) of 13 showed killing activity against ring, trophozoite and schizont stages. Further, 13 initiated the cascade of reactions that culminates in programmed cell death of parasites including translocation of phosphatidylserine from inner to outer membrane leaflet, loss of mitochondrial membrane potential, activation of caspase like enzyme, DNA fragmentation and chromatin condensation. The combinations of 13 + Artemisinin (ART) exhibited strong synergy (ΣFIC50:0.46 to 0.58) while 13 + CQ exhibited mild synergy (ΣFIC50: 0.7 to 0.98) to mild antagonism (ΣFIC50: 1.08 to 1.23) against PfIndo. In contrast, both combinations showed marked antagonism against Pf3D7(ΣFIC50: 1.33 to 3.34). These features of apoptosis and strong synergy with Artemisinin suggest that bischalcones possess promising antimalarial drug-like properties and may also act as a good partner drugs for artemisinin based combination therapies (ACTs) against Chloroquine resistant P. falciparum.