Withaferin A: A Potential Glucose Transporter Inhibitor for Malaria Management

From 2015 to 2019, multidrug resistance events in malaria increased from 3.9% to 20%. In a chronological synchronization of clinical presentations, we were impressed by the 100-fold increase in glucose demand of parasite-infected red blood cells. Therefore, restricting glucose uptake by parasite-infected red blood cells could become an alternative approach to conquering the global burden of malaria. The C28 steroidal lactone Withaferin A (WS-3), extracted from Withania somnifera, exhibited better thermodynamically stable interactions with glucose transporters (GLUT-1 and PfHT) compared to standard drugs, metformin, and lopinavir. MD simulations during 100 ns trajectories reflected stable interactions with interacting amino acid residues (such as Pro141, Gln161, Gln282, Gln283, Trp388, Phe389, Phe40, Asn48, Phe85, His168, Gln169, Asn311), which enhance the inhibitory activity of WS-3 against GLUT-1 and PfHT. In physiological environments, WS-3 did not exhibit hemolytic toxicity ( % hemolysis < 5%) at high concentrations (up to 1 mg/ml). However, in the parasite-containing environment (pH 5.0), % hemolysis significantly increased to 30.55 ± 0.929%. The increased hemolysis of WS-3 could be due to ROS production in an acidic environment. Furthermore, flow cytometry-based analyses of parasite-infected red blood cells supported the inhibitory activity of WS-3 on both glucose transporters. The results showed lower mean fluorescence intensity for both target proteins with WS-3 compared to the conventional drugs, suggesting it as a potential sugar transporter inhibitor for managing malaria, targeting GLUT-1 and PfHT.