Identification of starvation-mimetic bioactive phytocomponent from Withania somnifera using in-silico molecular modelling and flow cytometry-based analysis for the management of malaria

Abstract

Multidrug resistance episodes in malaria increased from 3.9% to 20% from 2015 to 2019. Synchronizing the clinical manifestation in chronological sequence led to a unique impression on glucose demand (increased up to 100-fold) by the parasite-infected RBCs. Hence, restriction in the glucose uptake to parasite-infected RBCs could be an alternative approach to conquer the global burden of malaria to a greater extent. A C28 steroidal lactone Withaferin A (WS-3) isolated from Withania somnifera leave extract shows better thermodynamically stable interactions with the glucose transporters (GLUT-1 and PfHT) to standard drugs metformin and lopinavir. MD simulations for a trajectory period of 100 ns reflect stable interactions with the interactive amino acid residues such as Pro141, Gln161, Gln282, Gln283, Trp388, Phe389, and Phe40, Asn48, Phe85, His168, Gln169, Asn311 which potentiating inhibitory activity of WS-3 against GLUT-1 and PfHT respectively. WS-3 was non-hemotoxic (%hemolysis <5%) for a high concentration of up to 1 mg/ml in the physiological milieu. However, the %hemolysis significantly increased up to 30.55 ± 0.929% in a parasitophorous simulated environment (pH 5.0). Increased hemolysis of WS-3 could be due to the production of ROS in an acidic environment. Further, the inhibitory activity of WS-3 against both glucose transporters was supported with flow cytometry-based analysis of parasite-infected RBCs. Results show that WS-3 has low mean fluorescence intensities for both target proteins compared to conventional drugs, suggesting a potential sugar transporter inhibitor against GLUT-1 and PfHT for managing malaria.

Communicated by Ramaswamy H. Sarma

Highlights

• According to clinical studies, malaria-affected RBCs have a greater glucose need (up to 100 times higher).

• WS-3 isolated from Withania somnifera leaf extract has more thermodynamically stable interactions with the glucose transporters (GLUT-1 and PfHT) compared to standard drugs metformin and lopinavir.

• WS-3 was found to be non-hemotoxic (%hemolysis <5%) for a high concentration of up to 1 mg/ml in the physiological milieu.

• WS-3 exhibits substantial lysis of infected RBC in a parasitophorous simulated environment (pH 5.0) due to the formation of ROS in an acidic environment.

• WS-3 has low mean fluorescence intensities for both target proteins compared to conventional drugs, suggesting a potential sugar transporter inhibitor against GLUT-1 and PfHT for managing malaria.

Keywords:

• Malaria
• Withaferin A
• in-silico
• GLUT-1
• PfHT
• flow-cytometry
• ADMET

Acknowledgments

The DBT Builder project (BT/INF/22/SP45078/2022) funded the research activity. The authors acknowledge the help of the Department of Biotechnology (DBT), Govt. India. The authors are also grateful to Dr Prajwal Nandekar - Senior Scientist II, Schrödinger and team for providing the technical training on the Schrodinger suite.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The Department of Biotechnology, Ministry of Science and Technology, India Builder project funded the research with order no (BT/INF/22/SP45078/2022).