Unveiling the properties of ascorbic acid against M. tb through in silico approach: A comparative drug-based study

Tuberculosis (TB) is a highly contagious and potentially life-threatening disease caused by Mycobacterium tuberculosis (M. tb). According to the World Health Organization (WHO), 7.5 million people were diagnosed with TB in 2022. Combating this disease requires ongoing efforts in TB drug discovery and the development of new treatment regimens. Identifying novel drug targets and inhibitory molecules is crucial in the fight against latent TB, particularly due to the rising issue of M. tb drug resistance. In modern drug discovery, the focus has shifted towards identifying new, safe natural compounds with enhanced biological activity against TB. One promising compound is ascorbic acid (Vitamin C), which possesses pro-oxidant properties that generate free radicals along with the first and second-line anti-TB drugs, aiding in the eradication of M. tb during latent infections.

In the current research, extensive in silico studies have been conducted to investigate the potential of ascorbic acid as an inhibitor of various M. tb pathways, especially those involving protein folding (chaperone-mediated) and detoxification pathways. The proteins were analysed by various physicochemical and pharmacological parameters. Molecular docking of the selected proteins with existing first-line, second-line drugs and ascorbic acid was performed. Furthermore, the top-scoring molecular docking of ascorbic acid was subjected to Molecular Dynamics Simulation. The 500 ns Molecular Dynamics Simulation studies were carried out by GROMACS v2024.1 using CHARMM27 force field, TIP3P water model and using triclinic box for solvation. The obtained trajectories were analysed through XMGRACE tool.