Anti-mycobacterial activity of phytocompounds from Ricinus communis L. - an integrated in-vitro and in-silico approach.

Mycobacterium tuberculosis (Mtb) infection remains as a continuous blight on global health, but the treatment and prevention techniques to treat tuberculosis (TB) are generally stagnant in the past several decades. Although the existing antibiotic regimens have contributed to the improvement of the overall state of TB control, patients burdened with multidrug-resistant strains of Mtb are left with fewer treatment options. This study explores the anti-mycobacterial potential of Ricinus communis L. an ethnobotanically important plant that is known for its wide range of pharmacological health benefits including its anti-inflammatory and antibacterial activities. Using resazurin microtiter plate assay (REMA), chromatographically purified methanolic extract of R. communis methanolic extract of R. communis demonstrated significant inhibitory activity against Mycobacterium smegmatis at 250 µg/mL. This partially purified bioactive fraction was subjected to gas chromatography-mass spectrometry (GC-MS) analysis. The possible phytochemicals that were identified were further examined through in-silico approaches such as molecular docking, molecular dynamics simulation (MDS), and various interaction analyses, to assess their binding affinity and stability with target proteins of Mtb involved in the mycolic acid biosynthesis pathway namely FabD, MabA and KasA. Among the compounds identified, Dl-citrulline and deoxyspergualin demonstrated strong and stable interactions with key Mtb proteins, suggesting their potential as promising leads for the development of new antimycobacterial agents targeting mycolic acid synthesis.