Immunomodulatory Potential of Vernonia amygdalina L. In silico Screening and In vitro Validation of Bioactive Compounds for Gastrointestinal Immune Regulation

Abstract

Background: The gastrointestinal (GI) tract is a complex and dynamic system that plays a crucial role in maintaining overall health and homeostasis. The increasing prevalence of gastrointestinal disorders globally has prompted a significant interest in exploring natural remedies that can offer therapeutic benefits. Among these remedies is Vernonia amygdalina L., commonly known as bitter leaf. It has been widely recognised for its traditional medicinal properties. Aim: This study investigates the immunomodulatory potential of V. amygdalina, focusing on its bioactive compounds and their interactions with key proteins involved in gastrointestinal immune regulation.   Methods: Leaves of V. amygdalina were collected from a farm in Ado-Ekiti, Nigeria, and authenticated. The 10 g of V. amygdalina were subjected to successive solvent extraction with 95% ethanol (1:7, m/V) for 48 h by maceration at room temperature and filtered through Whatman No. 4 filter paper. The residues were re-extracted with 95% ethanol. The following procedures were carried out: Anti-Lipoxygenase Activity Analysis, Protein Denaturation Activity Analysis, Membrane Stabilising Activity Analysis, and Protein-Ligand Docking using standard methodologies. Ex-vivo biochemical assays were carried out, gas chromatography-mass spectrometry (GC-MS) for compound identification, and In silico docking studies to assess molecular interactions. GraphPad Prism software (version 9.0, GraphPad Software, Inc., was used for data analysis. All data are reported as mean values with standard deviation (mean ± SD). Significant difference was set at P < 0.05. Results: The biochemical analysis revealed significant anti-inflammatory activities, including anti-lipoxygenase and protein denaturation inhibition. In silico molecular docking demonstrated strong binding affinities of selected compounds against target proteins FABP4, COX-1, FFAR1, and PPARα/ PPARA involved in regulating gastrointestinal immune function, with binding energies ranging from -8.704 to -2.979 kcal/mol. Conclusion: These findings suggest that V. amygdalina has substantial potential as a therapeutic agent for gastrointestinal disorders, warranting further exploration through further experimental validation.