Multimodal screening and characterization of Rogeria adenophylla against trypanosoma brucei brucei

Abstract

   Advances in molecular modeling and in silico screening have significantly enhanced the identification of pharmaceutical phytochemicals. This study examined the phytochemical profile and multimodal antitrypanosomal potential of Rogeria adenophylla methanol extract (RAME) and its most potent fraction. Acute oral toxicity (LD50) of RAME was assessed using Lorke’s method, followed by its in vivo antitrypanosomal activity in Trypanosoma brucei brucei-infected rats at peak parasitemia (~10⁶ trypanosomes/mL), while serum antioxidant levels were measured using standard methods. RAME was fractionated, and the bioactivity and phytochemical content of its fractions were analyzed. One (1) μL of R. adenophylla n-butanol fraction (RABF) was subjected to Gas Chromatography-Mass Spectroscopy (GC-MS) and Fourier Transform Infra-Red (FTIR) analyses, while molecular docking evaluated the trypanocidal potential of RABF compounds and the drug-likeness and predicted toxicity (LD₅₀) of the most interactive phytoconstituents were assessed via in silico approaches. RAME acute oral toxicity was estimated as >5000 mg/kg and produced a dose-dependent (p < 0.05) decline in mean trypanosome load, achieving complete trypanosome clearance at 100 – 400 mg/kg in infected rats. RAME significantly (p<0.05) improved packed cell volume at 200 – 400 mg/kg, accompanied with a dose-related antioxidant effects. In vitro, RAME fractions caused a concentration-dependent (p<0.05) reductions in trypanosome motility, with complete motility cessation within 40 – 60 minutes at 10 – 20 mg/mL (RABF and RAEF). GC-MS and FTIR analyses of RABF identified 21 phytocompounds and 13 associated functional groups. Molecular docking revealed that most RABF phytocompounds showed strong binding affinity to trypanosomal targets (TbNH, TbDHFR, TbAK), with 1-β–d-ribofuranosyl-1H-imidazole-4-carboxamide derivative displaying the highest affinity (−7.8 kcal/mol) for TbNH as a pyrimidine nucleoside analogue. RABF compounds also exhibited favorable drug-like properties and broad safety margins (LD50: 2000 – 20000 mg/kg), supporting their trypanocidal potential. This finding highlights R. adenophylla therapeutic potential against African trypanosomiasis bridging traditional and computational techniques to facilitate antitrypanosomal drug development, with further studies needed to isolate RABF trypanocidal compounds and elucidate their mechanism of action.