Biological Activities of the medicinal plant Senna alexandrina: An In vivo, In Vitro, and In Silico Approach

Abstract

This study aims to evaluate the phytochemical composition as well as the antibacterial and gastroprotective activities of the aqueous extract of Senna alexandrina leaves. An in silico assessment of the natural compounds, conducted through molecular docking simulations, was used to analyze their inhibitory potential on ATPase and polymerase. LC-MS QTOF and FTIR analyses revealed a richness in bioactive compounds, notably polyphenols (28.42 ± 0.4 mg GAE/g), flavonoids (9.05 ± 0.84 mg QE/g), tannins (0.43 ± 0.026 mg CE/g), and the characteristic presence of sennosides, anthraquinone compounds typical of the species. The antibacterial activity was tested against E. coli (ATCC 25922), S. aureus (ATCC 25923), and P. aeruginosa (ATCC 27853) at various concentrations (0.3125–200 mg/ml). A dose-dependent effect was observed, with maximum inhibition zones at 200 mg/ml (12 mm for E. coli, 10 mm for S. aureus, and 9 mm for P. aeruginosa). MIC values were 10 mg/ml for E. coli and S. aureus, and 200 mg/ml for P. aeruginosa, with no bactericidal effect, indicating a bacteriostatic action, confirmed by the time-kill assay. The gastroprotective effect was evaluated in mice using ethanol-induced gastric ulcer model (96%, 0.1 ml/mouse). Two doses of the extract (100 and 200 mg/kg) were administered orally (by gavage), and compared to a positive control group treated with omeprazole. The results showed a dose-dependent reduction of gastric lesions, confirmed by a significant decrease in the ulcer index. Histological analysis revealed preserved mucosal integrity and reduced inflammation in treated groups. Molecular docking studies supported these experimental results by confirming potential interactions between the plants major bioactive compounds and various target proteins, notably the bacterial RNA polymerase enzyme and the gastric receptor (ATPASE proton pump). These findings support the results of the study, showing a strong correlation with the experimental data.