Pongamia pinnata (L.) Pierre leaf extract: in vitro, in vivo, and in silico approaches to combat the waterborne bacterial pathogens associated with diarrheal conditions.

Pongamia pinnata (L.) Pierre, a medicinal plant traditionally used in Indian ethnomedicine, was evaluated for its antidiarrheal, antibacterial, and antioxidant properties through a combination of in vitro, in vivo, and in silico approaches. This study aims to study the traditional use of plants in medicine and identify a suitable secondary metabolite that can help reduce bacterial growth in living systems, thereby lowering the risk of waterborne diseases and diarrhea. Screening of P. pinnata leaf extract confirmed the presence of various bioactive classes, including alkaloids, flavonoids, etc., and that it also had strong antioxidant activity. In vitro antibacterial assays revealed that the plant extract effectively inhibited multiple waterborne pathogens, particularly Shigella dysenteriae Castellani and Chalmers, 1919, and in vivo studies also showed significant dose-dependent antidiarrheal effects. Acute oral toxicity tests at high doses confirmed the extract's safety, with no adverse effects on body weight, behavior, or vital organs. GC-MS analysis revealed various secondary metabolites with N-decanoic acid as the most abundant in the plant extract. Notably, 1,2,5,6-di-O-isopropylidene-3-O-methanesulfonyl glucofuranose and spiro{2,4}heptane derivatives exhibited stronger binding affinities than the standard drug ampicillin in molecular docking studies with penicillin-binding proteins (PBPs). These findings suggest that P. pinnata harbors potent metabolites with significant antidiarrheal and antibacterial activity, offering promise for the development of plant-based therapeutics against waterborne bacterial pathogens. The integration of experimental and computational approaches strengthens its candidacy for future drug development targeting diarrheal diseases.