In Vitro Evaluation of the Antibacterial Activity of Arkadi Gana Against Enteropathogenic Bacteria Associated With Food Poisoning

Background: Food poisoning caused by enteropathogenic bacteria is a major global health burden, and rising antimicrobial resistance (AMR) among these pathogens has renewed interest in plant-based alternatives. Ayurveda describes a group of drugs, Arkadi Gana (Sushruta Samhita, Sutra Sthana 38/16–17), traditionally credited with Krimighna (antimicrobial) and Vishaghna (antitoxic) properties. Objective: To evaluate, in vitro, the bactericidal/bacteriostatic activity of aqueous extracts of four constituent drugs of Arkadi Gana — Arka (Calotropis procera, leaf), Apamarga (Achyranthes aspera, seed), Karanja (Pongamia pinnata, seed) and Bharangi (Clerodendrum serratum, root) — individually and in combination, against bacterial strains implicated in food poisoning. Methods: Aqueous extracts were prepared by cold maceration and concentrated using a rotary evaporator. Physicochemical (pH, loss on drying, ash values, extractive values) and phytochemical standardisation was carried out as per Ayurvedic Pharmacopoeia of India protocols. Antibacterial activity was screened by the agar well diffusion method at 5 mg/mL and 10 mg/mL against Bacillus subtilis MTCC121, Staphylococcus aureus MTCC96, Salmonella typhimurium MTCC733 and Escherichia coli MTCC43, using tetracycline as positive control and distilled water as negative control. Results: At 5 mg/mL, none of the extracts produced a measurable zone of inhibition (ZOI) against any strain. At 10 mg/mL, the Karanja extract produced a 3 mm ZOI and the combined Arkadi Gana extract a 1 mm ZOI, both selectively against S. typhimurium; no activity was observed against S. aureus, B. subtilis or E. coli. Tetracycline produced robust inhibition across all four strains (4–8 mm), validating the assay. Conclusion: Aqueous extracts of Karanja show selective, concentration-dependent antibacterial activity against Salmonella typhimurium, partially supporting the classical Krimighna attribution of Arkadi Gana. Overall antibacterial activity of the aqueous extracts was limited and solvent-dependent, indicating that alternative extraction media and higher concentrations should be explored in future work.