Preliminary Phytochemical Screening and In-Vitro Evaluation of the Anthelmintic and Antibacterial Activities of the Aqueous Extract of the Rachis (koor) of Azadirachta indica

Abstract

Helminthiasis and bacterial infections remain major global health issues, highlighting the need towards safer and more effective anthelmintic and antimicrobial agents. In Siddha Medicine, the rachis (koor) of Azadirachta indica is traditionally used in decoctions, yet its aqueous extract remains scientifically unexplored in Sri Lanka. This study evaluates the dose-dependent anthelmintic activity, antibacterial effectiveness and preliminary phytochemical screening of the aqueous extract of Azadirachta indica rachis. Anthelmintic activity against Pheretima posthuma displayed clear dose-dependent activity, with the highest concentration (200 mg/mL) resulting the shortest mean paralysis (31.0 ± 1.0 minutes) and death times (56.0 ± 2.0 minutes), effective than to albendazole 10 mg/mL (36.7 ± 1.5 minutes paralysis; 61.0 ± 1.5 minutes death). Even the lowest concentration (50 mg/mL) resulted significant activity, indicating effectiveness across all doses. Antibacterial activity against Escherichia coli and Staphylococcus aureus, resulted in inhibition zones of 12 ± 0 mm and 11 ± 0 mm, respectively, indicating broad-spectrum efficacy to bacteria. Phytochemical screening detected tannins, glycosides, steroids, saponins, and flavonoids, which possibly act synergistically to mediate both effects. These findings suggest that the aqueous extract of Azadirachta indica rachis possesses excellent dual anthelmintic and antibacterial properties, supporting its traditional usage, and highlight its potential for development into natural, safe, and cost-effective plant-based therapeutic agents.