In-vitro piscicidal activity and antifungal activity of Ageratum conyzoides

Abstract

Ageratum conyzoides L., a tropical invasive herb of the Asteraceae family, is traditionally used for its antimicrobial and insect-repellent properties across South America, Africa, and Asia. This study investigates the piscicidal and antifungal activities of its ethanolic leaf extracts to explore its potential as a natural biocontrol agent. Leaves were collected from Udham Singh Nagar, India, authenticated, and extracted with 70% ethanol using a Soxhlet apparatus. Phytochemical screening identified flavonoids, saponins, terpenoids, tannins, and alkaloids as key bioactive constituents. Piscicidal activity was assessed against Rose Danio fish at concentrations of 100, and 200 mg/L over 48 hours, monitoring mortality, time to death. Antifungal activity was evaluated against Marasmiellus cocophilus via disc diffusion at 10 and 20 mg/mL, measuring inhibition zones. The extract exhibited dose-dependent piscicidal effects, achieving 100% mortality at 200 mg/L within 48 hours, and notable antifungal activity, with inhibition zones of 7-8 mm at 20 mg/mL or 10 mg/L, approaching fluconazole’s efficacy. Terpenoids and flavonoids likely contribute to gill disruption in fish and fungal cell membrane damage. These results suggest A. conyzoides as a viable eco-friendly agent for aquaculture and antifungal applications, though further in vivo and toxicity studies are needed.