Abstract
Background:
Secondary metabolites from the aqueous extract of Clinacanthus nutans Lindau leaves (E.A.C.L.), particularly saponins and tannins, are known to have various bioactive properties. However, to the author's knowledge, no study has published the anthelmintic efficacy of E.A.C.L. against Haemonchus contortus in goats or other ruminants. Therefore, exploratory research on E.A.C.L. is needed as a botanical alternative for controlling haemonchosis in goats.

Aim:
To determine the efficacy of E.A.C.L. as an anthelmintic with vermicidal, ovicidal, and larvicidal properties against Haemonchus contortus in vitro.

Methods:
This study was conducted from May 2025 to August 2025, starting from: preparation of Clinacanthus nutans Lindau leaf samples and collection of female Haemonchus contortus specimens, qualitative and quantitative analysis of secondary metabolites, and anthelmintic efficacy treatment of E.A.C.L.

Results:
Qualitative phytochemical screening of E.A.C.L. showed the presence of saponins and tannins with grades of (+++) each. Quantitative analysis showed a tannin content of 4.48% w/w. For vermicidal efficacy, a concentration of 9 mg/mL E.A.C.L. reached 100% after 7 hours of exposure, which was significantly different from the other treatments (p < 0.05). The concentration of 17 mg/mL E.A.C.L. gave the highest ovicidal efficacy (86.34%), comparable to the positive control (p > 0.05), while the negative control was significantly lower (p < 0.05). The highest larvicidal efficacy was 89.95% at a concentration of 21 mg/mL E.A.C.L., comparable to the positive control (p > 0.05). This was followed by concentrations of 17 mg/mL and 25 mg/mL E.A.C.L., with larvicidal efficacies of 62.86% and 45.83%, respectively, whereas the negative control had an efficacy of 0.34%.

Conclusion:
E.A.C.L. treatment, with its active secondary metabolite content, particularly saponins and tannins, demonstrated significant vermicidal, ovicidal, and larvicidal activity against H. contortus in vitro. The most effective concentrations were 4.5% (vermicidal), 8.5% (ovicidal), and 10.5% (larvicidal). Further in vivo studies are needed to determine the optimal therapeutic dose for controlling haemonchosis in goats and other ruminants.

Key words: Clinacanthus nutans Lindau; Etnofarmakologi haemonchosis; Secondary metabolites.