Anthelmintic activity of a standardized extract from the rhizomes of Acorus calamus Linn. (Acoraceae) against experimentally induced cestodiasis in rats.

BACKGROUND: The rhizomes of a herb Acorus calamus Linn. (Acoraceae) have been widely used as a traditional medicine to cure intestinal-helminthic infections in India and South Africa.

AIM: This study was undertaken to investigate the in vivo anthelmintic activity of a standardized methanolic extract obtained from the rhizomes A. calamus in a rodent model.

MATERIALS AND METHODS: A methanolic extract obtained from rhizomes of A. calamus was characterized for active principle using nuclear magnetic resonance 1 H NMR, 13 C NMR, mass and infrared spectroscopy. The amount of active principle in rhizome isolated active fraction of plant was assayed using high-performance liquid chromatography (HPLC). Later, the standardized rhizome extract of plant and its active principle were tested for in vivo anthelmintic efficacy against experimentally induced Hymenolepis diminuta , a zoonotic cestode, infections in rats.

RESULTS: The study revealed that b-asarone is the active principle of plant. The HPLC analysis of local variety of A. calamus revealed that active fraction contains 83.54% (w/w) of b-asarone. The in vivo study revealed that treatment of H. diminuta infected rats by a single 800 mg/kg dose of rhizome extract for 5 days results into 62.30% reduction in eggs per gram of feces counts and 83.25% reduction in worm counts of animals. These findings compared well with the efficacy of a reference drug, praziquantel. The active principle b-asarone showed slightly better anthelmintic effects than crude extract. In acute toxicity assay, a single oral 2000 mg/kg dose of extract did not reveal any signs of toxicity or mortality in mice, and the LD50 of the extract was noted to be >2000 mg/kg.

CONCLUSION: Taken together, the results of this study indicate that rhizomes of A. calamus bear significant dose-dependent effects against intestinal helminths. Further, the Indian variety of A. calamus contains high b-asarone content. Therefore, there exists a great potential to develop some suitable anthelmintic herbal products from this plant.