Antifungal, molluscicidal and larvicidal assessment of anemonin and Clematis flammula L. extracts against mollusc Galba truncatula, intermediate host of Fasciola hepatica in Tunisia.

OBJECTIVE: To investigate the potential of anemonin and Clematis flammula (C. flammula) extracts against infective organisms.

METHODS: The molluscicidal activities of anemonin and C. flammula extracts against Galba truncatula Müll. (Lymnaeidae) and Fasciola hepatica larval stages contaminating this snail in Tunisia were assessed by testing six groups of snails in 250 mL of extracts and aqueous dechlorinated solutions with different concentrations (ranging from 2.5 to 20.0 mg/L) for 48 h. Besides, the antifungal potential of C. flammula leaves and flowers was evaluated by using the diffusion agar and broth dilution methods against four fungal strains: Aspergillus niger, Pythium catenulatum, Rhizoctonia solani and Fusarium phyllophilum.

RESULTS: As a result, hexane and ethyl acetate flower extracts exhibited significant molluscicidal activities with LC50 median lethal concentrations values of 11.87 and 11.65 mg/L, respectively while LC50 value of anemonin was 9.64 mg/L after 48 h exposure. The flower extracts showed a larvicidal effect with a deterioration rate exceeding 35.39% where flower ethyl acetate residue gave a deterioration rate of cercariae close to 97%. Moreover, C. flammula extracts were not noxious to the associated fauna survival. All extracts inhibited the growth of P. catenulatum, the leaves and flowers methanolic extracts had the more important fungicide action with minimum inhibitory concentrations of 1.56 and 3.12 mg/mL together with minimum fungistatic concentrations of 3.12 and 6.25 mg/mL respectively. Only flower extracts were active against Rhizoctonia solani with minimum inhibitory concentrations varying between 0.70 and 1.56 mg/mL and 6.25 mg/mL of minimum fungistatic concentration. Phytochemical tests showed that the antifungal activity may be attributed to the presence of the flavonoids/saponins in the methanolic extracts and the molluscicide effects could be due to the richness of hexane and ethyl acetate extracts on sterols and triterpenoids.

CONCLUSIONS: This study emphasizes the important molluscicidal and antiparasitic effects of flower ethyl acetate extracts and anemonin compound as well as the considerable antifungal activities of methanolic extracts. These results improve the therapeutic virtues of C. flammula aerial part extracts.