Dried extracts were diluted in distilled water to obtain five different concentrations: 625, 1?250, 2?500, 3?750 and 5?000 ¦Ìg/mL. Fresh eggs obtained from artificially infected mice feces were exposed to these different concentrations for 48 h. Time of contact for embryonated eggs was 6 h while L1 and L2 larvae were exposed for 24 h. Distilled water (placebo) and 1.5 % DMSO were used as negative controls.
Distilled water, and 1.5 % DMSO had no effect on embryonation, hatching and larval survival. Aqueous extracts of D. integrifolia showed a weak activity against all stages of the parasite at all concentrations tested. On the contrary, the ethanolic extract of D. integrifolia inhibited the embryonation of 87.5 % of fresh eggs, the hatching of 81.1 % of embryonated eggs and induced the mortality of 98.1 % and 98 % of L1 and L2 larvae respectively at 5?000 ¦Ìg/mL.
The results of the present study indicate that the ethanolic extracts of D. integrifolia contained compounds with ovicidal and larvicidal properties. In spite of these results, in vivo tests, studies on toxicity and mechanism of action of active compounds are also needed to validate the utilisation of this medicinal plant by population of Dschang-Cameroon to treat gastro-intestinal parasites.