Anti-Opisthorchis felineus effects of artemisinin derivatives: An in vitro study

The drug of choice for the treatment of opisthorchiasis caused by trematodes Opisthorchis viverrini and O. felineus is praziquantel (PZQ), but there is a constant search for new anthelmintics, including those of plant origin. Positive results on the use of artemisinin derivatives against O. viverrini opisthorchiasis have been shown previously, but the effect of these compounds on O. felineus has not been studied. Therefore, here, a comparative analysis of anthelmintic properties of artemisinin derivatives (artesunate [AS], artemether [AM], and dihydroartemisinin [DHA]) was carried out in vitro in relation to PZQ. Experiments were performed on newly excysted metacercariae (NEMs) and adult flukes of O. felineus. Dose- and time-dependent effects of artemisinin derivatives and of PZQ were assessed in terms of motility and mortality of both NEMs and adult flukes. The most pronounced anthelmintic action was exerted by DHA, whose half-maximal inhibitory concentrations (IC50) of 1.9 (NEMs) and 2.02 µg/mL (adult flukes) were lower than those of PZQ (0.56 and 0.25 µg/mL, respectively). In contrast to PZQ, the effects of DHA and AS were similar when we compared the two developmental stages of O. felineus (NEMs and adult flukes). In addition, AM, AS, and especially DHA at doses of 100 µg/mL disrupted tegument integrity in adult flukes, which was not observed with PZQ. Artemisinin derivatives (AS, AM, and DHA) have good anthelmintic efficacy against the trematode O. felineus, and the action of these substances is comparable to (and sometimes better than) the effects of PZQ.