PURPOUSE: The present study evaluated in vitro the action of the plant protease papain (EC 3.4.22.2) on intact eggs of Taenia solium and Taenia saginata. METHODS: Two experimental groups were composed for each of the gastrointestinal helminths: control group (G1) and treated group (G2). In each replicate corresponding to the control group, 100 µL of the suspension containing approximately 100 intact eggs (T. solium) or 50 eggs (T. saginata) and 100 µL of distilled water were added, while for the treated group 100 µL of the egg suspension and 100 µL of the papain solution at a concentration of 15% (m/v) were added. The experiment was conducted in four replicates. The groups were incubated in BOD at 28 ± 1 ºC in the dark for a period of 24 h. RESULTS: The results demonstrated that there was a significant reduction (p <
0.01) of intact eggs, with average reduction percentages for T. saginata and T. solium of 74.36% and 64.29%, respectively. CONCLUSIONS: This study is the first report on the in vitro control of helminth eggs (T. saginata and T. solium) using pure papain.