In vitro EVALUATION OF HYDROALCOHOLIC EXTRACTS OF MYCELIUM, BASIDIOMATA AND SPENT SUBSTRATE OF Pleurotus ostreatus AGAINST Haemonchus contortus

Background. The edible mushroom Pleurotus ostreatus is a potential alternative for the control of gastrointestinal nematodes due to their nematoxins and secondary metabolites. Objective. To evaluate the in vitro anthelmintic activity of hydroalcoholic extracts of mycelium, basidiomata and spent substrate of the edible mushroom P. ostreatus against eggs and unsheathed larvae of Haemonchus contortus. Methodology. The mycelium of P. ostreatus was extracted with ethanol–water (70:30) and the basidiomata and the spent substrate with methanol–water (70:30) which were concentrated to obtain the mycelium (MHA), basidiomata (BHA) and spent mushroom substrate extract (SMSE) extracts. The eggs and larvae of H. contortus were exposed to different extracts in 96-well plates. The tests used were the egg-hatch and larval mortality tests. Three exposure times, 24, 48 and 72 h, were considered. The data were analyzed with a factorial design and the comparison of means by Duncan test. Results. The percentage anthelmintic effectiveness of the mycelium hydroalcoholic extract (MHA) of P. ostreatus against eggs and larvae of H. contortus were 93 and 96.8% at 12.8 and 240 mg/mL (respectively) after 72 h. Also, activity was observed for SMSE and BHA against eggs, with values of 87.2 and 100%, respectively, at 25.6 mg/mL after 72 h. However, SMSE showed no activity against H. contortus larvae, while the BHA extract showed less than 70% corresponding activity. Implications. This was an exploratory study of in vitro tests; the in vivo studies are still needed. Conclusion. The MHA extract of P. ostreatus showed anthelmintic activity against the eggs and larvae of H. contortus.