Abstract:

To investigate the effects of niclosamide and EDTA on the activity of phenoloxidase(PO) from Oncomelania hupensis in different ages. Methods The soft tissues from Oncomelania hupensis in different ages, such as adult snails, young snails and the eggs of snails, were homogenated and centrifugated to obtain crude enzyme liquid, then purified by salt precipitation, dialysis and gel filtration to obtain PO. The activity of PO was detected with catechol as the substrate in the condition of different concentrations of niclosamide and EDTA. Results The activity of PO from Oncomelania hupensis in different ages was decreasing with the concentration elevating of niclosamide and EDTA. Conclusion Both niclosamide and EDTA have inhibition effect on the activity of POfrom Oncomelania hupensis in different ages.

Key words: EDTA, Niclosamide, Oncomelania hupensis, Phenoloxidase(PO), Enzyme activity