[Molluscicidal mechanism of combining use of extract of Glycyrrhiza uralensis and niclosamide].
OBJECTIVE
To investigate the molluscicidal mechanism of combining use of the extract of Glycyrrhiza uralensis (GE) and niclosamide (Nic).


METHODS
The Oncomelania hupensis snails were immersed in Nic, GE and GE+Nic solutions for 24 h and 48 h respectively, and then were put into fresh water to confirm their survival condition. The alive ones were dissected to obtain their livers. The effects of the drugs on the protein and glycogen of the liver of O. hupensis were observed, and the effects on contractile activity of vola pedis of the snails were studied by the experimental method of isolated smooth muscles of 0. hupensis.


RESULTS
GE had no obvious effects on the protein and glycogen in the liver of O. hupensis (all P > 0.05), but it could inhibit the contractions and decrease the contractile frequency of smooth muscles of vola pedis of O. hupensis (all P < 0.05). Nic could significantly decrease the levels of protein and glycogen in the liver of O. hupensis (all P < 0.05) , as well as enhance the contractions and contractile frequencies of smooth muscles of vola pedis of O. hupensis (P < 0.05). GE combined with Nic could further decrease the levels of protein and glycogen in the liver of O. hupensis (all P < 0.05), meanwhile, it could inhibit the contractions and decrease the contractile frequency of smooth muscles of vola pedis of O. hupensis (all P < 0.05).


CONCLUSIONS
The combining use of GE and Nic can accelerate the liver damage of O. hupensis, and also can inhibit the contractions of smooth muscles of vola pedis of O. hupensis which increases the contacting time of the drug, thus leads to the synergism of molluscicidal effect.
Deng-zhao
DZ
Jiang
Hui-min
HM
Li
D000818:Animals; D004357:Drug Synergism; D029882:Glycyrrhiza uralensis / Q000737:chemistry*; D008099:Liver / Q000187:drug effects; D008975:Molluscacides / Q000633:toxicity*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D009534:Niclosamide / Q000494:pharmacology*; D010936:Plant Extracts / Q000633:toxicity*; D012908:Snails / Q000187:drug effects* / Q000502:physiology
D008975:Molluscacides; D010936:Plant Extracts; D009534:Niclosamide