[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.

[Elementary exploration of the origin and development of marine Chinese materia medica].

According to archaeological discoveries, humans began to make use of marine natural resources early in the Palaeolithic era. In the Spring and Autumn period and Warring States period, they began to use marine life as medicines and also had simple cognitions on their efficacy and processing. In the Qin and Han dynasties, people further deepened the understanding of the marine Chinese materia medica and created prescriptions making use of marine drugs. In the Tang and Song period, the number of marine Chinese materia medica species and corresponding prescriptions apparently increased. The cognitions of the property, flavor, efficacy as well as the compatible principle of marine Chinese materia medica was further deepened and the scope of their treatment also significantly expanded. In the Ming and Qing dynasties, the cognition of the marine Chinese materia medica was mainly the conclusions of the previous experience. After the founding of the People's Republic of China (PRC), with the development of science and technologies, the ability of exploiting and utilizing the marine Chinese materia medica by people dramatically increased, and the species of marine Chinese materia medica reached more than one thousand. However, the development of marine Chinese materia medica is confronted with new problems; although the number of species of marine Chinese materia medica increased, the understanding of their property and flavor is obviously lagging behind, which seriously affects the clinical application of marine Chinese materia medica.