OBJECTIVETo compare the antitussive activity of three kinds of Stemonae Radix specified in the Chinese Pharmacopoeia, including roots of Stemona sessilifolia, S. japonica and S. tuberosa.

METHODThe antitussive activity was determined in mouse after cough induction by ammonia aerosol stimulation and the number of cough in 2 min were detected with codeine as positive control.

RESULTAll the decoctions, the total alkaloid fractions and non-alkaloid fractions of S. sessilifolia, S. japonica and three chemical types of S. tuberosa showed significant antitussive effect and exhibited a dose-dependent inhibition of coughing. The ED50 values showed that the antitussive activity strength for both total alkaloid fractions and the decoctions are: S. tuberosa (Type I) > S. sessilifolia > S. japonica. The total alkaloid fractions had more potent atitussive activity than the decoctions and non-alkaloid fractions. The antitussive activity strength for the three chemical types of S. tuberosa is: Type I > Type III > Type II. The samples from different producing areas for the same species of Stemonae Radix had no significant differences in antitussive activity. The result also showed that the honey-processed slice had much stronger antitussive activity than raw slice.

CONCLUSIONThe antitussive efficacies of Stemonae Radix were influenced by chemical diversity both in same species and among different species, different fractions and processed method.

Animals ; Antitussive Agents ; administration & dosage ; Cough ; drug therapy ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Male ; Mice ; Mice, Inbred ICR ; Stemonaceae ; chemistry

Objective The aim of this study was to investigate the response in health-related epidemiological investigation among Chinese population aged 15 and over.We analyzed the specific causes of non-response,and explored the effective ways to improve the response rate,so as to provide reference for future epidemiological studies of this kind.Methods Two modes of studies regarding the prevalence of important cardiovascular diseases were used in Chongqing,during the 12th Five-Year Plan period in oder to find out the cause related to non-response.Intervention programs were carried out to evaluate the effects.Results When using the concentrated mode (CM),the completion rate to the questionnaires was only 20.00％ in the pre-investigation,with the response rate as 13.48％.In the deconcentrated mode (DM),the completion rate was 31.16％,with the response rate as 25.19％.After a series of incentives provided to both the respondents and the project-related core staff in the two modes,response rates of the two modes increased to the expected 60％.Conclusions CM appeared having advantages on quality control,but was more time consuming,with higher cost,and without effective follow-up measures to improve the response rate.However,DM had the advantages on controlling the cost and could increase the response rate through making advanced appointment with the households but quality control remained difficult.Two key points should be strengthened to improve the response rates,which including:Precisely finding out the research objects and providing incentives to the respondents to attract their interests of participating in the investigation.