Chemical variations of the essential oils in flower heads of Chrysanthemum indicum L. from China.

The volatile compositions of hydrodistilled essential oils in the flower heads of Chrysanthemum indicum L. from eight populations in China were analyzed by GC/MS. A total of 169 compounds representing 88.79-99.53% of the oils were identified, and some remarkable differences were found in the constituent percentages of the eight populations. The predominant components of the essential oils were 1,8-cineole (0.62-7.34%), (+)-(1R,4R)-camphor (0.17-27.56%), caryophyllene oxide (0.54-5.8%), ß-phellandrene (0.72-1.87%), (-)-(1S,2R,4S)-borneol acetate (0.33-8.46%), 2-methyl-6-(p-tolyl)hept-2-ene (0.3-8.6%), 4,6,6-trimethylbicyclo[3.1.1]hept-3-en-2-yl acetate (0.17-26.48%), and hexadecanoic acid (0.72-15.97%). The chemotaxonomic value of the essential-oil compositions was discussed according to the results of cluster analysis (CA) and principal-component analysis (PCA). The eight populations were divided into five groups as different chemotypes (Groups A-E), and the scores together with the loadings revealed clearly different chemical properties of each population. In conclusion, GC/MS in combination with chemometric techniques provided a flexible and reliable method for characterizing the essential oils of different populations of C. indicum L.

[Studies on resistance of Schistosoma to praziquantel Xâ ¥ Biological characteristics of praziquantel-resistant isolates of Schistomoma japonicum in Oncomelania hupensis snails].

OBJECTIVE: To investigate the difference of biological characteristics between the praziquantel-resistant and -susceptible isolates of Schistosoma japonicum in intermediate host Oncomelania hupensis snails. METHODS: Mice were infected with cercariae of praziquantel-resistant and -susceptible isolates of S. japonicum, and the parasite eggs were collected 37 days post-infection to hatch miracidium. Then, the snails were infected with the miracidium of each parasite isolate. The snail infection, survival rate of infected snails, prepatent period of cercariae, and the total number of cercariae shed from each infected snail were observed and compared between the praziquantel-resistant and -susceptible isolates of S. japonicum. RESULTS: If each snail was exposed to a single miracidium, there were significant differences between the praziquantel-resistant and -susceptible Jiangsu isolates in the snail infection (8.99% vs. 19.74%; χ2 = 3.948, P = 0.047) and the number of cercaria released from a single snail (1 460.2 vs. 1 039.3; t = 2.507, P = 0.02), and there were significant differences between the praziquantel-susceptible and -resistant Hunan isolates in the snail infection (10.00% vs. 21.52%; χ2 = 3.980, P = 0.046) and the number of cercaria released from a single snail (1 319.4 vs. 1 003.5; t = 2.566, P = 0.017). However, there were no significant differences between the praziquantel-resistant and -susceptible isolates of S. japonicum in the prepatent period of cercariae and the survival rate of infected snails (P > 0.05). CONCLUSIONS: The praziquantel-resistant isolate of S. japonicum has a higher susceptibility to O. hupensis but less cercaria released from each infected snail than the susceptible isolate.

[Studies on resistance of Schistosoma to praziquantel XVII Biological characteristics of praziquantel-resistant isolates of Schistosoma japonicum in mice].

OBJECTIVE: To investigate the biological characteristics of the praziquantel-resistant isolate of Schistosoma japonicum in mice, so as to explore the pathogenicity to definitive hosts and transmission intensity of the praziquantel-resistant isolate of S. japonicum. METHODS: Mice were infected with the cercariae released from two praziquantel-resistant isolates and two praziquantel-susceptible isolates of S. japonicum. The mouse-Oncomelania hupensis snail-mouse cycle was established and maintained in the laboratory. The prepatent period of parasite eggs, egg production, egg distribution in mice, parasite susceptibility to mice and egg size were investigated in each parasite isolate. RESULTS: The prepatent period of parasite eggs, egg counts in mouse feces, adult worms recovered from each mouse, egg counts in mouse tissues, egg counts in the mouse liver, and egg counts in intestine tissues were 36.1 d and 36.8 d (t = 0.907, P = 0.372), 14.6 / 100 mg and 21.2 / 100 mg (t = 2.946, P = 0.007), 20.5 and 25.1 worms per mouse (t = 2.128, P = 0.042), 31 303 and 38 594 per paired adult worm (t = 2.185, P = 0.04), 14 810 and 19 715 per paired adult worm (t = 2.934, P = 0.007), and 16 493 and 18 879 per paired adult worm (t = 1.044, P = 0.309) in the mice infected with Jiangsu praziquantel-susceptible and -resistant isolates of S. japonicum, respectively, and there were no significant differences between Jiangsu praziquantel-susceptible and -resistant isolates of S. japonicum in the length of paired adult worms (t = 0.328, P = 0.744), female adult worms (t = 0.386, P = 0.701) or male adult worms (t = 0.332, P = 0.741). The prepatent period of parasite eggs, egg counts in mouse feces, adult worms recovered from each mouse, egg counts in mouse tissues, egg counts in the mouse liver, and egg counts in intestine tissues were 35.5 d and 35.6 d (t = 0.169, P = 0.867), 13.3/100 mg and 18.9/100 mg (t = 3.622, P = 0.001), 17.6 and 25.1 worms per mouse (t = 3.153, P = 0.004), 30 932 and 53 903 per paired adult worm (t = 3.865, P = 0.001), 12 307 and 26 363 per paired adult worm (t = 4.388, P < 0.01), and 18 625 and 27 541 per paired adult worm (t = 2.679, P = 0.012) in the mice infected with Hunan praziquantel-susceptible and -resistant isolates of S. japonicum, respectively, and there were no significant differences between Hunan praziquantel - susceptible and - resistant isolates of S. japonicum in the length of paired adult worms (t = 0.853, P = 0.397), female adult worms (t = 0.573, P = 0.569) or male adult worms (t = 0.742, P = 0.461). CONCLUSIONS: The praziquantel-resistant isolate of S. japonicum has a higher parasite egg production and more eggs deposited in the mouse liver than drug-susceptible isolate, suggesting that the praziquantel-resistant isolate of S. japonicum exhibits a greater pathogenicity to definitive hosts. In addition, more parasite eggs are detected in the feces of mice infected with the praziquantel-resistant isolate of S. japonicum relative to the drug-susceptible isolate, indicating that the praziquantel-resistant isolate of S. japonicum exhibits a greater transmissibility than the drug-susceptible isolate.

[Studies on spray of niclosamide ethanolamine salt. I. development and effect assessment of spray of niclosamide ethanolamine salt].

OBJECTIVE: To develop a spray of niclosamide ethanolamine salt for prevention of bovine from Schistosoma japonicum infection, and explore its characteristics and effect. METHODS: The solubilizers, penetrating agents, emulsifiers were screened, and the spray of niclosamide ethanolamine salt was formulated according to the screening results. The niclosamide ethanolamine salt was determined by using a HPLC technique, and the stability was observed. The preventive effect of the spray was assessed by in-vitro trials against cercariae and protection trials in mice. RESULTS: The screened formulation was presented as following: 1% niclosamide ethanolamine salt was dissolved in 18% dimethyl sulfoxide, and then added with 1% azone and 2% span, together with 78% ethanol, to yield a 1% spray of niclosamide ethanolamine salt. The spray appeared golden flowing liquid, with 1% niclosamide ethanolamine salt in content (W/W), pH 7.4-7.8, and good thermal and cold stability. All cercariae died (100%) while exposed to the spray at a concentration of 1.00 mg/L for 2 min, and the similar effect was achieved while exposed to 0.50 mg/L of the spray for 5 min or 0.10 mg/L for 30 min. The spray at concentrations less than 0.05 mg/L had no evident toxicity to cercariae. A volume of 0.5 ml of the 1% spray was sprayed on the abdomen of mice, 1-3 d later, the mice were infected with S. japonicum cercariae on the spraying sites, no mice were infected, with a protection rate of 100%. Five days post-spraying, the protection rate was 40%, and the worm burden reduction rate was 65.87%. Ten days later, all the mice were infected, however, the worm burden reduction rate was 51.98%. The worm burdens on days 5 or 10 post-spraying were significantly lower than those of the control (P < 0.01). The spray exhibited a good preventive efficacy to mice from S. japonicum infection in lab. CONCLUSIONS: The spray of niclosamide ethanolamine salt has stable physical and chemical property, and is a novel liquid preventive agent against bovine schistosomiasis. In addition, it has a rapid activity against S. japonicum cercariae, so can prevent bovine from S. japonicum infection.

A new dicoumarin and anticoagulant activity from Viola yedoensis Makino.

A new dicoumarin, named as dimeresculetin (1), together with another dicoumarin, euphorbetin (2) and esculetin (3) were isolated from the ethyl acetate extract of the dried whole plants of Viola yedoensis Makino. The structure of 1 was elucidated as 7-hydroxy-6-[(6,7-dihydroxy-2-oxo-2H-1-benzopyran-5-yl)oxy]-2H-1-benzopyran-2-one on the basis of extensive NMR, as well as the other spectral analysis. Compounds 1-3 exhibited anticoagulant activities with respect to activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT).