| Eupatorium adenophorum, belonging to the family Asteraceae (Compositae), is a perennial herb, mainly distributes in Central America, Mexico and other tropical and temperate regions. It has become a dangerous weed which harms crops, the natural environment and forests around the world. Currently, as a harmful and invasive weed, E. adenophorum has caused environmental and ecological hazards in at least 30 countries. E. adenophorum becomes the most important invasive alien species in China, and widely distributes in various provinces, such as Chongqing, Sichuan, Guizhou, Yunnan, Tibet, Guangxi, Hebei and Taiwan, which severely harms the local ecology. Even more noteworthy, E. adenophorum is bringing great disaster to other symbiotic plants. In recent years, researchers have begun to realize the potential of E. adenophorum as a source of plant-derived drugs. Effective utilization this alien invasive plants as a natural drugs, changing waste into a valuable resource is a research focus currently. The aim of this present study was to evaluate the therapeutic efficacy of botanical extracts from E. adenophorum against the animal ectoparasitic mite disease, at the same time, isolation and identification of the acaricidal composition from petroleum ether extract of E. adenophorum. The results of research are summarized as following:1. Acaricidal activity of extract from E. adenophorum against the P. cuniculi and S. scabiei in vitroThe possible acaricidal activity of E. adenophorum was analyzed using extracts created by water decocting, ethanol thermal circumfluence, and steam distillation. The toxic effect of each extract was tested against P. cuniculi and S. scabiei in vitro. Ethanol thermal circumfluence extract had a strong toxicity against mites, killing all S. scabiei at 0.5 and 1.0 g/ml (w/v) concentration, meanwhile 1.0 g/ml exlract was also found to kill all P. cuniculi within a four hour period. Similarly,0.25,0.5 and 1.0 g/ml concentration of extract had a strong toxicity against S. scabiei. Additionally,0.5 g/ml and 1.0 g/ml showed a strong acaricidal action against P. cuniculi.The median lethal concentration (LC50) values were 0.22 g/ml for S.scabiei and 0.64 g/ml for P. cuniculi in 1 h. The results indicated that E. adenophorum contains potent acaricidal ingredients.2. Clinical efficacy of botanical extracts from E. adenophorum against the scab mite, P. cuniculiA 30-day experiment was performed using New Zealand rabbits which were naturally infested with P. cuniculi on a farm. New Zealand rabbits were randomly divided into five groups (6 animals per group); animals in groups A, B and C were treated in each ear topically with 2 ml of 1.0,0.5 and 0.25 g/ml (w/v) E. adenophorum ethanol extract, respectively. Animals in groups D and E were treated with ivermectin (by injection; positive controls) and glycerol with water only (by embrocation; negative controls), respectively. Each New Zealand rabbit was treated twice with separate treatments on days 0 and 7. Rabbits were observed daily and detailed examinations were performed on days 0,7,14 and 30, to inspect the presence or absence of mites and scabs/crusts. Clinical infection and the degree of recovery were evaluated, and the rate of reduction in mites and clinical efficacy rate (%) were calculated. The clinical effect of treatment with E. adenophorum extracts was similar to treatment with ivermectin. After two treatments (7-day interval), the New Zealand rabbits in groups A, B, C and D had recovered completely on 30 days after the last treatment, and no recurrences of infection were observed. The results indicated that E. adenophorum contains potent acaricidal ingredients.3. Clinical efficacy of botanical extracts from E. adenophorum against the S. scabiei (Sarcoptidae:Sarcoptes) in rabbitsNew Zealand rabbits of naturally infested with S. scabiei in the toes and of artificially infected in the external ear margin with S. scabiei were treated with botanical extracts from E.adenophorum twice on days 0 and 7. After two treatments, the S. scabiei was completely eliminated in the New Zealand rabbits treated with the concentrations of 1.0 or 0.5 g/ml of the extracts. On day 14, the treatment recovery score of the toe (external ear margin) infection was reduced from 4.50 (4.55),4.25 (4.45) and 4.32 (4.18) to 0.77 (0.73),0.87 (0.87) and 3.83 (3.90), respectively. The rabbits treated with ivermectin (positive controls) and those treated with the extracts of concentrations of 1.0 or 0.5 g/ml achieved remarkable therapeutic efficacy; no mites were present in toes of rabbits in these groups on day 14, which confirmed a 100% therapeutic efficacy rate up to day 30 of the trial. These results indicated that E. adenophorum contains potent compounds for the effective control of sarcoptidosis.4. Acaricidal activity of petroleum ether extract from E. adenophorum against Chorioptes texanus and preliminary analyze the principal component of petroleum ether extract from E. adenophorumWe use three different concentrations of the ethanol extract and petroleum ether extract from E. adenophorum against C. texanus in vitro; evaluate the in vitro effects of these extracts against the C. texanus. At the same time, a 60-day experiment was performed using 24 dairy cattle that were naturally infested with C. texanus from three farms. Dairy cattle were randomly divided into four groups (6 animals per group); animals in groups A and B were treated topically with petroleum ether extract from E. adenophorum, respectively. Animals in groups C and D were treated with fenvalerate and glycerol with water only, respectively. The results showed that, the extracts at concentrations of 1.0,0.5,0.25 g/ml (w/v) were highly toxic to C. texanus, the effect achieved 100%,100% and 96.7%, while the effect of difference concentrations of petroleum ether extract from E. adenophorum against the C. texanus achieved 100%, 93.3% and 80.0%. In the clinical trials, after two treatments (7-days interval), the 12 cattles in groups A and B had recovered completely,60 days after the last treatment and no recurrences of infection were observed. The clinical effect of treatment with E. adenophorum extracts was similar to treatment with fenvalerate. The results indicated that E. adenophorum may potentially provide new acaricidal compounds that can effectively control mites in livestock. In order to track the insecticidal activity ingredients from E. adenophorum, we used the methods of Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) to analyze the principal component of petroleum ether extract of E. adenophorum. The result showed that, this extract contains 5-6 principal components.5. Isolation and identification of the acaricidal composition from petroleum ether extract of E. adenophorumWe use the method of multiple silica gel column chromatographies coupled with ’H-NMR and 13C-NMR to separate and identify the active ingredients from petroleum ether extract of E. adenophorum. We obtained five single components, and identified four components of these ingredients, including 9-OXO-ageraphorone, 9-OXO-10,11-dehydro-ageraphorone, stigamasterol and 9β-hydroxy-ageraphorone. The toxic effect of each component was tested against P. cuniculi in vitro. We found that, components of 9-OXO-ageraphorone,9-OXO-10,11-dehydro-ageraphorone, and 9β-hydroxy-ageraphorone had a strong toxicity against P. cuniculi in vitro. |
PDF Full Text Request