[22] Clinical efficacy of botanical extracts from Eupatorium adenophorum against the scab mite, Psoroptes cuniculi

This study evaluated the in vivoclinicalefficacyof Crofton weed (Eupatoriumadenophorum)extractsagainstthescabmite,Psoroptescuniculi. A 30-day experiment was performed using New Zealand rabbits that were naturally infested withP.cuniculion a farm. 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.adenophorumethanol 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 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.Clinicalinfection and the degree of recovery were evaluated, and the rate of reduction in mites andclinicalefficacyrate (%) were calculated. Theclinicaleffect of treatment withE.adenophorumextractswas similar to treatment with ivermectin. Seven days after the initial treatment, the meanclinicalscores (presence of scabs/crusts) decreased from 3.32, 3.08 and 3.17 to 0.37, 0.47 and 0.48 in the left ears of animals in groups A, B and C, respectively, and from 3.53, 3.73 and 3.67 to 0.40, 0.45 and 0.48 in the right ears of animals in groups A, B and C, respectively, which were similar to the observations recorded in the positive control rabbits. However, theclinicalscore for negative control rabbits did not decrease significantly (P>0.05) during the experiment, and this changed from 3.32 to 2.75 in the left ears and from 3.50 to 3.25 in the right ears, and there were no significant differences inclinicalefficacybetween left and right ears. After two treatments (7 days space), the rabbits in groups A, B, C and D had recovered completely 30 days after the last treatment and no recurrences of infection were observed. These results indicate thatE.adenophorumcontains potent compounds for the effective control of animal acariasis.

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