In vitro and in vivo acaricide action of juvenoid analogs produced from the chemical modification of Cymbopogon spp. and Corymbia citriodora essential oil on the cattle tick Rhipicephalus (Boophilus) microplus.

The present study aimed to evaluate the acaricidal action of the chemically modified essential oil of Cymbopogon spp. and Corymbia citriodora on Rhipicephalus (Boophilus) microplus. Citronellal was converted into N-butylcitronellylamine and in N-prop-2-inylcitronellylamine, analogs of juvenoids, by reductive amination using butylamine (N1 to N3) and propargylamine (N4 to N7). In vitro assays included the adult immersion, and larval packet tests. Engorged females were weighed in groups of 10 and tested in three replicates for six concentrations. They were immersed in the modified oils or control solution and incubated. In the larval packet test, the same substances and concentrations were evaluated in three replicates. In the in vivo test, six pastured heifers naturally infested with R. (B.) microplus were used per treatment: negative control, positive control (amitraz, Triatox(®)), original oil of C. citriodora at 1.5%, and modified oil containing 0.9% N-prop-2-inylcitronellylamine (N7). Ticks were counted in the right side of the body in 24 animals from day D-3 to D21. LC50 and LC90 were obtained by Probit analysis, while the in vivo results were log transformed and compared using the Tukey test. Among the nitrocellylamines tested in vitro, N6 was most effective on the engorged females (100% efficacy at 50mg/mL) and N7 on the larvae (100% efficacy at 6.25mg/mL). In the test with larvae, the original oil of C. citriodora was less effective than the counterpart modified oil (N7), proving that the chemical modification optimized its effect. In the in vivo test, no significant difference was observed between N7 and the negative control. The average numbers of ticks on the animals' right side were 32.8, 8.1, 37.9 and 35.4 for the negative control, positive control, original oil and N7, respectively. The chemical modification improved the efficacy in vitro, but it was not observed in vivo, perhaps due to the low stability of the amines under field conditions. The evaluation carried out here has not been previously studied, so this concept expands the horizon for research into chemically modified substances for parasite control and shed light on the challenges to find effective formulations and application methods.

[Effects of aqueous extracts of Mentha piperita L. and Chenopodium ambrosioides L. leaves in infective larvae cultures of gastrointestinal nematodes of goats]. / Efeitos dos extratos aquosos de folhas de Mentha piperita L. e de Chenopodium ambrosioides L. sobre cultivos de larvas infectantes de nematóides gastrintestinais de caprinos.

Phitotherapy has been frequently utilized in parasitism control for numerous animal species. The aim of this experiment was to evaluate the in vitro effects of aqueous extracts of Mentha piperita L. and Chenopodium ambrosioides L. leaves in larvae cultures of gastrointestinal nematodes of goats. Six different concentrations of M. piperita extracts (196; 150.7; 115.9; 89.1; 68.5 e 52.7 mg/mL) and C. ambrosioides extracts (110,6; 85; 65,3; 50,2; 38,6 e 29,6 mg/mL) were used for the treatment of larvae cultures, in triple assays. Distilled water and doramectin were used in larvae cultures as negative and positive controls, respectively. The results revealed a reduction of more than 95% of the infective larvae when M. piperita extracts were used in the concentrations of 115.9 and 196 mg/mL, and C. ambrosioides extract in the concentration of 110.6 mg/mL, supporting the effect of these extracts in the in vitro treatment of gastrointestinal nematodes of goats.

Ocorrência de aflatoxinas em amendoim e seus produtos comercializados no Estado da Bahia durante o ano de 2002 / Occurrence of Aflatoxins in peanut and peanut products commercialized in the state of Bahia during the year 2002

Este estudo teve como objetivo avaliar a contaminação por aflatoxinas (B1,B2,G1 e G2) em amostras de amendoim comercializadas em alguns municípios do estado da Bahia. Foram analisadas 100 amostras, sendo 33 de amendoim e 67 de produtos a base de amendoim. A coleta das amostras foi realizada aleatoriamente em diferentes estabelecimentos comerciais da cidade de Salvador (75 amostras) e em municípios do estado da Bahia (25 amostras) durante o período de janeiro a outubro de 2002. A extração foi realizada com acetonitrila:água (84:16, v/v), e a quantificação das aflatoxinas procedida pelo método de Cromatografia Líquida de Alta Eficiência (CLAE), empregando detecção por fluorescência. Das 31 amostras de amendoim analisadas, 29 (93,55 por cento) foram positivas, sendo que 17 (54,84 por cento), apresentaram teor de contaminação por B1 + B2 + G1+G2 superior a 20 ug/kg. Para as 69 amostras de derivados de amendoim, apenas 6 (8,7 por cento) apresentaram contaminação por aflatoxinas B1+B2+G1+G2 superior ao limite. Os resultados ainda revelaram que 20(80 por cento) do total de amostras coletadas nos municípios do Estado (25) e 38 (50,7 por cento) das 75 amostras procedentes de Salvador foram positivas. Os resultados ressaltam a necessidade de um controle eficaz dos níveis de aflatoxinas destes produtos na região