RESUMO
Helminth infections represent a serious problem for the production of small ruminants that is currently aggravated by resistance to anthelmintic products and has induced a search for control alternatives, such as natural products. In this study, extracts of Turnera ulmifolia L. (leaves and roots), Parkia platycephala Benth. (leaves and seeds) and Dimorphandra gardneriana Tul. (leaves and bark), which have been cited in ethnoveterinary studies and selected naturally by goats in the cerrado (Brazilian savanna), were tested in vitro against Haemonchus contortus. Hydroacetonic (ACT) and hydroalcoholic (ETH) extracts were evaluated using an Egg Hatching Assay (EHA), a Larval Exsheathment Inhibition Assay (LEIA) and a Larval Development Assay (LDA). A second set of incubations was performed using polyvinylpolypyrrolidone (PVPP) to determine the influence of polyphenols on the anthelmintic effects of EHA and LEIA. Data from each extract were used to calculate inhibition concentrations (IC50). All tested extracts showed activity against at least one life stage of H. contortus. The use of PVPP revealed that the tannins are not the only extracts of secondary metabolites responsible for the anthelmintic effects. The results showed clear in vitro anthelmintic activities against H. contortus at different stages and indicated the potential use of these species as a promising alternative approach to control helminthic infections of small ruminants.
Assuntos
Anti-Helmínticos/farmacologia , Fabaceae/química , Haemonchus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Turnera/química , Animais , Brasil , Pradaria , Casca de Planta/química , Folhas de Planta/química , Raízes de Plantas/química , Sementes/químicaRESUMO
Neste trabalho foi investigado o efeito do extrato hidroalcoólico de própolis (EHP) de Scaptotrigona aff. postica sobre o desenvolvimento do tumor de Ehrlich na forma sólida, sobre a celularidade dos órgãos linfóides dos animais portadores de tumor, bem como, sobre a produção de óxido nítrico (NO) pelos macrófagos destes animais. Camundongos Swiss foram divididos em quatro grupos: controle, EHP 0,5; EHP 5 e EHP 50, os quais foram tratados por via intraperitoneal com dose única de solução salina (NaCl 0,9 por cento); 0,5; 5 ou 50 mg de EHP/kg de animal, respectivamente. Depois de 48 h do tratamento, os animais foram inoculados com 10(5) células do tumor de Ehrlich nas patas. Os resultados mostraram que o tratamento com EHP nas doses de 5 e 50 mg/kg inibiu de forma significativa o desenvolvimento do tumor a partir do 6º dia pós-inóculo quando comparado ao controle e ao EHP 0,5. Além disso, houve aumento significativo da celularidade do baço e da medula óssea nos grupos EHP 0,5 e EHP 5 em relação ao controle. A produção de NO estimulada com concanavalina A (ConA) apresentou uma significante diminuição nos grupos tratados com EHP em relação ao controle. Pode-se concluir que o tratamento com EHP apresentou efeito antitumoral quando administrado nas doses de 5 e 50 mg/kg, o que pode estar relacionado com a sua composição química e com a inibição da produção de NO.
It was investigated the effect of hydroalcoholic extract (HEP) of propolis from Scaptotrigona aff. postica on the solid Ehrlich tumor, on the tumor-bearing mice lymphoid organs and on the nitric oxide (NO) production. Swiss mice were divided in 4 groups: control, HEP 0.5; HEP 5 and HEP 50 that was treated by intraperitoneal route with a single dose of saline solution (NaCl 0.9 percent) or 0.5 or 5 or 50 mg of HEP/kg body weight, respectively. After 48 h of treatment, the animals were inoculated with 10(5) tumor cells in their footpad. The results showed that the treatment with HEP in the doses of 5 and 50 mg/kg inhibited the development of the tumor from the 6th day post inoculums when compared to the control and to the HEP 0.5 groups. Besides, there was an increase of spleen and bone marrow cell number in HEP 0.5 and HEP 5 as compared to the control. Concanavalin A (ConA)-stimulated NO production was decreased in all HEP-treated groups when compared to the control. In conclusion, the treatment with HEP had an anti-tumor effect what may be related to its chemical composition and to the inhibition of NO production.