RESUMO
Cisplatin is a widely used chemotherapeutic drug, but its side effects are a major limiting factor. Nephrotoxicity occurs in one third of patients undergoing cisplatin treatment. The acute tubular injury caused by cisplatin often leads to a defective repair process, which translates into chronic renal disorders. In this way, cisplatin affects tubular cells, and maladaptive tubules regeneration will ultimately result in tubulointerstitial fibrosis. Kinins are well known for being important peptides in the regulation of inflammatory stimuli, and kinin B1 receptor deficiency and antagonism have been shown to be beneficial against acute cisplatin nephrotoxicity. This study aimed to analyze the effects of kinin B1 receptor deletion and antagonism against repeated cisplatin-induced chronic renal dysfunction and fibrosis. Both the deletion and the antagonism of B1 receptor exacerbated cisplatin-induced chronic renal dysfunction. Moreover, the inhibition of B1 receptor increased tubular injury and tubulointerstitial fibrosis after repeated treatment with cisplatin. The balance between M1/M2 macrophage polarization plays an important role in renal fibrosis. Kinin B1 receptor antagonism had no impact on M1 markers when compared to cisplatin. However, YM1, an M2 marker and an important molecule for the wound healing process, was decreased in mice treated with kinin B1 receptor antagonist, compared to cisplatin alone. Endothelin-1 levels were also increased in mice with B1 receptor inhibition. This study showed that kinin B1 receptor inhibition exacerbated cisplatin-induced chronic renal dysfunction and fibrosis, associated with reduced YM1 M2 marker expression, thus possibly affecting the wound healing process.
RESUMO
We determined the inhibitory allelopathic effects of the volatile extracts of Cinnamomum zeylanicum Ness, Lippia sidoides Cham. and Cymbopogum nardus L. on seed germination and root growth of seedlings of Bidens pilosa. The experiment was conducted at the Seed Analysis Laboratory of the Department of Plant Science, Federal University of Ceará. For this end, we used oils at the concentrations of 0.01, 0.02, 0.04 and 0.08% (v/v). Five treatments were used for each of the oils arranged in a completely randomized design with four replications of 25 seeds. The seeds were sown in Petri dishes lined with filter paper moistened with distilled water and, aiming at the indirect contact with each oil, two sheets of filter paper were placed on top of the lid, in which three (3) mL of each oil solution were added. Then, the dishes were incubated in a germination chamber at 25°C. The pH did not contribute to alter the results; the volatile extracts of essential oils of C. zeylanicum, L. sidoides and C. nardus inhibited seed germination and root growth of seedlings of B. pilosa, which shows allelopathic potential; and the concentration of 0.08% of oils caused the overall deterioration of the roots and death of seedlings of B. pilosa.
Determinou-se o efeito alelopático inibitório dos extratos voláteis de Cinnamomum zeylanicum Ness, Lippia sidoides Cham. e Cymbopogum nardus L., sobre a germinação de sementes e o crescimento de raiz de plântulas de Bidens pilosa. O experimento foi conduzido no Laboratório de Análises de Sementes do Departamento de Fitotecnia da Universidade Federal do Ceará. Para isso, utilizaram-se óleos essenciais nas concentrações 0,01, 0,02, 0,04 e 0,08%. (v/v). Foram utilizados cinco tratamentos para cada óleo dispostos em delineamento inteiramente casualizado com quatro repetições de 25 sementes. As sementes foram semeadas em placas de Petri forradas com papel de filtro umedecido com água destilada e, visando o contato indireto com cada óleo, foram colocadas duas folhas de papel de filtro na parte superior interna da tampa, onde foi adicionado 3(três) mL da solução de cada óleo. Em seguida, as placas foram incubadas em câmara de germinação a 25ºC. O pH não contribuiu para alterar os resultados; os extratos voláteis de óleos essenciais de C. zeylanicum, L. sidoides and C. nardus inibiram a germinação de sementes e o crescimento da raiz de plântulas de B. pilosa, evidenciando potencial alelopático; a concentração de 0,08% dos óleos causaram a deterioração total das raízes e morte das plântulas de B. pilosa.
