OBJECTIVES: The aim of the present study was to characterize glycyrrhizic acid (GA) and assess its immunomodulatory potential in a model of experimental visceral leishmaniasis. METHODS: The antileishmanial activity of GA was tested in an amastigote-macrophage model and its non-cytotoxic dose was measured by a cell viability assay. To understand the effector mechanism of GA-treated macrophages against leishmanial parasites, real-time PCR analysis of inducible nitric oxide synthase 2 (iNOS2) was carried out followed by measurement of nitric oxide generation by Griess reagent. The effect of GA on the production of cytokines, such as interleukin (IL)-12, tumour necrosis factor (TNF)-α, IL-10 and transforming growth factor (TGF)-β, was measured by ELISA (protein) and real-time PCR. The expression of iNOS2 and cyclooxygenase-2 (Cox-2) was studied by western blotting. The parasite burden of the liver and spleen following GA treatment was determined by the stamp-smear method, and T cell proliferation was assessed via [³H]thymidine uptake, measured by a liquid scintillation counter. RESULTS: Results showed that GA treatment caused an enhanced expression of iNOS2 along with inhibition of Cox-2 in Leishmania donovani-infected macrophages. GA treatment in infected macrophages enhanced the expression of IL-12 and TNF-α, concomitant with a down-regulation of IL-10 and TGF-β. GA increased macrophage effector responses via inhibition of Cox-2-mediated prostaglandin E2 release in L. donovani-infected macrophages. GA also decreased hepatic and splenic parasite burden and increased T cell proliferation in Leishmania-infected BALB/c mice. CONCLUSIONS: These results provide a mechanistic understanding of GA-mediated protection against leishmanial parasites within the host.
OBJECTIVES: The aim of the present study was to characterize glycyrrhizic acid (GA) and assess its immunomodulatory potential in a model of experimental visceral leishmaniasis. METHODS: The antileishmanial activity of GA was tested in an amastigote-macrophage model and its non-cytotoxic dose was measured by a cell viability assay. To understand the effector mechanism of GA-treated macrophages against leishmanial parasites, real-time PCR analysis of inducible nitric oxide synthase 2 (iNOS2) was carried out followed by measurement of nitric oxide generation by Griess reagent. The effect of GA on the production of cytokines, such as interleukin (IL)-12, tumour necrosis factor (TNF)-α, IL-10 and transforming growth factor (TGF)-β, was measured by ELISA (protein) and real-time PCR. The expression of iNOS2 and cyclooxygenase-2 (Cox-2) was studied by western blotting. The parasite burden of the liver and spleen following GA treatment was determined by the stamp-smear method, and T cell proliferation was assessed via [³H]thymidine uptake, measured by a liquid scintillation counter. RESULTS: Results showed that GA treatment caused an enhanced expression of iNOS2 along with inhibition of Cox-2 in Leishmania donovani-infected macrophages. GA treatment in infected macrophages enhanced the expression of IL-12 and TNF-α, concomitant with a down-regulation of IL-10 and TGF-β. GA increased macrophage effector responses via inhibition of Cox-2-mediated prostaglandin E2 release in L. donovani-infected macrophages. GA also decreased hepatic and splenic parasite burden and increased T cell proliferation in Leishmania-infected BALB/c mice. CONCLUSIONS: These results provide a mechanistic understanding of GA-mediated protection against leishmanial parasites within the host.
Authors: Igor A Rodrigues; Ana Maria Mazotto; Verônica Cardoso; Renan L Alves; Ana Claudia F Amaral; Jefferson Rocha de Andrade Silva; Anderson S Pinheiro; Alane B Vermelho Journal: Mediators Inflamm Date: 2015-10-11 Impact factor: 4.711
Authors: Yasmina E Hernandez-Santana; Eduardo Ontoria; Ana C Gonzalez-García; M Antonieta Quispe-Ricalde; Vicente Larraga; Basilio Valladares; Emma Carmelo Journal: PLoS One Date: 2016-09-26 Impact factor: 3.240