RESUMO
Due to the increasing resistance to common medicinal compounds, the use of medicinal plants has received special attention. Therefore, the current survey was designed to study the antileishmanial effects of Nectaroscordum koelzi Trautv. methanolic extract against Leishmania major. In this study, after preparing the methanolic extract of N. koelzi, its effect on the amastigotes of L. major and triggering the nitric oxide (NO) were measured. Then, the in vivo effect of the methanol extract on cutaneous leishmaniasis in mice was evaluated. The best anti-amastigote effect was for the methanol extract of N. koelzi along with meglumine antimony with 50% inhibitory concentrations value of 17.4 µg/ml (p < 0.001). The 50% cytotoxic concentrations values of methanol extract, meglumine antimoniate, and methanol extract + meglumine antimoniate were 596.3, 784.6, and 296.4 µg/ml, respectively. Macrophages treated with the methanolic extract markedly (p < 0.001) induced the release of nitric oxide. After 28 days of treatment, lesions were completely (p < 0.001) healed in mice treated with the methanolic extract (100 mg/kg) + meglumine antimoniate (25 mg/kg). N. koelzi methanolic extract mainly in combination with meglumine antimoniate showed favorable antileishmanial effects on L. major, concluding that the methanolic extract of N. koelzi can be used for the production of new leishmanicidal agents agaist cutaneous leishmaniasis. Although we revealed that NO trigerring and inhibition of infection in host cells are the antileishmanial mechanism action of N. koelzi methanolic extract, more studies must be performed to clear the mechanisms and its safety.
RESUMO
BACKGROUND: Today, a suitable vaccine has not yet been discovered to prevent Toxoplasma gondii infection. Therefore, prophylaxis can be suggested as the preferred approach to prevent toxoplasmosis. This study aims to evaluate the prophylactic effects of synthesized zinc nanoparticles (ZnNPs) using Lavandula angustifolia Vera., by microwave method on chronic toxoplasmosis in mice. METHODS: BALB/c Mice orally administrated with ZnNPs the doses of 32.5, 75, 150 mg/kg/day for two weeks. On the 15th day, the mice were intraperitoneally infected with the Tehran strain of T. gondii (25 tissue cysts). The mean diameter and the numbers of brain tissue cysts, as well as the mRNA levels of inducible nitric oxide synthesize (iNOs), and interferon-gamma (IFN-γ) in mice of each experimental group were evaluated. RESULTS: The synthesized ZnNPs represent a spherical form with a size ranging from 30 to 80 nm. The results revealed that oral administration of Zn NPs at the doses of 32.5 (p < 0.001) and 75 mg/kg/day (p < 0.001) for 14 days significantly reduced the mean number and diameter of the brain tissue cysts in tested mice. No T. gondii tissue cyst was observed after oral administration of Zn NPs at the doses of 150 mg/kg. Based on the results of Real-time PCR analysis, the expression level of IFN-γ and iNOs was significantly increased (p < 0.001) in mice treated with 32.5, 75, 150 mg/kg/day for two weeks. CONCLUSION: The obtained findings of the current investigation exhibit the significant prophylactic effects of ZnNPs against chronic toxoplasmosis in mice; so that oral administration of ZnNPs the doses 32.5, 75, 150 mg/kg reduced the parasite load and even completely controlled the infection in mice. The results show that the ZnNPs had strengthened the innate immune system which could be the reason for its strong prophylactic effects. However, further in vivo and clinical investigations are required to confirm these results as well as other possible mechanisms that can trigger these pharmacological properties.