Synthesis of Tellurium Oxide (TeO2) Nanorods and Nanoflakes and Evaluation of Its Efficacy Against Leishmania major In Vitro and In Vivo.

PURPOSE: Today, the use of natural products and nanostructures has increased. Given the reports on beneficial effects of various organotellurane compounds on types of visceral leishmaniasis, we decided to investigate the effect of TeO2 NPs on Leishmania major (L. major). Tellurium can cause cell apoptosis in cancer cells without activating the caspase-pathway. METHODS: TeO2 NPs at first synthesized and the structure was checked by XRD, SEM and EDS tests. The cytotoxic effect of TeO2 NPs against L. major promastigotes, amastigotes and macrophages was assessed by MTT test or counting. The possible apoptosis of L. major by TeO2 NPs was evaluated by flow cytometry test. For in vivo assay, the lesions of infected BALB/c mice with L. major promastigotes were treated with TeO2 NPs, then the lesion size and survival rate were evaluated. RESULTS: The synthesis of TeO2 with tetragonal structure was confirmed by XRD. The combination of nanorods and nanoflakes and the presence of Te were proven by SEM and EDS, respectively. According the effects of nanoparticle on promastigotes and amastigotes, the IC50 values of TeO2 after 72 h of incubation were 15.13 and 52.22 µg/ml, respectively. TeO2 NPs induced apoptosis in about 41% of promastigotes. The ulcer greatly healed and survival rate was higher in treated mice compared to those in control group. CONCLUSION: Based on the data, favorable anti-leishmanial properties were observed by using TeO2 NPs. TeO2 NPs have cytotoxic impacts on L. major promastigotes and amastigotes in vitro and in vivo and may be regarded as a therapy option.

Comparison of the Effects of Sambucus ebulus Leaf and Fruit Extracts on Leishmania major In Vitro.

BACKGROUND: Leishmaniasis is one of the major diseases caused by the intracellular parasite of Leishmania. It has become one of the most dangerous health problems today. Our aim of the present study is to compare the effects of Sambucus ebulus leaf and fruit extracts on Leishmania major in vitro. METHODS: In this study, we used MTT, promastigote and amastigote assay to evaluate the effect of different concentrations of the extract on parasite and we compared their effects. The flow cytometry technique was also used to detect the apoptotic effect of the extracts on promastigotes. RESULTS: According to MTT experiment IC50 concentration of leaf and fruit extracts on parasite was 157 µg/ml and 265 µg/ml, respectively. After analysis by flow cytometry, leaf and fruit extracts also showed the apoptosis effect. Leaf and fruit extract caused 40.2 and 2.67 percent apoptosis. CONCLUSION: Based on the above assessment, we determined that the S. ebulus leaf extract has a more toxic effect on promastigotes and amstigotes than its fruit extract and maybe in the future that be used as a drug candidate.

Efficacy of green synthesized silver nanoparticles via ginger rhizome extract against Leishmania major in vitro.

INTRODUCTION: Leishmaniasis is a major public health problem that causes by parasite of the genus Leishmania. The pentavalent antimonial compounds that used for treatment are not safe or effective enough. The aim of the present study was preparation and evaluation of the efficacy of green synthesized silver nanoparticles against Leishmania major (L. major) in vitro. METHODS: To synthesis silver (Ag) nanoparticles (NPs), ginger extract was added to the 0.2mM AgNO3 aqueous solution (1:20). Effects of different concentrations of Ag-NPs on the number of L. major promastigotes were investigated using counting assay. The MTT test was applied to determine the toxicity of Ag-NPs on promastigotes of L. major, as well as, macrophage cells. Then, to evaluate the anti-amastigotes effects of Ag-NPs, parasites within the macrophages were counted by light microscope. Furthermore, to determine the induced apoptosis and necrotic effects of Ag-NPs on promastigotes, flow cytometry method was employed using annexin staining. RESULTS: The effect of Ag-NPs on promastigotes and amastigotes of L. major was effective and has a reverse relationship with its concentration. According to the results of anti-amastigote assay, the IC50 value of this nanoparticle was estimated 2.35 ppm after 72h. Also, Ag-NPs caused Programmed Cell Death (PCD) in promastigotes of L. major and showed 60.18% of apoptosis. DISCUSSION: Based on the mentioned results, it can be concluded that Ag NPs has a beneficial effect on promastigote and amastigote forms of L. major in vitro. Hence, these nanoparticles could be applied as promising antileishmanial agents for treatment of Leishmania infections.

Efficacy of manganese oxide (Mn2O3) nanoparticles against Leishmania major in vitro and in vivo.

BACKGROUND: The pentavalent antimonial compounds are the first drug of choice for leishmania infection, but have several side effects that cause some restriction for use. Extension of nanoparticle use in biological research and proven effectiveness of manganese nanoparticles on fungi and bacteria, along with the lack of information about its antileishmanial effects, have motivated this study. Manganese can induce cell apoptosis by increasing FOXO3a-Bim/PUMA mRNA activation and activating of caspase-3 pathway. METHODS: This study was aimed to examine the efficacy of manganese oxide nanoparticles againstLeishmania major (MRHO/IR/75/ER) in vitro and in vivo. To evaluate the antileishmanial activity of NPs, light microscopic observation was used to determine the number of remaining parasites in each well. The MTT test was used to determine the cytotoxicity effects of Mn2O3 NPs against L. major promastigotes and macrophage cells. The effect of nanoparticles on cultured amastigotes under in vitro conditions was also investigated. The possible apoptosis of L. major by Mn2O3 NPs was evaluated with flow cytometry assay. Additionally, the preventive and therapeutic effects of Mn2O3 NPs in BALB/c mice following cutaneous L. major infection was tested. The effect of Mn2O3 NPs on promastigotes and amastigotes were proven by MTT assay and amastigote assay, respectively. RESULTS: The IC50 value of Mn2O3 NPs against L. major promastigotes and macrophages was 15 and 40 µg ml-1 respectively. The results of flow cytometry showed about 57% of the promastigotes were induced to apoptosis with Mn2O3 NPs. In in vivo studies, the size of the ulcers were significantly reduced, and the survival rate of the mice, in comparison with the control group, was increased. CONCLUSION: Mn2O3 NPs has a beneficial effect on L. major promastigotes in vitro and in vivo and could be considered as a candidate for the treatment of this infection.