• Parasites, Hosts and Diseases
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• 제53권4호
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• pp.385-394
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• 2015

Leishmaniasis is a worldwide uncontrolled parasitic disease due to the lack of effective drug and vaccine. To speed up effective drug development, we need powerful methods to rapidly assess drug effectiveness against the intracellular form of Leishmania in high throughput assays. Reporter gene technology has proven to be an excellent tool for drug screening in vitro. The effects of reporter proteins on parasite infectivity should be identified both in vitro and in vivo. In this research, we initially compared the infectivity rate of recombinant Leishmania major expressing stably enhanced green fluorescent protein (EGFP) alone or EGFP-luciferase (EGFP-LUC) with the wild-type strain. Next, we evaluated the sensitivity of these parasites to amphotericin B (AmB) as a standard drug in 2 parasitic phases, promastigote and amastigote. This comparison was made by MTT and nitric oxide (NO) assay and by quantifying the specific signals derived from reporter genes like EGFP intensity and luciferase activity. To study the amastigote form, both B10R and THP-1 macrophage cell lines were infected in the stationary phase and were exposed to AmB at different time points. Our results clearly revealed that the 3 parasite lines had similar in vitro infectivity rates with comparable parasite-induced levels of NO following interferon-${\gamma}$/lipopolysaccharide induction. Based on our results we proposed the more reporter gene, the faster and more sensitive evaluation of the drug efficiency.

• 대한수의학회지
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• 제41권2호
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• pp.211-218
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• 2001

병원성 내장리슈만편모충(Leishmania donovani)에서 추출한 GP63 또는 LPG 항원을 liposome으로 캡슐화하고 보강제로서 BCG를 조합하여 DBA-2N 마우스에 면역접종을 한 후, 내장리슈만편모충의 병원성 amastigote를 접종하여 이들 물질의 방어면역 효과를 관찰하였다. 그 결과 GP63 과 LPG, 그리고 BCG를 모두 첨가하여 접종한 마우스의 간 조직에서 유의성 있는 내장리슈만편모충의 감소가 관찰되었으나 감소율은 27.4%에 불과하였다. 실험적 피부리슈만편모충증에 대하여 성공적인 방어면역성을 나타낸 GP63이 내장리슈만편모충 감염에 대하여 방어면역성을 상실한 원인을 분석하기 위한 실험에서 C3H 마우스에 GP63-GST 단백질과 BCG를 혼합하여 면역접종하고 내장리슈만편모충의 병원성 amastigote로 접종한 후, 혈청 내 특이항체와 비장세포에서의 감마인터페론 및 IL-5의 생산을 관찰하였다. 그 결과 GP63-GST와 BCG를 혼합하여 면역 접종한 마우스의 간 조직에서도 유의성 있는 amastigote의 감소는 관찰되지 않았다. 한편 이들 마우스의 비장세포에서는 BCG 만을 접종한 군에 비해 10배 이상의 감마인터페론과 3배의 IL-5가 생산되었다. 이와 같은 사실은 GP63-GST 단백질과 BCG를 혼합하여 접종한 마우스에서 Th1 및 Th2 타입 면역반응이 모두 활성화되었음을 시사하며, Th1 뿐만 아니라 Th2 타입 면역 반응도 함께 활성화된 것이 실험적 내장리슈만편모충 감염에 대한 방어면역에 실패한 원인 중의 하나일 것으로 사료되었다.

• Parasites, Hosts and Diseases
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• 제53권1호
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• pp.21-27
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• 2015

Plants used for traditional medicine contain a wide range of substances that can be used to treat various diseases such as infectious diseases. The present study was designed to evaluate the antileishmanial effects of the essential oil and methanolic extract of Myrtus communis against Leishmania tropica on an in vitro model. Antileishmanial effects of essential oil and methanolic extract of M. communis on promastigote forms and their cytotoxic activities against J774 cells were evaluated using MTT assay for 72 hr. In addition, their leishmanicidal activity against amastigote forms was determined in a macrophage model, for 72 hr. Findings showed that the main components of essential oil were ${\alpha}$-pinene (24.7%), 1,8-cineole (19.6%), and linalool (12.6%). Findings demonstrated that M. communis, particularly its essential oil, significantly (P<0.05) inhibited the growth rate of promastigote and amastigote forms of L. tropica based on a dose-dependent response. The $IC_{50}$ values for essential oil and methanolic extract was 8.4 and $28.9{\mu}g/ml$ against promastigotes, respectively. These values were 11.6 and $40.8{\mu}g/ml$ against amastigote forms, respectively. Glucantime as control drug also revealed $IC_{50}$ values of 88.3 and $44.6{\mu}g/ml$ for promastigotes and amastigotes of L. tropica, respectively. The in vitro assay demonstrated no significant cytotoxicity in J774 cells. However, essential oil indicated a more cytotoxic effect as compared with the methanolic extract of M. communis. The findings of the present study demonstrated that M. communis might be a natural source for production of a new leishmanicidal agent.

• Parasites, Hosts and Diseases
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• 제48권3호
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• pp.245-246
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• 2010

Post kala-azar dermal leishmaniasis (PKDL) is a rare disease. This is a solitary case report from Orissa, India. We describe a case of PKDL in a 55-year-old male who presented with multiple nodular lesions over face, trunk, and extremities. The patient had been to an endemic area of kala-azar and had a previous history of leishmaniasis. Fine needle aspiration cytology samples from skin nodules revealed Leishmania amastigotes.

• Parasites, Hosts and Diseases
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• 제57권4호
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• pp.359-368
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• 2019

In this study, we carried out extensive in vitro studies on various concentrations of tioxolone along with benzoxonium chloride and their niosomal forms against Leishmania tropica. Niosomes were prepared by the hydration method and were evaluated for morphology, size, release study, and encapsulation efficiency. This study measured leishmanicidal activity against promastigote and amastigote, apoptosis and gene expression levels of free solution and niosomal-encapsulated tioxolone along with benzoxonium chloride. Span/Tween 60 niosome had good physical stability and high encapsulation efficiency (more than 97%). The release profile of the entrapped compound showed that a gradual release rate. The combination of niosomal forms on promastigote and amastigote were more effective than glucantime. Also, the niosomal form of this compound was significantly less toxic than glucantime ($P{\leq}0.05$). The flowcytometric analysis on niosomal form of drugs showed that higher number of early apoptotic event as the principal mode of action (89.13% in $200{\mu}g/ml$). Also, the niosomal compound increased the expression level of IL-12 and metacaspase genes and decreased the expression level of the IL-10 gene, which further confirming the immunomodulatory role as the mechanism of action. We observed the synergistic effects of these 2 drugs that induced the apoptotic pathways and also up regulation of an immunomodulatory role against as the main mode of action. Also, niosomal form of this combination was safe and demonstrated strong anti-leishmaniasis effects highlights further therapeutic approaches against anthroponotic cutaneous leishmaniasis in future planning.

• Parasites, Hosts and Diseases
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• 제47권2호
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• pp.109-115
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• 2009

This study investigated whether trinitroglycerine (TNG) as nitric oxide (NO) releasing agent had anti-leishmanial effects and mediated pathology in BALB/c mice infected with Leishmania major. Cutaneous leishmaniasis (CL), a zoonotic infection caused by leishmania protozoa is still one of the health problems in the world and in Iran. NO is involved in host immune responses against intracellular L. major, and leishmania killing by macrophages is mediated by this substance. Moreover, application of CL treatment with NO-donors has been recently indicated. In our study, TNG was used for its ability to increase NO and to modify CL infection in mice, in order to evaluate NO effects on lesion size and formation, parasite proliferation inside macrophages, amastigote visceralization in target organs, and NO induction in plasma and organ suspensions. Data obtained in this study indicated that TNG increased plasma and liver-NO, reduced lesion sizes, removed amastigotes from lesions, livers, spleens, and lymph nodes, declined proliferation of amastigotes, hepatomegaly, and increased survival rate. However, TNG reduced spleen-NO and had no significant effects on spelenomegaly. The results show that TNG therapy reduced leishmaniasis and pathology in association with raised NO levels. TNG had some antiparasitic activity by reduction of positive smears from lesions, livers, spleens, and lymph nodes, which could emphasize the role of TNG to inhibit visceralization of L. major in target organs.

• Parasites, Hosts and Diseases
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• 제54권1호
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• pp.9-14
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• 2016

Tamoxifen is an antagonist of the estrogen receptor and currently used for the treatment of breast cancer. The current treatment of cutaneous leishmaniasis with pentavalent antimony compounds is not satisfactory. Therefore, in this study, due to its antileishmanial activity, effects of tamoxifen on the growth of promastigotes and amastigotes of Leishmania major Iranian strain were evaluated in vitro. Promastigotes and amastigotes were treated with different concentrations (1, 5, 10, 20, and $50{\mu}g/ml$) and time periods (24, 48, and 72 hr) of tamoxifen. After tamoxifen treatment, MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5 biphenyl tetrazolium bromide assay) was used to determine the percentage of live parasites and Graph Pad Prism software to calculate $IC_{50}$. Flow cytometry was applied to investigate the induction of tamoxifen-induced apoptosis in promastigotes. The half maximal inhibitory concentration ($IC_{50}$) of tamoxifen on promastigotes was $2.6{\mu}g/ml$ after 24 hr treatment. Flow cytometry analysis showed that tamoxifen induced early and late apoptosis in Leishmania promastigotes. While after 48 hr in control group the apoptosis was 2.0%, the $50{\mu}g/L$ concentration of tamoxifen increased it to 59.7%. Based on the in vitro antileishmanial effect, tamoxifen might be used for leishmaniasis treatment; however, further researches on in vivo effects of tamoxifen in animal models are needed.