Leishmaniasis is a zoonotic disease caused by protozoan parasites of the genus Leishmania.Conventional chemotherapy remains to be the most preferred measure against leishmaniasis despite being associated with high tox...Leishmaniasis is a zoonotic disease caused by protozoan parasites of the genus Leishmania.Conventional chemotherapy remains to be the most preferred measure against leishmaniasis despite being associated with high toxicity and relapse rates.They are also expensive and require hospitalization.Plant-based compounds provide a better treatment alternative because they are effective,cheap,and less associated with toxicity and resistance.This study examined the therapeutic potential of Warburgia ugandensis,Prunus africana,and Piliostigma thonningii against Leishmania donovani infection in BALB/c mice.Anti-promastigote and toxicity studies were evaluated by incubating the test compound with promastigotes and Vero cells,respectively.Serum was obtained from the mice for total immunoglobulin gamma(IgG)quantification.For in vivo studies,the mice were infected with virulent Leishmania donovani then treated with methanolic extracts of Warburgia ugandensis,Prunus africana,and Piliostigma thonningii and control drug,pentostam(sodium stibogluconate).Treatment with the plant extracts and standard drug resulted to significant reduction in parasite burden.Outcomes in the mice treated with plant extracts were comparable to those treated with pentostam(P≥0.05).In the promastigote assay,all the test compounds killed more than half of the promastigotes at the highest concentration(500μg/mL).Warburgia ugandensis,P.thonningii,and P.africana reduced the number of promastigotes from 2.0×10^(6) to 7.7×10^(3),72.0×10^(3),and 5.0×10^(3),respectively.Pentostam had the lowest IC50(210μg/mL),followed by Warburgia ugandensis(IC50 of 270μg/mL).Piliostigma thonningii and P.africana were less toxic with IC50 of 720μg/mL and 500μg/mL,respectively.There was low production of IgG antibodies following treatment with the plant extracts and high levels in the untreated control.展开更多
AIM: The anti-leishmanial activity of methanolic extracts of Calendula officinalis flowers, Datura stramonium seeds, and Salvia officinalis leaves against extracellular(promastigote) and intracellular(amastigote) form...AIM: The anti-leishmanial activity of methanolic extracts of Calendula officinalis flowers, Datura stramonium seeds, and Salvia officinalis leaves against extracellular(promastigote) and intracellular(amastigote) forms of Leishmania major were evaluated in this study. METHOD: In the first stage, promastigote forms of L. major, were treated with different doses of the plant extracts in a 96-well tissue-culture microplate and IC50 values for each extract were measured with colorimetric MTT assay. In the second stage, macrophage cells were infected with L. major promastigotes. Infected macrophages were treated with plant extracts. Then the macrophages were stained with Gimsa and the number of infected macrophages and amastigotes were counted with a light microscope. RESULTS: The results indicated that the plant extracts inhibited the growth of promastigotes and amastigotes of L. major. Inhibitory concentrations(IC50) for promastigote assay were 108.19, 155.15, and 184.32 μg·mL-1 for C. officinalis flowers, D. stramonium seeds and S. officinalis, respectively. The extracts also reduced the number of amastigotes in macrophage cells from 264 for control group to 88, 97, and 102 for test groups. Although the anti-leishmanial activity of the extracts were not comparable with the standard drug, miltefosine; but they showed significant efficiency in reducing the number of amastigotes in macrophages, in comparison with the control group(P < 0.001). These plant extracts had lower toxicity compared with miltefosine. CONCLUSION: This study demonstrates the potential efficacy of the methanolic extracts of C. officinalis flowers, D. stramonium seeds, and S. officinalis leaves to control of cutaneous leishmaniasis.展开更多
Leishmania parasites undergo a dimorphic life cycle.Diagnosis of cutaneous leishmaniasis(CL)is primarily made by the microscopic identification of the amastigote form of the parasite in a smear.Therefore,correct ident...Leishmania parasites undergo a dimorphic life cycle.Diagnosis of cutaneous leishmaniasis(CL)is primarily made by the microscopic identification of the amastigote form of the parasite in a smear.Therefore,correct identification of Leishman-Donovan(LD)bodies in smears is crucial for CL confirmation.The aim of this study was to provide a broad overview of different cytomorphologies of LD bodies to improve the sensitivity of microscopic detection of Leishmania donovani,which causes CL in Sri Lanka.A total of 125 smears,prepared from patients who met the positive diagnostic criteria of CL,were Giemsa stained and examined microscopically.The density,cellular location and all possible cytomorphological forms of the parasite were documented.A total of 10 different cytomorphological forms of LD bodies were identified.Among them,the round form was observed only intracellularly.The other morphological forms,namely the pear shape,cigarette shape,candle flame form,embryo shape,flagellate form,binary form and rosette form,were found only extracellularly.The spindle form and lens shape were observed in both intracellular and extracellular locations.L.donovani amastigotes have a wide range of morphologies besides their classical forms.Although Leishmania are considered as obligatory intracellular parasites,theymanage to survive successfully within the extracellular hostile conditions as well.Therefore,having a broader view of different morphological forms for Leishmania parasites may help to improve diagnosis of CL.展开更多
Background:Leishmaniasis causes alterations and lesions in the genital system,which leads to azoospermia and testicular atrophy in animals during the chronic phase of the infection.The aim of this study was to reveal ...Background:Leishmaniasis causes alterations and lesions in the genital system,which leads to azoospermia and testicular atrophy in animals during the chronic phase of the infection.The aim of this study was to reveal the kinetics of Leishmania chagasi infection in the genital system of male golden hamsters(Mesocricetus auratus).Methods:Animals were intraperitoneally inoculated with amastigotes from L.chagasi.At different time points animals were euthanized and genital organs processed for histo-pathological,qPCR,cytokines and testosterone detection assays.Results:Our results showed a high parasite load in testis,followed by an increase of pro-inflammatory cytokines IL1-β,TNF-αand IFN-γ,and testosterone.Subsequently,IL-4 expression was upregulated and basal parasite persistence in testis was observed using the experimental approach.Conclusion:Extracellular amastigotes migrated to the epididymis posing as a potential major factor of parasite persistence and venereal transmission of L.chagasi infection in hamsters.展开更多
文摘Leishmaniasis is a zoonotic disease caused by protozoan parasites of the genus Leishmania.Conventional chemotherapy remains to be the most preferred measure against leishmaniasis despite being associated with high toxicity and relapse rates.They are also expensive and require hospitalization.Plant-based compounds provide a better treatment alternative because they are effective,cheap,and less associated with toxicity and resistance.This study examined the therapeutic potential of Warburgia ugandensis,Prunus africana,and Piliostigma thonningii against Leishmania donovani infection in BALB/c mice.Anti-promastigote and toxicity studies were evaluated by incubating the test compound with promastigotes and Vero cells,respectively.Serum was obtained from the mice for total immunoglobulin gamma(IgG)quantification.For in vivo studies,the mice were infected with virulent Leishmania donovani then treated with methanolic extracts of Warburgia ugandensis,Prunus africana,and Piliostigma thonningii and control drug,pentostam(sodium stibogluconate).Treatment with the plant extracts and standard drug resulted to significant reduction in parasite burden.Outcomes in the mice treated with plant extracts were comparable to those treated with pentostam(P≥0.05).In the promastigote assay,all the test compounds killed more than half of the promastigotes at the highest concentration(500μg/mL).Warburgia ugandensis,P.thonningii,and P.africana reduced the number of promastigotes from 2.0×10^(6) to 7.7×10^(3),72.0×10^(3),and 5.0×10^(3),respectively.Pentostam had the lowest IC50(210μg/mL),followed by Warburgia ugandensis(IC50 of 270μg/mL).Piliostigma thonningii and P.africana were less toxic with IC50 of 720μg/mL and 500μg/mL,respectively.There was low production of IgG antibodies following treatment with the plant extracts and high levels in the untreated control.
文摘AIM: The anti-leishmanial activity of methanolic extracts of Calendula officinalis flowers, Datura stramonium seeds, and Salvia officinalis leaves against extracellular(promastigote) and intracellular(amastigote) forms of Leishmania major were evaluated in this study. METHOD: In the first stage, promastigote forms of L. major, were treated with different doses of the plant extracts in a 96-well tissue-culture microplate and IC50 values for each extract were measured with colorimetric MTT assay. In the second stage, macrophage cells were infected with L. major promastigotes. Infected macrophages were treated with plant extracts. Then the macrophages were stained with Gimsa and the number of infected macrophages and amastigotes were counted with a light microscope. RESULTS: The results indicated that the plant extracts inhibited the growth of promastigotes and amastigotes of L. major. Inhibitory concentrations(IC50) for promastigote assay were 108.19, 155.15, and 184.32 μg·mL-1 for C. officinalis flowers, D. stramonium seeds and S. officinalis, respectively. The extracts also reduced the number of amastigotes in macrophage cells from 264 for control group to 88, 97, and 102 for test groups. Although the anti-leishmanial activity of the extracts were not comparable with the standard drug, miltefosine; but they showed significant efficiency in reducing the number of amastigotes in macrophages, in comparison with the control group(P < 0.001). These plant extracts had lower toxicity compared with miltefosine. CONCLUSION: This study demonstrates the potential efficacy of the methanolic extracts of C. officinalis flowers, D. stramonium seeds, and S. officinalis leaves to control of cutaneous leishmaniasis.
文摘Leishmania parasites undergo a dimorphic life cycle.Diagnosis of cutaneous leishmaniasis(CL)is primarily made by the microscopic identification of the amastigote form of the parasite in a smear.Therefore,correct identification of Leishman-Donovan(LD)bodies in smears is crucial for CL confirmation.The aim of this study was to provide a broad overview of different cytomorphologies of LD bodies to improve the sensitivity of microscopic detection of Leishmania donovani,which causes CL in Sri Lanka.A total of 125 smears,prepared from patients who met the positive diagnostic criteria of CL,were Giemsa stained and examined microscopically.The density,cellular location and all possible cytomorphological forms of the parasite were documented.A total of 10 different cytomorphological forms of LD bodies were identified.Among them,the round form was observed only intracellularly.The other morphological forms,namely the pear shape,cigarette shape,candle flame form,embryo shape,flagellate form,binary form and rosette form,were found only extracellularly.The spindle form and lens shape were observed in both intracellular and extracellular locations.L.donovani amastigotes have a wide range of morphologies besides their classical forms.Although Leishmania are considered as obligatory intracellular parasites,theymanage to survive successfully within the extracellular hostile conditions as well.Therefore,having a broader view of different morphological forms for Leishmania parasites may help to improve diagnosis of CL.
基金supported by grants and fellowships from Fundação de AmparoàPesquisa do Estado de Minas Gerais,Conselho Nacional de Desenvolvimento Científico e Tecnológico,and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.
文摘Background:Leishmaniasis causes alterations and lesions in the genital system,which leads to azoospermia and testicular atrophy in animals during the chronic phase of the infection.The aim of this study was to reveal the kinetics of Leishmania chagasi infection in the genital system of male golden hamsters(Mesocricetus auratus).Methods:Animals were intraperitoneally inoculated with amastigotes from L.chagasi.At different time points animals were euthanized and genital organs processed for histo-pathological,qPCR,cytokines and testosterone detection assays.Results:Our results showed a high parasite load in testis,followed by an increase of pro-inflammatory cytokines IL1-β,TNF-αand IFN-γ,and testosterone.Subsequently,IL-4 expression was upregulated and basal parasite persistence in testis was observed using the experimental approach.Conclusion:Extracellular amastigotes migrated to the epididymis posing as a potential major factor of parasite persistence and venereal transmission of L.chagasi infection in hamsters.
