Tropical Medicine

Pharmacological and analytical aspects of artemisinin for malaria: Advances and challenges Sravani Karri, Sanjay Sharma, Ginpreet Kaur Asian Pacific Journal of Tropical Medicine 2019 12(8):339-346 Malaria remains a major tropical health burden owing to the development of resistance and decreased sensitivity to the frequently used conventional antimalarial drugs. The drug like artemisinin possesses potent antimalarial activities, but has some limitations. Therefore, new strategies are to be implemented for optimal utilization of artemisinin to improve its therapeutic effectiveness and to overcome its limitations. The present review focuses on present scenario of malaria and pharmacological as well as analytical aspects of artemisinin. Data from 2000 to 2018 were collected from NCBI for understanding the various analytical techniques used for estimation of artemisinin. This review will reveal the facts about artemisinin which can be utilized to develop novel drug delivery system either in a combination or as alone for the wellbeing of the patients suffering from malaria.

The cholera epidemic of 2004 in Douala, Cameroon: A lesson learned Christoph J Hemmer, Jürgen Nöske, Stefan Finkbeiner, Günter Kundt, Emil C Reisinger Asian Pacific Journal of Tropical Medicine 2019 12(8):347-352 Objective: To describe the outbreak of 2004 with a view of retrospectively identifying factors that might explain the low case fatality rate. Methods: Outbreak data from 4 915 Cholera patients from registers of the Regional Health Delegation in Douala were analyzed using SPSS. Chi-square test, univariate and multivariate analysis were applied. Results: The outbreak started January 2004, peaking at 187 cases per week in February. After a decrease in April, case numbers rose to 688 cases per week in June. The outbreak was over in September 2004 ( <10 cases per week). The case fatality rate was higher in treatment centers with fewer than one nurse per two patients, than in those with more nursing staff. A temporary staff reduction after the first wave of the epidemic was associated with the increase of the case fatality rate during the second wave. This increase was reversed after re-instating full staff capacity. Conclusions: Providing sufficient nursing staff helps to lower the case fatality rate of cholera. Besides a lack of staff, age above 40 years is a risk factor for death in this disease.

Evaluation of in vitro and in vivo immunostimulatory activities of poly (lactic-co-glycolic acid) nanoparticles loaded with soluble and autoclaved Leishmania infantum antigens: A novel vaccine candidate against visceral leishmaniasis Emrah Sefik Abamor, Adil Allahverdiyev, Ozlem Ayse Tosyali, Melahat Bagirova, Tayfun Acar, Zeynep Mustafaeva, Serap Derman Asian Pacific Journal of Tropical Medicine 2019 12(8):353-364 Objective: To prepare and characterize poly lactic-co-glycolic acid (PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of antigen encapsulated nanoparticles. Methods: Water/oil/water double emulsion technique was employed to synthesize PLGA nanoparticles, and scanning electron microscopy, Fourier transform infrared spectroscopy and Zeta-potential measurements were used to identify the characteristics of nanoparticles. Cytotoxicity of synthetized nanoparticles on J774 macrophage were investigated by MTT assays. To determine the in vitro immunostimulatory efficacies of nanoparticles, griess reaction and ELISA was used to measure the amounts of NO and cytokines. During the in vivo analysis, Balb/c mice were immunized with vaccine formulations, and protective properties of nanoparticles were measured by Leishman Donovan unit in the liver following the infection. Cytokine levels in spleens of mice were determined by ELISA. Results: MTT assay showed that neither soluble leishmanial antigen nor autoclaved leishmanial antigen encapsulated nanoparticles showed cytotoxicity against J774 macrophage cells. Contrary to free antigens, both autoclaved leishmanial antigen-nanoparticle and soluble leishmanial antigen-nanoparticle formulations led to a 10 and 16-fold increase in NO amounts by macrophages, respectively. Leishman Donovan unit calculations revealed that soluble leishmanial antigen-nanoparticles and autoclaved leishmanial antigen-nanoparticles yielded 52% and 64% protection against visceral leishmaniasis in mouse models. Besides, in vitro and in vivo tests demonstrated that by increasing IFN-γ and IL-12 levels and inhibiting IL-4 and IL-10 secretions, autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigennanoparticles triggered Th1 immune response. Conclusions: Both autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigen-nanoparticles formulations provide exceptional in vitro and in vivo immunostimulatory activities. Hence, PLGA-based antigen delivery systems are recommended as potential vaccine candidates against visceral leishmaniasis.

Tioxolone niosomes exert antileishmanial effects on Leishmania tropica by promoting promastigote apoptosis and immunomodulation Maryam Hakimi Parizi, Iraj Sharifi, Saeedeh Farajzadeh, Abbas Pardakhty, Mohammad Hossein Daie Parizi, Hamid Sharifi, Ali Reza Keyhani, Mahshid Mostafavi, Mehdi Bamorovat, Ahmad Khosravi, Daryoush Ghaffari Asian Pacific Journal of Tropical Medicine 2019 12(8):365-374 Objective: To explore the antileishmanial effect of tioxolone and its niosomal form against Leishmania tropica. Methods: Tioxolone niosomes were prepared by the hydration method and were evaluated for morphology, size, release study, and encapsulation efficiency. The cytotoxicity of tioxolone and its niosomal form was measured by MTT assay, leishmanicidal activity against promastigote and amastigote by MTT assay, apoptosis by flow cytometry, IL-12, IL-10 and metacaspase gene expression levels by q-PCR. Results: Span/Tween 40 and Span/Tween 60 niosomes had good physical stability as depicted in their size distribution curves and high encapsulation efficiency (>99%). The release profile of the entrapped compounds showed Fickian’s model of tioxolone delivery based on diffusion through lipid bilayers. With the IC50 value for amastigote as (24.5±2.1) μg/mL and selectivity index as 10.5, the Span/Tween 60 niosome (NT2) had a superior effect to other drugs. The CC50 value and IC50 of promastigote value for NT2 were (257.5±24.5) μg/mL and (164.8±20.6) μg/ mL, respectively. The flow cytometric analysis showed that tioxolone and niosomal forms induced apoptosis of Leishmania tropica promastigotes in a dose-dependent manner. NT2 increased the expression level of IL-12 and metacaspase genes and decreased the expression level of the IL-10 gene. Conclusions: Niosomes of tioxolone play an immunomodulatory role in increasing Th1 cytokine profile and inhibiting the Th2 cytokine profile. It could be used for treatment of anthroponotic cutaneous leishmaniasis.

Molecular identification of hemoplasmas in free ranging non–human primates in Thailand Parut Suksai, Supakarn Kaewchot, Piya Sereerak, Sirinan Boonnan, Bongkotchamat Phimsin, Taksina Jaruwattananon, Kacharin Raschasin, Mutchamon Kaewparuehaschai, Sorraya Siriphet, Benjaporn Bhusri Asian Pacific Journal of Tropical Medicine 2019 12(8):375-379 Objective: To survey hemoplasmas infection in free ranging non-human primates from 8 provinces in Thailand. Methods: DNA from ethylenediaminetetraacetic acid blood of 262 free ranging non-human primates were identified as hemoplasmas using PCR and phylogenetic analysis based on 16S rRNA and rnpB genes. Results: A total of 148 non-human primates (56.49%) were determined positive for Candidatus Mycoplasma haemomacaque, including 125 Macaca fascicularis and 23 Macaca mulatta. Hemoplasmas can cause anemia in monkey but all positive samples were healthy. The positive rates in male and female non-human primates were not significantly different. Conclusions: Candidatus Mycoplasma infection is prevalent in free ranging Macaca fascicularis and Macaca mulatta in Thailand.

Chlamydoconidium-producing Trichophyton tonsurans: Atypical morphological features of strains causing tinea capitis in Ceará, Brazil Raimunda Sâmia Nogueira Brilhante, Germana Costa Paixäo, Jonathas Sales de Oliveira, Vandbergue Santos Pereira, Marcos Fábio Gadelha Rocha, Reginaldo Gonçalves de Lima-Neto, Debora de Souza Collares Maia Castelo-Branco, Rossana de Aguiar Cordeiro, Jose Julio Costa Sidrim Asian Pacific Journal of Tropical Medicine 2019 12(8):380-384 Objective: To report atypical morphological features of Trichophyton (T.) tonsurans strains associated with tinea capitis. Methods: Eighty-two T. tonsurans strains isolated in Ceará, Brazil, were analyzed regarding macro and micromorphological features and nutritional patterns. Results: Fifty-two samples presented abundant chlamydoconidia, which were produced in chains. Macroscopically, these strains developed small glabrous colonies that were firmly attached to the surface of the culture medium, with few or no aerial mycelia and intense rusty yellow pigmentation. Seven strains did not grow with stimulus from thiamine. Samples were heterogeneous regarding urease production and none presented in vitro hair perforation. Conclusions: The observation of T. tonsurans strains with distinct phenotypic features indicates the need to revise the taxonomic criteria for routine identification of this dermatophyte.