Treatment Outcome of the Drug-resistant Zoonotic Cutaneous Leishmaniasis by Glucantime

Cutaneous leishmaniasis situation analysis in the Islamic Republic of Iran in preparation for an elimination plan

Iran has invariably been under the growing public health threat of cutaneous leishmaniasis (CL), a significant barrier to local development that hinders the prevention and control efforts toward eliminating the disease. So far, no comprehensive and in-depth epidemiological analysis of the CL situation has been carried out nationwide. This study aimed to employ advanced statistical models to analyze the data collected through the Center for Diseases Control and Prevention of Communicable Diseases during 1989-2020. However, we emphasized the current trends, 2013-2020, to study temporal and spatial CL patterns. In the country, the epidemiology of CL is incredibly intricate due to various factors. This fact indicates that the basic infrastructure, the preceding supports, and the implementation plan related to preventive and therapeutic measures need crucial support. The leishmaniasis situation analysis is consistent with desperate requirements for efficient information on the control program in the area. This review provides evidence of temporally regressive and spatially expanding incidence of CL with characteristic geographical patterns and disease hotspots, signifying an urgent need for comprehensive control strategies. This information could be a suitable model and practical experience in the Eastern Mediterranean Region, where over 80% of CL is reported.

Antileishmanial activity, cytotoxicity and cellular response of amphotericin B in combination with crotamine derived from Crotalus durissus terrificus venom using in vitro and in silico approaches

OBJECTIVE

To investigate the in vitro activity, synergism, cytotoxicity and cellular immunological response, as well as the molecular affinity between amphotericin B (AmB) and crotamine (CTA), derived from Crotalus durissus terrificus venom against Leishmania amazonensis.

METHODS

This study performed the inhibition of promastigotes and amastigotes' growth under different concentrations of the drug and pharmacological combinations (AmB + CTA) based on the Berimbaum method (synergism study). The lactate dehydrogenase (LDH) quantification method was used to determine the cytotoxicity of the drug and combinations employing four cell lines (J774, HepG2, VERO, and C2C12). Following, the levels of Tumour Necrose Factor-alpha (TNF-α) and Interleukin-12 (IL-12) cytokines, using enzyme-linked immunosorbent assay (ELISA) and nitrites, as an indirect measure of Nitric Oxide (NO), using the Griess reaction were assessed in the supernatants of infected macrophages. In silico approach (molecular docking and dynamics) and binding affinity (surface plasmon resonance) between the drug and toxin were also investigated.

RESULTS

CTA enhanced AmB effect against promastigote and amastigote forms of L. amazonensis, decreased the drug toxicity in different cell lines and induced the production of important Th1-like cytokines and NO by infected macrophages. The pharmacological combination also displayed consistent molecular interactions with low energy of coupling and a concentration-dependent profile.

CONCLUSION

Our data suggest that this pharmacological approach is a promising alternative treatment against L. amazonensis infection due to the improved activity (synergistic effect) achieved against the parasites' forms and to the decreased cytotoxic effect.

Clinical and laboratory evaluation of cured and non-cured patients with cutaneous leishmaniasis treated by Glucantime

BACKGROUND & OBJECTIVES

Insufficient treatment of cutaneous leishmaniasis (CL) by conventional drugs is a major barrier in control strategies. This study was aimed to evaluate Glucantime efficacy and the susceptibility of Glucantime unresponsive and responsive CL isolates in the field and laboratory.

METHODS

Chi-square test (x^[2]) was used to determine the significance of difference between proportions in Glucantime-treated patients. The inhibitory activity of various concentrations of Glucantime against Leishmenia tropica stages was evaluated by a colorimetric cell viability MTT and macrophage assays. Mixed model, t-test and ANOVA were performed to determine the significance of difference between various concentrations of Glucantime unresponsive or responsive isolates and untreated control group and p <0.05 was defined as significant level. Altogether, 89.8% of the patients were cured by Glucantime, whilst 10.2% remained non-cured.

RESULTS

The overall Glucantime efficacy in different age groups and genders was similar. The IC₅₀ values of promastigotes and amastigotes for Glucanime unresponsive isolates were 2.1 and 2.6 times higher than the equivalent rates obtained for responsive cases, respectively. The overall mean number of amastigotes within macrophages in unresponsive isolates was significantly higher (32.68 ± 1.24) than that in responsive ones (18.68 ± 1.52, p <0.001). Glucantime unresponsive and responsive field isolates of anthroponotic CL (ACL) caused by L. tropica strongly correlated to in vitro assays.

INTERPRETATION & CONCLUSION

Monitoring of Glucantime unresponsiveness by the health surveillance system is extremely important, where anthroponotic transmission occurs in humans. Hence, physicians should be aware of such clinical unresponsive presentations with ACL for antimonial therapeutic failure to improve management of disease in endemic regions.

Effects of topical gel formulation of Ficus carica latex on cutaneous leishmaniasis induced by Leishmania major in BALB/c mice

Objectives

The current study aimed to evaluate the effects of Ficus carica latex on the treatment of cutaneous leishmaniasis (CL), induced by Leishmania major. A 5% topical gel with F. carica latex was prepared. BALB/c mice were infected by inoculation of amastigotes form of L. major. Thirty BALB/c mice were divided into five groups, where the first group was treated daily, the second group twice per day, and the third group every other day with the 5% topical gel, for 3 weeks. The sizes of the lesions were measured before and during the course of treatment.

Results

Although the mean size of lesions in the mice group treated with the 5% F. carica gel, especially in the group receiving daily treatment, was less than the mean size of the lesions in the control group, yet, the differences was not statistically significant (p > 0.05). The findings of the current study demonstrated that the 5% F. carica latex with a 3-week course of treatment had no considerable effect in recovery or control of CL induced by L. major in the murine model. Using higher concentration of F. carica latex and with longer treatment lengths may increase its efficacy in the treatment of CL.

Treatment Failure in Cutaneous Leishmaniasis Patients Referred to the School of Public Health, Tehran University of Medical Sciences during 2008-2017

BACKGROUND

Cutaneous leishmaniasis (CL) is a vector borne disease predominantly found in tropical and subtropical countries, including Iran. For more than 6 decades, pentavalent antimonials have been used successfully worldwide for the treatment of leishmaniasis, but over the past few years, clinical resistance to these medications has increased. In this study, we evaluated CL patients who did not show any desirable responses to the anti-leishmanial treatment within a 10-year period (2008 to 2017).

METHODS

All patients from different parts of Iran suspected of having cutaneous leishmaniasis, who were referred to the laboratory of leishmaniosis in Tehran University of Medical Sciences from 2008-2017 were parasitological examined.

RESULTS

During this period, a total of 1480 suspected CL patients were referred to the laboratory of leishmaniosis. Samples from 655 patients (70.8%) suspected of having CL were positive microscopically. The failure rate in patients treated with anti-leishmaniasis medications for a minimum of three complete treatment periods was 1.83% (12 cases). There was no association between the number and size of skin lesions and patient characteristics. Also, the route of drug administration had no significant effect on the number and size of lesions.

CONCLUSION

In the present study, treatment failure was found in some confirmed CL patients treated with meglumine antimoniate. Over the past few years, it seems that had been increased in resistance to these medications. So, a review of the correct implementation of the treatment protocol and/or a combination therapy may be helpful in preventing an increase in the rate of treatment failure.

Antileishmanial drugs activate inflammatory signaling pathways via toll-like receptors (docking approach) from Leishmania amazonensis-infected macrophages

The activation of proinflammatory cellular processes and signals such as those linked to NF-kB in macrophages are involved in the control of infection by Leishmania ssp. However, little is known about the influence of the drugs used in the treatment on the host cellular inflammatory signaling pathways. This study aimed to evaluate the effects of different drugs used in the treatment of leishmaniasis on inflammatory profile related to Toll-like receptors (TLRs) from L. amazonensis-infected macrophages. J774 macrophage-like cells were infected with the promastigote forms (5:1) and 24 hs incubated with Amphotericin B (AmB), Glucantime® (GLU) or Pentamidine (Pent). The following inflammatory pathways were evaluated: NF-κB p65, NF-κB p65 phosphorylated (Ser536), stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK) phosphorylated (Thr183/Tyr185), p38 mitogen activated protein kinase (MAPK p38) phosphorylated (Thr180/Tyr182), signal transducer and activator of transcription-3 (Stat3) phosphorylated (Tyr705) and inhibitor kappa B-α (IκB-α) phosphorylated (Ser32). In silico tests were performed to evaluate the molecular affinity between TLRs and antileishmanial drugs. Molecular docking showed that affinities varied significantly among the binders evaluated. The lowest affinity (-8.6 Kcal/Mol) was calculated for AmB in complex with TLR4. Pent showed higher values for TLR1, TLR2 and TLR3, while for TLR4 the affinity value was lower (5.5 Kcal/Mol). The values obtained for GLU were the highest for the set of binders tested. From the infected macrophages, treatments inhibited NF-kB p65 for GLU (65.44%), for Pent (46.43%) and for AmB (54.07%) compared to untreated infected macrophages. The activation of the signaling pathway of NF-kB, SAPK/JNK and IκB-α caused by AmB and Pent may potentiate the microbicidal mechanisms of the infected macrophages.

Geospatial-temporal distribution of Tegumentary Leishmaniasis in Colombia (2007-2016)

BACKGROUND

Tegumentary Leishmaniasis (TL) is a neglected disease with worldwide distribution and considered a public health problem, especially in Latin America. In Colombia, the governmental epidemiological surveillance system (SIVIGILA) is responsible for collecting information on the presentation of cases of TL from each of the municipalities and departments. In absence of a study compiling and analyzing currently available metadata of TL in Colombia, this study describes the geospatial-temporal distribution of TL and identifies the regions of the country on which prevention measures should be established in order to control the disease.

METHODOLOGY/PRINCIPAL FINDINGS

This is an exploratory descriptive analysis of the distribution of TL in Colombia. Information was collected on new cases of the disease during the years 2007-2016 from the Colombian reporting system (SIVIGILA). Incidence calculations were made based on population estimates by departments and biogeographical regions. Time evolution is shown in biennial maps. A 10-year series was analyzed, showing that the Amazon region is the most affected in terms of incidence, while the Andean region has the highest number of cases with a high variability among the departments that make it up. In those departments where there is a greater reported diversity of vector species, a large number of cases was observed.

CONCLUSIONS/SIGNIFICANCE

Transmission dynamics of TL in Colombia in the past 10 years have been variable, with a greater concentration of cases in the central and southern departments. The present study contributes to improve the understanding of the patterns of distribution of TL in Colombia and can be a basis for future studies of impact evaluation of Health policies in the country and the region.