Capparis spinosa inhibits Leishmania major growth through nitric oxide production in vitro and arginase inhibition in silico.

Cutaneous leishmaniasis is an infectious disease, considered as a major public health problem in different regions of the world. The current treatments are limited due to their toxicity and treatment failures, which have increased the search for new substances of natural origin to control this infection. Capparis spinosa is an important medicinal plant, rich in biochemical compounds with a broad range of activities including antimicrobial effects. Nevertheless, more investigations are still needed to determine its effect on Leishmania parasites. This study aimed to evaluate the effect of C. spinosa' extracts on Leishmania major promastigotes and amastigotes growth as well as on L-arginine metabolic pathways, especially the production of leishmanicidal molecules such as nitric oxide. Our results showed that C. spinosa' methanolic and aqueous extracts contained polyphenols and flavonoids at different concentrations. The methanolic extract of C. spinosa, compared to the aqueous extract, showed significantly higher amounts of total polyphenols (21.23 ± 1.08) mg GAE/g of dw (P < 0.05), as well as a higher antioxidant activity evaluated respectively by Reducing Power and DPPH (EC50: 0.31 ± 0.02 and 7.69 ± 1.28) mg/ml. Both extracts significantly inhibited L. major promastigotes and intra-macrophagic amastigotes growth in vitro in a dose-dependent manner (P < 0.001) and induced NO production not only in Leishmania-infected macrophages but also in uninfected macrophages, without showing any cytotoxicity in vitro. Furthermore, in silico docking studies showed that C. spinosa compounds identified by RP-HPLC exhibited inhibitory activity against the arginase enzyme. The leishmanicidal effect of C. spinosa may be due to its phenolic content and its mechanism of action may be mediated by an increase in NO production and by the inhibition of arginase enzyme in silico. These findings support the hypothesis that C. spinosa might be a valuable source of new biomolecules for leishmaniasis treatment.

[Generalized old world leishmaniasis: first Moroccan case in an immunocompetent adult?] / Leishmaniose généralisée de l'Ancien monde : Premier cas marocain chez un adulte immunocompétent ?

Background: Post-kala-azar dermal Leishmaniasis (PKDL) is a rare skin syndrome observed after treatment of visceral Leishmaniasis (VL) with pentavalent antimonial organic salts, never described in Morocco before. Here we report a case in an immunocompetent adult. Case: A 36-year-old-man from Tata in southern Morocco, with a history of visceral Leishmaniasis 2 years before and treated with meglumine antimoniate and amphotericin B with good clinical course, was hospitalized in dermatology for an erythematous papulo-nodular closet of the face. Six months ago, he presented oral mucosa involvement, then 3 months later, cutaneous lesions appeared on the face. The dermatological examination revealed a papulo-nodular erythematous closet extending to the nose and both cheeks, crusty and lupoid lesions on the forehead, around the eyes and chin, associated with an ulcerative and painless lesion on the heeL. The examination of the oral mucosa revealed an ulceration of the posterior third of the tongue and a papillomatous aspect of the soft palate. The skin biopsy and smear found some amastigote forms of Leishmania bodies. ITS1 PCR was positive (genus Leishmania). The HIV serology was negative. The diagnosis of PKDL was then evoked. The patient received intra-muscular injections of meglumine antimoniate with good progress. Conclusion: To our knowledge, this is the first case of generalised leishmaniasis suggesting PKDL reported in a Moroccan immunocompetent adult.

Gastric IL-1ß, IL-8, and IL-17A expression in Moroccan patients infected with Helicobacter pylori may be a predictive signature of severe pathological stages.

INTRODUCTION: Helicobacter pylori induces acute gastritis that can progress to serious diseases such as gastric cancer. H. pylori interacts with host cells within the gastric mucosa, resulting in activation of multiple innate immune signalling pathways, leading to pro-inflammatory cytokines production and immune cells recruitment. Various studies have shown that there are ethnic- and population-related differences in the expression of these cytokines. Although the H. pylori infection is a major public health problem in Morocco, to our knowledge, no study has been carried out in gastric cytokine expression from H. pylori-infected Moroccan patients. Thus we aimed to (i) determine the IL-1ß, IL-8 and IL-17A gene expression in gastric biopsies from Moroccan patients infected with H. pylori, and (ii) to determine the cytokine signature of each pathological stages associated with this infection. MATERIAL AND METHODS: 71 patients with epigastralgic pain were included in this study. The H. pylori detection on gastric biopsies was performed by histopathological and PCR analysis. The IL-1ß, IL-8 and IL-17A mRNA expression in the antrun and fundus biopsies was performed by RT-qPCR. RESULTS: The histopathological and PCR analyses revealed that 87.32% of the patients were infected with H. pylori. IL-1ß mRNA expression was significantly lower in the antral mucosa of H. pylori-infected patients (p = 0.0038) than in the uninfected while there was no significant difference in the expression of IL-8 and IL-17A mRNA. The expression of the three cytokines was higher in the fundic mucosa of H. pylori-infected patients than in the uninfected patients, but only IL-8 and IL-17A expression reached statistical significance (p = 0.042 and p = 0.0179 respectively). Furthermore, the multivariate predictive analysis highlighted a cytokine signature that may predict metaplasia during the infection progression that involves a specific down-regulation of IL17A and an up-regulation of IL1ß in antral and fundic metaplasia respectively.

Transcriptional Analysis of Human Skin Lesions Identifies Tryptophan-2,3-Deoxygenase as a Restriction Factor for Cutaneous Leishmania.

Disease manifestation after infection with cutaneous Leishmania species is the result of a complex interplay of diverse factors, including the immune status of the host, the infecting parasite species, or the parasite load at the lesion site. Understanding how these factors impact on the pathology of cutaneous leishmaniasis (CL) may provide new targets to manage the infection and improve clinical outcome. We quantified the relative expression of 170 genes involved in a diverse range of biological processes, in the skin biopsies from patients afflicted with CL caused by infection with either L. major or L. tropica. As compared to healthy skin, CL lesions bear elevated levels of transcripts involved in the immune response, and conversely, present a significant downregulation in the expression of genes involved in epidermal integrity and arginine or fatty acid metabolism. The expression of transcripts encoding for cytotoxic mediators and chemokines in lesions was inversely correlated with the expression of genes involved in epidermal integrity, suggesting that cytotoxicity is a major mediator of CL pathology. When comparing the transcriptional profiles of lesions caused by either L. major or L. tropica, we found them to be very similar, the later presenting an aggravated inflammatory/cytotoxic profile. Finally, we identified genes positively correlated with the parasite load in lesions. Among others, these included Th2 or regulatory cytokines, such as IL4 or IL10. Remarkably, a single gene among our dataset, encoding for tryptophan-2,3-deoxygenase (TDO), presented a negative correlation with the parasite load, suggesting that its expression may restrict parasite numbers in lesions. In agreement, treatment of macrophages infected with L. major in vitro with a TDO inhibitor led to an increase in parasite transcripts. Our work provides new insights into the factors that impact CL pathology and identifies TDO as a restriction factor for cutaneous Leishmania.

Concomitant visceral and localized cutaneous leishmaniasis in two Moroccan infants.

BACKGROUND: Leishmaniases are vector-borne diseases caused by the protozoa of the Leishmania genus. The clinical spectrum of these diseases extends from benign dermal lesions to visceral forms. In the Mediterranean region, zoonotic visceral leishmaniasis (ZVL) is caused by L. infantum. If untreated within two years, the disease usually leads to death. In Morocco, ZVL is endemic in the north, with a hundred cases notified each year, mostly in children aged below five years. Here, we report on two clinical observations in infants presenting unusual concomitant VL and cutaneous leishmaniasis (CL) in Morocco. CASE PRESENTATION: In this case study, we report on two infants aged nine and 12 months old. They both have a history of febrile splenomegaly, anemia, and pallor of mucous membranes. Visceral leishmaniasis was confirmed by parasitological diagnosis (positive bone marrow smear and screening of anti-L. infantum antibodies). However, the clinical examination also showed cutaneous lesions that suggested the presence of CL. This was reinforced by the patients having a history of living or traveling to endemic foci. Thus, direct examination, culture, and PCR-RFLP (ITS1-Hae 3) were carried out on the patients' dermal exudates. In one of the infants, CL was associated with L. infantum, while in the other it was associated with L. tropica. The infants were treated as according to the recommendations of the Ministry of Health. Both patients were cured in two months; defervescence, reduction of splenomegaly, and healing of cutaneous lesions were all observed. CONCLUSIONS: These singular patients illustrate the clinical polymorphism of CL and the necessity of updating the differential diagnosis of leukemia-like syndromes, including VL, in children living in or travelling to known endemic areas. These observations suggest a change in the Mediterranean VL phenotype that may be associated with CL.

Moroccan strains of Leishmania major and Leishmania tropica differentially impact on nitric oxide production by macrophages.

BACKGROUND: Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease caused by protozoa of the genus Leishmania. In Morocco, CL is a public health problem mainly caused by Leishmania major and Leishmania tropica, which are responsible for zoonotic and anthroponotic CL, respectively. Macrophages are the primary cells infected by Leishmania parasites and their capacity to produce nitric oxide (NO) is of critical importance for parasite elimination. To our knowledge, the role of NO on autochthonous infections has never been investigated before. In this study, we evaluated in vitro the capacity of autochthonous primary dermotropic strains of L. major and L. tropica to modulate NO production by J774-macrophages and determine the sensitivity of both species to exogenous NO. METHODS: The infectivity of the J774 cell line was analyzed by optical microscopy. NO production by macrophages was measured by the Griess method. The sensitivity to NO by the two strains was assessed by the MTT assay using NO donors. RESULTS: Our results show that the percentage of infected macrophages and the average number of parasites per macrophage were similar for L. major and L. tropica strains. While L. tropica significantly inhibited NO production induced by LPS and IFN-γ stimulation in J774 macrophages, L. major did not affect it. However, soluble Leishmania antigens (SLAs) from both autochthonous primary strains significantly inhibited the production of NO by J774-macrophages in a dose-dependent manner. Finally, our results demonstrated that promastigotes and amastigotes from both strains are sensitive to SNAP NO donor in a dose-dependent manner, although L. tropica demonstrated an increased sensitivity. CONCLUSIONS: Our results suggest a differential ability of L. major and L. tropica strains to modulate the capacity of macrophages to produce NO. The increased ability of L. tropica to inhibit NO production by macrophages might come as a necessity due to its higher sensitivity to NO donor. Our results provide one explanation for the tendency of L. tropica to cause chronic lesions and may contribute to the different physiopathology of CL in Morocco.