piperidines and Leishmaniasis--Visceral

The use of repellents is considered an alternative against biting insects, including Lutzomyia longipalpis (Diptera: Psychodidae), the main vector of the protozoan Leishmania infantum, visceral leishmaniasis's (VL) etiologic agent in the Americas. This study aimed to evaluate the repellent efficacy of icaridin nanostructured solution applied on cotton knitting fabric against L. longipalpis. Arm-in-cage tests were performed in eight volunteers at different concentrations (5%, 10%, 25%, and 50%), using L. longipalpis (n = 30). The bioassay was performed in 1, 24, 48, 72, 96, 120, and 144 h after impregnation and one test after washing the fabrics with icaridin. The total repellency rate (%R) > 95% was used as a reference to define a minimum effective concentration (MEC). The results revealed that the insects' landing mean decreased significantly in different icaridin concentrations, compared with the control tests (p < 0.05) and the 25% and 50% concentrations compared to lower concentration (5%) (p < 0.05). The higher concentrations (25% and 50%) provided longer complete protection times (CPTs) with 120 and 144 h of protection, respectively and the %R of 100% for 72 and 96 h after impregnation, respectively. The 25% was the MEC (%R Total = 98.18%). Our results indicate, for the first time, that icaridin nanostructured solution applied on cotton knitting fabric proved to be an efficient repellent against L. longipalpis with the presence of repellent action even after washing. The concentration of 25% showed better efficiency and may become an efficient method for L. longipalpis biting control.

Topics: Animals; Brazil; Humans; Insect Repellents; Insect Vectors; Leishmania infantum; Leishmaniasis, Visceral; Piperidines; Psychodidae

Amphotericin B (AmB) exhibits potential antileishmanial activity, with only a little rate of recurrence. However, low bioavailability and severe nephrotoxicity are among the major shortcomings of AmB-based therapy. Various AmB nanoformulations have been developed, which to an extent, have reduced its toxicity and increased the drug efficacy. To further reduce the nonspecific tissue distribution and the cost of the treatment, the current AmB-based formulations require additional improvements. Combination of natural bioenhancers with AmB is expected to further increase its bioavailability. Therefore, we developed a nanoformulation of AmB and piperine (Pip), a plant alkaloid, known to enhance the bioavailability of various drugs, by entrapping them in guar gum, a macrophage targeting polymer. Owing to the ease of oral delivery, these nanoparticles (NPs) were coated with eudragit to make them suitable for oral administration. The formulated eudragit-coated AmB and Pip-loaded NPs (Eu-HDGG-AmB-Pip-NPs) exhibited controlled release of the loaded therapeutic agents and protected the drug from acidic pH. These NPs exhibited effective suppression of growth of both promastigotes and amastigotes of Leishmania donovani parasite under in vitro. In vivo evaluation of these NPs for therapeutic efficacy in golden hamster-L. donovani model demonstrated enhanced drug bioavailability, non-nephrotoxic nature, and potential antileishmanial activity with up to 96% inhibition of the parasite. Graphical abstract.

Topics: Alkaloids; Amphotericin B; Animals; Benzodioxoles; Cricetinae; Drug Carriers; Galactans; Leishmaniasis, Visceral; Mannans; Nanoparticles; Piperidines; Plant Gums; Polyunsaturated Alkamides

New drugs are needed for leishmaniasis because current treatments such as pentavalent antimonials are toxic and require prolonged administration, leading to poor patient compliance. Ibrutinib is an anticancer drug known to modulate T-helper type 1 (Th1)/Th2 responses and has the potential to regulate immunity against infectious disease.. In this study, we evaluated the efficacy of oral ibrutinib as a host-targeted treatment for visceral leishmaniasis (VL) caused by Leishmania donovani using an experimental mouse model.. We found that oral ibrutinib was significantly more effective than the pentavalent antimonial sodium stibogluconate (70 mg/kg) for the treatment of VL caused by L. donovani. Ibrutinib treatment increased the number of interleukin 4- and interferon γ-producing natural killer T cells in the liver and spleen and enhanced granuloma formation in the liver. Further, ibrutinib treatment reduced the influx of Ly6Chi inflammatory monocytes, which mediate susceptibility to L. donovani. Finally, ibrutinib treatment was associated with the increased production of the cytokines interferon γ, tumor necrosis factor α, interleukin 4, and interleukin 13 in the liver and spleen, which are associated with protection against L. donovani.. Our findings show that oral ibrutinib is highly effective for the treatment of VL caused by L. donovani and mediates its antileishmanial activity by promoting host immunity. Therefore, ibrutinib could be a novel host-targeted drug for the treatment of VL.

Topics: Adenine; Administration, Oral; Animals; Cytokines; Disease Models, Animal; Female; Immunity, Cellular; Immunologic Factors; Leishmania donovani; Leishmaniasis, Visceral; Mice; Mice, Inbred BALB C; Piperidines; Protein Kinase Inhibitors; Pyrazoles; Pyrimidines; Treatment Outcome

Topics: Alkaloids; Antiprotozoal Agents; Benzodioxoles; Capsaicin; Chromatography, High Pressure Liquid; Drug Synergism; Inhibitory Concentration 50; Leishmania infantum; Leishmaniasis, Visceral; Magnetic Resonance Spectroscopy; Meglumine; Meglumine Antimoniate; Organometallic Compounds; Piperidines; Polyunsaturated Alkamides; Spectrophotometry, Ultraviolet

Present studies are aimed to find out the utility of oil-in-water emulsions also known as lipid nanospheres (LN) or fat emulsions for delivering piperine for the treatment of visceral leishmaniasis. Lipid nanosphere formulations of piperine were prepared using soybean oil, egg lecithin, cholesterol, stearylamine and phosphatidylethanolamine distearylmethoxypolyethyleneglycol (DSPE-PEG) by homogenization followed by ultrasonication of oil and aqueous phases. Antileishmanial activity of all the formulations was assessed in BALB/c mice infected with Leishmania donovani AG83 for 60 days. A single dose (5 mg/kg) of piperine, or lipid nanospheres of piperine (LN-P), or lipid nanosphere of piperine with stearylamine (LN-P-SA) or pegylated lipid nanospheres of piperine (LN-P-PEG) was injected intravenously. Mice were sacrificed after 15 days of treatment with piperine or formulations and Leishman Donovan Unit (LDU) is counted. Toxicity of formulations and pure piperine was assessed in normal mice. The size distribution of formulations ranged from 200 to 885 nm. Piperine reduced the parasite burden in liver and spleen by 38% and 31% after 15 days post infection respectively. LN-P reduced the parasite burden in liver and spleen by 63% and 52% after 15 days post infection, respectively. LN-P-PEG reduced the parasite burden in liver and spleen by 78% and 75% after 15 days post infection, respectively. LN-P-SA reduced the parasite burden in liver and spleen by 90% and 85% after 15 days post infection, respectively. LN-P, LN-P-PEG, LN-P-SA treated mice did not show any significant changes in the serum levels of SGOT, ALP, creatinine and urea compared to normal mice. Stable and sterile formulations of lipid nanospheres of piperine were developed. A single dose of 5 mg/kg of lipid nanospheres of piperine could significantly reduce the liver and splenic parasite burden.

Topics: Algorithms; Alkaloids; Animals; Antiprotozoal Agents; Benzodioxoles; Chemical Phenomena; Chemistry, Pharmaceutical; Chemistry, Physical; Emulsions; Leishmania donovani; Leishmaniasis, Visceral; Liposomes; Liver; Mice; Mice, Inbred BALB C; Microspheres; Oils; Particle Size; Piperidines; Polyunsaturated Alkamides; Solutions; Spleen; Sterilization; Water

The leishmanicidal property of piperine intercalated in liposomes and in mannose-coated liposomes was tested in experimental visceral leishmaniasis in hamsters. Mannose-coated liposomal piperine eliminated intracellular amastigotes of Leishmania donovani in splenic macrophages much more efficiently than did the liposomal piperine or free piperine. At a dose equivalent to 6 mg/kg body wt every 4th day for a total of 4 doses in 12 days, the mannose-coated liposomal piperine was found to reduce spleen parasite load to the extent of 90% in comparison to that achieved by liposomal piperine (77%) or free piperine (29%). Histological examination of spleen and liver function tests showed that the toxicity of piperine was reduced when mannosylated liposomal piperine was administered.

Topics: Alkaloids; Animals; Antiprotozoal Agents; Benzodioxoles; Cricetinae; Drug Carriers; Leishmaniasis, Visceral; Liposomes; Liver Function Tests; Macrophages; Mannose; Mesocricetus; Piperidines; Polyunsaturated Alkamides; Spleen

The therapeutic efficacy of CP-46,665-1, a synthetic lipoidal amine with proven immunomodulatory and anti-tumor properties, in combination with chemotherapy was evaluated in L. donovani-infected C57Bl/6 mice. Immunostimulation and drug treatment resulted in a 10-fold lesser infection level than in untreated mice, while animals treated with Glucantime alone exhibited only a modest amelioration of the infection. We also studied the capacity of CP-elicited peritoneal macrophages of C57Bl/6 mice cultured alone or in combination with Glucantime and/or lymphokine to eliminate intracellular L. donovani amastigotes. When CP-elicited cells were incubated with Glucantime, they exhibited a significantly higher killing potential than did drug treated thioglycollate-elicited cells. CP-macrophages stimulated with lymphokine alone or in combination with antimonial drug, killed amastigotes more rapidly and efficiently than similarly treated thioglycollate-elicited macrophages. In vivo and in vitro results of this study show that a combined regimen of immunostimulation with CP and antimonial drug is more effective in treatment of L. donovani infection than either treatment alone.

Topics: Adjuvants, Immunologic; Animals; Antimony; Antiprotozoal Agents; Drug Therapy, Combination; Female; Leishmania; Leishmaniasis, Visceral; Lymphokines; Macrophage Activation; Macrophages; Meglumine; Meglumine Antimoniate; Mice; Mice, Inbred C57BL; Organometallic Compounds; Piperidines; Thioglycolates