Leishmanicidal activities of biosynthesized BaCO3 (witherite) nanoparticles and their biocompatibility with macrophages.

The aim of this study was cost-effective and greener synthesis of barium carbonate (BaCO3 or witherite) nanoparticles with economic importance, and to evaluate their therapeutic potentials and biocompatibility with immune cells. Barium carbonate nanoparticles were biosynthesized using black elderberry extract in one step with non-toxic precursors and simple laboratory conditions; their morphologies and specific structures were analyzed using field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX). The therapeutic capabilities of these nanoparticles on the immune cells of murine macrophages J774 and promastigotes Leishmania tropica were evaluated. BaCO3 nanoparticles with IC50 = 46.6 µg/mL were more effective than negative control and glucantium (positive control) in reducing promastigotes (P < 0.01). Additionally, these nanoparticles with a high value of cytotoxicity concentration 50% (CC50) were less toxic to macrophage cells than glucantime; however, they were significantly different at high concentrations compared to the negative control.

Sageretia thea (Osbeck.) modulated biosynthesis of NiO nanoparticles and their in vitro pharmacognostic, antioxidant and cytotoxic potential.

NiO nanoparticles are biosynthesized using Sageretia thea (Osbeck.) aqueous leave extracts and their biological activities are reported. Nanoparticles (∼18 nm) were characterized through XRD, ATR-FTIR, EDS, SAED, HR-SEM/TEM and Raman spectroscopy. Antibacterial activity was investigated against six pathogenic bacterial strains (gram positive and gram negative) and their corresponding minimum inhibitory concentrations (MICs) were calculated. UV-exposed nanoparticles were investigated to have reduced MICs relative to the NiO nanoparticles have not been exposed to UV. Moderate linear fungal growth inhibition was observed while Mucor racemosus (percentage inhibition 64% ± 2.30) was found to be most susceptible. Cytotoxicity was confirmed using brine shrimps lethality assay (IC50 42.60 µg/ml). MTT cytotoxicity was performed against Leishmania tropica-KWH23 promastigotes and amastigotes revealed significant percentage inhibition across the applied concentrations. IC50 values were calculated as 24.13 µg/ml and 26.74 µg/ml for the promastigote and amastigote cultures of Leishmania tropica. NiO nanoparticles were found. Moderate, antioxidant potential was concluded through assays like DPPH, TAP and TAC. Furthermore, protein kinase inhibition and alpha amylase inhibition is also reported.

A nanotechnology based new approach for chemotherapy of Cutaneous Leishmaniasis: TIO2@AG nanoparticles - Nigella sativa oil combinations.

Since toxicity and resistance are the major drawbacks of current antileishmanial drugs, studies have been recently focused on combination therapy in fight against leishmaniasis. Combination therapy generally provides opportunity to decrease toxicity of applied agents and enhance their antimicrobial performance. Moreover, this method can be effective in preventing drug resistance. Highly antileishmanial effects of silver doped titanium dioxide nanoparticles (TiAgNps) and Nigella sativa oil were demonstrated in previous studies. However, toxicity is still an important factor preventing use of these molecules in clinic. By considering high antileishmanial potential of each agent and basic principles of combination therapy, we propose that use of combinations including non-toxic concentrations of TiAgNps and N. sativa oil may compose more effective and safer formulations against Leishmania parasites. Therefore, the main goal of the present study was to investigate antileishmanial effects of non-toxic concentrations of TiAgNps and Nigella sativa oil combinations on promastigote and amastigote-macrophage culture systems and also to develop nanotechnology based new antileishmanial strategies against Cutaneous Leishmaniasis. Numerous parameters such as proliferation, metabolic activity, apoptosis, amastigote-promastigote conversion, infection index analysis and nitric oxide production were used to detect antileishmanial efficacies of combinations. Investigated all parameters demonstrated that TiAgNps-N. sativa oil combinations had significant antileishmanial effect on each life forms of parasites. Tested combinations were found to decrease proliferation rates of Leishmania tropica promastigotes in a range between 1,5-25 folds and metabolic activity values between 2 and 4 folds indicating that combination applications lead to virtually inhibition of promastigotes and elimination of parasites were directly related to apoptosis manner. TiAgNps-N. sativa combinations also demonstrated killing effects on L. tropica amastigotes by decreasing infection index values of macrophages 5-20 folds, inhibiting their metabolic activities up to 5 fold, preventing amastigote-promastigote conversion and producing high amounts of nitric oxide. All these results emphasize high potential of TiAgNps-N. sativa oil combinations as new, safer and effective antileishmanial formulations against Cutaneous Leishmaniasis.

In vitro cultivation of axenic amastigotes and the comparison of antioxidant enzymes at different stages of Leishmania tropica.

The present study aimed to establish a simple method to yield large amounts of Leishmania tropica amastigote-like forms in axenic cultures and to compare the superoxide dismutase (SOD) and glutathione peroxidase (GPX) enzymes at different stages of L. tropica. Different culture conditions were tested to find the optimum condition of axenic amastigotes generation. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were determined at logarithmic and stationary phases and axenic amastigote stage of the parasite. A high proportion (88%) of amastigote-like forms of L. tropica was observed in BHI medium supplemented with 20% FCS, pH 4.5, and incubated at 37ºC with 5% CO(2). The results showed that SOD activity was at the lowest level in the logarithmic phase of promastigotes and increased towards the stationary phase of promastigotes and amastigote stage. The results showed that the optimum condition for differentiation of L. tropica promastigotes to axenic amastigotes was BHI medium containing 20% FCS at pH 4.5, incubated at 37ºC in the presence of 5% CO(2). It seems that SOD, but not GPX is a major determinant of intracellular survival of the parasite.