Bioinspired Calcium Phosphate Nanoparticles Featuring as Efficient Carrier and Prompter for Macrophage Intervention in Experimental Leishmaniasis.

PURPOSE: To develop a biocompatible and bioresorbable calcium phosphate (CaP) nanoparticles (NPs) bearing Amphotericin B (AmB) with an aim to provide macrophage specific targeting in visceral leishmaniasis (VL). MATERIALS & METHODS: CaP-AmB-NPs were architectured through emulsion precipitation method. The developed formulation was extensively characterized for various parameters including in-vitro and in-vivo antileishmanial activity. Moreover, plasma pharmacokinetics, tissue biodistribution and toxicity profile were also assessed. RESULTS: Optimized CaP-AmB-NPs exhibited higher entrapment (71.1 ± 6.68%) of AmB. No trend related to higher hemolysis was apparent in the developed formulation as evidenced in commercially available colloidal and liposomal formulations. Cellular uptake of the developed CaP-AmB-NPs was quantified through flow cytometry in J774A.1 cell line, and a 23.90 fold rise in uptake was observed. Fluorescent microscopy also confirmed the time dependent rise in uptake. In-vivo multiple dose toxicity study demonstrated no toxicity upto 5 mg/kg dose of AmB. Plasma kinetics and tissue distribution studies established significantly higher concentration of AmB in group treated with CaP-AmB-NPs in liver and spleen as compared to CAmB, LAmB and AmB suspension group. In-vivo animal experimental results revealed that the CaP-AmB-NPs showed higher splenic parasite inhibition compared to CAmB and LAmB in leishmania parasite infected hamsters. CONCLUSIONS: The investigated CaP-AmB-NPs are effective in provoking macrophage mediated uptake and collectively features lower toxicity and offers a suitable replacement for available AmB-formulations for the obliteration of intra-macrophage VL parasite.

Quantitative Structure-Activity Relationship Analysis of Selective Rho Kinase Inhibitors as Neuro-regenerator Agents.

OBJECTIVES: To understand the role of Rho (serine/threonine) kinases in the treatment of neurological segments, attempts have been made to find potent inhibitors of Rho enzyme by a 2D quantitative structure-activity relationship (QSAR) model. MATERIALS AND METHODS: QSAR studies were executed on urea-based scaffolds from aniline and benzylamine analogues, which were aligned for generation of a chemometric-based model. Multivariate statistical approaches were applied including linear and nonlinear analysis such as multiple linear regression, partial least square and artificial neural network for the generation of model, and also an application of (in silico) absorption, distribution, metabolism, excretion studies was performed to ascertain the novelty and drug-like properties of the intended molecules. RESULTS: Ligand based analysis was implemented and showed excellent statistical relevance such as S value=0.38, F value=48.41, r=0.95, r²=0.91, and r²cv=0.86. Five illuminating variables, i.e., vesicle-associated membrane protein (VAMP) polarization YY component (whole molecule), VAMP dipole Y component (whole molecule), VAMP dipole Z component (whole molecule), Kier ChiV6 path index (whole molecule), and moment of inertia 2 size (whole molecule), were found and they have a profound influence on the potency of the compounds. CONCLUSION: The values of standard statistical parameters reveal the predictive power and robustness of this model and also provide valuable insight into the significance of five descriptors. The acquired physicochemical properties (electronic, topological, and steric) show the important structural features required for activity against Rho kinase. After performing Lipinski's rule of five on urea-based derivatives no molecule was violating the rule. Therefore, these features can be effectively employed for the modeling and screening of active neurological agents as novel Rho kinase inhibitors.

In-Silico Screening of Ligand Based Pharmacophore, Database Mining and Molecular Docking on 2, 5-Diaminopyrimidines Azapurines as Potential Inhibitors of Glycogen Synthase Kinase-3ß.

BACKGROUND: Glycogen synthase kinase-3ß plays a significant role in the regulation of various pathological pathways relating to the Central Nervous System (CNS). Dysregulation of Glycogen synthase kinase 3 (GSK-3) activity gives rise to numerous neuroinflammation and neurodegenerative related disorders that affect the whole central nervous system. OBJECTIVE: By the sequential application of in-silico tools, efforts have been attempted to design the novel GSK-3ß inhibitors. METHOD: Owing to the potential role of GSK-3ß in nervous disorders, we have attempted to develop the quantitative four featured pharmacophore model comprising two Hydrogen Bond Acceptors (HBA), one Ring Aromatic (RA), and one Hydrophobe (HY), which were further affirmed by costfunction analysis, rm2 matrices, internal and external test set validation and Guner-Henry (GH) scoring analysis. Validated pharmacophoric model was used for virtual screening and out of 345 compounds, two potential virtual hits were finalized that were on the basis of fit value, estimated activity and Lipinski's violation. The chosen compounds were subjected to dock within the active site of GSK-3ß. RESULT: Four essential features, i.e., two Hydrogen Bond Acceptors (HBA), one Ring Aromatic (RA), and one Hydrophobe (HY), were subjected to build the pharmacophoric model and showed good correlation coefficient, RMSD and cost difference values of 0.91, 0.94 and 42.9 respectively and further model was validated employing cost-function analysis, rm2-matrices, internal and external test set prediction with r2 value of 0.77 and 0.84. Docked conformations showed potential interactions in between the features of the identified hits (NCI 4296, NCI 3034) and the amino acids present in the active site. CONCLUSION: In line with the overhead discussion, and through our stepwise computational approaches, we have identified novel, structurally diverse glycogen synthase kinase inhibitors.

Chondroitin nanocapsules enhanced doxorubicin induced apoptosis against leishmaniasis via Th1 immune response.

Current leishmaniasis treatment is strangled due to concealed residence of parasite and reduced host cell mediated immune response. To circumvent above challenges, novel macrophage targeted oily core polymeric shell based doxorubicin (DOX) loaded nanocapsules (NCAPs) were fabricated employing chondroitin sulphate (CHD) for complimentary immunotherapy coupled chemotherapy against leishmaniasis. Excellent encapsulation efficiency along with pH dependent drug release was demonstrated by NCAPs. Improved cell cycle arrest at G1-S phase (1.56 folds) and apoptosis against promastigotes (6.26 folds), support the remarkable in-vitro antileishmanial activity of NCAPs (IC50: 0.254±0.038 µg/ml) compared to free DOX (IC50: 0.543±0.012 µg/ml). In-vivo antileishmanial activity in hamsters represented a significantly enhanced parasitic inhibition by NCAPs (1.42 folds). Improved activity was mediated via immunotherapeutic activity of NCAPs which up-regulated Th1 immune response (IL-12, INF-γ, and TNF-α) and down-regulated Th2 immune response (IL-4, IL-10, and TGF-ß). In conclusion, current novel nano-formulation could be a viable option against leishmaniasis.

Neglected disease - african sleeping sickness: recent synthetic and modeling advances.

Human African Trypanosomiasis (HAT) also called sleeping sickness is caused by subspecies of the parasitic hemoflagellate Trypanosoma brucei that mostly occurs in sub-Saharan Africa. The current chemotherapy of the human trypanosomiases relies on only six drugs, five of which have been developed more than 30 years ago, have undesirable toxic side effects and most of them show drug-resistance. Though development of new anti-trypanosomal drugs seems to be a priority area research in this area has lagged far behind. The given review mainly focus upon the recent synthetic and computer based approaches made by various research groups for the development of newer anti-trypanosomal analogues which may have improved efficacy and oral bioavailability than the present ones. The given paper also attempts to investigate the relationship between the various physiochemical parameters and anti-trypanosomal activity that may be helpful in development of potent anti-trypanosomal agents against sleeping sickness.