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Mitochondrial fitness is governed by mitochondrial quality control pathways comprising mitochondrial dynamics and mitochondrial-selective autophagy (mitophagy). Disruption of these processes has been implicated in many human diseases, including viral infections. Here, we report a comprehensive analysis of the effect of dengue infection on host mitochondrial homeostasis and its significance in dengue disease pathogenesis. Despite severe mitochondrial stress and injury, we observed that the pathways of mitochondrial quality control and mitochondrial biogenesis are paradoxically downregulated in dengue-infected human liver cells. This leads to the disruption of mitochondrial homeostasis and the onset of cellular injury and necrotic death in the infected cells. Interestingly, dengue promotes global autophagy but selectively disrupts mitochondrial-selective autophagy (mitophagy). Dengue downregulates the expression of PINK1 and Parkin, the two major proteins involved in tagging the damaged mitochondria for elimination through mitophagy. Mitophagy flux assays also suggest that Parkin-independent pathways of mitophagy are also inactive during dengue infection. Dengue infection also disrupts mitochondrial biogenesis by downregulating the master regulators PPARγ and PGC1α. Dengue-infected cells release mitochondrial damage-associated molecular patterns (mtDAMPs) such as mitochondrial DNA into the cytosol and extracellular milieu. Furthermore, the challenge of naive immune cells with culture supernatants from dengue-infected liver cells was sufficient to trigger proinflammatory signaling. In correlation with our more...

Background: Drug resistance by the cancer cells towards current chemotherapeutic approaches poses a great challenge. In the present study, an indole analogue of a well-known plant derived anticancer molecule, curcumin, was tested for its Multidrug Resistance (MDR) reversing potential in induced multi drug resistant A549 cell line. Materials and Methods: Human lung cancer cell line A549 was made Multidrug Resistant (MDR) by prolonged treatment with low dosage of Docetaxel, an established anticancer drug. The MDR induction was confirmed by morphological evidence, Hoechst 33342 staining, MTT assay, Rhodamine123 staining and RT-PCR of ABCB1 gene. Protein expression studies were carried out using western blotting technique Results and Discussions: The induced MDR A549 cells exhibited significant increase in the gene expression of ABCB1 gene at the transcriptional level. Retention and efflux studies with Pglycoprotein (P-gp) substrate Rh123 indicated that indole curcumin inhibited P-gp mediated efflux of Rhodamine. Furthermore, treatment of MDR A549 cells with indole curcumin showed downregulation of gene expression of ABCB1 and COX 2. This was also confirmed from the decreased protein expression of COX 2. Conclusion: The results of the present study indicate that indole curcumin reverses multi drug resistance by downregulating the expression of ABCB1 and COX 2 genes. Thus, indole curcumin may act as a potent modulator for ABCB1 and COX 2 mediated MDR in lung cancer. more...

The challenge of next-generation nanoparticles (NPs) includes limited cellular uptake and loss by phagocytosis. General surface modification of NPs potentially enhances evasion from phagocytosis. However, active targeting and enhanced cellular uptake of nanoparticles are possible by surface functionalisation with molecules that have selective affinity for cancer cells. ROR1 is a cell surface receptor that is over-expressed in cancer cells. Hence, its conjugate antibody could be a potential surface functionalisation molecule. In the current study, anti-ROR1 antibody has been covalently attached to nanoparticles’ surface, thereby imparting its active targeting potential. Physicochemical and in vitro characterisations of the antibody-conjugated nanoparticles were performed. Surface functionalisation of nanoparticles was confirmed by scanning electron microscopy, isothermal calorimetry, and elemental analysis. Additionally, biomarkers of metastasis and epithelial-mesenchymal transition (EMT) were studied. Anti-ROR1 mAb tagged nanoparticles further confirmed therapeutic efficacy against colon cancer cells, SW480, thus, opening scope for further in vivo studies. more...

Purpose Previously we showed that BDMC, an analogue of curcumin suppresses growth of human breast and laryngeal cancer cell line by causing apoptosis. Here, we demonstrate the enhanced anti-cancer activity of a heterocyclic ring (indole) incorporated curcumin analogue ((1E, 6E)-1, 7-di (1H-indol-3-yl) hepta-1, 6-diene-3, 5-Dione), ICA in short, in comparison to curcumin. Method ICA was synthesized by a one pot condensation reaction. Anti-cancer potential of ICA was assessed in three human cancer cell lines of different origin (Lung adenocarcinoma (A549), leukemia (K562) and colon cancer (SW480)) by MTT assay. Mode of cell death was determined by acridine orange-ethidium bromide (Ao-Eb) staining. Putative cellular targets of ICA were investigated by molecular docking studies. Cell cycle analysis following curcumin or ICA treatment in SW480 cell line was carried out by flow cytometry. Expression levels of Cyclin D1 and apoptotic markers, such as Caspase 3, 8 and 9 were studied by western blot analysis in SW480 cell line treated with or without ICA and curcumin. Results The yield of ICA synthesis was found to be 69% with a purity of 98%. ICA demonstrated promising anti-cancer activity compared to curcumin alone, as discerned by MTT assay. ICA was non-toxic to the cell line of normal origin. We further observed that ICA is ∼2 fold more potent than curcumin in inhibiting the growth of SW480 cells. Ao-Eb staining revealed that ICA could induce apoptosis in all the cell lines tested. Molecular docking studies suggest that ICA may possibly exhibit its anticancer effect by inhibiting EGFR in A549, Bcr-Abl in K562 and GSK-3β kinase in SW480 cell line. Moreover, ICA showed strong binding avidity for Bcl-2 protein in silico, which could result in induction of apoptosis. Cell cycle analysis revealed that both curcumin and ICA induced concomitant cell cycle arrest at G0/G1 and G2/M phase. Western blot shows that ICA could effectively down regulate the expression of cell cycle protein cyclin D1, while promoting the activation of Caspase 3, 8 and 9 when compared to curcumin in human colon cancer cell line SW480. Conclusion The result of this study indicates that ICA could hold promise to be a potential anti-cancer agent. Since ICA has shown encouraging results in terms of its anti-cancer activity compared to curcumin, further research is necessary to fully delineate the underlying molecular mechanism of its anticancer potential. more...

Understanding the influence of ubiquitously present plant steroids on mammalian cell biology is currently of interest. Feedback inhibition of HMGCoA reductase (HMGCR) catalytic activity in the transformation of HMG-CoA to mevalonate is a significant regulatory step in sterol biosynthetic pathway. To assess the role of dietary steroids in this biochemical transformation, the phytosteroid isoform 28-homobrassinolide (28-HB), 90 % pure, obtained from Godrej Agrovet (India) was used to determine its effect on mammalian HMG-CoA reductase. Photometric assay of pure human and select rat tissue HMGCR post 28-HB oral feed, PCR-HMGCR gene expression, and in silico docking of 28-HB and HMGCoA on HMGCR protein template were carried out. Using an oral feed regimen of pure 28-HB, we noted a decrease of 16 % in liver, 17.1 % in kidney and 9.3 % in testicular HMGCR enzyme activity, 25 % in HMGCR gene expression and 44 % in the activity of pure human HMGCR due to this plant oxysterol. In silico docking studies yielded binding metrics for 28-HB-HMGCR lower than for HMGCoA-HMGCR, indicating stronger binding of HMGCR by this ligand. 28-HB exerts differential effects on rat tissue HMGCR, down regulates liver HMGCR gene expression and significantly inhibits HMGCR activity. more...

The major therapeutic limitation of curcumin and indole-incorporated curcumin analog is its low bioavailability. We hypothesized that nano-encapsulation of indole-incorporated curcumin analog and curcumin as a biodegradable polymeric nanoparticle may enhance its bioavailability with extended drug retention time. Indole-incorporated curcumin analog and curcumin loaded PLGA nanoparticles were synthesized by solvent evaporation technique. Physicochemical characterizations and anti-cancer potential of the nanoparticles were evaluated in human colon cancer cell line SW480. The synthesized NPs had a size range of 50–150 nm diameter. The nano-formulation preserved the drug from degradation in wide ranges of pH environments. The nanoparticles treatment against SW480 cancer cell line triggered nuclear fragmentation, cell cycle blockade, inhibition of apoptosis and metastatic biomarkers. These drug-loaded nanoparticles may be potent nano-formulations against colon cancer because of its ability to tolerate extreme pH environments, thus having potential of oral drug-delivery. more...

Aim: Our hypothesis was to prove that surface modifiers themselves can be used as stabilizers and that their entrapment efficiency is directly influenced by the type of stabilizers used. Materials & methods: Particle size and the polydispersity index of the nanoparticles (NPs) were measured by dynamic light scattering, whereas the morphology of the NPs was studied by scanning electron microscopy. Percentage nanoparticle yield, entrapment efficiency and drug loading capacity were measured by ultraviolet absorbance. The physical rigidity, robustness and drug releasing capability of these NPs were also assessed. Conclusion: Physiochemical characterization and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay suggest that polysorbate 80 has the dual capability of being a stabilizer and a surface modifier in addition to having better drug entrapment properties than Pluronic®188. Disulfiram, the drug that was loaded on these NPs, is also observed for the first time to show significant anticancer potential against hepatocellular carcinoma (Hep3B) cell lines. more...

Aim: Stabilizers are known to be an integral component of polymeric nanostructures. Ideally, they manipulate physicochemical properties of nanoparticles. Based on this hypothesis, we demonstrated that disulfiram (drug) and Poly-lactide-co-glycolide (polymer) interactions and physicochemical properties of their nanoparticles formulations are significantly influenced by the choice of stabilizers. Methodology: Electron microscopy, differential scanning calorimetry, x-ray diffraction, Raman spectrum analysis, isothermal titration calorimetry and in silico docking studies were performed. Results & discussion: Polysorbate 80 imparted highest crystallinity while Triton-X 100 imparted highest rigidity, possibly influencing drug bioavailability, blood-retention time, cellular uptake and sustained drug release. All the molecular interactions were hydrophobic in nature and entropy driven. Therefore, polymeric nanoparticles may be critically manipulated to streamline the passive targeting of drug-loaded nanoparticles., Lay abstract Polymeric nanoparticles are futuristic drug-delivering platforms that have many potential advantages above conventional drug-delivery tools. They are mainly composed of a polymer, stabilizer and the therapeutic ingredient. A number of researches are on-going to improvise various characteristics of polymeric nanoparticles, in order to enhance its efficacy. The current study is one such domain where we emphasize on identifying potential stabilizing factors that are involved in nanoparticles formation and their drug entrapment and release properties. more...