Biosynthesis of gold nanoparticles by Penicillium rubens and catalytic detoxification of ochratoxin A and organic dye pollutants / Biosíntesis de nanopartículas de oro por Penicillium rubens y desintoxicación catalítica de ocratoxina A y contaminantes colorantes orgánicos

The environmental pollution caused by chemical dyes is a growing concern nowadays. Limitations of traditional methods opened the route for nanotechnology; owing to the versatile properties of nanomaterials, gold nanoparticles (AuNPs) became a potential strategy for different applications. In the present study, biosynthesis of gold nanoparticles (BioAuNPs) was carried out by reacting chloroauric acid (HAuCl4) with cell-free filtrate of Penicillium rubens sp. nov. NCIM 1937. The AuNPs were then characterized by UV–visible spectroscopy, HR-TEM, FTIR, and DLS analysis to further examine their efficacious biosynthesis and morphological properties including size, shape, and stability. The biogenic AuNPs are polydisperse in nature, with a mean size of 14.92 ± 5 nm. These AuNPs exhibited promising antimicrobial activity against Escherichia coli NCIM-2065, Bacillus subtilis NCIM-2010, and Penicillium verrucosum MTCC 4935. In vitro quantitative HPLC results revealed that BioAuNPs significantly inhibited the biosynthesis of ochratoxin A (OTA). Microbial fuel cells (MFCs) are intriguing for power generation and wastewater treatment since they can directly transform chemical energy stored in organic matter to electricity by extracellular electron transfer (EET) via membrane proteins. AuNPs also showed excellent potential for dye degradation of organic pollutants, viz., methylene blue (MB), phenol red (PR), bromothymol blue (BTB), Congo red (CR), and 4-nitrophenol (4-NP). All dye removal efficiencies were estimated and fitted to pseudo-first-order processes using kinetic rate constants (Ka).The present study reveals a simple, original, and eco-friendly method for the synthesis of multifunctional biogenic AuNPs that could be effective in OTA detoxification in food products and organic pollutant removal during wastewater treatment for a sustainable environment.(AU)

Biosynthesis of gold nanoparticles by Penicillium rubens and catalytic detoxification of ochratoxin A and organic dye pollutants.

The environmental pollution caused by chemical dyes is a growing concern nowadays. Limitations of traditional methods opened the route for nanotechnology; owing to the versatile properties of nanomaterials, gold nanoparticles (AuNPs) became a potential strategy for different applications. In the present study, biosynthesis of gold nanoparticles (BioAuNPs) was carried out by reacting chloroauric acid (HAuCl4) with cell-free filtrate of Penicillium rubens sp. nov. NCIM 1937. The AuNPs were then characterized by UV-visible spectroscopy, HR-TEM, FTIR, and DLS analysis to further examine their efficacious biosynthesis and morphological properties including size, shape, and stability. The biogenic AuNPs are polydisperse in nature, with a mean size of 14.92 ± 5 nm. These AuNPs exhibited promising antimicrobial activity against Escherichia coli NCIM-2065, Bacillus subtilis NCIM-2010, and Penicillium verrucosum MTCC 4935. In vitro quantitative HPLC results revealed that BioAuNPs significantly inhibited the biosynthesis of ochratoxin A (OTA). Microbial fuel cells (MFCs) are intriguing for power generation and wastewater treatment since they can directly transform chemical energy stored in organic matter to electricity by extracellular electron transfer (EET) via membrane proteins. AuNPs also showed excellent potential for dye degradation of organic pollutants, viz., methylene blue (MB), phenol red (PR), bromothymol blue (BTB), Congo red (CR), and 4-nitrophenol (4-NP). All dye removal efficiencies were estimated and fitted to pseudo-first-order processes using kinetic rate constants (Ka).The present study reveals a simple, original, and eco-friendly method for the synthesis of multifunctional biogenic AuNPs that could be effective in OTA detoxification in food products and organic pollutant removal during wastewater treatment for a sustainable environment.

Aptamer Tethered Bio-Responsive Mesoporous Silica Nanoparticles for Efficient Targeted Delivery of Paclitaxel to Treat Ovarian Cancer Cells.

Ovarian cancer is the leading cause of cancer deaths in female patients. The current therapeutics in ovarian cancer are limited and inefficient in curing the disease. To tackle this, we have synthesized tetrasulfide derivative of silica doped, biodegradable, glutathione-responsive targeted mesoporous silica nanoparticles modified with heterobifunctional polyethylene glycol as a linker and mucin-1 aptamer for triggered paclitaxel delivery to the ovarian cancer cells. Degradable mesoporous silica nanoparticles were synthesized by a modified sol-gel method with tetraethyl orthosilicate and Bis (triethoxysilylpropyl) tetrasulfide. The degradable mesoporous silica nanoparticles were characterized by dynamic light scattering, Fourier-transform infrared spectroscopy, Scanning electron microscopy and Transmission electron microscopy. The degradable mesoporous silica nanoparticles had good paclitaxel encapsulation efficiency and glutathione-responsive paclitaxel release ability. The glutathione utilization assay and visual destruction observed within 10 days in transmission electron microscopy images confirmed the degradation of the mesoporous silica nanoparticles in the tumor cell environment. The targeted degradable mesoporous silica nanoparticles were efficiently taken up by ovarian cancer cell lines OVACAR-3 and PA-1. The cytotoxicity of bare mesoporous silica nanoparticles evaluated on NIH-3T3 cell line showed good biocompatibility (>90% cell viability). Significant toxicity on OVACAR-3 (IC50 25.66 nM) and PA-1 (IC50 42.93 nM) cell lines was observed when treated with paclitaxel-loaded targeted degradable mesoporous silica nanoparticles. Results of this study demonstrated that mucin-1 targeted, glutathione-responsive mesoporous silica nanoparticles loaded with paclitaxel had a significant antitumor effect on ovarian cancer cells. All these findings demonstrated that developed nano-formulation could be suitable for ovarian cancer treatment.

Challenges and emerging strategies for next generation liposomal based drug delivery: An account of the breast cancer conundrum.

The global cancer burden is witnessing an upsurge with breast cancer surpassing other cancers worldwide. Furthermore, an escalation in the breast cancer caseload is also expected in the coming years. The conventional therapeutic regimens practiced routinely are associated with many drawbacks to which nanotechnological interventions offer a great advantage. But how eminent could liposomes and their advantages be in superseding these existing therapeutic modalities? A solution is reflected in this review that draws attention to a decade-long journey embarked upon by researchers in this wake. This text is a comprehensive discussion of liposomes, the front runners of the drug delivery systems, and their active and passive targeting approaches for breast cancer management. Active targeting has been studied over the decade by many receptors overexpressed on the breast cancer cells and passive targeting with many drug combinations. The results converge on the fact that the actively targeted formulations exhibit a superior efficacy over their non-targeted counterparts and the all liposomal formulations are efficacious over the free drugs. This undoubtedly underlines the dominion of liposomal formulations over conventional chemotherapy. These investigations have led to the development of different liposomal formulations with active and passive targeting capacities that could be explored in depth. Acknowledging and getting a deeper insight into the liposomal evolution through time also unveiled many imperfections and unchartered territories that can be explored to deliver dexterous liposomal formulations against breast cancer and more in the clinical trial pipeline.

Mechanistic insight into differential interactions of iron oxide nanoparticles with native, glycated albumin and their effect on erythrocytes parameters.

Nanoparticles and protein bioconjugates have been studied for multiple biomedical applications. We sought to investigate the interaction and structural modifications of bovine serum albumin (BSA) with iron oxide nanoparticles (IONPs). The IONPs were green synthesized using E. crassipes aqueous leaf extract following characterization using transmission electron microscopy, energy dispersive X-ray analysis and X-ray diffraction. Two different concentrations of native/glycated albumin (0.5 and 1.5 mg/ml) with IONPs were allowed to interact for 1 h at 37 °C. Glycation markers, protein modification markers, cellular antioxidant, and hemolysis studies showed structural modifications and conformational changes in albumin due to the presence of IONPs. UV-visible absorbance resulted in hyperchromic and bathochromic effects of IONPs-BSA conjugates. Fluorescence measurements of tyrosine, tryptophan, advanced glycated end products, and ANS binding assay were promising and quenching effects proved IONPs-BSA conjugate formation. In FTIR of BSA-IONPs, transmittance was increased in amide A and B bands while decreased in amide I and II bands. In summary, native PAGE, HPLC, and FTIR analysis displayed a differential behaviour of IONPs with native and glycated BSA. These results provided an understanding of the interaction and structural modifications of glycated and native BSA which may provide fundamental repercussions in future studies.

Inhalable particles containing isoniazid and rifabutin as adjunct therapy for safe, efficacious and relapse-free cure of experimental animal tuberculosis in one month.

We investigated the preclinical efficacy and safety/tolerability of biodegradable polymeric particles containing isoniazid (INH) and rifabutin (RFB) dry powder for inhalation (DPI) as an adjunct to oral first-line therapy. Mice and guinea pigs infected with Mycobacterium tuberculosis H37Rv (Mtb) were treated with ∼80 and ∼300 µg of the DPI, respectively, for 3-4 weeks starting 3, 10, and 30 days post-infection. Adjunct combination therapy eliminated culturable Mtb from the lungs and spleens of all but one of 52 animals that received the DPI. Relapse-free cure was not achieved in one mouse that received DPI + oral, human-equivalent doses (HED) of four drugs used in the Directly Observed Treatment, Short Course (DOTS), starting 30 days post-infection. Oral doses (20 mg/Kg/day, each) of INH + RFB reduced Mtb burden from ∼106 to ∼103 colony-forming units. Combining half the oral dose with DPI prevented relapse of infection four weeks after stopping the treatment. The DPI was safe in rodents, guinea pigs, and monkeys at 1, 10, and 100 µg/day doses over 90 days. In conclusion, we show the efficacy and safety/tolerability of the DPI as an adjunct to oral chemotherapy in three different animal models of TB.

Stimuli-responsive biodegradable polyurethane nano-constructs as a potential triggered drug delivery vehicle for cancer therapy.

Polyurethanes (PUs) constitute an essential class of stimuli-responsive and biodegradable material, which has significantly contributed to the advancement of polymers utilization in the biomedical field. The bio-erodible PUs construct an active corridor for facilitating drug into tumor cells, which has significantly impacted the progression of nano-micellar delivery systems. The self-assembledcolloidal PUs pose distinctive features such as enhancing the solubility of hydrophobic chemotherapeutics, rapid cellular uptake, triggered erosion and drug release, bio-stimulus sensitivity, improvement in the targeting and proficiency ofbioactive. Cationic PUs can easily be condensed with genetic material to form polyplexes and have shown excellent transfection efficiency for potential gene therapy against various cancers. Their modifiable chemistry offers a tool to impart the desired multifunctionality such as biocompatibility, sensitivity to pH, redox, temperature, enzyme, etc. and ligand conjugation for active targeting. These diverse exceptional properties make them excellent nano-carrier for a variety of bioactive, including chemotherapeutic drugs, DNA, RNA, and diagnostic moieties to the target tissue or cells. The PUs based nano-devices have certainly uncovered the path to achieve ideal systems for controlled personalized therapy. The literature discussed in this review shed light on the research innovations carried out in the last ten years for the development of multifunctional PUs for triggered delivery of bioactive to treat various cancers.

Highly sensitive label-free bio-interfacial colorimetric sensor based on silk fibroin-gold nanocomposite for facile detection of chlorpyrifos pesticide.

Herein, the preparation of gold nanoparticles-silk fibroin (SF-AuNPs) dispersion and its label-free colorimetric detection of the organophosphate pesticide, namely chlorpyrifos, at ppb level are reported. The silk fibroin solution was extracted from B. mori silk after performing degumming, dissolving and dialysis steps. This fibroin solution was used for synthesis of gold nanoparticles in-situ without using any external reducing and capping agent. X-ray Diffractometry (XRD), Field Emission Transmission Electron Microscopy (FETEM) along with Surface Plasmon Resonance based optical evaluation confirmed generation of gold nanoparticles within SF matrix. The resultant SF-AuNPs dispersion exhibited rapid and excellent colorimetric pesticide sensing response even at 10 ppb concentration. Effect of additional parameters viz. pH, ionic concentration and interference from other pesticide samples was also studied. Notably, SF-AuNPs dispersion exhibited selective colorimetric pesticide sensing response which can be calibrated. Furthermore, this method was extended to various simulated real life samples such as tap water, soil and agricultural products including plant residues to successfully detect the presence of chlorpyrifos pesticide. The proposed colorimetric sensor system is facile yet effective and can be employed by novice rural population and expert researchers alike. It can be exploited as preliminary tool for label-free colorimetric chlorpyrifos pesticide sensing in water and agricultural products.

Correction: Topical Application of Ochratoxin A Causes DNA Damage and Tumor Initiation in Mouse Skin.

[This corrects the article DOI: 10.1371/journal.pone.0047280.].

Analysis of tail-anchored protein translocation pathway in plants.

Tail-anchored (TA) proteins are a special class of membrane proteins that carry out vital functions in all living cells. Targeting mechanisms of TA proteins are investigated as the best example for post-translational protein targeting in yeast. Of the several mechanisms, Guided Entry of Tail-anchored protein (GET) pathway plays a major role in TA protein targeting. Many in silico and in vivo analyses are geared to identify TA proteins and their targeting mechanisms in different systems including Arabidopsis thaliana. Yet, crop plants that grow in specific and/or different conditions are not investigated for the presence of TA proteins and GET pathway. This study majorly investigates GET pathway in two crop plants, Oryza sativa subsp. Indica and Solanum tuberosum, through detailed in silico analysis. 508 and 912 TA proteins are identified in Oryza sativa subsp. Indica and Solanum tuberosum respectively and their localization with respect to endoplasmic reticulum (ER), mitochondria, and chloroplast has been delineated. Similarly, the associated GET proteins are identified (Get1, Get3 and Get4) and their structural inferences are elucidated using homology modelling. Get3 models are based on yeast Get3. The cytoplasmic Get3 from O. sativa is identified to be very similar to yeast Get3 with conserved P-loop and TA binding groove. Three cytoplasmic Get3s are identified for S. tuberosum. Taken together, this is the first study to identify TA proteins and GET components in Oryza sativa subsp. Indica and Solanum tuberosum, forming the basis for any further experimental characterization of TA targeting and GET pathway mechanisms in crop plants.

Baicalin and chrysin mixture imparts cyto-protection against methylglyoxal induced cytotoxicity and diabetic tubular injury by modulating RAGE, oxidative stress and inflammation.

Protective effect of mixture of flavonoids baicalin and chrysin (BCH) was studied against methylglyoxal (MG, a precursor of AGEs) induced cytotoxicity in NRK 52E kidney epithelial cells. Flow cytometry and microscopic analysis showed increased ROS generation, compromised antioxidant status, depolarization of mitochondria and apoptosis in MG stressed cells which were significantly transformed (p≤0.01) during BCH co-treatment. In vivo studies in streptozotocin induced diabetic rats increased protein levels of iNOS, protein kinase C (PKC) and decreased IκB which was modulated by oral BCH treatment (75mg baicalin and 10mg chrysin/kg b.wt.). Increased levels of AGEs and their receptor proteins (RAGE) in diabetic rats were reduced significantly (p≤0.01) in BCH treated group. Renal tubular injuries and deranged kidney function were significantly improved in BCH treated animals. The results indicate that the protection accorded by BCH through its antioxidant and anti-inflammatory effects can be explored for management of diabetic nephropathy.

Cell factory-derived bioactive molecules with polymeric cryogel scaffold enhance the repair of subchondral cartilage defect in rabbits.

We have explored the potential of cell factory-derived bioactive molecules, isolated from conditioned media of primary goat chondrocytes, for the repair of subchondral cartilage defects. Enzyme-linked immunosorbent assay (ELISA) confirms the presence of transforming growth factor-ß1 in an isolated protein fraction (12.56 ± 1.15 ng/mg protein fraction). These bioactive molecules were used alone or with chitosan-agarose-gelatin cryogel scaffolds, with and without chondrocytes, to check whether combined approaches further enhance cartilage repair. To evaluate this, an in vivo study was conducted on New Zealand rabbits in which a subchondral defect (4.5 mm wide × 4.5 mm deep) was surgically created. Starting after the operation, bioactive molecules were injected at the defect site at regular intervals of 14 days. Histopathological analysis showed that rabbits treated with bioactive molecules alone had cartilage regeneration after 4 weeks. However, rabbits treated with bioactive molecules along with scaffolds, with or without cells, showed cartilage formation after 3 weeks; 6 weeks after surgery, the cartilage regenerated in rabbits treated with either bioactive molecules alone or in combinations showed morphological similarities to native cartilage. No systemic cytotoxicity or inflammatory response was induced by any of the treatments. Further, ELISA was done to determine systemic toxicity, which showed no difference in concentration of tumour necrosis factor-α in blood serum, before or after surgery. In conclusion, intra-articular injection with bioactive molecules alone may be used for the repair of subchondral cartilage defects, and bioactive molecules along with chondrocyte-seeded scaffolds further enhance the repair. Copyright © 2015 John Wiley & Sons, Ltd.

Cutaneous exposure to clinically-relevant pigeon pea (Cajanus cajan) proteins promote TH2-dependent sensitization and IgE-mediated anaphylaxis in Balb/c mice.

Epicutaneous (EC) sensitization to food allergens may occur when the skin has been lightly damaged. The study here tested whether cutaneous exposure to pigeon pea protein(s) may cause allergic sensitization. BALB/c mice were either orally gavaged or epicutaneously sensitized by repeated application of pigeon pea crude protein extract (CPE) on undamaged areas of skin without any adjuvant; afterwards, both groups were orally challenged with the pigeon pea CPE. Anaphylactic symptoms along with measures of body temperature, MCPT-1, TSLP, pigeon pea-specific IgE and IgG1, myeloperoxidase (MPO) activity, TH2 cytokines, TH2 transcription factors (TFs) and filaggrin expression were determined. Mast cell staining, eosinophil levels and histopathological analysis of the skin and intestines were also performed. In the epicutaneously-sensitized mice, elevated levels of specific IgE and IgG1, as well as of MCPT-1, TSLP, TH2 cytokines and TFs, higher anaphylactic scores and histological changes in the skin and intestine were indicative of sensitization ability via both routes in the pigeon pea CPE-treated hosts. Elevated levels of mast cells were observed in both the skin and intestine; increased levels of eosinophils and MPO activity were noted only in the skin. Decreased levels of filaggrin in skin may have played a key role in the skin barrier dysfunction, increasing the chances of sensitization. Therefore, the experimental data support the hypothesis that in addition to oral exposure, skin exposure to food allergens can promote TH2-dependent sensitization, IgE-mediated anaphylaxis and intestinal changes after oral challenge. Based on this, an avoidance of cutaneous exposures to allergens might prevent development of food anaphylaxis.

Deoxynivalenol induced mouse skin tumor initiation: Elucidation of molecular mechanisms in human HaCaT keratinocytes.

Among food contaminants, mycotoxins are toxic to both human and animal health. Our prior studies suggest that Deoxynivalenol (DON), a mycotoxin, behaves as a tumor promoter by inducing edema, hyperplasia, ODC activity and activation of MAPK's in mouse skin. In this study, topical application of DON, 336 and 672 nmol significantly enhanced ROS levels, DNA damage and apoptosis with concomitant downregulation of Ki-67, cyclin D, cyclin E, cyclin A and cyclin-dependent kinases (CDK4 and CDK2) thereby resulting in tumor initiation in mouse skin. Further, the elucidation of molecular mechanisms of tumor initiation by DON (0.42-3.37 nmol/ml) in HaCaT keratinocytes, revealed (i) enhanced ROS generation with cell cycle phase arrest in G0/G1 phase, (ii) increase in levels of 8-OxoG (6-24 hr) and γH2AX protein, (iii) significant enhancement in oxidative stress marker enzymes LPO, GSH, GR with concomitant decrease in antioxidant enzymes catalase, GPx, GST, SOD and mitochondrial membrane potential after DON (1.68 nmol) treatment, (iv) suppression of Nrf2 translocation to nucleus, enhanced phosphorylation with subsequent activation ERK1/2, p38 and JNK MAPK's following DON (1.68 nmol) treatment, (v) overexpression of c-jun, c-fos proteins, upregulation of Bax along with downregulation of Bcl-2 proteins, (vi) increase in cytochrome-c, caspase-9, caspase-3 and poly ADP ribose polymerase levels leads to apoptosis. Pretreatment of superoxide dismutase, mannitol and ethanol to HaCaT cells resulted in significant reduction in ROS levels and apoptosis indicating the role of superoxide and hydroxyl radicals in DON induced apoptosis as an early event and skin tumor initiation as a late event.

Reversion of Asthmatic Complications and Mast Cell Signalling Pathways in BALB/c Mice Model Using Quercetin Nanocrystals.

The tranquillizing effects of quercetin on allergic asthma are promising, but its poor water solubility and bioavailability is still a bottleneck. In this study, an ovalbumin (OVA) sensitized BALB/c mice asthma model was used to investigate the potential of quercetin nanocrystals (nQ) on relieving asthma aggravation. The water soluble nQ was prepared by the homogenization using the high energy sonication method. X-ray diffraction data showed the formation of nQ (10-30 nm) which was in agreement with transmission electron microscopy. The nQ was found to be more stable and soluble in PBS, and sera of BALB/c mice compared to bulk quercetin. Dose dependent experiments with nQ on OVA sensitized asthma mice exhibited significant anti-asthmatic potential of nQ at much lower dose (1 mg/kg body weight) compared to bulk quercetin. The treatment of nQ remarkably resulted in reduced OVA specific immunoglobulin E (sIgE) production, anaphylaxis signs and type 1 skin test. The nQ also significantly modulated the expression of Th2 cytokines like IL-4 and IL-5, which are responsible for IgE class switching and suppressed the degranulation/secretion of different chemical mediators (PGD2, mMCPT-1 Cys-L and TSLP) from activated mast cells. The levels of FcεR1, Syk, c-Yes, PI-3, p-PI-3, PLC-γ2, and p-PLC-γ2 were found to be reduced in the OVA sensitized BALB/c mice treated with nQ compared to those treated with OVA only. The results indicate that nQ alleviate pulmonary inflammation and airway hyporesponsiveness in allergic asthma at much lower dose compared to bulk quercetin and may be considered as a potential drug for the treatment of asthmatic patients.

Bilayer Cryogel Wound Dressing and Skin Regeneration Grafts for the Treatment of Acute Skin Wounds.

In this study, the potential of cryogel bilayer wound dressing and skin regenerating graft for the treatment of surgically created full thickness wounds was evaluated. The top layer was composed of polyvinylpyrrolidone-iodine (PVP-I) cryogel and served as the antiseptic layer, while the bottom regenerative layer was made using gelatin cryogel. Both components of the bilayer showed typical features of a cryogel interconnected macropore network, rapid swelling, high water uptake capacity of about 90%. Both PVP and gelatin cryogel showed high tensile strength of 45 and 10 kPa, respectively. Gelatin cryogel sheets were essentially elastic and could be stretched without any visible deformation. The antiseptic PVP-I layer cryogel sheet showed sustained iodine release and suppressed microbial growth when tested with skin pathogens (zone of inhibition ∼2 cm for sheet of 0.9 cm diameter). The gelatin cryogel sheet degraded in vitro in weeks. The gelatin cryogel sheet supported cell infiltration, attachment, and proliferation of fibroblasts and keratinocytes. Microparticles loaded with bioactive molecules (mannose-6-phosphate and human fibrinogen) were also incorporated in the gelatin cryogel sheets for their role in enhancing skin regeneration and scar free wound healing. In vivo evaluation of healing capacity of the bilayer cryogel was checked in rabbits by creating full thickness wound defect (diameter 2 cm). Macroscopic and microscopic observation at regular time intervals for 4 weeks demonstrated better and faster skin regeneration in the wound treated with cryogel bilayer as compared to untreated defect and the repair was comparable to commercial skin regeneration scaffold Neuskin-F. Complete skin regeneration was observed after 4 weeks of implantation with no sign of inflammatory response. Defects implanted with cryogel having mannose-6-phosphate showed no scar formation, while the wound treated with bilayer incorporated with human fibrinogen microparticles showed early signs of skin regeneration; epidermis formation occurred at 2 weeks after implantation.

Mitochondrial dysfunction induced by Bisphenol A is a factor of its hepatotoxicity in rats.

Bisphenol A (BPA), an estrogenic and endocrine disrupting agent, is widely used in manufacturing of polycarbonate plastics and epoxy resins. BPA and other endocrine disrupting chemicals (EDCs) act via multiple mechanisms including interference with mitochondrial functions. Mitochondria are the hub of cellular energy pool and hence are the target of many EDCs. We studied perturbation of activities of mitochondrial enzymes by BPA and its possible role in hepatotoxicity in Wistar rats. Rats were exposed to BPA (150 mg/kg, 250 mg/kg, 500 mg/kg per os, for 14 days) and activities of enzymes of mitochondrial electron transport chain (ETC) were measured. Besides, other biochemical parameters such as superoxide generation, protein oxidation, and lipid peroxidation (LPO) were also measured. Our results indicated a significant decrease in the activities of enzymes of mitochondrial ETC complexes, i.e., complex I, II, III, IV, and V along with significant increase in LPO and protein oxidation. Additionally, a significant increase in mitochondrial superoxide generation was also observed. All these findings could be attributed to enhanced oxidative stress, decrease in reduced glutathione level, and decrease in the activity of superoxide dismutase in rat liver mitochondria isolated from BPA-treated rats. BPA treatment also caused a significant increase in serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase indicating its potential hepatotoxicity. Furthermore, histopathological findings revealed marked edema formation, hepatocellular degeneration, and necrosis of liver tissue in BPA-exposed rats. In conclusion, this study provides an evidence of impaired mitochondrial bioenergetics and liver toxicity after high-dose BPA exposure in rats. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1922-1934, 2016.

Dietary administration of Nexrutine inhibits rat liver tumorigenesis and induces apoptotic cell death in human hepatocellular carcinoma cells.

Epidemiological studies suggested that plant-based dietary supplements can reduce the risk of liver cancer. Nexrutine (NX), an herbal extract from Phellodendronamurense, has been shown to have anti-inflammatory, anti-microbial and anti-tumor activities. In the present study, we have shown the anti-tumor potential of NX against Solt-Farber model with elimination of PH, rat liver tumor induced by diethylnitrosoamine (DEN) as carcinogen and 2-acetylaminofluorene (2-AAF) as co-carcinogen. The elucidation of mechanistic pathways was explored in human liver cancer cells. Dietary intake of NX significantly decreased the cell proliferation and inflammation, as well as increased apoptosis in the liver sections of DEN/2-AAF-treated rats. Moreover, NX (2.5-10 µg/ml) exposure significantly decreased the viability of liver cancer cells and modulated the levels of Bax and Bcl-2 proteins levels. NX treatment resulted in increased cytochrome-c release and cleavage of caspases 3 and 9. In addition, NX decreased the expression of CDK2, CDK4 and associated cyclins E1 and D1, while up-regulated the expression of p21, p27 and p53 expression. NX also enhanced phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK1/2, p38 and JNK1/2. Collectively, these findings suggested that NX-mediated protection against DEN/2-AAF-induced liver tumorigenesis involves decrease in cell proliferation and enhancement in apoptotic cell death of liver cancer cells.

Benzanthrone induced immunotoxicity via oxidative stress and inflammatory mediators in Balb/c mice.

Benzanthrone (BA) is an important dye intermediate which is used in the manufacturing of several polycyclic vat and disperse dyes in textile industries. Several studies have indicated that the general population is also exposed to BA owing to its release from furnace effluents and automobile exhausts in the environment. In several clinical studies, it has been shown that workers exposed to BA developed itching, burning sensation, erythema and hyperpigmentation of the skin, which could be an outcome of the dysregulated immune response. In this study, we have used female Balb/c mice as a model to study the immuno-inflammatory changes after systemic administration of BA (7.5mg/kgb.w. and 15mg/kgb.w.) for one week. BA exposed animals exhibited the signs of intense systemic inflammation as evident by enhanced DTH response, MPO activity, hyperplastic and dysplastic histopathological organization of spleen and lung tissue. Splenic evaluation revealed enhanced oxidative stress, upregulation of prominent inflammatory markers like iNOS and COX-2 and DNA damage. In coherence with the observed immuno-inflammatory alterations, the levels of several inflammatory and regulatory cytokines (IL-17, TNF-α, IFN-γ, IL-1, IL-10, IL-4) were significantly enhanced in serum as well as the spleen. In addition, BA administration significantly induced the activation of ERK1/2, p38, JNK MAPKs and their downstream transcription factors AP-1 (c-fos, c-jun), NF-κB and Nrf2 which comprise important mechanistic pathways involved in inflammatory manifestations. These results suggest the immunotoxic nature of the BA and have implications for the risk assessment and management of occupational workers, and even common masses considering its presence as an environmental contaminant.