Activation of ERK/NF-kB Pathways Contributes to the Inflammatory Response in Epithelial Cells and Macrophages Following Manganese Exposure.

Different types of metals, including manganese (Mn), are constantly encountered in various environmental matrices due to natural and anthropogenic activities. They induce a sustained inflammatory response in various organs, which is considered to be an important priming event in the pathogenesis of several diseases. Mn-induced neuroinflammation and subsequent neurodegeneration are well recognized. However, emerging data suggest that occupationally and environmentally relevant levels may affect various organs, including the lungs. Therefore, the present study was carried out to investigate the effects of Mn (as Mn2+) exposure on the inflammatory response in human normal bronchial (BEAS-2B) and adenocarcinoma alveolar basal (A549) epithelial cells, as well as in murine macrophages (J774). Mn2+ exposure significantly induced mRNA and protein expression of various pro-inflammatory mediators (cytokines and chemokines) in all cells compared to corresponding vehicle controls. Furthermore, Mn2+ treatment also led to increased phosphorylation of extracellular-signal-regulated kinase (ERK)1/2 and nuclear factor-kappa B (NF-kB) p65 in both epithelial cells and macrophages. As expected, cells treated with inhibitors of ERK1/2 (PD98059) and NF-kB p65 (IMD0354) effectively mitigated the expression of various pro-inflammatory mediators induced by Mn2+, suggesting that ERK/NF-kB pathways have a critical role in the Mn2+-induced inflammatory response. Further, in vivo studies are required to confirm these in vitro findings to support clinical translation.

Anti-virulence properties of catechin-in-cyclodextrin-in-phospholipid liposome through down-regulation of gene expression in MRSA strains.

Methicillin resistant Staphylococcus aureus (MRSA) is a prime pathogen responsible for various infections in human beings. Expression of virulence factors is a biggest challenge in MRSA, which results in failure of conventional antibiotic therapy. In connection to the search for natural and safe anti-virulence compounds, the present study focused to evaluate the anti-virulence potential of catechin-in-cyclodextrin-in-phospholipid liposome (CCPL) on MRSA strains. CCPL inhibited young biofilm (64.15-72.70%) as well degraded mature biofilm (55.60-63.65%) at ½ and » MIC doses, which was further confirmed by scanning electron microscopy and confocal laser scanning microscope studies. CCPL was capable enough to modify the surface hydrophobicity (40.26-48.59%), reduce the EPS production (1.71-2.25 folds) and bacterial motility. In addition, CCPL inhibited the synthesis of virulence factors like slime production (0.40-0.50 folds), DNase production, hemolytic activity (28.08-49.07%), proteolytic production (14.65-18.04%), lipase production, autolysis and cell auto-aggregation. CCPL prevented the staphyloxanthin production and thereby increased the susceptibility of MRSA strains towards H2O2. Further, CCPL significantly down-regulated the virulence genes (agrA, agrC, clfA, clfB, fnbA, fnbB, icaA, icaD, hla, hld, rna III, atlA, sarA, sigB & geh). Thus, the results of present study revealed that the CCPL can effectively reduce the virulence properties and its application could inhibit the pathogenicity and also prevents the development of drug-resistance in MRSA strains.

Anti-asthmatic effects of tannic acid from Chinese natural gall nuts in a mouse model of allergic asthma.

Asthma is a chronic inflammatory disease of the airways, which is characterized by infiltration of inflammatory cells, airway hyperresponsiveness (AHR), and airway remodeling. This study aimed to explore the role and mechanism of tannic acid (TA), a naturally occurring plant-derived polyphenol, in murine asthma model. BALB/c mice were given ovalbumin (OVA) to establish an allergic asthma model. The results revealed that TA treatment significantly decreased OVA-induced AHR, inflammatory cells infiltration, and the expression of various inflammatory mediators (Th2 and Th1 cytokines, eotaxin, and total IgE). Additionally, TA treatment also attenuated increases in mucins (Muc5ac and Muc5b) expression, mucus production in airway goblet cells, mast cells infiltration, and airway remodeling induced by OVA exposure. Furthermore, OVA-induced NF-κB (nuclear factor- kappa B) activation and cell adhesion molecules expression in the lungs was suppressed by TA treatment. In conclusion, TA effectively attenuated AHR, inflammatory response, and airway remodeling in OVA-challenged asthmatic mice. Therefore, TA may be a potential therapeutic option against allergic asthma in clinical settings.

Apoptotic mechanisms of myricitrin isolated from Madhuca longifolia leaves in HL-60 leukemia cells.

Myricitrin, a naturally occurring flavonoid in Madhuca longifolia, possesses several medicinal properties. Even though our earlier work revealed its role against the proliferation of acute myelogenous leukemia cells (HL-60), its molecular mechanisms have not yet been revealed. The current study aims to explore the molecular mechanisms of myricitrin (isolated from an ethnomedicinal drug Madhuca longifolia) to induce apoptosis in HL-60 cells. Treatment with IC-50 dose of myricitrin (353 µM) caused cellular shrinkage and cell wall damage in HL-60 cells compared to untreated control cells. Myricitrin treatment reduced the mitochondrial membrane potential (22.95%), increased DNA fragmentation (90.4%), inhibited the cell survival proteins (RAS, B-RAF, & BCL-2) and also induced pro-apoptotic proteins (p38, pro-caspase-3, pro-caspase-9 and caspase-3) in the HL-60 cells. The present study provides scientific evidence for the apoptosis caused by myricitrin in HL-60 leukemia cells. Hence, the phytochemical myricitrin could be considered as a potential candidate to develop an anticancer drug after checking its efficacy through suitable pre-clinical and clinical studies.

Synergic effect of eugenol oleate with amphotericin B augments anti-leishmanial immune response in experimental visceral leishmaniasis in vitro and in vivo.

Present treatment regimen on visceral leishmaniasis has multiple limitations including severe side effects, toxicity, and resistance of Leishmania strains. Amphotericin B is a well-established pharmacologically approved drug; however, mainly toxicity is a foremost issue with that drug. Recently, our group identified eugenol oleate as an anti-leishmanial immunomodulatory compound. The important objectives of this present study was to evaluate the possible synergistic effect of eugenol oleate with amphotericin B to reduce the toxicity of this approved drug. Results obtained from this study signified that combination of eugenol oleate and amphotericin B showed indifferent combinatorial effect against promastigotes with xΣFIC 1.015, while, moderate synergistic activity with xΣFIC 0.456 against amastigotes. It was also notable that eugenol oleate (2.5 µM) with low concentrations of amphotericin B (0.3125 µM) showed 96.45% parasite reduction within L. donovani-infected murine macrophages. Furthermore, eugenol oleate and amphotericin B significantly (p < 0.01) enhanced the nitrite generation, and pro-inflammatory cytokines (IL-12, IFN-γ and TNF-α) in infected macrophages in vitro and in BALB/c mice in vivo. Eugenol oleate (10 mg/Kg b. wt.) with amphotericin B (1 mg/Kg b.wt.) significantly (p < 0.01) controlled the parasite burden in liver by 96.2% and in spleen by 93.12%. Hence, this study strongly suggested the synergic potential of eugenol oleate with low concentration of amphotericin B in experimental visceral leishmaniasis through anti-leishmanial immune response.

Lead Generation for Human Mitotic Kinesin Eg5 Using Structure-based Virtual Screening and Validation by In-vitro and Cell-based Assays.

BACKGROUND: Human mitotic kinesins play a crucial role in mitotic cell division. Targeting the spindle separation phase of mitosis has gained much attention pharmaceutically in cancer chemotherapy. Spindle segregation is carried out mainly by Eg5 kinesin, and currently, it has many inhibitors in different phases of clinical trials. All the current drug candidates bind un-competitively with ATP/ADP at allosteric site 1 (formed by loop L5, helix α2 and helix α3). Recent experiments show that inhibitors that bind to the site 2 (formed by helix α4 and helix α6) are either competitive or uncompetitive to ATP/ADP. OBJECTIVES: To identify suitable lead compounds that target the mitotic kinesin Eg5, using in silico screening and their validation using in vitro and cell-based assays. METHODOLOGY: Potential inhibitors were screened for human Eg5 (kinesin-5) through structurebased virtual screening and the top-scoring compounds were validated using steady-state ATPase assay, differential scanning fluorimetry, and microscale thermophoresis. The anti-cancer activity of the compounds was evaluated in the epithelial (A549) and chronic myelogenous leukemia (K562) cancer cell lines. A known strong binding inhibitor, S-trityl-L-cystine, is used as a reference compound. RESULTS: Out of the many compounds tested, MM01 and MM03 showed good cell-based activity against the cancer cell lines A549 and K562 and can be further studied in animal models. CONCLUSION: In this study, a structure-based approach was used to identify the potential inhibitors and validate them using different in-vitro and cell-based assays.

Tannic acid alleviates experimental pulmonary fibrosis in mice by inhibiting inflammatory response and fibrotic process.

Pulmonary fibrosis (PF) is a chronic and irreversible scarring disease in the lung with limited treatment options. Therefore, it is critical to identify new therapeutic options. This study was undertaken to identify the effects of tannic acid (TA), a naturally occurring dietary polyphenol, in a mouse model of PF. Bleomycin (BLM) was intratracheally administered to induce PF. Administration of TA significantly reduced BLM-induced histological alterations, inflammatory cell infiltration and the levels of various inflammatory mediators (nitric oxide, leukotriene B4 and cytokines). Additionally, treatment with TA also impaired BLM-mediated increases in pro-fibrotic (transforming growth factor-ß1) and fibrotic markers (alpha-smooth muscle actin, vimentin, collagen 1 alpha and fibronectin) expression. Further investigation indicated that BLM-induced phosphorylation of Erk1/2 (extracellular signal-regulated kinases 1 and 2) in lungs was suppressed by TA treatment. Findings of this study suggest that TA has the potential to mitigate PF through inhibiting the inflammatory response and fibrotic process in lungs and that TA might be useful for the treatment of PF in clinical practice.

Oxidative stress mediated cytotoxicity in leukemia cells induced by active phyto-constituents isolated from traditional herbal drugs of West Bengal.

ETHNOPHARMACOLOGICAL RELEVANCE: In search of safe and effective therapeutic agents as alternative to synthetic chemotherapeutics for the treatment of leukemia, the herbal drugs (Leaf of Madhuca longifolia, leaf of Prosopis cineraria and bark of Flacourtia indica) with long traditional use in West Bengal have received our attention. AIM OF THE STUDY: Present work was conducted to isolate and identify the active compounds of the selected herbal drugs using bio-assay guided fractionation and also to investigate their anticancer mechanism in leukemia cell lines. MATERIALS AND METHODS: Bio-assay guided fractionation was used for the isolation of active constituents such as myricitrin, vitexin and vanillin from the aqueous extracts of M. longifolia, P. cineraria and F. indica, respectively using liquid partitioning and column chromatography and the compounds were characterized by HPLC, MS and NMR. Dose and time-dependent cytotoxicity of isolated compounds were studied against leukemia cells and their anticancer mechanism such as cell wall damage, nuclear damage, ROS and NO generation, SOD level, LDH release and lipid peroxidation were investigated. RESULTS: Aqueous extract of M. longifolia, P. cineraria and F. indica exhibited maximum anti-proliferative activity against HL-60 (Acute myeloid leukemia, AML, 72.06%), K-562 (Chronic myeloid leukemia, CML, 42.14%) and Jurkat (Acute lymphoblastic leukemia, ALL, 51.71%) cells. Myricitrin, vitexin and vanillin exhibited dose-dependent (IC-50 values 164.4, 147 & 29.22 µg/ml) and time-dependent activity with maximum cytotoxicity at 48 h. All these three compounds caused apoptosis in leukemia cells by inducing free radicals such as ROS (1.33-2.65 Arbitrary units) and NO (11.17-18.53 µM), cell membrane damage and nuclear condensation which were evidenced by increased release of LDH (1326-1439 U/L), improved lipid peroxidation (10.19-14.41 nM/mg protein) and reduced SOD level (6.2-9.21 U/mg protein) in leukemia cells. CONCLUSIONS: Based on anti-proliferative activity, the isolated phyto-compounds myrcitrin, vitexin and vanillin from M. longifolia, P. cineraria and F. indica could be developed as natural drugs for treating AML, CML and ALL leukemia types, respectively.

Tannic acid prevents macrophage-induced pro-fibrotic response in lung epithelial cells via suppressing TLR4-mediated macrophage polarization.

BACKGROUND: Polarized macrophages induce fibrosis through multiple mechanisms, including a process termed epithelial-to-mesenchymal transition (EMT). Mesenchymal cells contribute to the excessive accumulation of fibrous connective tissues, leading to organ failure. This study was aimed to investigate the effect of tannic acid (TA), a natural dietary polyphenol on M1 macrophage-induced EMT and its underlying mechanisms. MATERIALS: First, we induced M1 polarization in macrophage cell lines (RAW 264.7 and THP-1). Then, the conditioned-medium (CM) from these polarized macrophages was used to induce EMT in the human adenocarcinomic alveolar epithelial (A549) cells. We also analysed the role of TA on macrophage polarization. RESULTS: We found that TA pre-treated CM did not induce EMT in epithelial cells. Further, TA pre-treated CM showed diminished activation of MAPK in epithelial cells. Subsequently, TA was shown to inhibit LPS-induced M1 polarization in macrophages by directly targeting toll-like receptor 4 (TLR4), thereby repressing LPS binding to TLR4/MD2 complex and subsequent signal transduction. CONCLUSION: It was concluded that TA prevented M1 macrophage-induced EMT by suppressing the macrophage polarization possibly through inhibiting the formation of LPS-TLR4/MD2 complex and blockage of subsequent downstream signal activation. Further, our findings may provide beneficial information to develop new therapeutic strategies against chronic inflammatory diseases.

Tannic acid protects against experimental acute lung injury through downregulation of TLR4 and MAPK.

Acute lung injury (ALI) and its severe form acute respiratory distress syndrome (ARDS) remain a major cause of morbidity and mortality in critically ill patients, and no specific therapies are still available to control the mortality rate. Thus, we explored the preventive and therapeutic effects of tannic acid (TA), a natural polyphenol in the context of ALI. We used in vivo and in vitro models, respectively, using lipopolysaccharide (LPS) to induce ALI in mice and exposing J774 and BEAS-2B cells to LPS. In both preventive and therapeutic approaches, TA attenuated LPS-induced histopathological alterations, lipid peroxidation, lung permeability, infiltration of inflammatory cells, and the expression of proinflammatory mediators. In addition, in-vitro study showed that TA treatment could reduce the expression of proinflammatory mediators. Further studies revealed that TA-dampened inflammatory responses by downregulating the LPS-induced toll-like receptor 4 (TLR4) expression and inhibiting extracellular-signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) activation. Furthermore, cells treated with the inhibitors of ERK1/2 (PD98059) and p38 (SB203580) mitigated the expression of cytokines induced by LPS, thus suggesting that ERK1/2 and p38 activity are required for the inflammatory response. In conclusion, TA could attenuate LPS-induced inflammation and may be a potential therapeutic agent for ALI-associated inflammation in clinical settings.

Potential anti-proliferative activity of AgNPs synthesized using M. longifolia in 4T1 cell line through ROS generation and cell membrane damage.

To overcome the problem of breast cancer, silver nanoparticles (AgNPs) synthesized using Indian medicinal plant Madhuca longifolia could be explored as an alternative anticancer medicine. Synthesized AgNPs were studied their characteristics and their anti-proliferative property was investigated in breast cancer cell line (4T1). Based on zeta sizer analysis, the size of the AgNPs was 103.5 nm and potential -9.57 eV. Fe-SEM results showed particle size of 69.4-99.4 nm while TEM images indicated the particle size of 18-24 nm. In dose-dependent study, AgNPs showed 93% of anti-proliferative activity at 50 µg/ml whereas the methanolic extract of M. longifolia showed 80% activity only at 10-fold increased concentration (500 µg/ml). AgNPs exhibited higher level of cytotoxicity in breast cancer cell line than extract through cell wall degradation and ROS generation. Such effective AgNPs could be investigated further through in vivo models with a view to develop anticancer drug.

Self assembled nano fibers of betulinic acid: A selective inducer for ROS/TNF-alpha pathway mediated leukemic cell death.

The main complication in betulinic acid (BA) based drug delivery has been observed due to its bulk structure. The present study demonstrates the potential effects of self assembled nano size betulinic acid (SA-BA) by treating human leukemic cell lines (KG-1A and K562) and its normal counterpart. Self assembly property of BA was investigated using SEM and DLS study which showed that the BA forms fibrous structure having few nanometers in diameter. Selective anti-leukemic efficacy study of SA-BA was investigated by cell viability assay. Mode of leukemic cell death and probable pathway of apoptosis was monitored by measuring ROS level, pro and anti-inflammatory cytokine status and expression of caspase-8 and caspage-3 by immunocytochemistry. Higher efficacy of SA-BA over non-assemble BA was monitored toward cancer cells, with no relevant toxicity to normal blood cells. SA-BA facilitated reactive oxygen species (ROS) mediated leukemic cell death, confirmed by pre-treatment of N-acetyl-L-cysteine. Induction of apoptosis by SA-BA treatment increased pro-inflammatory cytokines, specifically potentiated TNF-α mediated cell death, confirmed by expression of caspase-8 and caspage-3 by immunocytochemistry. This study explored the better anti-leukemic efficacy of SA-BA over BA and this modification will enrich the use of BA in cancer therapy.

Self-assembled betulinic acid augments immunomodulatory activity associates with IgG response.

Studies relating to the adjuvanic role of self assembly, nanosized betulinic acid (SA-BA) are relatively limited. The concept of immunostimulatory activity of SA-BA is based on the activation of immune system against cancer antigen. This study showed that SA-BA, a pentacyclic triterpene isolated from the bark of the Ziziphus jujube tree, elevated the immunological functions of cancer antigen in anticancer immunotherapy. We found that, SA-BA pulsed human macrophages secreted elevated level of pro-inflammatory cytokines with an increased CD4(+) cell population. Pulse macrophages were also significantly arrested the KG-1A and K562 cell growth in vitro setup at 1:10 ratio for 48h. The use of TNF-α inhibitors confirmed the association between SA-BA with TNF-α function. SA-BA pulsed macrophages displayed substantial T cell allostimulatory capacity and promoted the generation of cytotoxic T lymphocytes (CTLs). The adjuvanticity of SA-BA was proved by the generation of in vivo IgG response. Collectively, these findings will enrich the biomedical applications of SA-BA as a potent immune stimulating agent. Moreover, the macrophage stimulating efficacy of SA-BA might be an effective way in the cancer immunotherapy.

Phytopharmacological approach of free radical scavenging and anti-oxidative potential of eugenol and Ocimum gratissimum Linn.

OBJECTIVE: To evaluate phytopharmacologically eugenol and two extract products of Ocimum gratissimum Linn. (O. gratissimum) (Labiaceae) on free radical scavenging and antioxidant activity. METHODS: Aqueous and methanol extract of fresh aerial part of O. gratissimum were prepared and eugenol (1-allyl-4-hydroxy-3-methoxybenzene) was isolated from fresh leaves and characterized by high performance liquid chromatography, fourier transform infrared spectroscopy, 1 h nuclear magnetic resonance. To establish the antioxidant potentiality of aqueous extract, methanol extract and eugenol, 1, 1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, nitric oxide scavenging activity, antioxidant activity by ferric thiocyanate and reducing power were measured in chemical system in vitro. RESULTS: Significant (P<0.05) concentration-dependent free radical scavenging activity, antioxidant activity, and reducing power was observed by O. gratissimum products. Moreover, eugenol is more potent than the two extract products of O. gratissimum, but lower than potent antioxidant ascorbic acid. CONCLUSIONS: Hence, O. gratissimum presents a potentially valuable source of natural antioxidant and bioactive material.

Double mutation in the pfmdr1 gene is associated with emergence of chloroquine-resistant Plasmodium falciparum malaria in Eastern India.

Malaria is a major public health problem in tropical and subtropical countries, including India. This study elucidates the cause of chloroquine treatment failure (for Plasmodium falciparum infection) before the introduction of artemisinin combination therapy. One hundred twenty-six patients were randomized to chloroquine treatment, and the therapeutic efficacy was monitored from days 1 to 28. An in vitro susceptibility test was performed with all isolates. Parasitic DNA was isolated, followed by PCR and restriction digestion of different codons of the pfcrt gene (codons 72 to 76) and the pfmdr1 gene (N86Y, Y184F, S1034C, N1042D, and D1246Y). Finally, sequencing was done to confirm the mutations. Forty-three (34.13%) early treatment failure cases and 16 (12.69%) late treatment failure cases were observed after chloroquine treatment. In vitro chloroquine resistance was found in 103 isolates (81.75%). Twenty-six (60.47%) early treatment failure cases and 6 (37.5%) late treatment failure cases were associated with the CVMNK-YYSNY allele (the underlined amino acids are those that were mutated). Moreover, the CVIEK-YYSNY allele was found in 8 early treatment failure (18.60%) and 2 late treatment failure (12.5%) cases. The presence of the wild-type pfcrt (CVMNK) and pfmdr1 (YYSNY) double mutant allele in chloroquine-nonresponsive cases was quite uncommon. In vivo chloroquine treatment failure and in vitro chloroquine resistance were strongly correlated with the CVMNK-YYSNY and CVIEK-YYSNY haplotypes (P < 0.01).

A prospective strategy to restore the tissue damage in malaria infection: Approach with chitosan-trypolyphosphate conjugated nanochloroquine in Swiss mice.

Accumulating evidence indicates that wide range of polymer based nanoconjugated drug have the ability to overcome the microbial infection. The present study was to evaluate the effects of nanoconjugated chloroquine (Nch) against Plasmodium berghei NK65 (P. berghei) infection on selective makers of oxidative damage, antioxidant status, pro-inflammatory and anti-inflammatory cytokines in liver and spleen. P. berghei infected Swiss mice were treated with Nch (250mg/kg bw for 15 days) compared with chloroquine. The stress markers, pro-inflammatory cytokines were increased significantly (P<0.05) and the anti-oxidant enzymes level, redox ratio (GSH/GSSG), anti-inflammatory markers were decreased significantly (P<0.05) in liver and spleen of infected mice compared with uninfected mice. Chloroquine and Nch effectively decreased the stress markers, pro-inflammatory cytokines, as well as, increased antioxidants level in liver and spleen of the infected mice. Moreover, the favorable effect Nch is better than the chloroquine defending the tissue damage during malarial infection. These findings suggested that the potential use and prospective role of Nch than only chloroquine against P. berghei induced pathology as well as oxidative damage in liver and spleen.

A novel chitosan based antimalarial drug delivery against Plasmodium berghei infection.

Chitosan is a natural polysaccharide that has attracted significant scientific interest during the last two decades and chitosan based nanodrug delivery systems seem to be a hopeful and viable strategy for improving disease treatment. This study aims to evaluate the potency of the polymer based nanochloroquine in application for attenuation of Plasmodium berghei infection in Swiss mice and effectiveness against the parasite induced oxidative stress and deoxyribo nucleic acid (DNA) damage in lymphocytes. Nanoparticle was prepared by ionotropic gelation between chitosan and sodium tripolyphosphate. The chloroquine was treated by the actual drug content of effective nanochloroquine and the nanodrug was charged with its effective dose for fifteen days, after successive infection development in Swiss mice. Gimsa staining of thin smear and flow cytometry analysis was pursued to reveal the parasitemia. Different oxidative markers, inflammatory markers, antioxidant enzymes level and also lymphocytic deoxyribo nucleic acid damage study were performed. The present study reveals the potency of the nanodrug which has been found as more prospective than only chloroquine treatment to combat the parasite infection, oxidative stress as well as inflammation and DNA damage. From the study, we conclude this nanodrug may be applicable as potent therapeutic agent than only chloroquine.

In vitro time-dependent vancomycin-resistant Staphylococcus aureus-induced free radical generation and status of antioxidant enzymes in murine peritoneal macrophage.

Staphylococcus aureus is most frequently isolated pathogen causing bloodstream infections, skin and soft tissue infections, and pneumonia. The immune cells use reactive oxygen species (ROS) for carrying out their normal functions, while an excess amount of ROS can attack cellular components that lead to cell damage. The aim of the present study was to evaluate the free radical generation and status of the antioxidant enzymes in murine peritoneal macrophage during in vitro vancomycin-resistant S. aureus (VRSA) treatment with different time intervals. Peritoneal macrophages were treated with 5 × 10(6) colony-forming units (CFU)/mL VRSA cell suspension in vitro for different time intervals (1, 2, 3, 6, 12, and 24 h), and superoxide anion generation, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, myeloperoxidase (MPO) activity, nitric oxide (NO) generation, antioxidant enzyme status, and components of glutathione cycle were analyzed. Superoxide anion generation, NADPH oxidase activity, MPO activity, and NO generation got peak at 3 h indicates maximum free radical generation through activation of NADPH oxidase in murine peritoneal macrophages during VRSA infection. Reduced glutathione level, glutathione peroxidase, glutathione reductase, and glutathione S-transferase activity were decreased significantly (P < 0.05) with increasing time of VRSA infection. But the oxidized glutathione level was time-dependently increased significantly (P < 0.05) in murine peritoneal macrophages. All the changes in peritoneal macrophages after 3 h in vitro VRSA treatment had no significant difference. From this study, it may be summarized that in vitro VRSA infection not only generates excess free radical but also affects the antioxidant status and glutathione cycle in murine peritoneal macrophages.

Antioxidative effect of folate-modified chitosan nanoparticles.

OBJECTIVE: To evaluate the potency of carboxymethyl chitosan-2, 2' ethylenedioxy bis-ethylamine-folate (CMC-EDBE-FA) on tissue injury, antioxidant status and glutathione system in tissue mitochondria and serum against nicotine-induced oxidative stress in mice. METHODS: CMC-EDBE-FA was prepared on basis of carboxymethyl chitosan tagged with folic acid by covalently linkage through 2, 2' ethylenedioxy bis-ethylamine. Animals were divided into four groups, i.e., control, nicotine (1 mg/kg bw/day), CMC-EDBE-FA (1 mg/kg bw/day) and nicotine (1 mg/kg bw/day) and CMC-EDBE-FA (1 mg/kg bw/day) for 7 days. Levels of lipid peroxidation, oxidized glutathione level, antioxidant enzyme status and DNA damage were observed and compared. RESULTS: The significantly increase of lipid peroxidation, oxidized glutathione levels and DNA damage was observed in nicotine treated group as compared with control group; those were significantly reduced in CMC-EDBE-FA supplemented group. Moreover, significantly reduced antioxidant status in nicotine treated group was effectively ameliorated by the supplementation of CMC-EDBE-FA. Only CMC-EDBE-FA treated groups showed no significant change as compared with control group; rather than it repairs the tissue damage of nicotine treated group. CONCLUSIONS: These findings suggest that CMC-EDBE-FA is non-toxic and ameliorates nicotine-induced toxicity.

Nitric oxide mediated Staphylococcus aureus pathogenesis and protective role of nanoconjugated vancomycin.

OBJECTIVE: To test the survival of Staphylococcus aureus (S. aureus) inside lymphocyte that contributes to the pathogenesis of infection and possible anti-inflammatory and antioxidative effect of nanoconjugated vancomycin against in vivo S. aureus infection in a dose and duration dependent manner. METHODS: 5×10(6) CFU/mL vancomycin-sensitive S. aureus (VSSA) and vancomycin-resistive S. aureus (VRSA) were challenged in Swiss male mice for 3 days, 5 days, 10 days and 15 days, respectively. Bacteremia and inflammatory parameters were observed to evaluate the duration for development of VSSA and VRSA infection. 100 mg/kg bw/day and 500 mg/kg bw/day nanoconjugated vancomycin were administrated to VSSA and VRSA infected group for 5 days. Bacteremia, inflammatory parameters and oxidative stress related parameters were tested to observe the effective dose of nanoconjugated vancomycin against VSSA and VRSA infection. Nanoconjugated vancomycin was treated at a dose of 100 mg/kg bw/day and 500 mg/kg bw/day, respectively, to VSSA and VRSA infected group for successive 5 days, 10 days and 15 days. Bacteremia, inflammatory parameters and oxidative stress related parameters were observed to assess the effective duration of nanoconjugated vancomycin against VSSA and VRSA infection. RESULTS: The result revealed that in vivo VSSA and VRSA infection developed after 5 days of challenge by elevating the NO generation in lymphocyte and serum inflammatory markers. Administration with nanoconjugated vancomycin to VSSA and VRSA infected group at a dose of 100 mg/kg bw/day and 500 mg/kg bw/day, respectively, for successive 10 days eliminated bacterimia, decreased NO generation in lymphocyte, serum inflammatory markers and increased antioxidant enzyme status. CONCLUSIONS: These findings suggest, in vivo challenge of VSSA and VRSA for 5 days can produce the highest degree of damage in lymphocyte which can be ameliorated by treatment with nanoconjugated vancomycin for 10 successive days.