C-Phycocyanin inhibits 2-acetylaminofluorene-induced expression of MDR1 in mouse macrophage cells: ROS mediated pathway determined via combination of experimental and In silico analysis

Comparative study on the effect of dietary β-carotene and phycocyanin extracted from Spirulina platensis on immune-oxidative stress biomarkers, genes expression and intestinal enzymes, serum biochemical in Nile tilapia, Oreochromis niloticus

The current trial investigated the roles of β-carotene and phycocyanin extracted from Spirulina platensis on growth, serum biochemical, digestive enzymes, antioxidant defense, immune responses, and immune gene expression in Nile tilapia (Oreochromis niloticus). Fish (1.52 ± 0.10 g) were randomly stocked to three treatments with three replicates (12 fish per replicate) in nine aquaria (60 L glass aquarium for each), and reared for 70-days. Three tested diets were formulated to be isonitrogenous and isolipidic, and were offered for experimental fish until ad-libitum three times daily at 09:00 a.m., 11.00 a.m. and 3:00 p.m. The first diet (control) was without supplementation. About 50 mg β-carotene and 50 mg phycocyanin kg^-1 were supplemented to the other experimental diets, respectively. Results indicated that feed intake was not (P > 0.05) differ among experimental diets. Compared to control diet wight gain and specific growth rate were significantly (P < 0.05) in fish fed diet containing β-carotene, while, the highest weight gain and the best FCR were detected in phycocyanin diet. Survival fish among treatments was significantly (P < 0.05) differ and the highest survival rate was showed in fish fed diet supplemented with phycocyanin. Either β-carotene or phycocyanin significantly (P < 0.05) improved the intestinal digestive enzymes compared with control diet, where the highest values of chymotrypsin, trypsin, lipase and amylase were noticed in fish fed phycocyanin. Diets supplemented with β-carotene and phycocyanin significantly (P < 0.05) improved hematology parameters contents compared with to the control diet, and the best contents were detected in fish fed diet supplemented with phycocyanin. The highest significant (P < 0.05) phagocytic, lysozyme, immunoglobulin M (IgM), superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and total antioxidant capacity (T-AOC) activities were recorded in diet supplemented with phycocyanin. The transcripts of interferon gamma and interleukin 1β genes were (P < 0.05) up-regulated in the liver of fish fed diet supplemented with β-carotene and phycocyanin, but expression of HSP70 gene down-regulated in fish fed β-carotene and phycocyanin containing diet compared control. The highest gene expression of the interferon gamma and interleukin 1β was observed in fish fed phycocyanin.

Spirulina Extract Enhanced a Protective Effect in Type 1 Diabetes by Anti-Apoptosis and Anti-ROS Production

Interest in the nutritional value and pharmacological activities of blue-green algae has gradually increased. Spirulina extracts show protective effects against apoptosis and inflammatory damage in various cell types. Here, we investigated the protective effects of extracts from Spirulina maxima in a cytokine-mediated type 1 diabetes model in vitro and in streptozotocin-induced diabetic Wistar rats in vivo. Interleukin-1β and interferon-gamma induced substantial cytotoxicity to RINm5F rat insulinoma cells, increasing nitric oxide (NO) production, nuclear factor-kappa B (NF-κB) activity, the expression of endoplasmic reticulum (ER) stress genes, and activation of mitogen-activated protein kinases and key genes related apoptosis. However, the cytotoxicity of cytokines was significantly attenuated by Spirulina extract, which effectively prevented NO production by inhibiting the synthesis of cytokine-activated NO synthase (iNOS), and apoptosis was suppressed. These results suggest that Spirulina extract might be effective to preserve the viability and function of pancreatic β-cells against cytotoxic conditions. Moreover, diabetic mice orally administered Spirulina extract showed decreased glucose levels, increased insulin, and improvement in liver enzyme markers. The antioxidant effect of Spirulina extract may be helpful in treating type 1 diabetes by enhancing the survival, and reducing or delaying cytokine-mediated β-cells destruction.

C-Phycocyanin: Cellular targets, mechanisms of action and multi drug resistance in cancer

C-Phycocyanin (C-PC) has been shown to be promising in cancer treatment; however, although several articles detailing this have been published, its main mechanisms of action and its cellular targets have not yet been defined, nor has a detailed exploration been conducted of its role in the resistance of cancer cells to chemotherapy, rendering clinical use impossible. From our extensive examination of the literature, we have determined as our main hypothesis that C-PC has no one specific target, but rather acts on the membrane, cytoplasm, and nucleus with diverse mechanisms of action. We highlight the cell targets with which C-PC interacts (the MDR1 gene, cytoskeleton proteins, and COX-2 enzyme) that make it capable of killing cells resistant to chemotherapy. We also propose future analyses of the interaction between C-PC and drug extrusion proteins, such as ABCB1 and ABCC1, using in silico and in vitro studies.

Lacritin Salvages Human Corneal Epithelial Cells from Lipopolysaccharide Induced Cell Death

Innate immunity of the corneal epithelium is conferred by proteinaceous secretions from the epithelium and associated lacrimal and meibomian glands. Lacritin, an eye-specific protein with anti-microbial, cytoprotective and wound-healing properties, predominantly secreted by lacrimal glands, is absent in conditions such as Dry eye and Keratitis. In view of the biological significance of lacritin in human eye, we investigated its role in human corneal epithelial (HCE) cells during lipopolysaccharide (LPS)-induced infection. LPS-challenged HCE cells demonstrated apoptosis-mediated cell death and elevated lacritin levels. The LPS-induced cell death is alleviated with exogenous supplementation of recombinant lacritin. This cytoprotective effect of lacritin is mediated through Cyclooxygenase-2 (COX-2). This study is the first to highlight the protective role of lacritin and mechanism of its action during bacterial infection of cornea in vitro.

Discovery of a novel isoxazoline derivative of prednisolone endowed with a robust anti-inflammatory profile and suitable for topical pulmonary administration

A novel glucocorticoids series of (GCs), 6α,9α-di-Fluoro 3-substituted C-16,17-isoxazolines was designed, synthesised and their structure-activity relationship was evaluated with glucocorticoid receptor (GR) binding studies together with GR nuclear translocation cell-based assays. This strategy, coupled with in silico modelling analysis, allowed for the identification of Cpd #15, an isoxazoline showing a sub-nanomolar inhibitory potency (IC50=0.84 nM) against TNFα-evoked IL-8 release in primary human airways smooth muscle cells. In Raw264.7 mouse macrophages, Cpd #15 inhibited LPS-induced NO release with a potency (IC50=6 nM)>10-fold higher with respect to Dexamethasone. Upon intratracheal (i.t.) administration, Cpd #15, at 0.1 μmol/kg significantly inhibited and at 1 μmol/kg fully counteracted eosinophilic infiltration in a model of allergen-induced pulmonary inflammation in rats. Moreover, Cpd #15 proved to be suitable for pulmonary topical administration given its sustained lung retention (t1/2=6.5h) and high pulmonary levels (>100-fold higher than plasma levels) upon intratracheal administration in rats. In summary, Cpd #15 displays a pharmacokinetic and pharmacodynamic profile suitable for topical treatment of conditions associated with pulmonary inflammation such as asthma and COPD.

Chebulagic acid from Terminalia chebula causes G1 arrest, inhibits NFκB and induces apoptosis in retinoblastoma cells

Background

Plants are the valuable source of natural products with important medicinal properties. Most of the approved anti cancer drugs have a natural product origin or are natural products. Retinoblastoma is the most common ocular cancer of children. Although chemotherapy is the preferred mode of therapy, a successful treatment for retinoblastoma requires enucleation. Chebulagic acid (CA) from Terminalia chebula was shown to have anti-proliferative properties in the studies on cancerous cell lines. Due to anti cancer properties of CA and due to limitation in treatment options for retinoblastoma, the present study is undertaken to understand the role of CA on the proliferation of retinoblastoma cells.

Methods

Anti proliferative potential of CA was determined by MTT assay. The expression levels of various cell death mediators in retinoblastoma cells with CA treatment were assessed by Western blotting. Flowcytometer analysis was used to estimate the mitochondrial membrane potential (MMP) and to determine the percentage of cells undergoing apoptosis.

Results

The present study showed CA inhibited the proliferation of retinoblastoma cells in a dose dependent manner. CA modulated MMP, induced release of Cytochrome c, activated caspase 3 and shifted the ratio of BAX and Bcl2 towards cell death. G1 arrest, noticed in CA treated cells, is mediated by the increase in the expression of CDK inhibitor p27. CA treatment also decreased the levels of NFκB in the nucleus. This decrease is mediated by suppression in degradation of IκBα.

Conclusion

CA has shown significant anti proliferative potential on retinoblastoma cells. Our findings clearly demonstrate that CA induces G1 arrest, inhibits NFκB and induces apoptosis of retinoblastoma cells.

Protective role of C-phycocyanin against secondary changes during sodium selenite mediated cataractogenesis

Age related cataract is the leading cause of blindness associated with accumulation of oxidative stress in the eye lens. The present investigation reveals the rational of the beneficial effects of the natural compound C-phycocyanin (C-PC) is beneficial when administered to rat pups to protect against the secondary effects of sodium selenite induced cataractogenesis. A single subcutaneous dose of sodium selenite (19 μmol/kg body weight) on the 10th day of postpartum is adequate to induce cataract in rat pups. Serum biochemical parameters, such as the level of electrolytes, mean activities of anti-oxidant enzymes i.e. superoxide dismutase, catalase and reduced glutathione were observed to be significantly altered during selenite induced cataractogenic process. Histopathological examination revealed signs of degradation of normal cell architecture in the liver, kidney and eye lens. Interestingly, the deleterious effects of sodium selenite toxicity were restored with the simultaneous treatment with C-PC. The results suggest that an administration of 200 mg/kg body weight of C-PC has the ability to prevent/alter the secondary changes reflected in the serum biochemical and histological modifications in rats exposed to sodium selenite. These results complement the beneficial role of C-PC of cyanobacterial origin as a efficacious anti-cataractogenic agent against sodium selenite toxicity.

Inhibition of P-glycoprotein by HIV protease inhibitors increases intracellular accumulation of berberine in murine and human macrophages

BACKGROUND

HIV protease inhibitor (PI)-induced inflammatory response in macrophages is a major risk factor for cardiovascular diseases. We have previously reported that berberine (BBR), a traditional herbal medicine, prevents HIV PI-induced inflammatory response through inhibiting endoplasmic reticulum (ER) stress in macrophages. We also found that HIV PIs significantly increased the intracellular concentrations of BBR in macrophages. However, the underlying mechanisms of HIV PI-induced BBR accumulation are unknown. This study examined the role of P-glycoprotein (P-gp) in HIV PI-mediated accumulation of BBR in macrophages.

METHODOLOGY AND PRINCIPAL FINDINGS

Cultured mouse RAW264.7 macrophages, human THP-1-derived macrophages, Wild type MDCK (MDCK/WT) and human P-gp transfected (MDCK/P-gp) cells were used in this study. The intracellular concentration of BBR was determined by HPLC. The activity of P-gp was assessed by measuring digoxin and rhodamine 123 (Rh123) efflux. The interaction between P-gp and BBR or HIV PIs was predicated by Glide docking using Schrodinger program. The results indicate that P-gp contributed to the efflux of BBR in macrophages. HIV PIs significantly increased BBR concentrations in macrophages; however, BBR did not alter cellular HIV PI concentrations. Although HIV PIs did not affect P-gp expression, P-gp transport activities were significantly inhibited in HIV PI-treated macrophages. Furthermore, the molecular docking study suggests that both HIV PIs and BBR fit the binding pocket of P-gp, and HIV PIs may compete with BBR to bind P-gp.

CONCLUSION AND SIGNIFICANCE

HIV PIs increase the concentration of BBR by modulating the transport activity of P-gp in macrophages. Understanding the cellular mechanisms of potential drug-drug interactions is critical prior to applying successful combinational therapy in the clinic.

Spirulina prevents memory dysfunction, reduces oxidative stress damage and augments antioxidant activity in senescence-accelerated mice

Spirulina has proven to be effective in treating certain cancers, hyperlipidemia, immunodeficiency, and inflammatory processes. In this study, we aimed to investigate the effects of Spirulina on memory dysfunction, oxidative stress damage and antioxidant enzyme activity. Three-month-old male senescence-accelerated prone-8 (SAMP8) mice were randomly assigned to either a control group or to one of two experimental groups (one receiving daily dietary supplementation with 50 mg/kg BW and one with 200 mg/kg BW of Spirulina platensis water extract). Senescence-accelerated-resistant (SAMR1) mice were used as the external control. Results showed that the Spirulina-treated groups had better passive and avoidance scores than the control group. The amyloid β-protein (Aβ) deposition was significantly reduced at the hippocampus and whole brain in both Spirulina groups. The levels of lipid peroxidation were significantly reduced at the hippocampus, striatum, and cortex in both Spirulina groups, while catalase activity was significantly higher only in the 200 mg/kg BW Spirulina group than in the control group. Glutathione peroxidase activity was significantly higher only in the cortex of the 200 mg/kg group than in that of the SAMP8 control group. However, superoxide dismutase activity in all parts of the brain did not significantly differ among all groups. In conclusion, Spirulina platensis may prevent the loss of memory possibly by lessening Aβ protein accumulation, reducing oxidative damage and mainly augmenting the catalase activity.

Intracellular pharmacokinetics of telithromycin, a ketolide antibiotic, in alveolar macrophages

OBJECTIVES

Telithromycin, a ketolide antibiotic, has an antibacterial range that covers intracellular parasitic pathogens that survive or multiply intracellularly in alveolar macrophages. The intracellular pharmacokinetics of TEL in alveolar macrophages was evaluated in vitro.

METHODS

Telithromycin (50 microm) was applied to NR8383 as cultured alveolar macrophages, followed by incubation at 37 degrees C or 4 degrees C. After incubation, the amount of telithromycin in cells was determined.

KEY FINDINGS

Telithromycin exhibited high accumulation in NR8383 and its intracellular accumulation was temperature dependent. Also, telithromycin distributed to the organelles and cytosol in NR8383 and, in particular, it accumulated in the acidic organelle compartments.

CONCLUSIONS

This study suggests that the high accumulation of telithromycin in NR8383 is due to its high influx via active transport systems and trapping in acidic organelles, such as lysosomes. Moreover, this study provides important information for optimizing the treatment of respiratory intracellular parasitic infections based on the intracellular pharmacokinetics of antibiotics and parasitic sites.

C-Phycocyanin ameliorates 2-acetylaminofluorene induced oxidative stress and MDR1 expression in the liver of albino mice

AIM

To study the effect of C-Phycocyanin (C-PC), a biliprotein isolated from Spirulina platensis, on 2-acetylaminofluorene (2-AAF) induced oxidative stress and MDR1 expression in the liver of albino mice.

METHODS

In the present study, albino mice aged 40-60 days were used. The mice were randomly assigned to four groups of six animals each. The first group was treated with the vehicle (absolute alcohol), the second group was treated with C-PC (50 mg/kg body weight), the third group was treated with 2-AAF (25 mg/kg body weight) and the fourth group was treated with C-PC (50 mg/kg body weight) and 2-AAF, daily for 3 days. The mice were sacrificed and the tissues were collected and stored for histology and biochemical studies.

RESULTS

2-AAF induced liver tissue damage in albino mice. 2-AAF treatment resulted in upregulation of MDR1 expression and enhanced the generation of reactive oxygen species (ROS). It also induced phosphorylation of Akt and nuclear translocation of NF-kappaB. Co-administration of C-PC and 2-AAF inhibited the expression of MDR1 by preventing ROS generation, Akt phosphorylation and NF-kappaB nuclear translocation.

CONCLUSION

2-AAF-induced oxidative stress is reduced by C-PC treatment. C-PC inhibited the 2-AAF induced expression of MDR1 by interfering at the level of ROS generation, Akt phosphorylation and NF-kappaB translocation. This study reveals the usefulness of C-PC in preventing oxidative stress and downregulation of MDR1 induced by xenobiotics like 2-AAF.