Morin fosters apoptosis in experimental hepatocellular carcinogenesis model

Here we investigated the in vivo effect of morin (500 ppm in diet) in fostering apoptosis in diethylnitrosamine (DEN) (200 mg/kg bodyweight) mediated experimental hepatocellular carcinogenesis model. We analyzed the expression of cytosolic protein Akt and their important apoptotic downstream targets like caspase-9, Bcl-2, Bax, GSK-3βin vivo, by immunoblot analysis. In silico docking studies indicated that morin could serve as a better inhibitor than the classical PI3K inhibitor LY294002. The results obtained from in vivo studies confirm this. We also demonstrate here that morin's interaction with a defined set of amino acids of PI3K p110γ catalytic subunit resulted in the down-regulation of p-Akt^Ser473, p-Akt^Thr308 and total Akt causing the attenuation of its downstream targets in DEN-induced hepatocellular carcinoma. Further, morin caused the up-regulation of tumor suppressor PTEN, an important negative regulator of Akt, thus initiating apoptosis. Supplementation of morin to experimental animals modulated Bcl-2/Bax ratio causing the release of cyt C and up-regulation of caspase-3 and -9. Morin was also found to prevent the Akt-mediated suppression of GSK-3β possibly causing cell cycle arrest at the G1/S phase. These observations were supported by the DNA fragmentation and transmission electron microscopy results, which showed the occurrence of apoptosis. In conclusion, our findings demonstrate that morin begets apoptosis in DEN-induced hepatocellular carcinoma.     

Cyclosporin A does not increase the oxidative susceptibility of low density lipoprotein in vitro

Accelerated atherosclerosis is the leading cause of morbidity in renal transplant recipients. The pathogenic mechanisms responsible for the progression of atherosclerosis in renal transplant recipients have not been elucidated. Cyclosporin A (CsA) is an immunosuppressive agent used post-transplant and may contribute to increased oxidative susceptibility of low density lipoprotein (LDL). There is a paucity of data testing the effect of CsA on LDL oxidation. Hence, the aim of this study was to test the effect of in vitro enrichment of LDL with CsA on LDL oxidation. LDL oxidation in presence of different concentrations of CsA was tested using metal-dependent (copper), metal-independent (AAPH) and cell-mediated (macrophages) oxidation systems. In all 3 systems, CsA had no significant effect on LDL oxidation. Also, pre-incubation of LDL with CsA did not affect LDL oxidation and LDL alpha tocopherol levels. Thus, the results of our studies with CsA indicate that it is not a direct pro-oxidant.     

Is there a vitamin E paradox?

In addition to epidemiologic studies that suggest a benefit for high intakes of alpha-tocopherol, studies of supplementation in humans have clearly shown that alpha-tocopherol decreases lipid peroxidation, platelet aggregation, and functions as a potent anti-inflammatory agent. In the five large prospective clinical trials with alpha-tocopherol therapy, four have shown a beneficial effect on cardiovascular end-points (two studies on a primary end-point and two studies on other cardiovascular end-points). Thus, the totality of evidence based on the epidemiologic data, in-vitro studies and animal models, and the clinical trials appears to support a benefit for alpha-tocopherol supplementation in patients with pre-existing cardiovascular disease. However, definitive recommendations must await ongoing clinical trials.     

Identification of an atypical form of 30 kDa SOD—a possible virulence factor in clinical isolates of Shigella spp.

Diabetes-induced changes in glucose formation, intracellular and mitochondrial glutathione redox states as well as hydroxyl free radicals (HFR) generation have been investigated in rabbit kidney-cortex tubules. In contrast to renal tubules of control animals, diabetes-evoked increase in glucose formation in the presence of either aspartate+glycerol+octanoate or malate as gluconeogenic precursors (for about 50%) was accompanied by a diminished intracellular glutathione reduced form (GSH)/glutathione oxidised one (GSSG) ratio by about 30-40%, while the mitochondrial GSH/GSSG ratio was not altered. However, a relationship between the rate of gluconeogenesis and the intracellular glutathione redox state was maintained in renal tubules of both control and diabetic rabbits, as concluded from measurements in the presence of various gluconeogenic precursors. Moreover, diabetes resulted in both elevation of the glutathione reductase activity in rabbit kidney-cortex and acceleration of renal HFR generation (by about 2-fold). On the addition of melatonin, the hormone exhibiting antioxidative properties, the control values of HFR production were restored, suggesting that this compound might be beneficial during diabetes therapy. In view of the data, it seems likely that diabetes-induced increase in HFR formation in renal tubules might be responsible for a diminished intracellular glutathione redox state despite elevated glutathione reductase activity and accelerated rate of gluconeogenesis, providing glucose-6-phosphate for NADPH generation via pentose phosphate pathway.     

Alpha-tocopherol decreases tumor necrosis factor-alpha mRNA and protein from activated human monocytes by inhibition of 5-lipoxygenase

Cardiovascular disease is the leading cause of morbidity in Westernized populations. Low levels of alpha-tocopherol (AT) are associated with increased incidence of atherosclerosis and increased intakes appear to be protective. AT supplementation decreases interleukin 1 and 6 release from human monocytes. Thus, the aim of this study was to examine the effect of AT on an important proinflammatory cytokine, tumor necrosis factor-alpha (TNF) release from human monocytes. AT supplementation (1200 IU/day for 3 months) significantly decreased TNF release from activated human monocytes. Mechanisms that were examined included its effect as a general antioxidant, its inhibitory effect on protein kinase C (PKC), and the cycloxygenase-lipoxygenase pathway. While AT decreased TNF release from activated monocytes, other antioxidants had no effect on TNF release. Specific PKC inhibitors had no effect on TNF release from activated monocytes. The inhibition of TNF release by AT in activated monocytes was reversed by leukotriene B(4) (LTB(4)), a major product of the 5-lipoxygenase (5-LO) pathway. Similar observations were seen with inhibitors of 5-lipoxygenase. Indomethacin, a COX inhibitor, in the presence and absence of AT failed to affect TNF activity. These findings suggest that AT decreases TNF release from activated human monocytes via inhibition of 5-lipoxygenase. Also, AT as well as a 5-LO inhibitor significantly decreased TNF mRNA. Furthermore, AT and the 5-LO inhibitor decreased NFkappab-binding activity. Thus, in activated human monocytes, AT appears to inhibit TNF mRNA and protein by inhibition of 5-LO.     

Alpha tocopherol supplementation decreases serum C-reactive protein and monocyte interleukin-6 levels in normal volunteers and type 2 diabetic patients

Type 2 diabetic subjects have an increased propensity to premature atherosclerosis. Alpha tocopherol (AT), a potent antioxidant, has several anti-atherogenic effects. There is scanty data on AT supplementation on inflammation in Type 2 diabetic subjects. The aim of the study was to test the effect of RRR-AT supplementation (1200 IU/d) on plasma C-reactive protein (CRP) and interleukin-6 (IL-6) release from activated monocyte in Type 2 diabetic patients with and without macrovascular complications compared to matched controls. The volunteers comprised Type 2 diabetic subjects with macrovascular disease (DM2-MV, n = 23), Type 2 diabetic subjects without macrovascular complications (DM2, n = 24), and matched controls (C, n = 25). Plasma high sensitive CRP (Hs-CRP) and Monocyte IL-6 were assayed at baseline, following 3 months of supplementation and following a 2 month washout phase. DM2-MV subjects have elevated HsCRP and monocyte IL-6 compared to controls. AT supplementation significantly lowered levels of C-reactive protein and monocyte interleukin-6 in all three groups. In conclusion, AT therapy decreases inflammation in diabetic patients and controls and could be an adjunctive therapy in the prevention of atherosclerosis.     

Grape seed proanthocyanidins ameliorates isoproterenol-induced myocardial injury in rats by stabilizing mitochondrial and lysosomal enzymes: an in vivo study

This study was designed to examine the effects of grape seed proanthocyanidins (GSP) against myocardial injury (MI) induced by isoproterenol (ISO), in a rat model. Induction of rats with ISO (85 mg/kg body weight, subcutaneously) for 2 days resulted in a significant decrease in the activities of heart mitochondrial enzymes (isocitrate dehydrogenase, succinate dehydrogenase, malate dehydrogenase and alpha-ketoglutarate dehydrogenase) and respiratory chain enzymes (NADH dehydrogenase and cytochrome c oxidase). The activities of lysosomal enzymes (alpha-d-glucuronidase, alpha-d-N-acetylglucosaminidase, cathepsin-D, acid phosphatases and alpha-d-galactosidase) were increased significantly in the heart and serum of ISO-induced rats. The prior administration of GSP for 6 days a week for 5 weeks significantly increased the activities of mitochondrial and respiratory chain enzymes and significantly decreased the activities of lysosomal enzymes in the heart tissues of ISO-induced rats, which proves the stress stabilizing action of GSP. Oral administration of grape seed proanthocyanidins alone (50, 100 and 150 mg/kg) to normal rats did not show any significant effect in all the parameters studied. These biochemical functional alterations were supported by the macroscopic enzyme mapping assay of ischemic myocardium. Thus, this study shows that 100 and 150 mg/kg of GSP gives protection against ISO-induced MI and demonstrates that GSP has a significant effect in the protection of heart.     

Oligomeric proanthocyanidins mitigate cholesterol and cholic acid diet–induced hepatic dysfunction in male Sprague Dawley rats

Dysregulated synthesis of hepatic cholesterol is a critical determinant of atherosclerosis. The combination of cholesterol and cholic acid (CC) diet supplementation to animal models is associated with hepatic dysfunction‐mediated atherosclerosis. The current study was designed to investigate the hepatic cholesterol–lowering effects of oligomeric proanthocyanidins (OPC) in CC diet fed rats. CC diet–induced group exhibited significant increase in the hepatic lipid profile, activities of 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase (HMGR), PON‐1, LCAT, LPL, and LPO levels, and messenger RNA expression of HMGR, low‐density lipoprotein receptor (LDLr), and HNF‐4α. Administration of OPC (100 mg/kg/bwt) resulted in the significant reduction of lipid profile and HMGR levels, with concomitant increase in the levels of cholesterol‐regulating enzymes and upregulated expression of LDLr and HNF‐4α, which was similar to atorvastatin. Molecular docking studies also revealed that proanthocyanidins had a strong binding affinity to HMGR, similar to atorvastatin. Our findings suggest that OPC regulate the impaired cholesterol metabolism–associated atherosclerosis through hepatic cholesterol–lowering effect.     

DNABII proteins play a central role in UPEC biofilm structure

Most chronic and recurrent bacterial infections involve a biofilm component, the foundation of which is the extracellular polymeric substance (EPS). Extracellular DNA (eDNA) is a conserved and key component of the EPS of pathogenic biofilms. The DNABII protein family includes integration host factor (IHF) and histone‐like protein (HU); both are present in the extracellular milieu. We have shown previously that the DNABII proteins are often found in association with eDNA and are critical for the structural integrity of bacterial communities that utilize eDNA as a matrix component. Here, we demonstrate that uropathogenic Escherichia coli (UPEC) strain UTI89 incorporates eDNA within its biofilm matrix and that the DNABII proteins are not only important for biofilm growth, but are limiting; exogenous addition of these proteins promotes biofilm formation that is dependent on eDNA. In addition, we show that both subunits of IHF, yet only one subunit of HU (HupB), are critical for UPEC biofilm development. We discuss the roles of these proteins in context of the UPEC EPS.     

Genome Sequence of the Plant Growth-Promoting Rhizobacterium Pseudomonas putida S11

Here we report the genome sequence of a plant growth-promoting rhizobacterium, Pseudomonas putida S11. The length of the draft genome sequence is approximately 5,970,799 bp, with a G+C content of 62.4%. The genome contains 6,076 protein-coding sequences.