Putative involvement of sirtuin modulators in LPS-induced sickness behaviour in mice.

NAD+-dependent histone deacetylases (sirtuins 1-7) have been shown to be involved in various pathophysiological conditions including their involvement in cardiovascular, cancerous, neurodegenerative, immune dysregulation and inflammatory conditions. This study investigates the inflammomodulatory potential of resveratrol (RES), a sirtuin activator and sirtinol (SIR), a sirtuin inhibitor in lipopolysaccharide (LPS)-induced model of sickness behaviour in mice. Male Swiss albino mice were divided into five groups (n = 6) consisting of saline (SAL), LPS, RES, SIR, and fluoxetine (FLU) respectively, each group except LPS was prepared by intraperitoneally (i.p.) administration of SAL (10 mL/kg), RES (50 mg/kg), SIR (2 mg/kg) and FLU (10 mg/kg). Thirty minutes after the treatments, all the groups, except SAL were administered LPS (2 mg/kg, i.p.). The behavioural assays including, open field test, forced swim test, and tail suspension tests were conducted 1 h after LPS challenge. LPS administration significantly reduced the locomotor activity along with inducing a state of high immobility and that was prevented by pretreatment with RES and SIR. Further, various proinflammatory cytokines (TNF-α, IL-6, and IL-1ß), and oxidative stress markers (MDA and GSH) were found to be significantly elevated in the brain homogenates after LPS treatment. SIR pretreatment abrogated the LPS-induced neuroinflammatory and oxidative stress changes, whereas RES was only effective in reducing the oxidative stress and TNF-α levels. The results of this study speculate that the role of SIRT modulators in neuroinflammatory conditions could vary with their dose, regimen and chemical properties. Further studies with detailed molecular and pharmacokinetic profiling will be needed to explore their therapeutic potentials.

SIRT1 and SIRT2 modulators reduce LPS-induced inflammation in HAPI microglial cells and protect SH-SY5Y neuronal cells in vitro.

Neuroinflammation is associated with the development of depression. Deacetylases SIRT1 and SIRT2 are reported to exert neuroprotective effects in aging, neurogenesis, neurodegeneration and neuroinflammation. Therefore, this study aimed to investigate the effects of SIRT1 and SIRT2 modulators on LPS-induced neuroinflammation and neurodegeneration in vitro. To achieve this, HAPI rat microglial cells were pre-treated with the SIRT1 activator resveratrol (0.1-20 µM), the selective SIRT1 inhibitor EX527 (0.1; 1 µM), the dual SIRT1/SIRT2 inhibitor sirtinol (0.1-20 µM) and the SIRT2 inhibitor AGK2 (0.1; 1 µM), prior to exposure with LPS (5 ng/mL) for 20 h. The reference antidepressant drug fluoxetine and the nonsteroidal anti-inflammatory drug ibuprofen were also evaluated in the same paradigm, both at 1 µM. Resveratrol and sirtinol inhibited TNF-α production to a greater degree than either fluoxetine or ibuprofen. Resveratrol, sirtinol, EX527 and AGK2 significantly reduced PGE2 production by up to 100% in microglia. Then, the supernatant was transferred to treat SH-SY5Y cells for 24 h. In all cases, SIRT modulator pretreatment significantly protected undifferentiated SH-SY5Y human neuroblastoma cells from the insult of LPS-stimulated HAPI supernatant by up to 40%. Moreover, resveratrol and sirtinol also showed significantly better neuroprotection than fluoxetine or ibuprofen by up to 83 and 69%, respectively. In differentiated SH-SY5Y cells, only sirtinol (20, 10 µM) and AGK2 (0.1 µM) pretreatment protected the cells from LPS-stimulated HAPI supernatant. This study suggests that SIRT1 and SIRT2 modulators are effective in inhibiting LPS-stimulated production of TNF-α and PGE2 in HAPI microglial cells and protecting SH-SY5Y cells from inflammation. Thus, we provide proof of concept for further investigation of the therapeutic effect of SIRT1 and SIRT2 modulators and combination with current antidepressant medication as a treatment option.

Time to Stable Therapeutic Range on Initiation of Warfarin as an Indicator of Control.

OBJECTIVES: Warfarin remains widely used with a time in therapeutic range (TiTR) above 65% recommended for best outcomes. Patients not achieving or maintaining this warfarin control may be better suited to alternate anticoagulants. Despite this, there is limited data defining a suitable trial time in patients initiating warfarin therapy, therefore the aim of this study was to determine the mean time to stable therapeutic range (TtSTR). MATERIALS AND METHODS: Retrospective data was collected for patients with atrial fibrillation enrolled in a dedicated warfarin program at a private pathology practice within 7 days of warfarin initiation. TiTR at specified timepoints was calculated and median TtSTR determined as defined by TiTR ≥ 65% over three months. Comparisons were made of populations with TtSTR above or below the median. RESULTS: The 566 patients included in the study had a mean TiTR of 64.9±16.5% at month three and median TtSTR of six months. Patients with TtSTR≤6 months achieved a mean TiTR of 68.9±12.8% at month two and maintained a TiTR over 75% from month 3 to 24. Patients with a TtSTR>6 months obtained a TiTR of 66.4±10.6% at month nine and continued to achieve lower TiTR throughout the 24 months study period. CONCLUSIONS: A majority of patients can achieve a stable TiTR above 65% within six months so review at six to nine months is likely to be a good indicator of warfarin control and to determine if patients should continue warfarin or switch to alternate anticoagulant therapy.

O-GlcNAcylation of truncated NAC segment alters peptide-dependent effects on α-synuclein aggregation.

Numerous post-translational modifications (PTMs) of the Parkinson's disease (PD) associated α-synuclein (α-syn) protein have been recognised to play critical roles in disease aetiology. Indeed, dysregulated phosphorylation and proteolysis are thought to modulate α-syn aggregation and disease progression. Among the PTMs, enzymatic glycosylation with N-acetylglucosamine (GlcNAc) onto the protein's hydroxylated amino acid residues is reported to deliver protective effects against its pathogenic processing. This modification has been reported to alter its pathogenic self-assembly. As such, manipulation of the protein's O-GlcNAcylation status has been proposed to offer a PD therapeutic route. However, targeting upstream cellular processes can lead to mechanism-based toxicity as the enzymes governing O-GlcNAc cycling modify thousands of acceptor substrates. Small glycopeptides that couple the protective effects of O-GlcNAc with the selectivity of recognition sequences may prove useful tools to modulate protein aggregation. Here we discuss efforts to probe the effects of various O-GlcNAc modified peptides on wild-type α-synuclein aggregation.

Non-prescription medicines may contribute to non-adherence to prescription medicines in people living with chronic health conditions.

BACKGROUND: Non-adherence to prescribed medicines is linked to adverse health outcomes in people living with chronic health conditions (CHCs). Multiple factors are known to contribute to non-adherence to medicines including polypharmacy, demographic features and disease and health systems. Both non-prescription and prescription medicines contribute to polypharmacy; however, there is limited data on the influence of non-prescription medicines to non-adherence. AIM: Therefore, the aim of the study was to investigate the influence of non-prescription medicines to non-adherence in an Australian population. METHODS: Data from the 2016 National Survey of a random sample of Australian adult residents were utilised in this study to investigate factors associated with non-adherence. Descriptive statistics, χ2 , regression and generalised linear models were used to assess the relationships between variables of interest. Narrative response and comments were used to provide further insight. RESULTS: This study recruited 1217 participants to explore factors associated with non-adherence to medicines. Weak but statistically significant correlations were identified showing the number of CHCs, patient's age, number of prescription medicines, number of non-prescription medicines and total number of medicines associated with non-adherence. DISCUSSION: The findings suggest that people living with CHCs and taking multiple medicines, including non-prescription medicines, are likely to be non-adherent to prescription medicines. This study shows the possible involvement of non-prescription medicines in contributing to non-adherence in an Australian population and suggests that future studies with a broader demographic are warranted.

Effect of 8-weeks prebiotics/probiotics supplementation on alcohol metabolism and blood biomarkers of healthy adults: a pilot study.

PURPOSE: Modulating gut bacteria via regular prebiotics/probiotics consumption may improve the metabolism of acute alcohol ingestion. This study investigated the impact of 8-weeks prebiotics/probiotics supplementation on microbiome changes and responses to acute alcohol consumption. METHODS: 38 participants (21 females, 23.6 ± 3.4 kg m-2, mean ± SD) attended the laboratory on two occasions separated by an 8-week intervention period. On each of these visits, a dose of alcohol (0.40 ± 0.04 g kg-1, Vodka + Soda-Water) was consumed over 10 min. Breath alcohol concentration was sampled over 5 h and alcohol pharmacokinetics was analysed using WinNonlin non-compartmental modelling (C max, t max, AUClast). For the intervention, participants were randomised to receive Placebo + Placebo (PLA), Placebo + Prebiotics (PRE), Probiotics + Placebo (PRO), or Probiotics + Prebiotics (SYN) in a double-blinded manner. Probiotics were a commercially available source of Lactobacillus acidophilus (NCFM®) and Bifidobacterium lactis (Bi-07). Prebiotics were a commercially available source of Larch Gum (from Larix occidentalis). Placebo was microcrystalline cellulose. Each visit, participants provided a stool sample, which was analysed to determine the presence of L. acidophilus and B. lactis. Differences between trials were analysed using paired samples t tests. RESULTS: Increased counts for at least one bacterial strain (L. acidophilus or B. lactis) were observed for all participants on SYN (n = 10) and PRO (n = 10) trials. No difference in C max or t max was observed between trials when analysed by treatment condition or microbiome outcome. A significant decrease in AUClast was observed between trials for PLA (p = 0.039) and PRE (p = 0.030) treatments, and when increases in at least one bacterial strain (p = 0.003) and no microbiome changes (p = 0.016) were observed. CONCLUSION: Consumption of probiotics appears to alter faecal counts of supplemental bacterial strains in otherwise healthy individuals. However, translation to any possible beneficial impact on alcohol metabolism remains to be elucidated.

Warfarin control in patients transitioning to warfarin after non-vitamin K oral anticoagulant (NOAC) therapy.

Warfarin has long been the most widely prescribed oral anticoagulant. Introduction of non-vitamin K oral anticoagulants (NOACs) has provided anticoagulant options but also presented the potential challenge of transitioning between agents. Changes from NOACs to warfarin are particularly problematic with delays to therapeutic effect and limited real-world data regarding the impact on warfarin control. The aim of this study was to investigate the frequency of switching anticoagulants and the effect on warfarin control. Retrospective data was collected for patients at a warfarin program in Queensland Australia who had exited the program for NOACs plus those who had reverted to warfarin. Data included documented reasons for change and International Normalised Ratio (INR) results with time in therapeutic range (TTR) calculated as a measure of warfarin control. Over 5 years, a total of 3036 patients ceased warfarin to commence a NOAC but 142 (4.7%) reverted to warfarin. Majority of patients (60.6%) reverted to warfarin within 6 months of trialling NOACs with a median of 6 days to therapeutic INR. There was no significant difference in warfarin control before changing to NOACs and after reverting to warfarin (mean TTR 75%) but significantly more frequent testing and lower doses were required to achieve this control. Transitions from warfarin to NOACs results in almost a week to therapeutic effect and warfarin therapy may be further complicated by a need for increased frequency of testing. Further studies are required to refine transition strategies particularly from warfarin to NOAC and minimise potential risks to patients.

Pyocyanin induces systemic oxidative stress, inflammation and behavioral changes in vivo.

Pyocyanin (PCN) is a virulence factor secreted by Pseudomonas aeruginosa (P. aeruginosa) that has been shown to have numerous toxic effects in both in vitro and in vivo studies. Such toxicities include pro-inflammatory and pro-oxidant mediated responses. It is hypothesized that PCN can cross biological membranes and reach the systemic circulation, but no previous studies have investigated this. The aim of this study was, therefore, to quantify PCN in plasma and assess if systemic responses were occurring after localized intranasal administration in C57BL/6 J mice. This was achieved through the plasma quantification of PCN and assessment of changes to behavior using two commonly used tests, the forced swimming test and the open field test. Furthermore, evidence of systemic oxidative stress and inflammation was measured using malondialdehyde (MDA) and TNF-α post PCN exposure. PCN was found to cross into systemic circulation but in a variable manner. Furthermore, significant increases in plasma TNF-α and MDA (both p < 0.001) were observed along with changes in behavior indicative of systemic inflammatory responses.

The Sex, Age, Medical History, Treatment, Tobacco Use, Race Risk (SAMe TT2R2) Score Predicts Warfarin Control in a Singaporean Population.

BACKGROUND: Warfarin reduces stroke risk in atrial fibrillation (AF) patients but requires ongoing monitoring. Time in therapeutic range (TTR) is used as a measure of warfarin control, with a TTR less than 60% associated with adverse patient outcomes. The Sex, Age, Medical history, Treatment, Tobacco use, Race (SAMe-TT2R2) score has been identified as a model able to predict warfarin control, but this has been tested in mainly Caucasian populations. Therefore, the aim of this study was to determine the ability of the SAMe-TT2R2 score to predict warfarin control in a Singaporean population consisting of Chinese, Malay, and Indian race. METHODS: Retrospective data were collected from the National Heart Centre Singapore for AF patients receiving warfarin between January and June 2014. The TTR and the SAMe-TT2R2 score were calculated for each patient. RESULTS: The 1137 non-valvular AF patients had a mean TTR of 58.0 ± 34.3% and a median SAMe-TT2R2 score of 3. The categorized SAMe-TT2R2 scores (2 versus >2) showed a significant reduction in mean TTR for the entire population (63.2% versus 55.8%, P = .0004) and also when categorized according to race for Chinese (62.7% versus 56.9%, P = .0075) and Malay (68.4% versus 50.6%, P = .0131) populations. CONCLUSION: The SAMe-TT2R2 tool is effective in predicting warfarin control in a Singaporean population as patients with a score greater than 2 had poor control. The minimum score for non-Caucasian patients is 2; thus, in these patients, the presence of any additional risk factors identified in the SAMe-TT2R2 tool categorizes them as unlikely to achieve adequate warfarin control and possible candidates for alternative anticoagulants.

Molecular mechanisms underlying the effects of statins in the central nervous system.

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, commonly referred to as statins, are widely used in the treatment of dyslipidaemia, in addition to providing primary and secondary prevention against cardiovascular disease and stroke. Statins' effects on the central nervous system (CNS), particularly on cognition and neurological disorders such as stroke and multiple sclerosis, have received increasing attention in recent years, both within the scientific community and in the media. Current understanding of statins' effects is limited by a lack of mechanism-based studies, as well as the assumption that all statins have the same pharmacological effect in the central nervous system. This review aims to provide an updated discussion on the molecular mechanisms contributing to statins' possible effects on cognitive function, neurodegenerative disease, and various neurological disorders such as stroke, epilepsy, depression and CNS cancers. Additionally, the pharmacokinetic differences between statins and how these may result in statin-specific neurological effects are also discussed.

Paradoxical role of 3-methyladenine in pyocyanin-induced toxicity in 1321N1 astrocytoma and SH-SY5Y neuroblastoma cells.

The role of autophagy in pyocyanin (PCN)-induced toxicity in the central nervous system (CNS) remains unclear, with only evidence from our group identifying it as a mechanism underlying toxicity in 1321N1 astrocytoma cells. Therefore, the aim of this study was to further examine the role of autophagy in PCN-induced toxicity in the CNS. To achieve this, we exposed 1321N1 astrocytoma and SH-SY5Y neuroblastoma cells to PCN (0-100 µmol/L) and tested the contribution of autophagy by measuring the impact of the autophagy inhibitor 3-methyladenine (3-MA) using a series of biochemical and molecular markers. Pretreatment of 1321N1 astrocytoma cells with 3-MA (5 mmol/L) decreased the PCN-induced acidic vesicular organelle and autophagosome formation as measured using acridine orange and green fluorescent protein-LC3 -LC3 fluorescence, respectively. Furthermore, 3-MA (5 mmol/L) significantly protected 1321N1 astrocytoma cells against PCN-induced toxicity. In contrast pretreatment with 3-MA (5 mmol/L) increased PCN-induced toxicity in SH-SY5Y neuroblastoma cells. Given the influence of autophagy in inflammatory responses, we investigated whether the observed effects in this study involved inflammatory mediators. The PCN (100 µmol/L) significantly increased the production of interleukin-8 (IL-8), prostaglandin E2 (PGE2), and leukotriene B4 (LTB4) in both cell lines. Consistent with its paradoxical role in modulating PCN-induced toxicity, 3-MA (5 mmol/L) significantly reduced the PCN-induced production of IL-8, PGE2, and LTB4 in 1321N1 astrocytoma cells but augmented their production in SH-SY5Y neuroblastoma cells. In conclusion, we show here for the first time the paradoxical role of autophagy in mediating PCN-induced toxicity in 1321N1 astrocytoma and SH-SY5Y neuroblastoma cells and provide novel evidence that these actions may be mediated by effects on IL-8, PGE2, and LTB4 production.

Effects of Pseudomonas aeruginosa virulence factor pyocyanin on human urothelial cell function and viability.

PURPOSE: We determined the effects of Pseudomonas aeruginosa virulence factor pyocyanin on human urothelial cell viability and function in vitro. MATERIALS AND METHODS: RT4 urothelial cells were treated with pyocyanin (1 to 100 µM) for 24 hours. After exposure the treatment effects were measured according to certain end points, including changes in urothelial cell viability, reactive oxygen species formation, caspase-3 activity, basal and stimulated adenosine triphosphate release, SA-ß-gal activity and detection of acidic vesicular organelles. RESULTS: The 24-hour pyocyanin treatment resulted in a concentration dependent decrease in cell viability at concentrations of 25 µM or greater, and increases in reactive oxygen species formation and caspase-3 activity at 25 µM or greater. Basal adenosine triphosphate release was significantly decreased at all tested pyocyanin concentrations while stimulated adenosine triphosphate release was significantly inhibited at pyocyanin concentrations of 12.5 µM or greater with no significant stimulated release at 100 µM. Pyocyanin treated RT4 cells showed morphological characteristics associated with cellular senescence, including SA-ß-gal expression. This effect was not evident at 100 µM pyocyanin and may have been due to apoptotic cell death, as indicated by increased caspase-3 activity. An increase in acridine orange stained vesicular-like organelles was observed in RT4 urothelial cells after pyocyanin treatment. CONCLUSIONS: Exposure to pyocyanin alters urothelial cell viability, reactive oxygen species production and caspase-3 activity. Treatment also results in cellular senescence, which may affect the ability of urothelium to repair during infection. The virulence factor depressed stimulated adenosine triphosphate release, which to our knowledge is a novel finding with implications for awareness of bladder filling in patients with P. aeruginosa urinary tract infection.

Inhibition of autophagy by 3-methyladenine protects 1321N1 astrocytoma cells against pyocyanin- and 1-hydroxyphenazine-induced toxicity.

Central nervous system (CNS) infections due to Pseudomonas aeruginosa are difficult to treat and have a high mortality rate. Pyocyanin, a virulence factor produced by P. aeruginosa, has been shown to be responsible for the majority of P. aeruginosa's pathogenicity in mammalian cells. Several lines of evidence in respiratory cells suggest that this damage is primarily mediated by pyocyanin's ability to generate ROS and deplete host antioxidant defense mechanisms. However, it has yet to be established whether pyocyanin or 1-hydroxyphenazine have potential toxicity to the CNS. Therefore, the aim of this study was to compare the CNS toxicity of pyocyanin and 1-hydroxyphenazine in vitro and to provide insight into mechanisms that underlie this toxicity using 1321N1 astrocytoma cells. To achieve this, we investigated the contribution of oxidative stress and other mediators of cell death including autophagy, senescence and apoptosis. We show that oxidative stress is not a primary mediator of pyocyanin (0-100 µM) and 1-hydroxyphenazine (0-100 µM) induced toxicity in 1321N1 cells. Instead, our results suggest that autophagy may play a central role. The autophagy inhibitor 3-methyladenine (5 mM) protected 1321N1 astrocytoma cells against both pyocyanin and 1-hydroxyphenazine-induced cell injury and increased accumulation of acidic vesicular organelles, a hallmark of autophagy. Furthermore, apoptosis and senescence events may be secondary to autophagy in pyocyanin and 1-hydroxyphenazine-mediated cell injury. In conclusion, this study provides the first evidence on mechanisms underlying the toxicity of both pyocyanin and 1-hydroxyphenazine to astrocytoma cells and provides novel evidence suggesting that this toxicity may be mediated by the formation of acidic vesicular organelles, a hallmark of autophagic cell death.

Effects of glycyrrhizin on biliary transport and hepatic levels of glutathione in rats.

The purpose of the current study was to determine whether glycyrrhizin (GL) maintains hepatic glutathione (GSH) levels by inhibiting GSH biliary secretion in normal rats. The effects of glycyrrhizin on hepatic glutathione content, bile flow and biliary secretion of glutathione were examined. Because glutathione is a substrate for multidrug resistance associated protein-2 (Mrp2/ABCC2), the inhibitory effects of GL on Mrp2 in isolated perfused rat liver and in Mrp2-expressing Sf9 membrane vesicles were also examined using the Mrp2 substrate methotrexate (MTX) and estradiol-17-ß-glucuronide (E2 17G). The hepatic content of glutathione in rats following GL perfusion (43.7 µmol/l) in isolated liver perfusion and GL intravenous treatment (25 mg/kg) was significantly higher than that for the control. A marked and dose-dependent decrease in the excretion of glutathione was observed. In addition, the secretion rate of MTX was decreased by 57% in isolated liver perfusion in GL-treated rats. Moreover the ATP-dependent uptake of E2 17G by Mrp2 membrane vesicles was decreased by 75.9% in the 20 µm GL group and by 60.5% in the 2 µm GL group. In conclusion, glycyrrhizin increases hepatic glutathione content possibly through inhibition of Mrp2 which then reduces the biliary excretion of glutathione.

Silica-lipid hybrid (SLH) versus non-lipid formulations for optimising the dose-dependent oral absorption of celecoxib.

PURPOSE: To investigate the dose linearity of celecoxib (CEL) pharmacokinetics from various non-lipid and lipid-based formulations; to probe the mechanisms of CEL absorption from a nano-structured silica-lipid hybrid (SLH) microparticle dosage form. METHODS: Single-dose pharmacokinetic parameters of CEL were determined in fasted rats at dose levels of 5, 20 and 50 mg/kg in aqueous suspensions of pure CEL, Celebrex® and CEL-SLH microparticles formulated using medium-chain lipids (Miglyol 812 or Capmul MCM) and Aerosil® silica nanoparticles. An in vitro lipolysis model was used to characterise the dynamic solubilisation state of CEL under digesting conditions. RESULTS: CEL-SLH formulations and Celebrex® consistently produced a 2-fold higher maximum plasma concentration (C(max)) and bioavailability (AUC(0→∞)) than pure CEL in a dose-linear manner within the dose range of 5-50 mg/kg CEL (R² > 0.8). Lipolysis drug phase partition data indicate a 2.5-7.5-fold higher CEL solubilising capacity resulting from the digestion of SLH microparticles as compared to the simulated fasted state endogenous micelles. Strong correlations were obtained between maximum CEL solubilisation levels during lipolysis and in vivo pharmacokinetic parameters (R² > 0.9). CONCLUSIONS: Collectively, the results highlight the potential of the SLH microparticles in enhancing the bioavailability of CEL in a dose-linear manner as facilitated by supersaturated solubilisation of CEL in the intestinal milieu.

Antihyperglycemic effects of baicalin on streptozotocin - nicotinamide induced diabetic rats.

The aim of the study was to investigate the effects of baicalin on blood glucose, insulin and cytokine levels. Rat diabetes was induced by intraperitoneal (i.p.) injection of nicotinamide and streptozotocin. Diabetic rats were dosed with i.p. baicalin or oral metformin daily for 8 days. Blood glucose, insulin and hepatic glycogen were determined using conventional methods. The activity of hepatic hexokinase was determined using a coupled assay with glucose-6-phosphate dehydrogenase. Serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and adiponectin were measured by enzyme-linked immunosorbent assay. Administration of baicalin at 50 or 100 mg/kg significantly decreased plasma glucose levels in a dose dependent manner. The serum insulin level was not increased by baicalin treatment. Administration of baicalin at a high dose (100 mg/kg) resulted in a significant increase of liver glycogen content and a reduction of serum TNF-α. The activity of hepatic hexokinase was significantly increased after dosing baicalin at 25, 50 or 10 mg/kg. Administration of baicalin (50 or 10 mg/kg) or metformin (10 mg/kg) significantly alleviated the morphological injury to the pancreas caused by STZ. The possible mechanisms contributing to the hypoglycemic effect include increasing the hepatic glycogen content and glycolysis, and reducing the serum levels of TNF-α.

Silica nanoparticles to control the lipase-mediated digestion of lipid-based oral delivery systems.

We investigate the role of hydrophilic fumed silica in controlling the digestion kinetics of lipid emulsions, hence further exploring the mechanisms behind the improved oral absorption of poorly soluble drugs promoted by silica-lipid hybrid (SLH) microcapsules. An in vitro lipolysis model was used to quantify the lipase-mediated digestion kinetics of a series of lipid vehicles formulated with caprylic/capric triglycerides: lipid solution, submicrometer lipid emulsions (in the presence and absence of silica), and SLH microcapsules. The importance of emulsification on lipid digestibility is evidenced by the significantly higher initial digestion rate constants for SLH microcapsules and lipid emulsions (>15-fold) in comparison with that of the lipid solution. Silica particles exerted an inhibitory effect on the digestion of submicrometer lipid emulsions regardless of their initial location, i.e., aqueous or lipid phases. This inhibitory effect, however, was not observed for SLH microcapsules. This highlights the importance of the matrix structure and porosity of the hybrid microcapsule system in enhancing lipid digestibility as compared to submicrometer lipid emulsions stabilized by silica. For each studied formulation, the digestion kinetics is well correlated to the corresponding in vivo plasma concentrations of a model drug, celecoxib, via multiple-point correlations (R(2) > 0.97). This supports the use of the lipid digestion model for predicting the in vivo outcome of an orally dosed lipid formulation. SLH microcapsules offer the potential to enhance the oral absorption of poorly soluble drugs via increased lipid digestibility in conjunction with improved drug dissolution/dispersion.

Disposition of isosteviol in the rat isolated perfused liver.

1. The aim of the present study was to investigate the mechanisms involved in the clearance of isosteviol using the rat isolated perfused liver. 2. Six livers from male Sprague-Dawley rats were perfused with 15.7 mumol isosteviol in a recirculating system. Perfusate and bile samples were collected for 60 min and the liver was collected at the end of the perfusion. All samples collected were incubated with alpha-glucuronidase. Isosteviol-glucuronide was determined as equivalent isosteviol. Isosteviol concentrations were determined using a previously developed liquid chromatography-tandem mass spectrometry method. The final isosteviol liver/perfusate (L/P), bile/liver (B/L) and isosteviol-glucuronide in bile/liver (B(G)/L(G)) ratios were determined. 3. Isosteviol has a high clearance (21.4 +/- 4.8 mL/min) from the perfusate, with a short half-life (13 +/- 4 min). alpha-Glucuronidase incubation revealed that isosteviol is conjugated in the liver and excreted into the bile. There was no isosteviol-glucuronide detected in perfusate samples. The total recovery of the rat isolated perfused liver system is 74 +/- 14% and glucuronidated isosteviol accounted for 23 +/- 4% of the administered dose. 4. In conclusion, we are the first to characterize the metabolism of isosteviol using rat isolated liver perfusion. Our results strongly suggest that the liver is the main organ of isosteviol elimination and that isosteviol is glucuronidated in the liver before it is excreted into the bile.

The anti-inflammatory effect of baicalin on hypoxia/reoxygenation and TNF-alpha induced injury in cultural rat cardiomyocytes.

The aim of present study was to investigate the effect of baicalin on hypoxia/reoxygenation (H/R) injury in cardiomyocytes and the mechanisms involved, particularly in relation to cytokines. The cardiomyocytes for the H/R groups were placed into a hypoxic chamber for 12 h and then underwent reoxygenation for 1 h. The cells in the TNF-alpha groups were administered 100 ng/mL rrTNF-alpha and incubated for 13 h under normal conditions. The cells in the baicalin pretreatment groups were administered 10 microM baicalin 30 min prior to exposure to H/R or TNF-alpha. It was observed that pretreatment with baicalin (10 microM) significantly reduced the cell damage and death induced by H/R or TNF-alpha. In the culture medium of the H/R cells, the SOD activity increased, while TNF-alpha was decreased by baicalin. The levels of IL-6 in culture medium for H/R or TNF-alpha treated cells were suppressed by baicalin pretreatment. In contrast, the levels of IL-10 in culture medium for H/R or TNF-alpha treated cells were significantly elevated by baicalin. Moreover, baicalin inhibited the nuclear translocation of NF-kappaB induced by H/R or TNF-alpha. In conclusion, baicalin may protect cardiomyocytes from H/R injury through an anti-inflammatory mechanism.

Review of the anti-inflammatory effect of SIRT1 and SIRT2 modulators on neurodegenerative diseases.

Neurodegenerative disease refers to a range of chronic and progressive disorders that are characterized by dysfunction and loss of neurons. Neurodegeneration involves protein misfolding, oxidative injury, impaired mitochondrial function, neurotrophin deficiency and may also involve neuroinflammation. The sirtuin family of proteins plays a key role in this process suggesting that modulation of sirtuin can modify disease progression. This review examines experimental and clinical evidence relating to the potential role of SIRT1 and SIRT2, and their modulators in neurodegenerative diseases. Both neuroprotective effects and negative effects of SIRT1 activators, SIRT1 inhibitors and SIRT2 activators are discussed in a range of different disease models, including in vitro and in vivo Alzheimer's disease (AD), Parkinson's disease (PD), Huntingdon's disease (HD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS). This highlights the potential of SIRT1 and SIRT 2 modulators as potential therapeutic agents. However, there is a paucity of clinical trials related to the effects of selective SIRT1 modulators, selective SIRT2 modulators or dual SIRT1/2 modulators on neuroinflammation and subsequent neurodegeneration.