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1.
Metab Brain Dis ; 37(6): 1969-1976, 2022 08.
Article in English | MEDLINE | ID: mdl-35554791

ABSTRACT

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.


Subject(s)
Antioxidants , Enzyme Inhibitors , Illness Behavior , Oxidative Stress , Resveratrol , Sirtuins , Animals , Antioxidants/pharmacology , Enzyme Inhibitors/pharmacology , Fluoxetine/pharmacology , Illness Behavior/drug effects , Illness Behavior/physiology , Lipopolysaccharides , Male , Mice , Oxidative Stress/drug effects , Resveratrol/pharmacology , Sirtuins/antagonists & inhibitors , Tumor Necrosis Factor-alpha/metabolism
2.
J Neural Transm (Vienna) ; 128(5): 631-644, 2021 05.
Article in English | MEDLINE | ID: mdl-33821324

ABSTRACT

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.


Subject(s)
Inflammation , Microglia , Sirtuin 1 , Sirtuin 2 , Animals , Cell Line, Tumor , Inflammation/chemically induced , Inflammation/drug therapy , Lipopolysaccharides/toxicity , Microglia/drug effects , Rats , Sirtuin 1/drug effects , Sirtuin 2/drug effects
3.
J Stroke Cerebrovasc Dis ; 30(4): 105620, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33493875

ABSTRACT

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.


Subject(s)
Anticoagulants/therapeutic use , Atrial Fibrillation/drug therapy , Blood Coagulation/drug effects , Drug Monitoring , International Normalized Ratio , Stroke/prevention & control , Warfarin/therapeutic use , Aged , Aged, 80 and over , Atrial Fibrillation/blood , Atrial Fibrillation/diagnosis , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Retrospective Studies , Stroke/blood , Stroke/diagnosis , Time Factors , Treatment Outcome
4.
Antioxidants (Basel) ; 9(8)2020 Aug 09.
Article in English | MEDLINE | ID: mdl-32784832

ABSTRACT

The genus Echium L. from the Boraginaceae family consists of 67 recognised species. The genus is widely distributed in the Mediterranean, having been documented in the traditional medicine of the area since 300 B.C. Current pharmacological studies have validated early ethnomedicinal properties showing that Echium spp. possesses antioxidant, analgesic, anxiolytic, anti-inflammatory, antibacterial, and antiviral effects. Nevertheless, only limited papers report specifically on the phytochemistry of this genus. Furthermore, the potential of utilising extracts from Echium species as natural antioxidant preparations has been significantly neglected. For the first time, this review comprehensively describes and discusses the presence of recorded Echium species with ethnomedicinal uses, their antioxidative properties in vitro and in vivo when available, and major phytochemical components recognised as potent antioxidants, as well as the possibilities and opportunities for future research.

5.
ACS Chem Neurosci ; 11(15): 2303-2315, 2020 08 05.
Article in English | MEDLINE | ID: mdl-32551538

ABSTRACT

A series of novel furan-2-yl-1H-pyrazoles and their chemical precursors were synthesized and evaluated for their effectiveness at disrupting α-synuclein (α-syn) aggregation in vitro. The compounds were found to inhibit α-syn aggregation with efficacy comparable to the promising drug candidate anle138b. The results of this study indicate that compounds 8b, 8l, and 9f may qualify as secondary leads for the structure-activity relationship studies aimed to identify the suitable compounds for improving the modulatory activity targeted at α-syn self-assembly related to Parkinson's disease.


Subject(s)
Parkinson Disease , alpha-Synuclein , Furans/pharmacology , Humans , Parkinson Disease/drug therapy , Pyrazoles/pharmacology , Structure-Activity Relationship
6.
Int J Clin Pract ; 74(6): e13489, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32083362

ABSTRACT

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.


Subject(s)
Chronic Disease/drug therapy , Medication Adherence/statistics & numerical data , Nonprescription Drugs/therapeutic use , Polypharmacy , Prescription Drugs/therapeutic use , Adult , Aged , Australia , Chronic Disease/psychology , Female , Humans , Male , Medication Adherence/psychology , Middle Aged , Prescription Drugs/adverse effects
7.
Eur J Pharmacol ; 867: 172847, 2020 Jan 15.
Article in English | MEDLINE | ID: mdl-31812544

ABSTRACT

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.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Neurodegenerative Diseases/drug therapy , Neuroprotective Agents/pharmacology , Sirtuin 1/antagonists & inhibitors , Sirtuin 2/antagonists & inhibitors , Animals , Anti-Inflammatory Agents/therapeutic use , Brain/drug effects , Brain/immunology , Brain/pathology , Clinical Trials as Topic , Disease Models, Animal , Humans , Neurodegenerative Diseases/genetics , Neurodegenerative Diseases/immunology , Neurodegenerative Diseases/pathology , Neuroprotective Agents/therapeutic use , Polymorphism, Single Nucleotide , Sirtuin 1/genetics , Sirtuin 1/immunology , Sirtuin 1/metabolism , Sirtuin 2/genetics , Sirtuin 2/immunology , Sirtuin 2/metabolism , Treatment Outcome
8.
Bioorg Chem ; 94: 103389, 2020 01.
Article in English | MEDLINE | ID: mdl-31753312

ABSTRACT

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.


Subject(s)
Acetylglucosamine/metabolism , alpha-Synuclein/metabolism , Acetylglucosamine/chemistry , Carbohydrate Conformation , Dose-Response Relationship, Drug , Glycosylation , Humans , Parkinson Disease/metabolism , Protein Aggregates/drug effects , Structure-Activity Relationship , alpha-Synuclein/chemistry , alpha-Synuclein/genetics
9.
ACS Chem Neurosci ; 10(5): 2209-2221, 2019 05 15.
Article in English | MEDLINE | ID: mdl-30985105

ABSTRACT

Post-translational modifications (PTMs) of proteins are becoming the focus of intense research due to their implications in a broad spectrum of neurodegenerative diseases. Various PTMs have been identified to alter the toxic profiles of proteins which play critical roles in disease etiology. In Alzheimer's disease (AD), dysregulated phosphorylation is reported to promote pathogenic processing of the microtubule-associated tau protein. Among the PTMs, the enzymatic addition of N-acetyl-d-glucosamine (GlcNAc) residues to Ser/Thr residues is reported to deliver protective effects against the pathogenic processing of both amyloid precursor protein (APP) and tau. Modification of tau with as few as one single O-GlcNAc residue inhibits its toxic self-assembly. This modification also has the same effect on the assembly of the Parkinson's disease (PD) associated α-synuclein (ASyn) protein. In fact, O-GlcNAcylation ( O-linked GlcNAc modification) affects the processing of numerous proteins implicated in AD, PD, amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD) in a similar manner. As such, manipulation of a protein's O-GlcNAcylation status has been proposed to offer therapeutic routes toward addressing multiple neurodegenerative pathologies. Here we review the various effects that O-GlcNAc modification, and its modulated expression, have on pathogenically significant proteins involved in neurodegenerative disease.


Subject(s)
Acetylglucosamine/metabolism , Brain/metabolism , Neurodegenerative Diseases/metabolism , Protein Aggregation, Pathological/metabolism , Protein Processing, Post-Translational/physiology , Animals , Brain/pathology , Humans , Neurodegenerative Diseases/pathology , Protein Aggregation, Pathological/pathology , Protein Folding
10.
J Thromb Thrombolysis ; 46(4): 461-465, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30076515

ABSTRACT

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.


Subject(s)
Anticoagulants/therapeutic use , Drug Substitution/statistics & numerical data , Warfarin/therapeutic use , Administration, Oral , Adult , Aged , Humans , International Normalized Ratio , Middle Aged , Retrospective Studies
11.
J Clin Med ; 7(5)2018 May 01.
Article in English | MEDLINE | ID: mdl-29723987

ABSTRACT

BACKGROUND: Warfarin requires ongoing monitoring of the International Normalised Ratio (INR). This is because numerous factors influence the response, including drug interactions with commonly-prescribed medications, such as statins. The administration of statins with warfarin may change INR; however, there is limited information regarding the effects on warfarin control as measured by time in therapeutic range (TTR). Statins may also alter bleeds with warfarin, but there are conflicting reports demonstrating both increased and decreased bleeds, and limited data on diverse ethnic populations. Therefore, the aim of this study was to determine the effect of statin administration on warfarin control and bleeds in patients in Australia and Singapore. METHODS: Retrospective data were collected for patients on warfarin between January and June 2014 in Australia and Singapore. Patient data were used to calculate TTR and bleed events. Concurrent statin therapy was assessed and comparisons of TTR and bleed incidence were made across patient subgroups. RESULTS: Warfarin control in Australia and Singapore was not significantly affected by statins, as measured by TTR (83% and 58%, respectively), frequency of testing, and warfarin doses. In Australia, statin use did not significantly affect bleeds, whilst in Singapore the bleed incidence was significantly lower for patients on statins. CONCLUSIONS: Chronic concurrent administration of statins with warfarin does not adversely affect warfarin TTR in Australia or Singapore. In Singapore, patients on statins, compared to no statins, had a lower bleed incidence and this requires further investigation, especially given the potential genetic influences of ethnicity on both statin and warfarin metabolism.

12.
Toxicol Mech Methods ; 28(6): 410-414, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29338525

ABSTRACT

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.


Subject(s)
Behavior, Animal/drug effects , Malondialdehyde/blood , Oxidative Stress/drug effects , Pyocyanine/toxicity , Tumor Necrosis Factor-alpha/blood , Virulence Factors/toxicity , Administration, Intranasal , Animals , Inflammation , Male , Mice, Inbred C57BL , Motor Activity/drug effects , Pseudomonas aeruginosa/pathogenicity , Pyocyanine/blood , Swimming , Virulence Factors/blood
13.
Eur J Nutr ; 57(4): 1523-1534, 2018 Jun.
Article in English | MEDLINE | ID: mdl-28317073

ABSTRACT

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.


Subject(s)
Alcohol Drinking , Biomarkers/blood , Prebiotics , Probiotics , Adolescent , Adult , Aged , Double-Blind Method , Female , Humans , Male , Middle Aged , Pilot Projects , Young Adult
14.
Thromb Res ; 157: 120-125, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28738273

ABSTRACT

INTRODUCTION: Warfarin is widely used for patients with non-valvular atrial fibrillation (NVAF). Variations in warfarin control, as measured by time in therapeutic range (TTR), have been reported across different regions and ethnicities, particularly between Western and Asian countries. However, there is limited data on comparative factors influencing warfarin control in Caucasian and Asian patients. Therefore, the aim of this study was to determine warfarin control and potential factors influencing this in patients with NVAF in Australia and Singapore. METHODS: Retrospective data was collected for patients receiving warfarin for January to June 2014 in Australia and Singapore. TTR was calculated for individuals with mean patient TTR used for analysis. Possible influential factors on TTR were analysed including age, gender, concurrent co-morbidities, and concurrent medication. RESULTS: The mean TTR was significantly higher in Australia (82%) than Singapore (58%). At both sites, chronic kidney disease significantly lowered this TTR. Further factors influencing control were anaemia and age<60years in Australia, and vascular disease, CHA2DS2-VASc score of 6, and concurrent platelet inhibitor therapy in Singapore. DISCUSSION: Warfarin control was significantly higher in Australia compared to Singapore, however chronic kidney disease reduced control at both sites. The different levels of control in these two countries, together with patient factors further reducing control may impact on anticoagulant choice in these countries with better outcomes from warfarin in Australia compared to Singapore.


Subject(s)
Anticoagulants/therapeutic use , Atrial Fibrillation/drug therapy , Warfarin/therapeutic use , Aged , Aged, 80 and over , Anticoagulants/pharmacology , Atrial Fibrillation/pathology , Australia , Female , Humans , International Normalized Ratio , Male , Middle Aged , Retrospective Studies , Risk Factors , Singapore , Warfarin/pharmacology
15.
Basic Clin Pharmacol Toxicol ; 121(6): 499-504, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28639436

ABSTRACT

Warfarin reduces stroke risk in atrial fibrillation (AF) patients. The quality of warfarin control, measured by time in therapeutic range (TTR), impacts outcome and adverse events. One tool evaluating risk of adverse events and potential warfarin control would simplify risk-benefit assessment of warfarin. Recently, HASBLED was demonstrated effective for this purpose, but this was in well-controlled patients with deep vein thrombosis. HASBLED as a predictor of warfarin control has not been validated in other populations including differing indications, warfarin control levels and ethnicities. The aim of this study was to determine whether HASBLED can predict warfarin control in patients with AF in Australia and Singapore. Retrospective data were collected for patients receiving warfarin between January and June 2014 in Australia and Singapore. Patient data were used to calculate HASBLED at the start and end of the study period. TTR was calculated for each patient, and mean TTR used for analysis to stratified HASBLED scores. Of the 4370 patients, there were 3199 in Australia and 1171 in Singapore with mean TTRs of 82% and 58%, respectively. At the start of the study, a HASBLED score ≥3 predicted significantly lower TTR in Singapore, whilst at the end of the study, this score identified patients with poor control in both Australia and Singapore. A HASBLED score ≥3 in patients treated with warfarin can differentiate significantly lower TTRs in Australian and Singapore patients with AF. HASBLED may assess bleed risk and warfarin control, identifying patients at high risk of poor warfarin outcome requiring additional INR monitoring or alternative anticoagulation.


Subject(s)
Algorithms , Anticoagulants/therapeutic use , Atrial Fibrillation/drug therapy , Warfarin/therapeutic use , Aged , Aged, 80 and over , Asian People , Atrial Fibrillation/complications , Australia , Female , Humans , Hypertension/complications , International Normalized Ratio , Male , Middle Aged , Retrospective Studies , Risk Factors , Singapore , Stroke/etiology , Stroke/prevention & control , Treatment Failure , White People
16.
Drugs R D ; 17(1): 189-198, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28074333

ABSTRACT

BACKGROUND: Elimination of rosiglitazone in humans is via hepatic metabolism. The existing studies suggest that CYP2C8 is the major enzyme responsible, with a minor contribution from CYP2C9; however, other studies suggest the involvement of additional cytochrome P450 enzymes and metabolic pathways. Thus a full picture of rosiglitazone metabolism is unclear. OBJECTIVE: This study aimed to improve the current understanding of potential drug-drug interactions and implications for therapy by evaluating the kinetics of rosiglitazone metabolism and examining the impact of specific inhibitors on its metabolism using the substrate depletion method. METHODS: In vitro oxidative metabolism of rosiglitazone in human liver microsomes obtained from five donors was determined over a 0.5-500 µM substrate range including the contribution of CYP2C8, CYP2C9, CYP3A4, CYP2E1, and CYP2D6. RESULTS: The maximum reaction velocity was 1.64 ± 0.98 nmol·mg-1·min-1. The CYP2C8 (69 ± 20%), CYP2C9 (42 ± 10%), CYP3A4 (52 ± 23%), and CEP2E1 (41 ± 13%) inhibitors all significantly inhibited rosiglitazone metabolism. CONCLUSION: The results suggest that other cytochrome P450 enzymes, including CYP2C9, CYP3A4, and CEP2E1, in addition to CYP28, also play an important role in the metabolism of rosiglitazone. This example demonstrates that understanding the complete metabolism of a drug is important when evaluating the potential for drug-drug interactions and will assist to improve the current therapeutic strategies.


Subject(s)
Cytochrome P-450 Enzyme System/metabolism , Microsomes, Liver/metabolism , Thiazolidinediones/metabolism , Dose-Response Relationship, Drug , Humans , Kinetics , Microsomes, Liver/drug effects , Rosiglitazone , Structure-Activity Relationship , Thiazolidinediones/pharmacology
17.
J Stroke Cerebrovasc Dis ; 26(1): 64-69, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27671097

ABSTRACT

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.


Subject(s)
Anticoagulants/therapeutic use , Atrial Fibrillation , Racial Groups , Severity of Illness Index , Stroke , Tobacco Use/epidemiology , Warfarin/therapeutic use , Age Factors , Aged , Atrial Fibrillation/drug therapy , Atrial Fibrillation/epidemiology , Female , Humans , Male , Middle Aged , Retrospective Studies , Risk Factors , Sex Factors , Singapore/epidemiology , Stroke/epidemiology , Stroke/etiology , Stroke/prevention & control
18.
Nutrients ; 8(9)2016 Sep 20.
Article in English | MEDLINE | ID: mdl-27657121

ABSTRACT

BACKGROUND: Warfarin is a leading anticoagulant in the management of atrial fibrillation (AF) and deep vein thrombosis (DVT). Drug interactions influence the safety of warfarin use and while extensive literature exists regarding the effect on warfarin control and bleeding incidence with many medicines, there is little evidence on the influence of complementary medicines. The aim of this study was to assess the influence of fish and krill oil supplementation on warfarin control and bleeding incidence in AF and DVT patients. METHODS: A retrospective analysis was conducted utilising patient information from a large private pathology clinic. AF and DVT patients receiving long-term warfarin therapy (>30 days) at the clinic and taking fish and krill oil supplements were eligible for study inclusion. RESULTS: Of the 2081 patients assessed, a total of 573 warfarin users met the inclusion criteria with 145 patients in the fish and krill oil group (supplement group) and 428 patients in the control group. Overall, it was found that fish and krill oils did not significantly alter warfarin time in therapeutic range (TTR) or bleeding incidence, even when compared by gender. CONCLUSION: Omega-3 supplementation with fish and krill oil does not significantly affect long-term warfarin control and bleeding and thromboembolic events when consumed concurrently in patients managed at an anticoagulation clinic.

19.
Toxins (Basel) ; 8(8)2016 08 09.
Article in English | MEDLINE | ID: mdl-27517959

ABSTRACT

Pyocyanin has recently emerged as an important virulence factor produced by Pseudomonas aeruginosa. The redox-active tricyclic zwitterion has been shown to have a number of potential effects on various organ systems in vitro, including the respiratory, cardiovascular, urological, and central nervous systems. It has been shown that a large number of the effects to these systems are via the formation of reactive oxygen species. The limitations of studies are, to date, focused on the localized effect of the release of pyocyanin (PCN). It has been postulated that, given its chemical properties, PCN is able to readily cross biological membranes, however studies have yet to be undertaken to evaluate this effect. This review highlights the possible manifestations of PCN exposure; however, most studies to date are in vitro. Further high quality in vivo studies are needed to fully assess the physiological manifestations of PCN exposure on the various body systems.


Subject(s)
Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/pathogenicity , Pyocyanine/metabolism , Virulence Factors/metabolism , Animals , Humans , Inflammation/immunology , Inflammation/metabolism , Inflammation/microbiology , Inflammation Mediators/metabolism , Oxidative Stress , Pseudomonas Infections/immunology , Pseudomonas Infections/metabolism , Pseudomonas aeruginosa/immunology , Pseudomonas aeruginosa/metabolism , Pyocyanine/immunology , Reactive Oxygen Species/metabolism , Virulence Factors/immunology
20.
Reprod Toxicol ; 61: 162-8, 2016 06.
Article in English | MEDLINE | ID: mdl-27067916

ABSTRACT

Despite the fact that fetal drug exposure is common, the disposition of drugs in the fetus is poorly understood. This study aimed to investigate fetal placental and non-placental disposition of rosiglitazone in the pregnant ewe. Steady state was reached after day 5 of fetal infusion, and were ∼1.8 fold higher than maternal concentrations (P<0.001). The AUC for fetal rosiglitazone concentration throughout the infusion was inversely correlated with placental and fetal weight. Metabolic activity of the fetal liver microsomes were ∼25 fold lower than maternal microsomes (P<0.001). The findings suggest that trans-placental transfer is the major route through which rosiglitazone is cleared from the fetal compartment, while non-placental hepatic elimination makes only a minor contribution. This supports a limited capacity of the fetus for eliminating this class of drugs, and highlights the potential for drug toxicity when administering pharmacotherapy to the mother/fetus in human pregnancy.


Subject(s)
Fetus/metabolism , Hypoglycemic Agents/pharmacokinetics , Maternal-Fetal Exchange , Thiazolidinediones/pharmacokinetics , Amniotic Fluid/metabolism , Animals , Female , Hypoglycemic Agents/blood , Microsomes, Liver/metabolism , Placenta/metabolism , Pregnancy , Rosiglitazone , Sheep , Thiazolidinediones/blood
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