Impact of pharmaceutical validation on prescribing errors in a neonatal intensive care unit. Randomised and controlled study

Purpose

To compare the frequency of electronic prescription errors when the prescription was validated by the clinical pharmacist vs. when it was not.

Methods

This prospective randomised controlled study was conducted in three phases. A randomised phase, in which patients were divided into control and intervention groups, and a pre- and post-intervention phase were consecutively performed to analyse the impact of pharmaceutical validation of prescriptions in a neonatal intensive care unit (NICU). This study was performed at a highly complex NICU at a tertiary hospital. All patients born during the study period who were admitted to the NICU, with a stay lasting ≥24 h, and received active pharmacological treatment were included in the study. Pharmaceutical validation was performed according to the paediatric pharmaceutical care model. A high level of validation was selected for this study. In the intervention group, discrepancies found during the review process were communicated to the medical team responsible for the patients and resolved on the same day.

Results

In total, 240 patients were included in this study. Sixty-two patients were allocated to the pre-intervention (n = 38) or post-intervention (n = 24) groups, and 178 patients were randomly sorted into two groups, control (n = 82 newborns) and intervention (n = 96 newborns). During the randomisation phase, the number of prescription errors detected was significantly lower in the intervention group than that in the control group (129 vs. 270; p < 0.001). Similarly, prescription errors reaching the patient were significantly reduced from 40% (n = 108) in the control group to 1.6% (n = 2) in the intervention group. In the pre- and post-intervention periods, the prescription lines containing prescription errors decreased from 3.4% to 1.5% (p = 0.005).

Conclusions

This study showed that the pharmaceutical validation process decreased both the number of errors in the electronic prescribing tools and the number of prescription errors reaching the patient.

Primary care pharmacist-led medication review in older adult patients in coordination with general practitioners: an observational retrospective cohorts study

Background

Polypharmacy and risk of potentially inappropriate prescribing (PIP) in older adult are being continuously increased. Including a primary care pharmacist (PCP) in the healthcare team is associated with lower rates of medication-related problems (MRPs).

Objectives

To determine the impact (in terms of variation of PIP, MRPs and polymedication) of treatment reviews (TR) carried out by the PCP by comparing two cohorts: standard TR vs coordinated TR with prescribing General Practitioners (GP). To assess possible health outcomes in both groups 6 months post-TR.

Methods

This is an observational study of two retrospective cohorts (2018 to 2020). All patients who met the inclusion/exclusion criteria were analyzed. Patients ≥65 years, who underwent complete TR by the PCP were included. Patients in a situation of exitus at the time of TR and those who underwent a partial TR were excluded. Control group cohort consisted of patients who underwent standard TR, and intervention group cohort consisted of those who underwent TR coordinated with GP. Sociodemographic, clinical and pharmacological variables were analyzed.

Results

181 patients were enrolled. Mean age 84.4 ± 7.2 years, 78.5% women. Variables (GP-coordinated vs standard TRs) pre-post: decrease in drugs/patient 1.9 (95%CI: 1.4-2.4) vs 0.6 (95%CI: 0.2-1.3), p < 0.05; decrease in MRPs/patient 3.1 (95%CI: 2.8-3.4) vs 1.0 (95%CI: 0.6-1.4), p < 0.05; decrease in PIP/patient 2.0 (95% CI: 1.6-2.2) vs 0.6 (95% CI: 0.2-0.9), p < 0.05. Health outcomes: there was significant difference in average primary-care visits/patient 1.3 ± 0.5 vs 2.2 ± 1.8, p < 0.05.

Conclusions

Multidisciplinary interventions between PCP and GP, together with a systematic approach to TR can improve the quality of pharmacotherapy in the elderly. Prospective large follow-up studies are needed to demonstrate a positive trend in health outcomes.

A Diet Containing Rutin Ameliorates Brain Intracellular Redox Homeostasis in a Mouse Model of Alzheimer's Disease

Quercetin has been studied extensively for its anti-Alzheimer's disease (AD) and anti-aging effects. Our previous studies have found that quercetin and in its glycoside form, rutin, can modulate the proteasome function in neuroblastoma cells. We aimed to explore the effects of quercetin and rutin on intracellular redox homeostasis of the brain (reduced glutathione/oxidized glutathione, GSH/GSSG), its correlation with β-site APP cleaving enzyme 1 (BACE1) activity, and amyloid precursor protein (APP) expression in transgenic TgAPP mice (bearing human Swedish mutation APP transgene, APPswe). On the basis that BACE1 protein and APP processing are regulated by the ubiquitin-proteasome pathway and that supplementation with GSH protects neurons from proteasome inhibition, we investigated whether a diet containing quercetin or rutin (30 mg/kg/day, 4 weeks) diminishes several early signs of AD. Genotyping analyses of animals were carried out by PCR. In order to determine intracellular redox homeostasis, spectrofluorometric methods were adopted to quantify GSH and GSSG levels using o-phthalaldehyde and the GSH/GSSG ratio was ascertained. Levels of TBARS were determined as a marker of lipid peroxidation. Enzyme activities of SOD, CAT, GR, and GPx were determined in the cortex and hippocampus. ΒACE1 activity was measured by a secretase-specific substrate conjugated to two reporter molecules (EDANS and DABCYL). Gene expression of the main antioxidant enzymes: APP, BACE1, a Disintegrin and metalloproteinase domain-containing protein 10 (ADAM10), caspase-3, caspase-6, and inflammatory cytokines were determined by RT-PCR. First, overexpression of APPswe in TgAPP mice decreased GSH/GSSG ratio, increased malonaldehyde (MDA) levels, and, overall, decreased the main antioxidant enzyme activities in comparison to wild-type (WT) mice. Treatment of TgAPP mice with quercetin or rutin increased GSH/GSSG, diminished MDA levels, and favored the enzyme antioxidant capacity, particularly with rutin. Secondly, both APP expression and BACE1 activity were diminished with quercetin or rutin in TgAPP mice. Regarding ADAM10, it tended to increase in TgAPP mice with rutin treatment. As for caspase-3 expression, TgAPP displayed an increase which was the opposite with rutin. Finally, the increase in expression of the inflammatory markers IL-1β and IFN-γ in TgAPP mice was lowered by both quercetin and rutin. Collectively, these findings suggest that, of the two flavonoids, rutin may be included in a day-to-day diet as a form of adjuvant therapy in AD.

Peripheral IL-6 Levels but not Sarcopenia Are Predictive of 1-Year Mortality After Hip Fracture in Older Patients

BACKGROUND

Sarcopenic patients may have an increased risk of poor outcomes after a hip fracture. The objective of this study was to determine whether sarcopenia and a set of biomarkers were potential predictors of 1-year-mortality in older patients after a hip fracture.

METHODS

About 150 patients at least 80 years old were hospitalized for the surgical treatment of a hip fracture. The primary outcome measure was the death in the first year after the hip fracture. Sarcopenia was defined at baseline by having both low muscle mass (bioimpedance analysis) and handgrip and using the updated European Working Group on Sarcopenia in Older People (EWGSOP2) definition of probable sarcopenia. Janssen's (J) and Masanés (M) cutoff points were used to define low muscle mass.

RESULTS

Mortality 1 year after the hip fracture was 11.5%. In univariate analyses, baseline sarcopenia was not associated with mortality, using neither of the muscle mass cutoff points: 5.9% in sarcopenic (J) versus 12.4% in non-sarcopenic participants (p = .694) and 16% in sarcopenic (M) versus 9.6% in non-sarcopenic participants (p = .285). Probable sarcopenia (EWGSOP2) was not associated with mortality. Peripheral levels of IL-6 at baseline were significantly higher in the group of participants who died in the year after the hip fracture (17.14 ± 16.74 vs 11.42 ± 7.99 pg/mL, p = .026). TNF-α peripheral levels had a nonsignificant trend to be higher in participants who died. No other biomarker was associated with mortality.

CONCLUSIONS

Sarcopenia at baseline was not a predictor of 1-year mortality in older patients after a hip fracture. IL-6 was associated with a higher risk of mortality in these patients, regardless of sarcopenia status.

Biomarkers of sarcopenia in very old patients with hip fracture

BACKGROUND

Hip fracture is both a cause and a consequence of sarcopenia. Older persons with sarcopenia have an increased risk of falling, and the prevalence of sarcopenia may be increased in those who suffer a hip fracture. The aim of this study was to explore potential biomarkers (neuromuscular and peripheral pro-inflammatory and oxidative stress markers) that may be associated with sarcopenia in very old persons with hip fracture.

METHODS

We recruited 150 consecutive patients ≥80 years old admitted to an orthogeriatric unit for an osteoporotic hip fracture. Muscle mass was assessed pre-operatively using bioelectrical impedance analysis; Janssen's (J) and Masanés' (M) reference cut-off points were used to define low muscle mass. Muscle strength was assessed with handgrip strength (Jamar's dynamometer). Sarcopenia was defined by having both low muscle mass and strength and using the European Working Group on Sarcopenia in Older People 2 definition of probable sarcopenia (low grip strength). Peripheral markers-pro-inflammatory and oxidative stress parameters-were determined either in the plasma or in the erythrocyte fraction obtained from peripheral whole blood of every patient pre-operatively.

RESULTS

Mean age was 87.6 ± 4.9 years, and 78.7% were women. The prevalence of sarcopenia was 11.5% with Janssen's, 34.9% with Masanés' cut-offs, and 93.3% with the European Working Group on Sarcopenia in Older People 2 definition of probable sarcopenia. Among the four pro-inflammatory cytokines tested in plasma, only tumour necrosis factor-α was different (lower) in sarcopenic than in non-sarcopenic participants using both muscle mass cut-offs (J 7.9 ± 6.2 vs. 8.3 ± 5.8, M 6.8 ± 4.7 vs. 9.1 ± 6.2). Erythrocyte glutathione system showed a non-significant tendency to lower glutathione levels and glutathione/oxidized glutathione ratios in sarcopenic participants compared with non-sarcopenic subjects. Catalase activity was also lower in sarcopenic participants (J 2904 ± 1429 vs. 3329 ± 1483, M 3037 ± 1430 vs. 3431 ± 1498). No significant differences were found between groups in chymotrypsin-like activity of the 20S proteasome, superoxide dismutase, glutathione peroxidase and butyrylcholinesterase activity, C-terminal agrin fragment, interferon-γ, or interleukin-1β.

CONCLUSIONS

The prevalence of sarcopenia in patients with hip fracture varies according to the definition and the muscle mass reference cut-off points used. We did not find differences in most neuromuscular, pro-inflammatory, or oxidative stress markers, except for lower peripheral tumour necrosis factor-α levels and catalase activity in sarcopenic participants, which may be markers of an early inflammatory reaction that is hampered in sarcopenic patients.

Fall-risk increasing drugs and recurrent injurious falls association in older patients after hip fracture: a cohort study protocol

Polypharmacy and fall-risk increasing drugs (FRIDS) have been associated with injurious falls. However, no information is available about the association between FRIDS and injurious falls after hospital discharge due to hip fracture in a very old population. We aim to assess the association between the use of FRIDS at discharge and injurious falls in patients older than 80 years hospitalized due to a hip fracture. A retrospective cohort study using routinely collected health data will be conducted at the Orthogeriatric Unit of a teaching hospital. Patients will be included at hospital discharge (2014), with a 2-year follow-up. Fall-risk increasing drugs will be recorded at hospital discharge, and exposure to drugs will be estimated from usage records during the 2-year follow-up. Injurious falls are defined as falls that lead to any kind of health care (primary or specialized care, including emergency department visits and hospital admissions). A sample size of 193 participants was calculated, assuming that 40% of patients who receive any FRID at discharge, and 20% who do not, will experience an injurious fall during follow up. This protocol explains the study methods and the planned analysis. We expect to find a relevant association between FRIDS at hospital discharge and the incidence of injurious falls in this very old, high risk population. If confirmed, this would support the need for a careful pharmacotherapeutic review in patients discharged after a hip fracture. However, results should be carefully interpreted due to the risk of bias inherent to the study design.

[Prevalence of sarcopenia and characteristics of sarcopenic subjects in patients over 80 years with hip fracture]

INTRODUCTION

Aim: to estimate the prevalence of sarcopenia in very old patients admitted to an Orthogeriatric Unit for the treatment of a hip fracture (HF), and to compare characteristics of patients with and without sarcopenia. Methods: one hundred and fifty consecutive patients ≥ 80 years old admitted with HF were included. Sarcopenia was diagnosed with low muscle mass (bioimpedance, using two different cut-off points, Janssen and Masanés) and low grip strength (Jamar's dynamometer). Socio-demographic, nutritional variables (MNA-SF, body mass index [BMI], phase angle), cognitive (Pfeiffer, Reisberg's GDS) and functional variables (Barthel index, FAC) were registered, as well as the number of recent falls and medications on admission. Results: mean age: 87.6 ± 4.9 years (78.7% women). Prevalence of sarcopenia: 11.5% (Janssen's cut-offs) and 34.9% (Masanés cut-offs). Of the 77.5% who had independent ambulation before the fracture, 40% reported three or more recent falls. Before admission, 38% had dementia and 80.4% had mild to moderate dependence to BADL before admission; 14.2% were independent for all BADL. MNA was suggestive of malnutrition in 12.6%, and 85.2% were on four or more prescribed drugs. Sarcopenic (Masanés) had a lower BMI than non-sarcopenic participants (18.6 vs 24.3, p = 0.003), but no other significant differences were found between both groups. Phase angle was also unrelated to sarcopenia status. Conclusions: up to one third of very old patients with HF had sarcopenia on admission. Prevalence varied widely depending on the cut-off points selected to define low muscle mass. Sarcopenic patients in this setting were mostly similar to non-sarcopenic patients, except for a lower BMI.

Fall-risk increasing drugs and prevalence of polypharmacy in older patients discharged from an Orthogeriatric Unit after a hip fracture

BACKGROUND

Polypharmacy and fall-risk increasing drugs (FRIDS) have been associated with injurious falls. We aimed to estimate the prevalence of polypharmacy and FRIDS in older patients discharged from an Orthogeriatric Unit after a hip fracture surgery.

METHODS

This study describes the baseline findings of a 2-year retrospective cohort study. We included patients older than 80 years discharged from an Orthogeriatric Unit who were able to walk before surgery. Patient's baseline variables, total number of drugs, and FRIDS at hospital discharge were collected.

RESULTS

We included 228 patients. The mean number of drugs and FRIDS prescribed at discharge was 11.6 ± 3.0 and 2.9 ± 1.6, respectively. Polypharmacy was prevalent in all patients except in three: 23.3% (5-9 drugs) and 75.9% (≥ 10 drugs). Only 11 patients had no FRIDS and 35.5% were on > 3 FRIDS. The most prevalent FRIDS were: agents acting on the renin-angiotensin system (43.9%) and anxiolytics (39.9%). The number of FRIDS was higher in patients with extreme polypharmacy (3.4 ± 1.5) than in those on 5-9 drugs (1.5 ± 1.0, p < 0.05). Independent people in performing instrumental activities had lower risk of extreme polypharmacy (≥ 10 drugs) or > 3 FRIDS: OR 0.39 (95% CI 0.18-0.83) and OR 0.41 (95% CI 0.20-0.84), respectively. People living in a nursing home had higher risk of > 3 FRIDS: OR 4.03 (95% CI 1.12-14.53).

CONCLUSIONS

Polypharmacy and fall-risk increasing drugs are prevalent in patients discharged from orthogeriatric care after surgery for a hip fracture. Interventions on drug use at hospital discharge could have a potential impact on falls in this high-risk population.

Neurohormetic responses of quercetin and rutin in a cell line over-expressing the amyloid precursor protein (APPswe cells)

BACKGROUND

Plant secondary metabolites may induce adaptive cellular stress-responses in a variety of cells including neurons at the sub-toxic doses ingested by humans. Such 'neurohormesis' phenomenon, activated by flavonoids such as quercetin or rutin, may involve cell responses driven by modulation of signaling pathways which are responsible for its neuroprotective effects.

PURPOSE

We attempt to explore the molecular mechanisms involved in the neurohormetic responses to quercetin and rutin exposure, in a SH-SY5Y cell line which stably overexpresses the amyloid precursor protein (APP) Swedish mutation, based on a biphasic concentration-response relationship for cell viability.

METHODS

We examined the impact of both natural compounds, at concentrations in its hormetic range on the following cell parameters: chymotrypsin-like activity of the proteasome system; PARP-1 protein levels and expression and caspase activation; APP processing; and the main endogenous antioxidant enzymes.

RESULTS

Proteasome activities following quercetin or rutin treatment were significantly augmented in comparison with non-treated cells. Activity of caspase-3 was significantly attenuated by treatment with quercetin or rutin. Modest increased levels of PARP-1 protein and mRNA transcripts were observed in relation to the mild increase of proteasome activity. Significant reductions of the full-length APP and sAPP protein and APP mRNA levels were related to significant enhancements of α-secretase ADAM-10 protein and mRNA transcripts and significant increases of BACE processing in cells exposed to rutin. Furthermore, quercetin or rutin treatment displayed an overall increase of the four antioxidant enzymes.

CONCLUSIONS

The upregulation of the proteasome activity observed upon quercetin or rutin treatment could be afforded by a mild increased of PARP-1. Consequently, targeting the proteasome by quercetin or rutin to enhance its activity in a mild manner could avoid caspase activation. Moreover, it is likely that APP processing of cells upon rutin treatment is mostly driven by the non-amyloidogenic pathway leading to a putative reduction of βA production. Overall induction of endogenous antioxidant enzymes under quercetin or rutin treatments of APPswe cells might modulate its proteasome activity. We might conclude that quercetin and rutin might exert a neurohormetic cell response affecting various signaling pathways and molecular networks associated with modulation of proteasome function.

Age-dependent effects of esculetin on mood-related behavior and cognition from stressed mice are associated with restoring brain antioxidant status

Dietary antioxidants might exert an important role in the aging process by relieving oxidative damage, a likely cause of age-associated brain dysfunctions. This study aims to investigate the influence of esculetin (6,7-dihydroxycoumarin), a naturally occurring antioxidant in the diet, on mood-related behaviors and cognitive function and its relation with age and brain oxidative damage. Behavioral tests were employed in 11-, 17- and 22-month-old male C57BL/6J mice upon an oral 35day-esculetin treatment (25mg/kg). Activity of antioxidant enzymes, GSH and GSSG levels, GSH/GSSG ratio, and mitochondrial function were analyzed in brain cortex at the end of treatment in order to assess the oxidative status related to mouse behavior. Esculetin treatment attenuated the increased immobility time and enhanced the diminished climbing time in the forced swim task elicited by acute restraint stress (ARS) in the 11- and 17-month-old mice versus their counterpart controls. Furthermore, ARS caused an impairment of contextual memory in the step-through passive avoidance both in mature adult and aged mice which was partially reversed by esculetin only in the 11-month-old mice. Esculetin was effective to prevent the ARS-induced oxidative stress mostly in mature adult mice by restoring antioxidant enzyme activities, augmenting the GSH/GSSG ratio and increasing cytochrome c oxidase (COX) activity in cortex. Modulation of the mood-related behavior and cognitive function upon esculetin treatment in a mouse model of ARS depends on age and is partly due to the enhancement of redox status and levels of COX activity in cortex.

Discovery of alkenylboronic acids as neuroprotective agents affecting multiple biological targets involved in Alzheimer's disease

Alkenylboronic acids have shown important biological activities that contribute to neuroprotection. We have determined their influence on the β-amyloid (βA) aggregation process, β-secretase and acethylcholinesterase activities on cell-free systems, on the redox and lipid peroxidation status, and on the vulnerability to apoptotic death in an APPswe neuroblastoma cell line, before and after hydrogen peroxide treatment. We have discovered that 2-arylvinylboronic acids and some of their esters possess a set of properties which makes them highly useful as neuroprotective agents affecting multiple biological targets involved in AD. These properties are not paralleled by the related 2-arylboronic acids.

SNP-mediated neuroprotection under glucose deprivation is enhanced by Hypericum perforatum

Hypericum perforatum is a medicinal herb possessing ability for protecting neurons from oxidative stress. Since nitric oxide (NO) may be protective against oxidative stress-induced cell death as occurs in glucose deprivation (GD)-induced neurotoxicity, whether a standardized extract of H. perforatum (HP) increases the NO-mediated neuroprotective effect in GD-PC12 cells was investigated. Induced death in PC12 cells by GD exposure for 18 h was partially prevented by cell incubation with sodium nitroprusside (SNP), a NO-donor. SNP increased survival and nitrite production in GD-cells in a concentration-dependent manner. Co-incubation of cells with 10 μM SNP plus 50-100 μg/ml HP under GD insult significantly prevented GD-induced cell death to a higher extent than SNP alone as shown by an augmentation of cell survival and intracellular bcl-2 levels and a decrease of lipid peroxidation, caspase-3 activation and PARP cleavage. Cytoprotection by the NO-donor was almost abolished by the use of a NO scavenger and potentiated by the presence of superoxide dismutase. SNP and/or HP neuroprotection on GD-cells was significantly reversed by rotenone treatment. These results suggest that: (1) SNP could protect PC12 cells from GD-induced cytotoxicity through NO generation and (2) the enhancement of the SNP-mediated neuroprotective effect on GD-cells by HP might arise in part through scavenging of reactive oxygen species (ROS) and inhibition of mitochondrial dysfunction associated with the hypoglycemic episode. This current finding might highlight the development of therapeutic strategies aimed at manipulating NO-donors in combination with herb supplements containing ROS scavenger compounds for prophylaxis from brain ischemia.

Synthesis and evaluation of arylquinones as BACE1 inhibitors, β-amyloid peptide aggregation inhibitors, and destabilizers of preformed β-amyloid fibrils

BACE1 activity, inhibition of Aβ aggregation, and disaggregation of preformed Aβ fibrils constitute the three major targets in the development of small-molecule lipophilic new drugs for the treatment of Alzheimer's disease (AD). Quinones are widely distributed among natural products and possess relevant and varied biological activities including antitumor and antibiotic, inhibition of HIV-1 reverse transcriptase, antidiabetic, or COX-inhibition, among others. We report herein the interaction of several arylquinones and their derivatives with the amyloidogenic pathway of the amyloid precursor protein processing. Our studies put forward that these compounds are promising candidates in the development of new drugs which are effective simultaneously towards the three major targets of AD.

Involvement of Hsp70, a stress protein, in the resistance of long-term culture of PC12 cells against sodium nitroprusside (SNP)-induced cell death

Sodium nitroprusside (SNP)-treated PC12 cell line is being used in our laboratory as a cell model of nitric oxide (NO)-mediated damage for in vitro evaluation of potential neuroprotective compounds, thus cell response to SNP must be standardized to gain reproducible data. The NO-donor SNP has been shown to induce cell death at high concentrations in undifferentiated PC12 cells. Differences were found in sensitivity to SNP between cells from short- and long-term cultured cells. After 24-h exposure to 100-500 microM SNP, a decrease of cell viability was observed in both short- (17, 21 and 23rd passages) and long-term cultures (46, 49 and 50th passages), with IC(50) values of 312.72 and 462.90 microM, respectively. In cells from early passages, SNP-induced cell death was accompanied by significant increases of LDH leakage, nitrite production, malondialdehyde (MDA) levels, catalase (CAT) activity, cleavage of poly(ADP-ribose)polymerase (PARP) and caspase-3 activation in comparison with those from late passages. Furthermore, untreated and SNP-treated cells from long-term cultures displayed an increase of the stress protein Hsp70 levels when compared with those from short-term cultures. Up-regulated levels of Hsp70 may be associated with cell survival. Therefore, cells may acquire a certain resistance to SNP-induced toxicity associated with an increase in cell passage-dependent Hsp70. The protein Hsp70 might modulate the cellular response to the toxic insult by increasing CAT and GSH-Px activities and decreasing caspase-3 activation. Finally, it is crucial for the standardization of this cell model of neurotoxicity, at least in part, the use of PC12 cells in an optimum and reliable range of passages.

Differences of peripheral inflammatory markers between mild cognitive impairment and Alzheimer's disease

Multiple pathogenic factors may contribute to the pathophysiology of Alzheimer's disease (AD). Peripheral markers have been used to assess biochemical alterations associated with AD and mild cognitive impairment (MCI) involved in its pathophysiology. The present study was conducted to evaluate inflammatory peripheral markers in elderly patients with MCI, patients with AD and normal elderly subjects. We measured plasma levels of different cytokines (IL-6, TNF-alpha and IFN-alpha) and platelet levels of cyclooxigenase-2 (COX-2) from 34 patients with MCI, 45 patients with AD and 28 age-matched control subjects. MCI and AD patients showed similarities in TNF-alpha and COX-2 levels, and differences in IL-6 and INF-alpha. Whereas augmented IL-6 levels have been found in AD patients, a significant increase in INF-alpha has been detected only in patients with MCI possibly associated with the depression stage frequently found in cognitive impairment. In conclusion, inflammatory response may be an early factor in AD development and these changes in circulating markers are possibly related to the progression of MCI to AD.

Antioxidant properties and protective effects of a standardized extract of Hypericum perforatum on hydrogen peroxide-induced oxidative damage in PC12 cells

Free radical scavenging and antioxidant activities of a standardized extract of Hypericum perforatum (SHP) were examined for inhibition of lipid peroxidation, for hydroxyl radical scavenging activity and interaction with 1,1-diphenyl-2-picrylhydrazyl stable free radical (DPPH). Concentrations between 1 and 50 microg/ml of SHP effectively inhibited lipid peroxidation of rat brain cortex mitochondria induced by Fe2+/ascorbate or NADPH system. The results showed that SHP scavenged DPPH radical in a dose-dependent manner and also presented inhibitory effects on the activity of xanthine oxidase. In contrast, hydroxyl radical scavenging occurs at high doses. The protective effect of the standardized extract against H2O2-induced oxidative damage on the pheochromocytoma cell line PC 12 was investigated by measuring cell viability via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH) assays, caspase-3-enzyme activity and accumulation of reactive oxygen species [2',7'-dichlorofluorescin (DCF) assay]. Following 8-h cell exposure to H2O2 (300 microM), a marked reduction in cell survival was observed, which was significantly prevented by SHP (pre-incubated for 24 h) at 1-100 microg/ml. In a separate experiment, different concentrations of the standardized extract (0.1-100 microg/ml) also attenuated the increase in caspase-3 activity and suppressed the H2O2 -induced reactive oxygen species generation. Taken together, these results suggest that SHP shows relevant antioxidant activity both in vitro and in a cell system, by means of inhibiting free radical generation and lipid peroxidation.

Effects of Fraxetin on Glutathione Redox Status

We have evaluated the effects of an oral treatment of mice with fraxetin (25 mg/kg for 30 days) on the glutathione system (GSH, GSSG, and GSSG/GSH ratio as stress index), glutathione reductase (GR) and glutathione peroxidase (GPx) in liver supernatants from male C57BL/6J mice (18-month old). A significant antioxidant effect in vivo was found under this treatment by a decrease in the GSSG/GSH ratio and an increased activity of GR compared with the control mice. GSSG rate and GSSG/GSH ratio were correlated with the decline of GPx activity. Our results of increased GR activity could be considered as a supercompensation in glutathione redox status that involves a decrease in the accumulation of GSSG, as well as, in GSSG /GSH ratio. Finally, we suggest that this possible mechanism of supercompensation could lead to an enhancement in the average life span.

Modifications on antioxidant capacity and lipid peroxidation in mice under fraxetin treatment

Fraxetin belongs to an extensive group of natural phenolic antioxidants. We have investigated the modifications in endogenous antioxidant capacity; superoxide dismutase (SOD), catalase (CAT), total and selenium-dependent glutathione peroxidases (GPx) and glutathione reductase (GR) and stress index; glutathione disulphide (GSSG)/reduced glutathione (GSH) ratio and thiobarbituric acid-reactive substances (TBARs) in liver and brain supernatants of C57BL/6J male 12-month-old mice under fraxetin treatment for 30 days. Liver SOD and GPx (total and Se-dependent) activities were not significantly affected by fraxetin, whereas they were increased in the brain compared with control animals. GR activity increased significantly only in the liver of treated mice. Fraxetin treatment-related decreases were shown for GSSG/GSH ratio and rate of accumulation of TBARs (not significant in TBARs) in both tissues. We concluded that the net effect of fraxetin treatment on endogenous antioxidant capacity suggests that this compound might provide an important resistance to, or protection against, free-radical-mediated events which contribute to degenerative diseases of ageing.

Determination of malonaldehyde in Alzheimer's disease: a comparative study of high-performance liquid chromatography and thiobarbituric acid test

The concentration of malonaldehyde (MDA) was measured in human erythrocytes obtained from subjects suffering from senile dementia of the Alzheimer type (SDAT), non-demented elderly subjects, and from young controls by two methods: high-performance liquid chromatography (HPLC) and the thiobarbituric acid (TBA) test. The MDA concentration measured by HPLC showed significant differences between SDAT and young control groups (p < 0.01) and between SDAT and non-demented elderly groups (p < 0.01), respectively. Nevertheless, significant differences were not exhibited between young control and non-demented elderly. Moreover, the rate of accumulation of TBA-reactive substances was not significantly different among the three groups. Our results indicate that the HPLC method is highly specific and accurate and distinguishes between true MDA and other aldehydes that may react with TBA. Significant increases in the concentration of MDA of SDAT subjects were found in comparison with the two other groups, indicating that the measurement of MDA in erythrocytes could be used as a marker of oxidative damage in Alzheimer's disease.

Effects of fraxetin on glutathione redox status

We have evaluated the effects of an oral treatment of mice with fraxetin (25 mg/kg for 30 days) on the glutathione system (GSH, GSSG, and GSSG/GSH ratio as stress index), glutathione reductase (GR) and glutathione peroxidase (GPx) in liver supernatants from male C57BL/6J mice (18-month old). A significant antioxidant effect in vivo was found under this treatment by a decrease in the GSSG/GSH ratio and an increased activity of GR compared with the control mice. GSSG rate and GSSG/GSH ratio were correlated with the decline of GPx++ activity. Our results of increased GR activity could be considered as a supercompensation in glutathione redox status that involves a decrease in the accumulation of GSSG, as well as, in GSSG/GSH ratio. Finally, we suggest that this possible mechanism of supercompensation could lead to an enhancement in the average life span.