Selection of interventions aimed at improving medication adherence in patients with multimorbidity

Objectives

To select interventions aimed at improving medication adherence in patients with multimorbidity by means of a standardised methodology.

Methods

A modified Delphi methodology was used to reach consensus. Interventions that had demonstrated their efficacy in improving medication adherence in patients with multimorbidity or in similar populations were identified from a literature search of several databases (PubMed, EMBASE, the Cochrane Library, Center for Reviews and Dissemination, and Web of Science). 11 experts in medication adherence and/or chronic disease scored the selected interventions for appropriateness according to three criteria: strength of the evidence that supported each intervention, usefulness in patients with multimorbidity, and feasibility of implementation in clinical practice. The final set of interventions was selected according to appropriateness and agreement based on the Delphi methodology.

Results

566 articles were retrieved in the literature search. Nine systematic reviews were included. 33 interventions were initially selected for evaluation by the panellists. Consensus after two Delphi rounds was reached on 16 interventions. Five interventions were categorized as educational, six as behavioural and five were related to other aspects of interest.

Conclusions

The interventions selected following a comprehensive and standardized methodology, could be used to improve medication adherence in patients with multimorbidity.

Identification of the Medication Regimen Complexity Index as an Associated Factor of Nonadherence to Antiretroviral Treatment in HIV Positive Patients

BACKGROUND

Multiple studies have identified a relationship between the complexity of a medication regimen and non-adherence. However, most studies in people who live with HIV (PLWH) have focused on antiretroviral use and have failed to consider the impact of other medications.

OBJECTIVE

The aim of our study is to identify the Medication Regimen Complexity Index (MRCI) as an associated factor for nonadherence to antiretroviral treatment (ART). The secondary aim is to analyze the relationship between clinical and pharmacotherapeutical variables and adherence to antiretroviral treatment and to generate an adherence model.

METHODS

A transversal, observational study. Patients included were PLWH over 18 years of age on active antiretroviral therapy. Patients who participated in clinical trials or who did not meet the inclusion criteria were excluded. We had studied HIV transmission mode, viral load, treatment status, number of comorbidities and complexity index as factors associated with adherence to ART.

RESULTS

We included 619 patients in the study. Number of comorbidities ( p = 0.021; OR = 1.038-1.570); viral load ( p = 0.023; OR = 1.108-4.505) and MRCI ( p < 0.001; OR = 1.138-1.262) (ART and concomitant treatment) were the independent associated factors to ART nonadherence. The value of the Hosmer and Lemeshow test confirmed the validity of this model (P = 0.333).

CONCLUSION

A higher MRCI was associated with non-adherence. Therefore, the regimen complexity calculation may be appropriate in daily practice for identifying patients at a higher risk of becoming non-adherent.

Novel tool for deprescribing in chronic patients with multimorbidity: List of Evidence-Based Deprescribing for Chronic Patients criteria

AIM

To create a tool to identify drugs and clinical situations that offers an opportunity of deprescribing in patients with multimorbidity.

METHODS

A literature review completed with electronic brainstorming, and subsequently, a panel of experts using the Delphi methodology were applied. The experts assessed the criteria identified in the literature and brainstorming as possible situations for deprescribing. They were also asked to assess the influence of life prognosis in each criterion. A tool was composed of the most appropriate criteria according to the strength of their evidence, usefulness in patients with multimorbidity and applicability in clinical practice.

RESULTS

Out of a total of 100, 27 criteria were selected to be included in the final list. It was named the LESS-CHRON criteria (List of Evidence-baSed depreScribing for CHRONic patients), and was organized by the anatomical group of the Anatomical, Therapeutic, Chemical (ATC) classification system of the drug to be deprescribed. Each criterion contains: drug indication for which it is prescribed, clinical situation that offers an opportunity to deprescribe, clinical variable to be monitored and the minimum time to follow up the patient after deprescribing.

CONCLUSIONS

The "LESS-CHRON criteria" are the result of a comprehensive and standardized methodology to identify clinical situations for deprescribing drugs in chronic patients with multimorbidity. Geriatr Gerontol Int 2017; 17: 2200-2207.

[Interventions for improving adherence to treatment in patients with multiple pathologies: overview of systematic reviews]

Objetivo

Evaluar la evidencia disponible respecto a la eficacia de intervenciones destinadas a mejorar la adherencia al tratamiento que sean aplicables a pacientes pluripatológicos (PP).

Diseño

Revisión de revisiones sistemáticas.

Fuentes de datos

Se consultaron (septiembre de 2013): Pubmed, EMBASE, the Cochrane Library, CRD y WoS para detectar intervenciones para la mejora de la adherencia en PP, o en su defecto, pacientes con patologías definitorias de pluripatología o polimedicados.

Selección de estudios

Se incluyeron revisiones sistemáticas de ensayos clínicos con PP o de características similares. Estas debían comparar la eficacia de cualquier intervención destinada a mejorar el cumplimiento del tratamiento autoadministrado prescrito con la práctica habitual u otra intervención.

Extracción de datos

Se extrajo información sobre la población en estudio, la intervención ensayada y la eficacia de la misma en términos de mejora de la adherencia.

Resultados

Se recuperaron 566 artículos de los que se seleccionaron 9 revisiones sistemáticas. Ninguna se centraba específicamente en PP. Sí consideraban pacientes con múltiples patologías crónicas, patologías definitorias de pluripatología o polimedicados.

La eficacia global de las intervenciones fue modesta, no observándose diferencias relevantes entre las intervenciones de carácter conductual, educativo o combinado. Algunos componentes de estas intervenciones como son el asesoramiento al paciente o las estrategias de simplificación posológica parecen ser herramientas eficaces en la mejora de la adherencia en este grupo poblacional.

Conclusiones

Existe una gran heterogeneidad de intervenciones orientadas a la mejora de la adherencia de eficacia modesta, no habiendo sido diseñadas para una población de PP.

[Pharmacological treatment conciliation methodology in patients with multiple conditions]

Objetivo

Realizar una revisión bibliográfica para identificar las diferentes metodologías empleadas en el proceso de conciliación de los tratamientos farmacológicos que sean aplicables a pacientes pluripatológicos.

Diseño

Revisión sistemática.

Fuentes de datos

Se realizó una revisión bibliográfica (febrero de 2012) en las bases de datos Pubmed, EMBASE, CINAHL, PsycINFO e Índice Médico Español de métodos de conciliación del tratamiento en pacientes pluripatológicos, o en su defecto, ancianos o polimedicados.

Selección de estudios

Se recuperaron 273 artículos, de los que se seleccionaron 25.

Extracción de datos

Se extrajo información relativa a la metodología empleada: nivel asistencial en el que se realiza, fuentes de información, uso de formulario, tiempo establecido, profesional responsable, información recogida y variables registradas como errores de conciliación.

Resultados

La mayoría de estudios fueron al ingreso y al alta hospitalarios Como principales fuentes de información destacan la entrevista y la historia clínica. En la mayoría de trabajos no se especifica un tiempo preestablecido, ni se usa formulario, y el principal responsable es el farmacéutico clínico. Además de la medicación domiciliaria, los hábitos de automedicación y la fitoterapia también son registrados. Se recogen como errores de conciliación desde omisiones de fármacos hasta interacciones medicamentosas.

Conclusiones

Existe gran heterogeneidad en la metodología empleada para la actividad de la conciliación. No existe ningún trabajo realizado específicamente en el paciente pluripatológico, que por su complejidad y susceptibilidad a errores de conciliación requiere una metodología estandarizada.

Reliability of a questionnaire for pharmacological treatment appropriateness in patients with multiple chronic conditions

BACKGROUND

The original Medication Appropriateness Index was validated for elderly and polymedicated patients, both in hospital and outpatient contexts. However, no studies have applied this questionnaire in patients with multiple chronic conditions. The objective of this study is to assess the reliability of a modified Medication Appropriateness Index questionnaire in a population of patients with multiple chronic conditions.

METHODS

We selected patients with multiple chronic conditions who were included in an integrated care project conducted at the Hospital Universitario Virgen del Rocío. To determine inter-observer reliability, each professional (internist or hospital pharmacy specialist) applied the questionnaire under the same conditions and with the same resources. To determine intra-observer reliability, each physician applied the tool at baseline and two months later. We measured inter- and intra-observer reliability using the kappa coefficient. The proportion of overall agreement was also determined.

RESULTS

We obtained a weak overall kappa (k=0.38) for inter-observer reliability and moderate (k=0.52) and very good (k=0.84) values for intra-observer reliability of the internist and specialist in hospital pharmacy, respectively. The proportion of overall agreement is very high in all three situations: 96%, 98%, and 99%, respectively.

CONCLUSIONS

Despite its limitations, the Medication Appropriateness Index questionnaire modified by our group can be used, as a reliable method, to assess the appropriateness of pharmacotherapy in patients with multiple chronic conditions.

[Medication reconciliation on hospital admission in patients with multiple chronic diseases using a standardised methodology]

OBJECTIVES

To determine the incidence of medication errors when admitting patients with multiple chronic conditions to hospital, using a standard method.

MATERIAL AND METHOD

A prospective, observational study was conducted on patients with multiple chronic conditions admitted to a tertiary hospital. The medication reconciliation was performed using the standard method considered the most suitable for these patients by an expert panel, following the Delphi methodology. The main information source used for this was the computerised clinical notes, both in primary care and in the hospital, recurring to a clinical interview if necessary. Discrepancies justified by the clinician, as well as reconciliation errors were recorded. The type of error and the pharmacological group involved were analysed and the seriousness of each one of them was assessed.

RESULTS

A total of 114 patients were included, with reconciliation errors being found in 75.4% of cases. The patients had 1397 prescribed drugs, of which 234 had discrepancies that required clarification by the clinician responsible. The clinician modified the prescription in 184 of these discrepancies, which were considered reconciliation errors. The types of error were: medication omission (139), commission (9), dose, prescription or different routes (24) and by incomplete prescription (12). Anti-anaemic drugs, vitamins, and psychoanaleptics were among the pharmacotherapeutic groups most affected by the errors.

CONCLUSIONS

The percentage of patients with multiple chronic conditions with errors is elevated. The development of methods particularly directed at patients with multiple chronic conditions manages to detect and decrease a high percentage of medication errors associated with changes of care levels.

[Evaluation of the appropriateness of pharmacotherapy in patients with high comorbidity]

OBJECTIVE

[corrected] To analyze the appropriateness of pharmacotherapy and, if necessary, carry out interventions for its improvement in a cohort of patients with multiple chronic conditions.

DESIGN

Descriptive, prospective study of 21 months duration.

LOCATION

Hospital Universitario Virgen del Rocío.

PARTICIPANTS

Patients with multiple chronic conditions included in a project for integrated healthcare.

METHODS

The primary endpoint was the number of inappropriate treatments. To evaluate the appropriateness of pharmacotherapy, the specialist in hospital pharmacy followed a standardized procedure consisting of the Medication Appropriateness Index (MAI) questionnaire, modified as an implicit method, and the list of criteria of the Screening Tool of Older Person's Potentially Inappropriate Prescription/Screening Tool to Alert doctors to the Right (STOPP-START) as an explicit method.

RESULTS

A total of 244 patients were included, with a mean age of 76 ± 8 (± SD) years. Half (50%) of the patients were men. The mean number of diagnoses per patient was 8 ± 3 (± SD) and 12 ± 4 drugs (± SD). A total of 840 inappropriate treatments were detected, most of them being due to the presence of interactions. The STOPP criteria most not complied with, were duplicate drug class, and prolonged use of benzodiazepines with long half-life or long-acting metabolites, and START for ACE inhibitors in chronic heart failure and statins and antiplatelets in diabetes mellitus, if one or more coexisting risk factors.

CONCLUSIONS

We detected a large number of inappropriate treatments. This highlights the importance of evaluating the appropriateness of drug treatment in patients with multiple conditions. It is advisable to use a combined pharmacist intervention strategy that includes both an implicit method and an explicit method.

[Suitability of pharmacological treatment in patients with multiple chronic conditions]

OBJECTIVE

To identify tools for measuring the appropriateness of drug therapy useful in patients with multiple chronic conditions.

DESIGN

We performed a literature review.

DATA SOURCES

The following database were consulted (December 2009): Pubmed, EMBASE, CINAHL, PsycINFO and Spanish Medical Index (IME) to detect tools for measuring the appropriateness of treatment in patients with multiple chronic conditions, or otherwise elderly or polypharmacy.

STUDY SELECTION

Studies were identified both qualitative and quantitative methodology, both theoretical and field work, both original and revised work and included work from all areas of the health system. 108 articles were retrieved, of which we selected 59. The consultation of their references include 20 jobs allowed, resulting in a total of 59 articles.

DATA EXTRACTION

Of all the tools identified, the researchers performed a selection of those with possible utility for classified PP. The articles were classified into implicit and explicit methods and the characteristics of the field works were tabulated.

RESULTS

We identified two implicit methods (MAI and Hamdy) and 6 explicit methods (Beers criteria, IPET, STOPP/START, ACOVE, CRIME and NORGEP). None was specific to patients with multiple chronic conditions. The questionnaire MAI, the Beers criteria and its modifications are most often used in literature. The advantages of explicit criteria means that many of them have been developed recently.

CONCLUSION

There are several tools to measure the appropriateness and none of them has been designed for a population of patients with multiple chronic conditions yet, which by its nature requires a specific approach spreads.

The coffee constituent chlorogenic acid induces cellular DNA damage and formation of topoisomerase I- and II-DNA complexes in cells

Chlorogenic acid (CGA) is a plant polyphenol with known antioxidant properties. Although some studies suggest that CGA has anticancer properties, others indicate that this dietary constituent may cause DNA damage and induce carcinogenic effects. Because CGA is widely consumed in the form of coffee, it is important to further evaluate the putative DNA-damaging activity of CGA. Here we have employed two standard techniques commonly used for DNA damage detection (the comet assay and the γ- H2AX focus assay) and observed that CGA (0.5-5 mM) induces DNA damage in normal and cancer cells. We report for the first time that CGA induces high levels of topoisomerase I- and topoisomerase II-DNA complexes in cells (TARDIS assay). Catalase pretreatment abolished the formation of these topoisomerase-DNA complexes and reduced the cytotoxic activity of CGA, therefore indicating that hydrogen peroxide plays an important role in these activities. Lung cancer cells (A549) were more sensitive than normal lung fibroblasts (MRC5) to the cytotoxic activity of CGA, supporting previous findings that CGA may induce selective killing of cancer cells. Taking into consideration our results and the pharmacokinetic profile of CGA, the possible cancer preventive, carcinogenic and therapeutic potential of this dietary agent are discussed.

A review on the dietary flavonoid kaempferol

Epidemiological studies have revealed that a diet rich in plant-derived foods has a protective effect on human health. Identifying bioactive dietary constituents is an active area of scientific investigation that may lead to new drug discovery. Kaempferol (3,5,7-trihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) is a flavonoid found in many edible plants (e.g. tea, broccoli, cabbage, kale, beans, endive, leek, tomato, strawberries and grapes) and in plants or botanical products commonly used in traditional medicine (e.g. Ginkgo biloba, Tilia spp, Equisetum spp, Moringa oleifera, Sophora japonica and propolis). Some epidemiological studies have found a positive association between the consumption of foods containing kaempferol and a reduced risk of developing several disorders such as cancer and cardiovascular diseases. Numerous preclinical studies have shown that kaempferol and some glycosides of kaempferol have a wide range of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anticancer, cardioprotective, neuroprotective, antidiabetic, anti-osteoporotic, estrogenic/antiestrogenic, anxiolytic, analgesic and antiallergic activities. In this article, the distribution of kaempferol in the plant kingdom and its pharmacological properties are reviewed. The pharmacokinetics (e.g. oral bioavailability, metabolism, plasma levels) and safety of kaempferol are also analyzed. This information may help understand the health benefits of kaempferol-containing plants and may contribute to develop this flavonoid as a possible agent for the prevention and treatment of some diseases.

Effect of L-Carnitine and Propionyl-L-Carnitine on Endothelial Function of Small Mesenteric Arteries from SHR

BACKGROUND

The effect of treatment with either 200 mg x kg(-1) of L-carnitine (LC) or propionyl-L-carnitine (PLC) was studied on endothelial dysfunction of small mesenteric arteries (SMA) from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats.

METHODS

Systolic blood pressure (SBP) was measured and endothelial and vascular functions were assessed by the effect of carbachol (CCh) and phenylephrine (Phe). O2- produced by SMA and eNOS expression were evaluated by chemiluminescence and Western blot, respectively.

RESULTS

Although SBP was not affected, endothelial relaxation increased in both LC- and PLC-treated SHR. Nevertheless, the CCh-induced contraction remained sensitive to indomethacin in these rats. On the contrary, NO participation was increased in all the groups except for LC-treated WKY. Furthermore, high concentrations of Phe produced NO-dependent relaxation of SMA from PLC-treated rats. Both compounds decreased basal and NADPH-stimulated O2- in SHR toward values observed in WKY. Only PLC increased eNOS protein expression in SHR. Neither LC nor PLC affected endothelium-derived hyperpolarizing factor-induced relaxation.

CONCLUSIONS

LC and its propionate improved endothelial responses of SMA from SHR by decreasing O2- production and thus increasing NO availability. PLC also increased NO synthesis by enhancing eNOS expression.

Argan (Argania spinosa) oil lowers blood pressure and improves endothelial dysfunction in spontaneously hypertensive rats

Traditionally hand-pressed argan oil, obtained from Argania spinosa seeds, is eaten raw in south-west Morocco; its rich composition of tocopherols, MUFA and PUFA make a study of its actions on risk factors for CVD, such as hypertension, interesting. The effects of 7 weeks of treatment with argan oil (10ml/kg) on the blood pressure and endothelial function of spontaneously hypertensive rats (SHR) and normotensive Wistar–Kyoto rats were investigated. Systolic blood pressure and heart rate were measured every week by the tail-cuff method and endothelial function was assessed by carbachol (10−8 to 10−4m)-induced relaxations of aortic rings and small mesenteric arteries pre-contracted with phenylephrine. Argan-oil administration reduced the mean blood pressure of SHR after the fifth week of treatment (P<0·05) and increased (P<0·01) the endothelial responses of arteries from SHR. The NO synthase inhibitor, l-N-ω-nitroarginine (3×10−5m) revealed a greater participation of NO in the relaxant effect after the treatment. When cyclooxygenase (COX) was blocked with indomethacin (10−5m), an involvement of COX products in the endothelium-dependent response was characterized. Enzyme immunoassay of thromboxane B2 showed a significant decrease (P<0·05) in the release of thromboxane A2 in both aorta and small mesenteric artery after argan-oil treatment of SHR. Experiments in the presence of the thromboxane A2–prostaglandin H2 receptor antagonist ICI 192, 605 (10−5m) confirmed this result. Results after incubation with the antioxidants superoxide dismutase and catalase suggested that a decreased oxidative stress might contribute to explain the beneficial effects of argan-oil treatment.

Improvement of age-related endothelial dysfunction by simvastatin: effect on NO and COX pathways

The effects of oral administration of the HMG-CoA reductase inhibitor, simvastatin (SV), on age-related endothelial dysfunction were investigated in the aorta of male Wistar rats. Adult (12-14 weeks) and old (60-80 weeks) rats were treated daily for 12 weeks with either vehicle or SV (1 mg kg(-1)). In old rats, SV treatment did not significantly affect systolic blood pressure and LDL-cholesterol, but it reduced plasma cholesterol, triglycerides and oxidised LDL though it did not affect total antioxidant status. SV improved endothelium-dependent relaxation to acetylcholine and A-23187 in vessels from aged, but not adult, rats. This effect was linked to a greater NO vasodilatation via an increased expression of endothelial NO-synthase. A mechanism sensitive to superoxide dismutase and catalase also accounts for enhanced endothelial vasodilatation. Finally, SV did not affect the release of prostacyclin, but it inhibited the generation of thromboxane (TX) A2 from COX-2 isoform. The effect of the latter was sensitive to the Tp receptor antagonist, ICI-192,605. The present study provides evidence that oral administration of SV improves endothelial dysfunction in the aorta from aged rats by mechanisms associated with enhanced NO vasodilatation, reduced release of TXA2 from cyclo-oxygenase, and increased antioxidant properties of the vessel wall. These data underscore a new therapeutic perspective for SV in age-related endothelial dysfunction.

Regulation of Vascular Tone from Spontaneously Hypertensive Rats by the HMG-CoA Reductase Inhibitor, Simvastatin

The acute effect of simvastatin on aortic rings from spontaneously hypertensive rats (SHRs) was identified. Simvastatin-evoked relaxations of both depolarized and phenylephrine-precontracted arteries were independent of the presence of endothelium. This effect was inhibited by diltiazem and mevalonate, but not by the Rho-kinase inhibitor, Y-27632. Simvastatin prevented contraction induced by phenylephrine, calcium ionophore A-23187 and CaCl2 in Ca2+-free medium. Y-27632 decreased the effect of simvastatin. On the contrary, contraction induced by noradrenaline in Ca2+-free medium was not affected. These results suggest that simvastatin elicited an effect on vascular smooth muscle cells from SHRs that may involve blockade of extracellular calcium entry and decrease vascular contraction by affecting Rho-kinase.

Effects of simvastatin on endothelial function after chronic inhibition of nitric oxide synthase by L-NAME

Blood pressure, plasma NO(2) and NO(3) level, heart weight index, antioxidant enzyme activity, and vascular reactivity in rat intact aortic rings were assessed to investigate the effects of 8-week treatment with the hydroxy-methyl-glutaryl coenzyme A reductase inhibitor simvastatin (1 mg/kg per day) on endothelial dysfunction induced by chronic Nomega-nitro-l-arginine methyl ester (l-NAME 70 mg/kg per day). Results were compared with those obtained in rats receiving l-NAME, simvastatin or control animals. Coadministration of simvastatin did not restore l-NAME-increased blood pressure but normalized heart weight index (P < 0.05), endothelium-dependent relaxation to acetylcholine (P < 0.001), and plasma NO(2) and NO(3) concentration (P < 0.001) without affecting relaxation to sodium nitroprusside. Endothelium-dependent relaxation in these animals was abolished by acute incubation with l-NAME, unaffected by thromboxane synthetase inhibitor and TXA(2)/PGH(2) receptor antagonist, ridogrel, and decreased by indomethacin. Simvastatin treatment also increased plasma NO(2)+NO(3) without affecting endothelial function, heart weight index, and blood pressure of control rats. The presence of superoxide dismutase (SOD) and catalase improved endothelial relaxation only in l-NAME-treated rats, but O(2)- generated by hypoxanthine and xanthine oxidase inhibited the relaxant effect in both l-NAME and simvastatin plus l-NAME-treated rats. SOD activity was increased in all groups receiving simvastatin. Long-term treatment with simvastatin restored l-NAME-induced endothelial dysfunction, probably by preventing nitric oxide decrease. Other effects of simvastatin, including release of compensating vasodilatory cyclo-oxygenase products and increased SOD activity, could also be involved.

Endothelium-dependent vasorelaxation induced by L-carnitine in isolated aorta from normotensive and hypertensive rats

The aim of this work was to investigate the mechanism of the vasodilatory effect induced by L-carnitine. Relaxation produced by L-carnitine was studied in rat aortic rings with and without functional endothelium, pre-contracted with phenylephrine by adding cumulative doses of L-carnitine (10(-7) to 10(-3) M). The relaxation evoked by L-carnitine reached higher values in aortic rings from spontaneously hypertensive rats than those obtained in arteries from normotensive rats; no relaxation was produced in de-endothelialized arteries. However, in the presence of N(G)-nitro-L-arginine (3 x 10(-5) M, a nitric oxide synthase inhibitor), Ro 68070 (10(-4) M, a thromboxane synthetase inhibitor-thromboxane A2/prostaglandin H2 receptor antagonist) or ICI 192605 (10(-5) M, a thromboxane A2 receptor antagonist) the relaxant response to L-carnitine was significantly inhibited. These results show that L-carnitine induced endothelium-dependent relaxation in the rat aorta and the mechanism of this relaxation appeared to be mostly mediated by endothelial production of nitric oxide but#10; also could involve prevention of the action of cyclooxygenase endothelial products acting on the thromboxane A2/prostaglandin H2 receptor.

Effects of dietary oleic-rich oils (virgin olive and high-oleic-acid sunflower) on vascular reactivity in Wistar-Kyoto and spontaneously hypertensive rats

The effects of two monounsaturated fatty acid (MUFA)-rich diets, containing virgin olive oil (OO) and high-oleic-acid sunflower oil (HOSO), on development of vascular response from isolated thoracic rat aorta and lipid composition and fatty acid composition were studied and compared with samples from rats fed on a control diet. Dietary MUFA oils were fed for 6 weeks to spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats from 4 weeks of age. The maximum contraction of aortic ring preparations in response to phenylephrine (10(-6) m) was significantly decreased in SHR rats fed with OO (0.81 (sem 0.05) v. 1.18 (sem 0.09) g, and treatment with HOSO did not alter the phenylephrine-induced contractions. The relaxant responses to acetylcholine (10(-5) m) were significantly enhanced (30.03 (sem 0.70) v. 18.47 (sem 0.28) %, in the rings from SHR rats treated with OO, and were more pronounced than in WKY rats In the same way, OO attenuated the dose-response curves induced by phenylephrine (10(-8)-10(-5) m) from SHR rats, accompanied with a slower contraction. These results suggest that only the chronic feeding of OO diet was able to attenuate the vascular response of rat aorta. In addition, an increase in phospholipid content (186.7 (sd 3.2) v. 159.1 (sd 11.3) g/kg, and changes in the fatty acid composition of aorta (mainly a decrease in arachidonic acid) could contribute to improving endothelial function. Therefore, the effects can not be attributed exclusively to the content of MUFA (mainly oleic acid). Other components of OO, such as polyphenols, not present in HOSO, may help to explain the vascular protective effect of OO consumption.

A pharmacological study of Cecropia obtusifolia Bertol aqueous extract

Cecropia obtusifolia (Cecropiaceae) is a species from tropical America and its leaves are used in traditional medicine for the treatment of diabetes and as an anti-inflammatory agent. In the present study, the analgesic, anti-inflammatory and central nervous system depressant effects of the aqueous extract from the leaves of C. obtusifolia were investigated in different experimental models, with the purpose of validating its ethnomedical uses. The results obtained with the extract from the leaves of C. obtusifolia reflect a low toxicity, a substantial central depressor effect and analgesic activity and significant motor incoordination and muscle relaxant activity. Concerning the analgesic activity, using the hot plate test, the extract did not produce any effect, however it showed a significant effect on the pain induced by chemical stimuli (acetic and formalin test); this suggests the peripheral analgesic effect of the extract. The extract also showed a topical and systemic anti-inflammatory effect. Thus this work could justify the popular use of C. obtusifolia in rheumatic and kidney inflammation pathologies and reveals that this plant is an interesting species.

Effect of simvastatin on vascular smooth muscle responsiveness: involvement of Ca(2+) homeostasis

This report is focused on the study of simvastatin-induced relaxation of rat aorta through its effects on vascular smooth muscle and Ca(2+) signalling. The presence of endothelium affected only the simvastatin-induced relaxation of aortic rings precontracted with noradrenaline, but not by depolarization with KCl 80 mM. Blockade of Ca(2+) entry through voltage-operated Ca(2+) channels (VOCCs) by diltiazem abolished the endothelium-dependent and direct relaxation, whereas Ca(2+)-ATPase inhibition by cyclopiazonic acid (3 x 10(-5) M) only affected the endothelium-dependent relaxation. In KCl-depolarised arteries concentration-response curves for CaCl(2) were shifted to the right in the presence of simvastatin (3 x 10(-6) and 3 x 10(-5) M) or diltiazem (10(-6) and 10(-7) M). The transient contraction caused by noradrenaline in Ca(2+)-free medium, which is mainly due to intracellular Ca(2+) release, was inhibited by simvastatin (3 x 10(-5) M) or cyclopiazonic acid (3 x 10(-5) M) and the contraction induced by CaCl(2) (2 x 10(-3) M) added after noradrenaline was inhibited by diltiazem and simvastatin. All the reported effects of simvastatin were inhibited by the product of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, mevalonate (10(-3) M). These findings demonstrate that the vascular effects of simvastatin may involve both Ca(2+) release from intracellular stores, which could promote activation of endothelial factors, and blockade of extracellular Ca(2+) entry, which promote relaxations independent of the presence of endothelium. This action on Ca(2+) could be related to the inhibition of isoprenoid synthesis, which subsequently affects the function of G-proteins involved in communication among intracellular Ca(2+) pools and capacitative Ca(2+) entry.

Endothelium modulates contractile response to simvastatin in rat aorta

Simvastatin is an inhibitor of HMG-CoA reductase used in the treatment of hypercholesterolemia. In the present study simvastatin-induced contraction was observed in rat aortic thoracic rings, this effect increased when the endothelium was removed and when NO synthase was blocked by L-NOARG (3 x 10(-5) M). The contractile effect of simvastatin on intact aortic rings diminished when cyclo-oxygenase was inhibited with indomethacin (10(-5) M). Also in the presence of endothelium, pretreatment with mevalonate (1 mM), the product of HMG-CoA reductase activity, significantly inhibited the contraction. In other experiments carried out on endothelium-removed preparations and in medium containing the calcium antagonist, diltiazem (10(-5) and 10(-6) M), the contraction dose-response curves were significantly reduced and the same happened in the presence of the inhibitor of sarcoplasmic reticulum Ca-2+-ATPase, cyclopiazonic acid (CPA) (3 x 10(-6) M). The results suggest that simvastatin might increase intracellular calcium concentration. This effect could lead to an activation of NO synthase and cyclooxygenase pathways in endothelial cells and to contraction in vascular smooth muscle cells. This rise in Ca2+ concentration could be due to an inhibition of isoprenoid synthesis prevented by mevalonate.

Effects of chronic treatment with simvastatin on endothelial dysfunction in spontaneously hypertensive rats

OBJECTIVE

To investigate the effects of chronic treatment with simvastatin (SV) on endothelium-dependent relaxation and ouabain-induced contractions in aortic rings from spontaneously hypertensive rats (SHR), comparing with normotensive Wistar-Kyoto rats (WKY).

METHODS

After a 12-week period of administration of 1 or 2 mg/kg SV to SHR and WKY, systolic blood pressure (SBP) and vascular reactivity in endothelium-intact aortic rings were assessed.

RESULTS

Relaxation in response to acetylcholine (ACh) in WKY remained unaltered, but in SHR treated with 1 mg/kg SV, enhanced ACh-induced relaxation (P<0.05 versus untreated SHR) reached values observed in untreated WKY. The 2 mg/kg treatment also improved ACh relaxation (P<0.01 and P<0.05 versus untreated SHR and WKY respectively). Inhibiting cyclo-oxygenase (COX) with indomethacin (INDO) improved ACh relaxation in SHR (P<0.05) but not in WKY, independent of treatment with SV. Inhibition of nitric oxide synthase (NOS) with N(G)-nitro-L-arginine (L-NOARG) abolished ACh relaxations in all cases (P<0.001). The result was unaltered when combining INDO plus L-NOARG. SV treatment also decreased ouabain-induced contractions in endothelium-intact aortic rings from SHR, diminishing the percentage effect of contraction from 64.56+/-2.95 (untreated SHR) to 26.98+/-7.06 and 38.10+/-8.21 (1 and 2 mg/kg treated SHR respectively). Response to ouabain in WKY was not significantly affected by SV treatment

CONCLUSIONS

Chronic treatment of SHR with SV improves endothelium-dependent ACh relaxation of the aortic rings, probably by an NO-involving mechanism more than by inhibiting contractile COX-derived factors. An improvement in endothelial modulation of ouabain-induced contractions was also observed after treatment with SV in SHR, which might be due to an inhibition of a calcium-sodium exchanger.

Vasodilating effects of tetrazepam in isolated vascular smooth muscles: comparison with cromakalim and diltiazem

The vasodilating effects of tetrazepam (1,4-benzodiazepine derivative) were studied and compared with those of the K-channel activator, cromakalim and the Ca-channel blocker, diltiazem, in rat aorta smooth muscle and on the spontaneous contractile activity of the rat portal vein. In the aorta, tetrazepam (3 x 10(-7)-10(-4) M) and diltiazem (10(-8)-3 x 10(-6) M) concentration-dependently relaxed aortic rings contracted by 30 mM as well as 80 m KCl. Although cromakalim (10(-8)-3 x 10(-6) M) concentration-dependently relaxed aortic rings contracted by 30 mM KCl, it did not relax those contrated by 80 mm KCl. In the presence of the ATP-sensitive K-channel blocker, glibenclamide (10(-6) and 3 x 10(-6) M), 30 mM KCl concentration-response curves for the relaxant effect of tetrazepam and diltiazem were unaffected but cromakalim caused a progressive shift of these curves upwards. In the portal vein, tetrazepam inhibited spontaneous contractions, decreased amplitude and increased frequency. Similar behaviour was shown with diltiazem (10(-8)-10(-5) M) and in both cases, pre-treatment with glibenclamide (10(-6) M) was ineffective. Although cromakalim (10(-5)-10(-6) M) decreased both amplitude and frequency, this effect was blocked by glibenclamide. These results indicate that the vasodilator action of tetrazepam is not mediated to the opening of ATP-sensitive K-channels, unlike cromakalim. This may be mediated, like those of diltiazem, by the blockade of calcium movements across the cell membrane.

Spasmolytic effects of tetrazepam on rat duodenum and guinea-pig ileum

This study was designed to examine the inhibitory effects exerted by tetrazepam isolated rat duodenum and guinea pig ileum contractive responses and to further clarity the mechanisms involved. Tetrazepam produced concentration-dependent and complete relaxation of muscle contractions induced by KCl (80 mM) in guinea-pig ileum and this relaxant action was not antagonized by pretreatment with hexamethonium (0.1 mM), antagonist for nicotinic receptors, or atropine (1 microM), antagonist for muscarinic receptors, or PK 11195 (1 microM) antagonist for peripheral-type benzodiazepines receptors. Tetrazepam also modified the concentration-response curves of CaCl2 in calcium-free and high K/ depolarizing medium as soon as concentration-response curves of acetylcholine in Tyrode solution. The results suggested that tetrazepam inhibits the contractile responses to guinea-pig ileum and rat duodenum, probably through a reduction of calcium influx by way of calcium channels and these events are not related to high-affinity peripheral benzodiazepine binding sites.

Antiulcer effect of naringin on gastric lesions induced by ethanol in rats

This study was designed to determine the gastroprotective properties of naringin on and the involvement of endogenous prostaglandins in mucosal injury produced by absolute ethanol. Oral pretreatment with the highest dose of naringin (400 mg/kg), 60 min before absolute ethanol was the most effective antiulcer treatment. Subcutaneous administration of indomethacin (10 mg/kg) to the animals treated with naringin (400 mg/kg) partially inhibited gastric protection, but the prostaglandin E2 determination did not show any increase in prostanoid levels. The contents of gastric mucus and total proteins were not significantly modified. Naringin-treated rats showed a marked increase in hexosamine levels, but this increase was less in animals pretreated with indomethacin. These results show that naringin has a 'cytoprotective' effect against ethanol injury in the rat, but this property appears to be mediated by non-prostaglandin-dependent mechanisms.