Effects of Plantago ovata Husk on Levodopa (with Carbidopa) Bioavailability in Rabbits with Autonomic Gastrointestinal Disorders

P. 1434-1442Gastrointestinal dysfunction is common in Parkinson’s disease. Fiber therapy could be used to reduce the symptoms of gastrointestinal motility disorders. In a previous study, we showed that slowed gastrointestinal motility modified levodopa pharmacokinetics: area under the plasma concentration-time curve (AUC) and maximum plasma concentration (Cmax) decreased and the elimination was delayed. In this study, we evaluated whether or not the hydrosoluble fiber Plantago ovata husk is useful in improving levodopa pharmacokinetics in rabbits with autonomic gastrointestinal disorders induced by the administration of the anticholinergic biperiden. Levodopa carbidopa (20:5 mg/kg), biperiden (100 g/ kg), and P. ovata husk (at two different doses: 100 and 400 mg/kg) were administered orally to rabbits for two periods of time (7 or 14 days). In all groups of animals, the AUC values were approximately 50% higher on the final day of treatment than on day 1. Cmax was also higher, with the greater increase at the 400 mg/kg dose of fiber, which resulted in a boost of approximately 35%. On day 1 of treatment and with both doses of fiber, AUC values were very similar to those obtained in previous work in rabbits with normal gastrointestinal motility, but the Cmax was lower. However, after 7 or 14 days, the AUC values were higher, but Cmax remained lower. The greatest differences were observed in plasma concentration before drug administration (Cmin), for which the highest increase was obtained with the dose of 400 mg/kg fiber on day 14 of treatment (349.8%). P. ovata husk could be beneficial in patients with Parkinson’s disease because it regulates stool transit in the intestine and because it improves levodopa pharmacokinetics when gastrointestinal peristalsis is slowed. These changes could lead to a possible delay in the onset of dyskinesias and to changes in prognosis.S

Influence of two commercial fibers in the pharmacokinetics of ethinylestradiol in rabbits

P. 870-874Fiber formulations are used in human nutrition owing to their beneficial properties for health. It is probable that ingestion of fiber coincides with the oral administration of drugs, and a modification of its oral absorption, and therefore of its pharmacokinetics, can appear. In the present study, the compartmental and noncompartmental pharmacokinetic parameters of ethinylestradiol (EE) in rabbits after oral administration were determined. It was also studied whether the presence of two different fiber formulations [A, wheat bran (76.5%), fruit fiber (12%) and guar gum (2%) and B, Plantago ovata seeds (65%) and P. ovata seed cuticles (2.2%)] in the gastrointestinal tract modified the pharmacokinetics of EE when administered at the same time. Three groups of rabbits were used: control, fiber A and fiber B. The animals in all three groups received 1 mg/kg b. wt. EE. The estrogen was administered alone in the control group and in the presence of 4 g of fiber A and fiber B, respectively, in the other two groups. After compartmental (two-compartment open model) and noncompartmental analyses of plasma concentrations, statistical analysis revealed that the presence of fiber (both A and B) decreased between 29% and 35% the extent of EE absorbed (represented by the pharmacokinetic parameters area under the curve and the maximum plasma concentration) without affecting the rate of the absorption process (represented by the time to reach maximum concentration and the absorption rate constant).S

Hypoglycemic and hypolipidemic potential of a high fiber diet in healthy versus diabetic rabbits

P. 960568 - 960575The aim of this study was to investigate potential hypoglycaemic and hypolipidemic effects of Plantago ovata husk included in the diet, in healthy and diabetic rabbits. We also examined the effects of this fiber in other biochemical parameters. Two groups of 18 rabbits were used.The first group was fed with standard chow and the second with chow supplemented with Plantago ovata husk (3.5mg/kg/day). On day 14 diabetes mellitus was induced by the intravenous administration of alloxan (80mg/kg). After an oral glucose load (3 g), glucose, insulin, and other biochemical parameters were determined on day 14 (healthy rabbits) and on day 28 (diabetic rabbits). In healthy rabbits, fiber did not modify glucose or insulin levels but decreased significantly total cholesterol, LDL-cholesterol, atherogenic index, and glycosylated hemoglobin. In diabetic rabbits, fiber was more beneficial in mild diabetics than in severe diabetics with significant decreases in glucose levels and increases in insulin concentrations. In these animals fiber caused an important reduction in cholesterol, indicating a beneficial effect of Plantago ovata husk in diabetic rabbits. Although further studies in patients are necessary, we think that Plantago ovata husk offers interesting perspectives to be administered to patients with diabetes mellitus.S

Long-term treatment for emotional distress in women with breast cancer

[EN] Purpose: Breast cancer patients have many needs, including strategies to cope with the associated distress, during and after cancer treatment. Establishing and implementing adequate social and emotional support for these women, to reduce the detrimental effects of stress resulting from their treatment and disease, is the need of the hour. This study aims to assess how women, diagnosed and treated for breast cancer, combat emotional stress using mechanisms of coping and control and emotional defense, as well as to identify potential groups among them, with different long-term patterns and needs. Methods: 98 patients belonging to a local breast cancer support association (ALMOM), were enrolled in this study. A questionnaire specifically designed for them was administered, and its internal consistency and reliability assessed. A hierarchical clustering was employed to classify the women. The questionnaire focused on four sections, including personal feelings, coping strategies, environmental influences and maladaptive coping. Results: An adequate internal reliability was obtained with Cronbach's α near or greater than 0.60. Personal feelings were significant and clearly correlated with coping strategies and maladaptive coping. Three groups of women with different patterns of emotional characteristics and needs were identified: positivist, unsafe, and hopeless women, with different long-term emotional needs to be satisfied. Conclusions: Psychological therapeutic interventions should be maintained in many breast cancer patients over time, even after treatment completion, in order to consolidate adaptive and sustainable responsesS

Hydrosoluble fiber (Plantago ovata husk) and levodopa I: Experimental study of the pharmacokinetic interaction

P. 497.503Fiber therapy could be used in patients with Parkinson disease to reduce the symptoms of gastrointestinal disorders; however, it could interact with levodopa reducing its effectiveness. In this experimental study we have investigated whether the presence of Plantago ovata husk (water-soluble fiber) modifies in rabbits the bioavailability and other pharmacokinetic parameters of levodopa (20 mg/kg) when administered by the oral route at the same time. We have also studied whether pharmacokinetic modifications are fiber–dose dependent (100 and 400 mg/kg). The extent of levodopa absorbed when administering 100 mg/kg of fiber (AUC=43.4 Ag min ml 1) is approximately the same as when levodopa is administered alone (AUC=47.1 Ag min ml 1); however, Cmax is lower (1.04 versus 1.43 Ag ml 1). Results obtained indicate that fiber at the higher dose increases the extent of levodopa absorbed (AUC=62.2 Ag min ml 1), being the value of Cmax similar (1.46 Ag ml 1). The value of tmax increases from 10 min when levodopa is administered alone to 20 min when the animals receive fiber. On the other hand, since certain time on, levodopa concentrations are always higher in the groups that receive fiber: 60 min with 100 mg/kg fiber and 20 min with 400 mg/kg fiber. Fiber also increases the mean residence time (MRT). P. ovata husk administration with levodopa could be beneficial, not only in patients with constipation, due to: lower adverse reactions (lower values of Cmax) and longer and more stable effects (higher final concentrations and more time in the body).S

Hydrosoluble fiber (Plantago ovata husk) and levodopa II: Experimental study of the pharmacokinetic interaction in the presence of carbidopa

P. 505-509Levodopa combined with carbidopa constitutes one of the most frequent medication in the treatment of Parkinson’s disease. Plantago ovata husk (water-soluble fiber) improves levodopa absorption conditions, but when this drug is administered with carbidopa, fiber could reduce its effectiveness. The purpose of this study is to investigate whether the presence of P. ovata husk modifies in rabbits the bioavailability and other pharmacokinetic parameters of levodopa (20 mg/kg) when administered by the oral route with carbidopa (5 mg/ kg). We have also studied whether pharmacokinetic modifications are fiber–dose dependent (100 and 400 mg/kg). When levodopa and carbidopa were administered with 100 mg/kg P. ovata husk, the value of AUC for levodopa diminishes 29.7% (sign, n =6, P b0.05) and Cmax 28.1% (sign, n =6, P b0.05) in relation to the values obtained when these drugs were administered without fiber. If the dose of fiber was 400 mg/kg, the decrease was smaller: 20.4% for AUC (no significant difference) and 24.6% for Cmax (sign, n =6, P b0.05), that may indicate an inhibitory action of AADC by the fiber or any of its partial hydrolysis products. On the other hand, since certain time on, levodopa concentrations are always higher in the groups that receive fiber: 210 min with 100 mg/kg and 150 min with 400 mg/kg. The administration of P. ovata husk with levodopa/carbidopa to patients with Parkinson disease could be beneficial and in particular in those patients who also suffer constipation due to an improvement of levodopa kinetic profile with higher final concentrations, a longer plasma half-life and lower Cmax.S

A randomised clinical trial to evaluate the effects of Plantago ovata husk in Parkinson patients: changes in levodopa pharmacokinetics and biochemical parameters

P. 296-305Background: Plantago ovata husk therapy could be used in patients with Parkinson disease to reduce the symptoms of gastrointestinal disorders, but it is important to know whether this compound modifies levodopa pharmacokinetics. The maintenance of constant plasma concentrations of levodopa abolishes the clinical fluctuations in parkinsonian patients. The aim of this randomised clinical trial was to establish the influence of the fiber Plantago ovata husk in the pharmacokinetics of levodopa when administered to Parkinson patients well controlled by their oral medication. Methods: To evaluate the effects of this fiber on several biochemical parameters. 18 volunteers participated in the study and received alternatively two treatments (Plantago ovata husk or placebo) with their usual levodopa/carbidopa oral dose. On days 0 (initial situation), 14 and 35 of the study, blood samples were taken to assess levodopa pharmacokinetics and to determine biochemical parameters. Results: Levodopa Cmax was very similar in the initial situation (603.2 ng/ml) and after placebo administration (612.0 ng/ml), being slightly lower (547.8 ng/ml) when Plantago ovata husk was given. AUC was very similar in the three groups: initial situation.- 62.87 μg.min/ml, fiber treatment.- 64.47 μg.min/ml and placebo treatment.- 65.10 μg.min/ml. Fiber reduced significantly the number of peaks observed in the levodopa concentrations, maintaining concentrations more stable. No significant differences were found in total cholesterol, LDL-cholesterol and triglycerides with the administration of Plantago ovata husk. Conclusions: Plantago ovata husk administration caused a smoothing and homogenization of levodopa absorption, providing more stable concentrations and final higher levels, resulting in a great benefit for patients.S

Influence of two dietary fibers in the oral bioavailability and other pharmacokinetic parameters of ethinyloestradiol

P. 253-257Dietary fibers are widely used in hypoglycaemic, hypolipidemic, slimming diets. It is probable that their ingestion coincides with the oral administration of drugs and a modification of their pharmacokinetics can appear. In the present study, the influence of two soluble fibers (guar gum and psyllium) was evaluated on the pharmacokinetics of ethinyloestradiol (EE) when they were administered together to female rabbits via the oral route. Three groups of rabbits were used. All animals received 1 mg/kg of EE; this compound was administered alone in the control group and with 3.5 g of guar gum or psyllium in the other two groups. When guar gum was administered, there was a decrease in the extent of EE absorbed, but no change was observed in the rate of absorption. When psyllium was administered, the extent of EE absorbed increased slightly and the rate of absorption was slower.S

Assessing the expression of emotions in breast cancer survivors during the time of recovery: perspective from focus groups

[EN] Breast cancer has major public health implications, as it is the most frequent malignant tumor and the leading cause of cancer death in women. Survivors have many needs, including strategies to cope with the associated distress. We explore whether focus groups are useful for nurses to obtain information about the emotional state of breast cancer women, and develop strategies for coping with the stress that this disease entails. A qualitative study was carried out, involving 25 focus groups with 83 women treated for breast cancer, recruited from the local Breast Cancer Association (ALMOM). Four open-ended questions were employed, and 60-min discussions were carried out. They were transcribed, analyzed, coded, and the themes identified. Four major themes emerged, including “complex emotional evolution”, “emotional isolation”, “lack of information” and “inability to give advice”. Women admitted that this disease had been a stressful factor for them, causing emotional (anxiety, irritability, anger or guilt) and cognitive disorders (confusion, lack of concentration, forgetfulness). The use of focus groups in breast cancer survivors allows nurses to evaluate the expression of emotions in these women, and collect and share information about their feelings, thoughts and experiences, so that survivors can cope more easily with the stress related to their illness.S

Glucomanano: propiedades y aplicaciones terapéuticas

P. 45-50La fibra dietética glucomanano se utiliza con cierta frecuencia en Occidente desde hace dos décadas, dadas sus demostradas acciones beneficiosas para la salud, si bien su uso se remonta, en las civilizaciones orientales, a más de mil años. Esta fibra es el principal polisacárido obtenido de los tubérculos de la planta originaria del este asiático Amorphophallus konjac y que pertenece a la familia Araceae. La estructura química del glucomanano incluye Dmanosa y D-glucosa (en una proporción 8:5, respectivamente), unidas por enlace β(1→4). El glucomanano es una fibra muy soluble, que posee una excepcional capacidad de captar agua, formando soluciones muy viscosas. Posee un peso molecular y una viscosidad más elevados que cualquier fibra conocida. Se ha demostrado que es eficaz en la obesidad, por la sensación de saciedad que produce; en el estreñimiento debido a que aumenta el volumen fecal; como hipocolesterolemiante interfiriendo en el transporte de colesterol y ácidos biliares; y también disminuye los niveles de glucosa e insulina, probablemente debido a que retrasa el vaciado gástrico y, por tanto, dificulta el acceso de la glucosa a la mucosa intestinal. A estas propiedades beneficiosas, podemos añadir algunos inconvenientes como la producción de flatulencia, molestias abdominales, obstrucciones esofágicas o del tracto gastrointestinal, o incluso puede modificar la biodisponibilidad de otros fármacos que se administren al mismo tiempo que la fibra. Esta revisión recoge las principales características del glucomanano, así como sus propiedades, efectos fisiológicos y aplicaciones terapéuticas.S