Drugs under experimental and clinical research最新文献

D-003 is a mixture of high molecular weight aliphatic primary acids purified from sugar cane wax (Saccharum officinarum, L) with cholesterol-lowering and antiplatelet effects. Previous studies, including a 6-month study conducted in rats, have shown no D-003-related toxicity. The present study was undertaken to investigate the effects of D-003 orally administered for 9 months in beagle dogs. The animals were randomly distributed in three groups: a control group receiving the vehicle only and two groups orally administered D-003 (200 and 400 mg/kg). Body weight gain, food consumption and clinical signs were controlled throughout the study. The effects of D-003 on collagen-induced platelet aggregation, bleeding time (BT) and coagulation parameters (prothrombin time and kaolin-activated thromboplastin time) were also investigated. Most blood biochemistry and hematological parameters were assessed at baseline and after 6 and 9 months of treatment, while total cholesterol (TC), triglycerides, platelet aggregation, BT and coagulation parameters were determined at baseline and after 9 months of treatment. At study completion, the animals were sacrificed. D-003 at a dose of 200 and 400 mg/kg significantly reduced TC (p < 0.05), significantly inhibited platelet aggregation and increased BT compared with levels in controls. Data analyses of body weight gain, food consumption, clinical observations, the remaining blood biochemistry and hematology indicators (including coagulation parameters, organ weight ratios and histopathological findings) showed no trends with D-003 doses or significant differences between control animals and treated groups. In conclusion, D-003 administered for 9 months to beagle dogs induced the expected effects with no evidence of drug-related toxicity.

Osteoporosis is characterized by reduced bone mass, abnormal bone architecture and increased fracture risk. Ovariectomy impairs bone mass and metabolism in rats and ovariectomized rats are considered as a suitable model of postmenopausal osteoporosis. Mevalonate is required for producing lipoids that are important in osteoclast activity and thus drugs affecting mevalonate production can prevent bone loss in rodents. Policosanol is a cholesterol-lowering drug isolated from sugar cane wax that inhibits cholesterol biosynthesis through an indirect regulation of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase activity. The purpose of this study was to determine whether policosanol could prevent bone loss in the bones of ovariectomized rats by comparing its effects with those induced by estradiol. Sprague Dawley female rats were randomly distributed in four groups: a sham-operated group treated with Tween/H2O vehicle and three groups of ovariectomized rats treated with 17beta-estradiol (30 microg/kg/day) or policosanol (50 and 200 mg/kg/day), respectively, for 3 months. At treatment completion the rats were sacrificed, their bones removed and variables of bone resorption and formation were investigated by histomorphometry. Ovariectomy increased trabecular separation but diminished the number and thickness of trabecules. Estradiol and policosanol prevented these effects compared with ovariectomized controls. Both treatments also prevented an increase in the number of osteoclasts and their surface area induced by ovariectomy. Estradiol, but not policosanol, significantly prevented an increase of osteoblast surface area compared with ovariectomized controls. In conclusion, policosanol prevented bone loss and decreased bone resorption in ovariectomized rats, suggesting that it should be potentially useful in preventing bone loss in postmenopausal women.

In view of the high concentration of resveratrol found in a new autochthonous wine (Uvalino) and the notable antioxidant activity of this substance, we decided to assess whether this wine could inhibit the production of free radicals. Nowadays, free radicals are considered to be the most noxious factors for tissues, triggering the development of many diseases. The assessments were carried out using a direct and more precise technique, electronic paramagnetic resonance (EPR), which is able to detect the ability of an antioxidant agent to inhibit the formation of hydroxyl radicals (*OH), which are among the most noxious reactive oxygen species (ROS). The results show that Uvalino wine is able to eliminate ROS production almost completely. Consequently, it has beneficial effects on health in all the diseases in which ROS plays an important pathogenetic role.

Essential hypertension is often accompanied by abnormalities of the coagulation/fibrinolytic system predisposing to a procoagulant state. The aim of the present study was to examine the comparative efficacy of the angiotensin II type 1 receptor antagonists eprosartan and losartan on plasma levels of hemostatic/fibrinolytic and endothelial function markers in a cohort of previously untreated hypertensive patients. A total of 86 patients whose hypertension was controlled by monotherapy with eprosartan 600 mg (45 patients) or losartan 100 mg (41 patients) were studied. The plasma levels of plasminogen activator inhibitor-1 (PAI-1) antigen, tissue plasminogen activator inhibitor (tPA) antigen, thrombomodulin (TM), tissue factor pathway inhibitor (TFPI) antigen, and fibrinogen were determined before and after 6 months of therapy. Age, sex distribution, body mass index, lipid profile, systolic and diastolic blood pressure levels, and baseline values of the measured markers were similar in both groups. After 6 months of therapy, systolic blood pressure was significantly lower in patients treated with eprosartan, while no differences were observed with respect to diastolic blood pressure. Treatment with both drugs was associated with a significant decrease in PAI-1 antigen, TM, fibrinogen plasma levels and an increase in tPA antigen. The favorable modification of all the above parameters was significantly greater in the eprosartan than in the losartan group, while TFPI plasma levels were decreased to a similar extent with both drugs. In conclusion, the results of our study indicate that 6-month monotherapy with a new angiotensin II type 1 receptor blocker, eprosartan, is associated with a more favorable modification of hemostatic/fibrinolytic status than with losartan.

Olive oil phenolic compounds are generally believed to have beneficial antioxidant effects, but little is known about characteristics of their postprandial bioavailability in natural olive oil at real-life doses. The aim of the present study was to determine the concentrations of olive oil phenolic compounds in urine collected over 24 h (24-h urine) after a bolus ingestion of 25 ml of olive oil with different phenolic content, and to demonstrate the effect of this real-life olive oil dose on postprandial levels of blood lipids and oxidative stress biomarkers, as well as to examine the beneficial effects of olive oil phenols. Oral fat loads of 25 ml olive oil with high, moderate, and low phenolic content were administered to 12 healthy male volunteers in a randomized, controlled, crossover trial. Tyrosol and hydroxytyrosol were absorbed in a dose-dependent manner according to the phenolic content of the olive oil administered. The administered dose of 25 ml, which is close to that used daily in Mediterranean countries, did not induce significant postprandial lipemia nor did it promote an increase of in vivo oxidation markers. With regard to plasma antioxidant enzymes, glutathione peroxidase activity decreased postprandially after low phenolic content olive oil ingestion; however this was not observed after intake of moderate and high phenolic content olive oils. The phenolic content of the olive oils administered may account for the protection of the endogenous antioxidant defenses at postprandial state after ingestion of moderate and high phenolic content olive oils.

The medical and social impact of cough is substantial. Current antitussive agents at effective doses have adverse events such as drowsiness, nausea and constipation that limit their use. There is also recent evidence that standard antitussive agents, such as codeine, may not reduce cough during upper respiratory infections. Therefore, there is a need for more effective and better-tolerated agents. The efficacy of levocloperastine, a novel antitussive, which acts both centrally on the cough center and on peripheral receptors in the tracheobronchial tree in treating chronic cough, was compared with that of other standard antitussive agents (codeine, levodropropizine and DL-cloperastine) in six open clinical trials. The studies enrolled patients of all ages with cough associated with various respiratory disorders including bronchitis, asthma, pneumonia and chronic obstructive pulmonary disease. Levocloperastine significantly improved cough symptoms (intensity and frequency of cough) in all trials, and improvements were observed after the first day of treatment. In children, levocloperastine reduced nighttime awakenings and irritability, and in adults it was effective in treating cough induced by angiotensin-converting enzyme inhibitors. When compared with other antitussive agents, levocloperastine had improved or comparable efficacy, with a more rapid onset of action. Importantly, no evidence of central adverse events was recorded with levocloperastine, whereas drowsiness was reported by a significant number of patients receiving codeine. Levocloperastine is an effective antitussive agent for the treatment of cough in patients of all ages. It has a more rapid onset of action than standard agents with an improved tolerability profile.

Erdosteine is a new thiol compound with effects on bacterial adhesiveness as well as antioxidant and mucoactive properties. The EQUALIFE study, a fully randomized, double-blind, placebo-controlled, parallel-group, multicenter study, was designed to assets the effectiveness of long-term treatment with erdosteine in patients with moderate chronic obstructive pulmonary disease (COPD). One hundred and fifty-five patients received oral erdosteine, 300 mg b.i.d., or placebo for 8 months during the winter season to assess the effect of treatments on exacerbation rate, hospitalization, lung function and quality of life, assessed using the Short Form 36 and the St. George's Respiratory Questionnaire. A pharmacoeconomic analysis was also conducted to compare the two treatments. One hundred and twenty-four patients completed the study with erdosteine (n = 63) or placebo (n = 61). The group of COPD patients who received 8 months of continuous treatment with erdosteine had significantly fewer exacerbations and spent fewer days in the hospital than did the placebo group; furthermore, they had no loss of lung function. Patients in the erdosteine group also showed a significant improvement in health-related quality of life. The mean total COPD-related disease costs per patient were lower in the erdosteine group than in the placebo group over the study period. The results indicate that 8 months of treatment with erdosteine is effective in reducing exacerbation and hospitalization rates and in improving health status. The study suggests that erdosteine is likely to provide an important contribution to the therapy of patients with symptomatic COPD.

Since its introduction into clinical practice in 1967 by Charles Fox Jr., silver sulfadiazine has been the gold standard for topical burn therapy. The addition to it of hyaluronic acid, which forms a substantial part of the human tissue intercellular matrix, is aimed at overcoming one of its very few disadvantages, i.e. prolongation of the wound re-epithelialization process. Since both hyaluronic acid and silver sulfadiazine have been used in therapy for decades and their efficacy is well documented, a topical treatment combining these two agents was formulated. The aim of the study was to investigate the efficacy and tolerability of a cream containing a hyaluronic acid/silver sulfadiazine fixed combination, compared with silver sulfadiazine cream alone, for the treatment of superficial and deep second-degree burns in a prospective, double-blind, controlled clinical study. The findings of the study confirmed that the association of the two compounds in a new topical treatment significantly reduced the healing time and significantly accelerated the reduction of local edema occurring shortly after injury. Furthermore, this new hyaluronic acid and silver sulfadiazine formulation has proven to have favorable antibacterial, anti-edematous and local analgesic effects, together with a clear stimulatory activity on the re-epithelialization process. This product may, therefore, significantly enrich the assortment of topical medications available for the treatment of burns and skin defects of other origin.

Bisphosphonates inhibit bone resorption through mechanisms involving the metabolic pathway from mevalonate to cholesterol. Mevalonate is a precursor of the lipoids required for osteoclast activity and thus inhibition of its synthesis affects bone metabolism. Inhibitors of hydroxymethylglutaryl CoA (HMGCoA) reductase might increase experimentally new bone formation through a mevalonate-dependent effect. D-003 is a mixture of high molecular weight fatty acids isolated from sugar cane wax, which inhibits cholesterol biosynthesis through indirect regulation of HMGCoA reductase activity. This study was undertaken to determine whether D-003 could prevent bone loss in ovariectomized rats. Sprague Dawley female rats were ovariectomized or sham operated and were randomly distributed into five groups: a control ovariectomized and a sham (false-operated) group receiving Tween/H2O vehicle, a group treated with alendronate (3 mg/kg/day) and two groups treated with D-003 (50 and 200 mg/kg/day). Treatments were administered for 3 months. At sacrifice, bones were removed and histological variables of bone resorption and formation were studied by histomorphometry. Ovariectomy diminished trabecular number and thickness and increased trabecular gap, osteoclast number and surface. Alendronate and D-003 prevented a decrease in trabecular number and thickness as well as increases in trabecular separation, osteoclast number and surface compared with ovariectomized controls, thus preventing the bone loss and decreased bone resorption induced by ovariectomy, but failed to increase osteoblast surface compared with control ovariectomized rats. In conclusion, D-003 (50 and 200 mg/kg/day) prevented bone loss and decreased bone resorption in ovariectomized rats, which suggests that this substance could be promising in preventing or treating osteoporosis.

Catechins (flavanols) are strong antioxidants, free radical scavengers and inhibitors of lipid peroxidation. New bio-based antioxidant compounds obtained by depolymerization of plant polymeric flavanols (procyanidins) in the presence of cysteine or cysteamine, as well as their underivatized counterpart, (-)-epicatechin, were evaluated in terms of their percutaneous absorption profiles taking into account their free radical scavenging efficiency. The evaluation of the percutaneous absorption of flavanols was carried out by an in vitro methodology using both pig and human skin. A good correlation was obtained using both skins in the evaluation of the skin absorption profiles. It can be deduced that 4beta-(S-cysteinyl)epicatechin (Cys-Ec) has a tendency to be located mainly in the outermost layers of the skin, whereas 4beta-(2-aminoethylthio)epicatechin (Cya-Ec) has a pronounced percutaneous absorption capacity. Their antioxidant properties and their skin penetration profiles support their potential cosmetic or pharmacological applications.