Ruta Masteikova

Uncoupling and antioxidant effects of ursolic acid in isolated rat heart mitochondria.

Ursolic acid (1), a pentacyclic triterpene acid, is one of the major components of certain traditional medicinal plants and possesses a wide range of biological effects, such as anti-inflammatory, antioxidative, and cytotoxic activities. Furthermore, 1, when present at 1.6-5 ng/mL concentrations in commercial herbal preparations used for patients with cardiac disorders, may also exert pro-cardiac activities. There are several indirect suggestions that the cardioprotective mechanism of ursolic acid could involve the mitochondria; however the mechanism of action is still not known. Therefore, the effects of 0.4-200 ng/mL ursolic acid (1) on the functions of isolated rat heart mitochondria oxidizing either pyruvate and malate, succinate, or palmitoyl-l-carnitine plus malate were investigated. It was found that 1 induced a statistically significant uncoupling of oxidative phosphorylation. A statistically significant decrease in H₂O₂ production in the mitochondria was observed after incubation with 5 ng/mL 1. This effect was comparable to the effectiveness of the classical uncoupler carbonyl cyanide 3-chlorophenylhydrazone. Since mild mitochondrial uncoupling has been proposed as one of the mechanisms of cardioprotection, the present results indicate that ursolic acid (1) has potential use as a cardioprotective compound.

Soluble filler as a dissolution profile modulator for slightly soluble drugs in matrix tablets.

The purpose of this experimental work was the development of hydrophilic–lipophilic matrix tablets for controlled release of slightly soluble drug represented here by diclofenac sodium (DS). Drug dissolution profile optimization provided by soluble filler was studied. Matrix tablets were based on cetyl alcohol as the lipophilic carrier, povidone as the gel-forming agent, and common soluble filler, that is lactose or sucrose of different particle size. Physical properties of tablets prepared by melt granulation and drug release in a phosphate buffer of pH 6.8 were evaluated. In vitro studies showed that used filler type, filler to povidone ratio and sucrose particle size influenced the drug release rate. DS dissolution profile could be changed within a wide range from about 50% per 24 hours to almost 100% in 10 hours. The release constant values confirmed that DS was released from matrices by the diffusion and anomalous transport. The influence of sucrose particle size on the drug release rate was observed. As the particle size decreased, the drug release increased significantly and its dissolution profile became more uniform. Soluble fillers participated in the pore-forming process according to their solubility and particle size. Formulations containing 100 mg of the drug, 80 mg of cetyl alcohol, 40 mg of povidone, and 80 mg of either lactose or sucrose (particle size 250–125 μm) were considered optimal for 24-hour lasting dissolution of DS.

Optimization of carvacrol, rosmarinic, oleanolic and ursolic acid extraction from oregano herbs (Origanum onites L., Origanum vulgare spp. hirtum and Origanum vulgare L.)

The aim of our study was to increase the extraction efficiency of carvacrol, rosmarinic, oleanolic and ursolic acid from the different species of oregano herbs (Origanum onites L., Origanum vulgare spp. hirtum and Origanum vulgare L.). Various extraction methods (ultrasound-assisted, heat-reflux, continuous stirring, maceration, percolation) and extraction conditions (different solvent, material:solvent ratio, extraction temperature, extraction time) were used, and the active substances were determined by HPLC. The lowest content of carvacrol, rosmarinic, oleanolic and ursolic acid was obtained by percolation. During heat-reflux extraction, the content of active substances depended on the solvent used: ethanol/non-aqueous solvent (glycerol or propylene glycol) mixture was more effective compared with ethanol alone. The results showed that for each species of oregano the most optimal extraction method should be selected to maximize the content of biologically active substances in the extracts.

Formulation of Novel Layered Sodium Carboxymethylcellulose Film Wound Dressings with Ibuprofen for Alleviating Wound Pain

Effective assessment and management of wound pain can facilitate both improvements in healing rates and overall quality of life. From a pharmacological perspective, topical application of nonsteroidal anti-inflammatory drugs in the form of film wound dressings may be a good choice. Thus, the aim of this work was to develop novel layered film wound dressings containing ibuprofen based on partially substituted fibrous sodium carboxymethylcellulose (nonwoven textile Hcel NaT). To this end, an innovative solvent casting method using a sequential coating technique has been applied. The concentration of ibuprofen which was incorporated as an acetone solution or as a suspension in a sodium carboxymethylcellulose dispersion was 0.5 mg/cm2 and 1.0 mg/cm2 of film. Results showed that developed films had adequate mechanical and swelling properties and an advantageous acidic surface pH for wound application. An in vitro drug release study implied that layered films retained the drug for a longer period of time and thus could minimize the frequency of changing the dressing. Films with suspended ibuprofen demonstrated higher drug content uniformity and superior in vitro drug release characteristics in comparison with ibuprofen incorporation as an acetone solution. Prepared films could be potential wound dressings for the effective treatment of wound pain in low exuding wounds.

Direct Effects of (−)-Epicatechin and Procyanidin B2 on the Respiration of Rat Heart Mitochondria

Flavonol (−)-epicatechin and its derived dimer procyanidin B2, present in high amounts in cocoa products, have been shown to exert beneficial effects on the heart and cardiovascular system; however, their mechanism of action has not been fully elucidated. We studied effects of (−)-epicatechin and procyanidin B2 on the oxidative phosphorylation of isolated rat heart mitochondria. (−)-Epicatechin and procyanidin B2 had stimulating effect (up to 30% compared to control) on substrate-driven (State 2) mitochondrial respiration. Their effect was dependent on the respiratory substrates used. (−)-Epicatechin at higher concentrations (from 0.27 µg/mL) significantly decreased (up to 15%) substrate- and ADP-driven (State 3) mitochondrial respiration in case of pyruvate and malate oxidation only. Procyanidin B2 (0.7–17.9 ng/mL) inhibited State 3 respiration rate up to 19%, the most profound effect being expressed with succinate as the substrate. (−)-Epicatechin at concentrations of 0.23 µg/mL and 0.46 µg/mL prevented loss of the cytochrome c from mitochondria when substrate was succinate, supporting the evidence of membrane stabilizing properties of this flavonol. Thus, both (−)-epicatechin and procyanidin B2 directly influenced mitochondrial functions and the observed effects could help to explain cardiometabolic risk reduction ascribed to the consumption of modest amounts of cocoa products.

The evaluation of formulations for the preparation of new formula pellets

The aim of the study was to prepare pellets of maidenhair tree (Ginkgo biloba), motherwort (Leonurus cardiaca) and hawthorn (Crataegus monogyna) dry extracts by extrusion/spheronization method. The critical step of this process was the amount of added wetting liquid (water-ethanolic mixture) and the amount of extract in the formulation. The samples of pellets containing 30–50% of extracts were formulated: Pellets contained extracts of Ginkgo, Crataegi and Leonuri. The last sample was aimed at the formulation of pellets with the content of 30% of the mixture of Ginkgo, Leonuri and Crataegi extracts in a ratio of 1:5:6. The remainder of the solid compounds in all formulations was microcrystalline cellulose (Avicel® PH-101). It was not possible to find a way to adequately wet the formulations with the content of extracts higher than 30% because of the unsuitable properties of all three extracts used. On the basis of the experiments, pellets with mixtures of all three previously used extracts were prepared. These pellets showed perfect physico-mechanical properties: Hardness (10.00 ± 2.24 N), friability (0.06%), repose angle (20.99 ± 0.41°), flowability (6.97 ± 0.29 s/100g of pellets), sphericity (0.81 ± 0.05), compressibility index (4.65%), intraparticular porosity (0.09%) and interparticular porosity (45.11%), which predetermine them to other testing and usage (feeling into capsules, tableting, coating etc.).

Formulation and characterization of Turkish oregano microcapsules prepared by spray-drying technology

Abstract The aim of this study was optimization of spray-drying process conditions for microencapsulation of Turkish oregano extract. Different concentrations of maltodextrin and gum arabic as encapsulating agents (wall material) as well as influence of selected processing variables were evaluated. The optimal conditions were maintained on the basis of the load of main bioactive compounds – ursolic, rosmarinic acids and carvacrol – in prepared microparticles after comparison of all significant response variables using desirability function. Physicomechanical properties of powders such as flowability, wettability, solubility, moisture content as well as product yield, encapsulation efficiency (EE), density, morphology and size distribution of prepared microparticles have been determined. The results demonstrated that the optimal conditions for spray-drying mixture consisted of two parts of wall material solution and one part of ethanolic oregano extract when the feed flow rate was 40 mL/min and air inlet temperature –170 °C. Optimal concentration of wall materials in solution was 20% while the ratio of maltodextrin and gum arabic was 8.74:1.26.

The development and in vitro evaluation of herbal pellets coated with Eudragit FS 30

Abstract The objective of this study was to prepare pellets of thyme (Thymus vulgaris L.), stinging nettle (Urtica dioica L.) and sage (Salvia officinalis L.) dry extracts by extrusion–spheronization technique to improve technological properties and investigate dissolution profiles of pellets covered different levels of pH-sensitive polymer Eudragit® FS. Optimal sample of pellets were prepared using microcrystalline cellulose and lactose as excipients and demonstrated excellent technological quality properties such as Hausner ratio (1.07 ± 0.11) and compressibility index (6.73 ± 0.94%) value, spericity (0.87 ± 0.001) and friability (0.22 ± 0.08 N). Pellets were coated by 10–35% (w/w) of Eudragit® FS. Dissolution studies showed that less than 20% of coating could not prevent dissolution of phenols in pH 1.2, 20% Eudragit® FS coating is enough to prevent herbal extract against dissolution in the stomach. There were observed no statistical significant differences between 20% and 25% or higher amount of coating polymer to a dissolution of phenols in low pH.

Reduction of small arteries contractility with improving the relaxation properties by Ginkgo biloba extract

The effect of ethanolic Ginkgo biloba L. leaf extract (GE) on vascular smooth muscle contractility and endothelium-dependent relaxation were investigated in this study. Direct applications on isolated vessels from Wistar rats as well as animal feeding with the extract (dosage of 0.32 ml/kg for 10 days) were used. Vascular contractility of small isolated mesenteric arteries of the animals was examined using wire myography. The extract significantly suppressed the vascular contraction to KCl in dosedependent mode (4  10 -3 mg/ml of phenolic compounds (PC) – up to 82%; 4  10 -2 mg/ml of PC – 37%, p < 0.01; and 0.4 mg/ml of PC – 4%, p < 0.001). Ten (10) days of administration of the extract for the animals in drinking water resulted in slight decrease of contractility to KCl (95%) and phenylephrine (88%). Both the endothelium-dependent relaxation to acetylcholine and endothelium-independent relaxation to sodium nitroprusside (SNP) were slightly improved by shifting the dose–response curve leftward with the significantly improved maximum relaxation (86.39 ± 3.61 to 60.84 ± 12.45%, p < 0.05 with 1 mM acetylcholine and 82.86 ± 8 to 55.86 ± 10.85%; p < 0.05, with 1 mM SNP). These results suggested that GE improved and revealed the vasorelaxant effects mainly attributed to smooth muscle involving mechanisms without impairment of the endothelium-depended relaxation.

In vitro permeation studies of phenolics from horse chestnut seed gels prepared with different polyacrylic acid polymer derivatives

Abstract The aim of this study was to investigate the effects of polyacrylic acid polymers (Ultrez 10, Ultrez 20, Carbopol 980, and Carbopol 940) on the viscosity and the in vitro permeation of phenolic compounds from the gel prepared from natural horse chestnut seed extract. Experiments were performed in the presence and in the absence of peppermint oil (Mentha piperita). Our results showed that peppermint oil decreased the viscosity of the gels and permeation of phenolic compounds from all gel samples. Results show that the highest content of phenolic compounds (1.758 μg cm-2) permeated in vitro from gel based on Carbopol Ultrez 20 without peppermint oil added (p < 0.05 vs. other tested polymers).