Pycnogenol efficacy in the treatment of systemic lupus erythematosus patients

A pilot study was performed to evaluate the efficacy of Pycnogenol treatment in systemic lupus erythematosus (SLE) patients. Eleven SLE patients were treated with first line medication according to disease activity and in addition, six of them received Pycnogenol and five a placebo. The SLE disease activity index (SLEDAI), serum anti-dsDNA antibodies, fibrinogen, C-reactive protein levels, erythrocyte sedimentation rate, production of reactive oxygen species (ROS) by neutrophils, spontaneous apoptosis and p56(lck) specific activity in peripheral blood lymphocytes were evaluated. Pycnogenol treatment determined a significant reduction of ROS production, apoptosis, p56(lck) specific activity and erythrocyte sedimentation rate. In addition, the decrease of SLEDAI was significant in the Pycnogenol treated group compared with the placebo group (p = 0.018). The results obtained suggest that Pycnogenol could be useful for second line therapy to reduce the inflammatory feature of SLE.

Presence of fluticasone propionate on human nasal mucosal surface and in human nasal tissue over a period of 24 h after intranasal application

BACKGROUND

Once-daily use of nasally applied glucocorticoids was demonstrated to be effective in the treatment of allergic rhinitis. The aim of the study was to measure concentrations of fluticasone propionate (FP) in nasal secretion and nasal tissue over a period of 1 day after a single application of 100 microg FP.

METHODS

Twenty-six patients applied nasal FP spray at different time intervals before surgery. Cotton swabs, used to clean the mucosal surface, and resected nasal tissue were extracted. FP concentrations were determined by RIA.

RESULTS

FP was found in nasal secretions in concentrations from 15 to 1 microg/g over a period of 20 h, and in nasal tissue in concentrations from 200 to 13 ng/g up to 24 h after the single application.

CONCLUSION

The long-persisting high concentrations of FP provide the pharmacokinetic basis for once-daily treatment.

Binding of glucocorticoids to human nasal tissue in vitro

BACKGROUND

Intranasal application of glucocorticoids is an efficacious treatment of allergic rhinitis and some cases of nonallergic rhinitis. However, no data on binding of glucocorticoids to nasal tissue are available. Pronounced binding of the compound to the target tissue is favorable as it might serve as a local deposit delivering the glucocorticoid to specific receptors and it slows down the efflux of the compound into systemic circulation.

METHODS

Human nasal tissue was incubated with fluticasone propionate, budesonide, flunisolide and beclomethasone-17-monopropionate. Kinetics of binding and redistribution of the tissue-bound fraction into human plasma was monitored.

RESULTS

Binding of glucocorticoids to human nasal tissue was fast and highest for the lipophilic fluticasone propionate, followed by beclomethasone-17-monopropionate. Also, highest concentrations of these lipophilic glucocorticoids remained in nasal tissue after equilibration of drug-saturated tissue with plasma.

CONCLUSIONS

Lipophilic compounds exhibit a high tissue binding and retention which is an important property of topically applied glucocorticoids. It is the basis for prolonged action and low concentration of the compound in systemic circulation.

Urinary metabolites of French maritime pine bark extract in humans

After oral administration of 5.28 g and 1.06 g of French maritime pine bark extract to a human volunteer, metabolites of some of the components of the extract could be detected. Ferulic acid and taxifolin, conjugated as glucuronide/sulphate, were excreted within 18 h. The peak urinary excretion was observed approximately 2-3 h after intake. Recovery of ferulic acid in urine was 36-43% and 7-8% for taxifolin. Two further metabolites could be identified as delta-(3,4-dihydroxy-phenyl)-gamma-valerolactone and delta-(3-methoxy-4-hydroxyphenyl)-gamma-valerolactone conjugated with glucuronic acid/sulphate. These metabolites could also be detected after intake of 960 mg of a procyanidin fraction of French maritime pine bark extract. Thus, it was shown that procyanidins are metabolised by humans. Both metabolites show maximal urinary excretion 8-12 h after intake and are excreted within 28-34 h.

Time dependent effects of glucocorticoids on adrenocorticotropin secretion of rat pituitaries ex-vivo

Different glucocorticoids have been compared with respect to the inhibition of corticotropin-releasing factor (CRF)-mediated adrenocorticotropin (ACTH) secretion from pituitary fragments of the rat. The influence of time of exposure to glucocorticoids and glucocorticoid concentration has been investigated. CRF-stimulated ACTH secretion of perifused rat pituitary fragments was measured by a chemiluminescence immunoassay. ACTH secretion was monitored over three days. Inhibition of CRF-stimulated ACTH secretion by glucocorticoids was quantified by the area under the curve of CRF-stimulated ACTH secretion over baseline. Concentrations needed to inhibit ACTH secretion decreased with the receptor affinities of the glucocorticoids as follows: fluticasone propionate; receptor affinity 1800, concentration 10(-8) M; budesonide, 935 and 3-2.5 x 10(-8) M; flunisolide, 478 and 5 x 10(-7) M; prednisolone, 10 and 10(-6) M. CRF-stimulated secretion was inhibited by glucocorticoids after incubation for 1 min at concentrations between 10(-8) and 10(-6) M. The same absolute quantity of the glucocorticoids produced no inhibition when incubation was prolonged to 50 min or when a lower concentration was used. Immediately after the perifusion stimulation of ACTH secretion was observed. The results suggest the possibility of minimizing the side effects of glucocorticoids by prolonging drug release.

Inhibition of smoking-induced platelet aggregation by aspirin and pycnogenol

The effects of a bioflavonoid mixture, Pycnogenol, were assessed on platelet function in humans. Cigarette smoking increased heart rate and blood pressure. These increases were not influenced by oral consumption of Pycnogenol or Aspirin just before smoking. However, increased platelet reactivity yielding aggregation 2 hours after smoking was prevented by 500 mg Aspirin or 100 mg Pycnogenol in 22 German heavy smokers. In a group of 16 American smokers, blood pressure increased after smoking. It was unchanged after intake of 500 mg Aspirin or 125 mg Pycnogenol. In another group of 19 American smokers, increased platelet aggregation was more significantly reduced by 200 than either 150 mg or 100 mg Pycnogenol supplementation. This study showed that a single, high dose, 200 mg Pycnogenol, remained effective for over 6 days against smoking-induced platelet aggregation. Smoking increased platelet aggregation that was prevented after administration of 500 mg Aspirin and 125 mg Pycnogenol. Thus, smoking-induced enhanced platelet aggregation was inhibited by 500 mg Aspirin as well as by a lower range of 100-125 mg Pycnogenol. Aspirin significantly (p<0.001) increased bleeding time from 167 to 236 seconds while Pycnogenol did not. These observations suggest an advantageous risk-benefit ratio for Pycnogenol.

Comparison of tilidine/naloxone, tramadol and bromfenac in experimental pain: a double-blind randomized crossover study in healthy human volunteers

AIM

The analgesic efficacy and safety of single oral doses of two centrally acting compounds, the combination of 50 mg tilidine and 4 mg naloxone (Valoron N) and 50 mg tramadol (Tramal), were compared to 25, 50 and 75 mg of the non-steroidal antiinflammatory bromfenac in experimental pain.

SUBJECTS AND METHODS

It was a placebo-controlled double-blind 6-way crossover study design with 12 human volunteers. Acute pain was generated by electrical tooth pulp stimulation. Treatment effects were determined by recording somatosensory-evoked potentials and by subjective pain rating.

RESULTS

The tilidine/naloxone combination clearly was the most potent medication in this study, followed by bromfenac 75 mg, which produced an early pain relief. Tramadol produced poor analgesia, as did bromfenac 25 and 50 mg. There was no dose-response relationship for bromfenac. Control of plasma levels revealed pronounced interindividual differences in peak plasma concentrations for bromfenac, but not for tramadol. Tilidine/naloxone exerted adverse effects in 9, tramadol in 3 volunteers. Under medication with 25 and 50 mg bromfenac, respectively, only one subject reported adverse effects. No adverse effects were experienced with 75 mg bromfenac or placebo.

CONCLUSION

The results support previous conclusions about the analgesic efficacy of tilidine/naloxone and tramadol in experimental pain. Moreover, the findings suggest that 75 mg bromfenac might be suitable for fast but short relief of pain of non-inflammatory genesis.

Endothelium-dependent vascular effects of Pycnogenol

Pycnogenol (P) is purported to exhibit effects that could be beneficial in terms of prevention of chronic age-related diseases such as atherosclerosis. The most studied of these effects is its antioxidant/free radical-scavenging activity. In this study, we investigated the possibility that this supplement might produce vascular effects by stimulation of nitric oxide (NO) production by vascular endothelial cells. In the in vitro experiments, P (1-10 microg/ml) relaxed epinephrine (E)-, norepinephrine (NE)-, and phenylephrine (PE)-contracted intact rat aortic ring preparations in a concentration-dependent manner. However, when the endothelial lining of the aortic ring was removed, P had no effect, indicating an endothelium-dependent relaxing (EDR) effect. This EDR response was caused by enhanced NO levels, because the NO synthase (NOS) inhibitor N-methyl-L-arginine (NMA) reversed (or prevented) the relaxation, and this response, in turn, was reversed by addition of L-arginine, the normal substrate for NOS. Pycnogenol-induced EDR persisted after exposure of intact rings to high levels of superoxide dismutase (SOD), suggesting that the mechanism of EDR did not involve scavenging of superoxide anion. In addition to causing relaxation, preincubation of aortic rings with P (1-10 microg/ml) inhibited subsequent E- and NE-induced contractions in a concentration-dependent manner. Fractionation of P by Sephadex LH-20 chromatography resulted in three fractions, one of which (fraction 3, oligomeric procyanidins) exhibited potent EDR activity. These results indicate that P, in addition to its antioxidant activity, stimulates constitutive endothelial NOS (eNOS) activity to increase NO levels, which could counteract the vasoconstrictor effects of E and NE. Furthermore, additional protective effects could result from the well-established properties of NO to decrease platelet aggregation and adhesion, as well as to inhibit low-density lipoprotein (LDL) cholesterol oxidation, all of which could protect against atherogenesis and thrombus formation.

Binding kinetics of budesonide to the human glucocorticoid receptor

Glucocorticoid receptor-ligand binding kinetics of budesonide, a glucocorticoid used for inhalation therapy, were determined and compared with dexamethasone and fluticasone propionate using glucocorticoid receptors from human lung tissue. From the association constant of 18.9 x 10(5)l mol-1 min-1 and the dissociation constant of 25.0 x 10(-4) min-1 resulted the equilibrium dissociation constant KD of 1.32 nmol/l and a relative receptor affinity of 855 with dexamethasone as reference (100). The half-life of the budesonide-receptor complex was 4.6 h. Results agree with data derived from competition tests we performed earlier.

Biochemical characterization of a glucocorticoid-induced membrane protein (RM3/1) in human monocytes and its application as model system for ranking glucocorticoid potency

PURPOSE

Upon glucocorticoid stimulation, human mononuclear leucocytes express an antigen, RM3/1, which characterizes a subpopulation of human monocytes and macrophages evolving in late phase of inflammation. We investigated biochemical properties of the RM3/1 antigen and correlations between antigen expression and glucocorticoid potency.

METHODS

Biochemical properties were analyzed after solubilization by immunoaffinity methods and SDS-PAGE.

RESULTS

Induction of the RM3/1 antigen is a glucocorticoid receptor mediated process, in contrast, inflammatory mediators such as LPS or TPA were not able to upregulate RM3/1 expression. After SDS-PAGE, the antigen appeared as a 130 kDa (nonreduced)/150 kDa (reduced) glycoprotein with a 25 kDa N-linked glycoportion. The interdependence between antigen density and glucocorticoid efficacy was assessed by calculation of relative antigen expression induced by dexamethasone, fluticasone propionate, budesonide, triamcinolone acetonide, flunisolide, beclomethasone, prednisolone and triamcinolone. Relative antigen expression was significantly correlated with the relative receptor affinity of the glucocorticoid.

CONCLUSIONS

We described biochemical properties of the glucocorticoid-induced protein RM3/1. Though the precise role of the RM3/1 antigen in the antiinflammatory process is not fully understood yet, an useful application of the induced expression could already be demonstrated for pre-clinical screening of glucocorticoid potency.

Distribution of inhaled fluticasone propionate between human lung tissue and serum in vivo

High retention of inhaled glucocorticoids in the airways means prolonged anti-inflammatory action and low delivery into the serum. The objective of this study was to investigate the retention in and distribution of inhaled fluticasone propionate (FP) between central and peripheral human lung tissue and serum in vivo. In 17 patients undergoing lung resection surgery, a single 1.0 mg dose of FP was inhaled at varying time-points (range 2.8-21.7 h) preoperatively. Peripheral and central lung tissue was obtained, and blood was drawn simultaneously. FP concentrations in central lung tissue were approximately three to four times higher than peripheral lung tissue concentrations, which in turn, exceeded those found in serum by 10 times. FP was detectable up to 21 and 16 h, respectively, after inhalation, with drug levels falling almost in parallel in peripheral lung tissue and in serum. The results of this study demonstrate that fluticasone propionate is retained in lung tissue for a long time. Serum concentrations after a single inhaled dose are low. Retention of high concentrations of fluticasone propionate in the airways may promote high topical anti-inflammatory activity.

Antiinflammatory activities of procyanidin-containing extracts from Pinus pinaster Ait. after oral and cutaneous application

Orally in liquid diet administered procyanidin-containing extracts from Pinus pinaster Ait. decreased the croton oil-induced ear edema in mice or the compound 48/80-induced hind paw edema in rats to a statistically significant extent. Most effective were the extracts containing mainly oligomeric procyanidins with chain lengths greater then 4 units (extracts A or B). Further, the different extracts incorporated in various concentrations (1.0, 3.0 or 0.1%) in 5% hydroxyethylcellulose gel and applied topically on the shaved back of rats, inhibited significantly the ultraviolet radiation-induced increased capillary permeability. In these experiments, normalisation of capillary permeability was not correlated with the content of the extracts on higher oligomeric procyanidins.

Binding kinetics of fluticasone propionate to the human glucocorticoid receptor

Receptor-ligand interactions of fluticasone propionate (FP), a glucocorticoid used for inhalation therapy, were determined and compared with dexamethasone, budesonide, and beclomethasone-17-monopropionate, the active metabolite of beclomethasone dipropionate. Two approaches, evaluation of binding kinetics and competition assays, were applied to obtain relative receptor affinities (RRAs) with dexamethasone as reference. A higher association rate constant and a distinctly lower dissociation rate constant for FP compared with the other glucocorticoids resulted in an equilibrium dissociation constant (Kd) of 0.49 nmol/l. Kd dexamethasone was 9.36 nmol/l; derived RRA of FP was 1910. The calculated half-time of the FP-receptor complex was 10 h, thus exceeding the half-times of all other glucocorticoids as well as their RRAs. Competition assays clearly confirmed the rank order of the tested glucocorticoids, although RRAs were generally lower than those found in kinetic assays and strongly dependent on the assay conditions. The high receptor affinity of FP is reflected by clinical trials demonstrating its superiority to other glucocorticoids. For therapeutic application, the long half-time of the FP-receptor complex should support the practicality of longer dose-intervals.

Pharmacokinetics of bromfenac in healthy subjects after single oral administration of three different doses

The pharmacokinetic profile of bromfenac (2-amino-3-(4-bromobenzoyl) benzeneacetic acid, CAS91714-93-1) has been investigated in 12 healthy subjects (6 male and 6 female) after single oral doses of 25, 50 and 75 mg. Plasma concentrations were determined by a sensitive HPLC method with spectrophotometric detection. Sampling was performed up to 300 min after drug ingestion. Linear pharmacokinetics could be verified for this dose-range; there was a clear, positive dose-plasma concentration relationship. Bromfenac exhibits a cmax of 3.49 +/- 1.65-8.81 +/- 3.45 micrograms/ml at tmax 52 +/- 27-42 +/- 15 min. The elimination half-life was 39.8 +/- 7.3-34.2 +/- 8.0 min with a clearance (Cl/f) of 120.6 +/- 51.6-135.3 +/- 34.6 ml/min and a volume of distribution (Vd/f) 6.82 +/- 2.88-6.64 +/- 2.29 l. The results obtained show a fast absorption and rapid elimination of bromfenac when administered orally. The short plasma half-life of bromfenac apparently presents no direct relationship to its clinical effectiveness.

Low molecular weight PLA: a suitable polymer for pulmonary administered microparticles?

Beclomethasonedipropionate (BDP)-containing microparticles were prepared by the solvent evaporation/extraction method. Different preparation parameters were optimized before investigations. Polylactic acid (PLA) and polylactic/glycolic acid (PLGA) with molecular weights of 2000 and 15,000 were used as matrix polymers. In all experiments the mean diameter of the microparticles was 1-5 microns with a drug content > or = 23 per cent. Microparticles of PLA, MW 2000, showed a prolonged and complete release over 8 h, whereas those of PLGA liberated only 20 per cent of the encapsulated drug within 8 h. BDP was determined by a validated reversed-phase HPLC method with a detection limit of 20 ng/ml. The encapsulated steroid seemed to be dissolved within the polymer, as differential scanning calorimetry suggested. Considering mean particle size, drug load, release characteristics and the status of the drug inside the matrix, the dosage form showed very good characteristics for inhalatory application. Surface characteristics of the microparticles were visualized by scanning electron microscopy (SEM). Although in vitro studies with human bronchial fluid resulted in a strong deterioration of microparticles, main structures were still visible by SEM after an incubation of 36 h in diluted bronchial fluid ex vivo. Degradation in phosphate buffered saline, protein solution and even in port liver esterase suspension resulted in minor effects on the particle surface.

Activation of beclomethasone dipropionate by hydrolysis to beclomethasone-17-monopropionate

The relative affinity of beclomethasone (B), beclomethasone-17-monopropionate (17-BMP), beclomethasone-21-monopropionate (21-BMP), and beclomethasone dipropionate (BDP) has been determined. BDP binds to the glucocorticoid receptor with about half the affinity of the potent glucocorticoid dexamethasone (Dexa), B was found to be 0.75 times less active than Dexa. The 21-BMP has no binding affinity whereas the 17-BMP is about 13 times as potent as Dexa. The affinity data indicate that metabolism of BDP to 17-BMP is an important activation step. To evaluate the relationship between local and systemic activity incubation studies with BDP in human lung, simulated gastric and intestinal fluid and plasma were performed. In cytosol from human lung cells BDP is hydrolysed rapidly to the more stable 17-BMP. During gastric passage BDP is stable but is immediately hydrolysed to 17-BMP in intestinal fluid. In human plasma BDP is hydrolysed to 17-BMP and an interesterification of 17-BMP to the inactive 21-BMP was also found.

Evaluation of algesimetric parameters on the basis of tooth pulp stimulation in humans

Investigations concerning the validity and sensitivity of algesimetric parameters were performed on 23 healthy volunteers on the basis of electrical tooth pulp stimulation. Bipolar tooth pulp stimulation has been proved to be superior to monopolar stimulation in respect to the reproducibility of threshold of sensation. Verbal numerical scale (VNS) was found to discriminate better between stimulus intensities than visual analogue scale in terms of sensitivity and reproducibility. The long-term reproducibility of subjective pain rating by VNS was surprisingly high. The evaluation of the amplitude of the somatosensory-evoked potential (SEP) was performed by two methods. Calculation on the basis of the N(2), P(1), and P(2) signal gives a more sensitive connection to stimulus intensity. The VNS was found to be more sensitive than SEP in differentiating stimulus intensities.

Pharmacokinetics and dose linearity testing of methylprednisolone phosphate

The pharmacokinetics of methylprednisolone and methylprednisolone phosphate were investigated after intravenous administration of methylprednisolone phosphate to six healthy subjects at seven different doses between 16 and 1000 mg. Plasma, urine, and saliva were analyzed for methylprednisolone and methylprednisolone phosphate. Furthermore, endogenous hydrocortisone was measured in plasma. No non-linearity in the total body clearance of methylprednisolone phosphate or methylprednisolone could be detected. The average elimination half-life for the prodrug was 3.7 min indicating rapid hydrolysis. After 15 min more than 90 per cent of the phosphate has been hydrolyzed. No prodrug could be detected in saliva; very little of the ester (average 0.9 per cent of the dose) was excreted unchanged into the urine. Methylprednisolone is formed rapidly. The total body clearance was 21 1h-1, the terminal half-life 2.8 h. In the post-distribution phase methylprednisolone levels in saliva went parallel to plasma levels. The mean saliva/plasma ratio was 0.22. An average of 5.2 per cent of the dose was eliminated into the urine in the form of methylprednisolone. Hydrocortisone suppression was dose-dependent. For doses above 125 mg hydrocortisone levels were significantly lowered after 24 h. For doses above 500 mg the suppression was still significant after 48 h. The results indicate a rapid and predictable in vivo conversion of methylprednisolone phosphate to its active form methylprednisolone.

Determination of the alkyl lysophospholipid derivative ET-18-OCH3, a new antineoplastic drug, in plasma

We describe a sensitive method for measuring the concentration of the new antineoplastic drug ET-18-OCH3 in plasma. After plasma lipids are extracted, ET-18-OCH3 is separated from the excess of endogenous lipids by thin-layer chromatography and specific enzymatic hydrolysis of sphingomyelin by the action of sphingomyelinase. Analytical recovery after the complete isolation was 73.5% (CV = 9.8%, n = 15). [3H]-ET-18-OCH3 is used as internal standard. A densitometric method in which 8-anilino-1-naphthalenesulfonate, Mg salt, is used as fluorescent agent (excitation at 367 nm and emission greater than 390 nm) allows the sensitive determination of ET-18-OCH3 down to 0.1 mg/L (CV greater than 30%). The day-to-day CV is 25% for concentrations of 0.15 to 0.625 mg/L, 12% for 1.5 to 5.0 mg/L. Preliminary pharmacokinetic data reveal gastrointestinal absorption of ET-18-OCH3 after multiple oral administration.

Determination of the alkyl lysophospholipid derivative ET-18-OCH3, a new antineoplastic drug, in plasma

We describe a sensitive method for measuring the concentration of the new antineoplastic drug ET-18-OCH3 in plasma. After plasma lipids are extracted, ET-18-OCH3 is separated from the excess of endogenous lipids by thin-layer chromatography and specific enzymatic hydrolysis of sphingomyelin by the action of sphingomyelinase. Analytical recovery after the complete isolation was 73.5% (CV = 9.8%, n = 15). [3H]-ET-18-OCH3 is used as internal standard. A densitometric method in which 8-anilino-1-naphthalenesulfonate, Mg salt, is used as fluorescent agent (excitation at 367 nm and emission greater than 390 nm) allows the sensitive determination of ET-18-OCH3 down to 0.1 mg/L (CV greater than 30%). The day-to-day CV is 25% for concentrations of 0.15 to 0.625 mg/L, 12% for 1.5 to 5.0 mg/L. Preliminary pharmacokinetic data reveal gastrointestinal absorption of ET-18-OCH3 after multiple oral administration.

Glucocorticoid receptors in human synovial tissue and relative receptor affinities of glucocorticoid-21-esters

A dexamethasone binding protein was detected in cytosol of 11 human synovial tissues from patients with chronic polyarthritis. The apparent dissociation constant (KD) ranged from 3.3 to 17.1 (mean, 7.0 +/- 4.3) nmol/liter, and the receptor concentration (Ro) from 17 to 65 (mean, 42 + 15) fmol/mg protein. Results of competition assays with an excess of unlabeled aldosterone, estradiol, pregnenolone, and testosterone confirmed that the binding protein had characteristics of a glucocorticoid receptor. With the use of diisopropylfluorophosphate (DFP) for esterase inhibition, and considering the purity of the starting material and the hydrolysis products, we could determine the relative receptor affinities of glucocorticoid-21-esters. In contrast to the high affinity of the glucocorticoid-17-ester examined, esterification in position 21 abolishes binding affinities. Glucocorticoid-21-esters are true prodrugs for which the glucocorticoid action is caused only by the corresponding glucocorticoid alcohol.