Resazurin dye as a reliable tool for determination of cell number and viability in mesenchymal stem cell culture.

Human mesenchymal stem cells are a valuable cell source for tissue engineering. Determination of cell number and viability is crucial. However, this can be tested only at the end of cell culture. This study shows that Resazurin dye staining is a reliable tool for evaluation of cell number and viability in culture without cell perturbation.

JNJ-20788560 [9-(8-azabicyclo[3.2.1]oct-3-ylidene)-9H-xanthene-3-carboxylic acid diethylamide], a selective delta opioid receptor agonist, is a potent and efficacious antihyperalgesic agent that does not produce respiratory depression, pharmacologic tolerance, or physical dependence.

Mu-opioid analgesics are a mainstay in the treatment of acute and chronic pain of multiple origins, but their side effects, such as constipation, respiratory depression, and abuse liability, adversely affect patients. The recent demonstration of the up-regulation and membrane targeting of the delta-opioid receptor (DOR) following inflammation and the consequent enhanced therapeutic effect of delta-opioid agonists have enlivened the search for delta-opioid analgesic agents. JNJ-20788560 [9-(8-azabicyclo-[3.2.1]oct-3-ylidene)-9H-xanthene-3-carboxylic acid diethylamide] had an affinity of 2.0 nM for DOR (rat brain cortex binding assay) and a naltrindole sensitive DOR potency of 5.6 nM (5'-O-(3-[(35)S]thio)triphosphate assay). The compound had a potency of 7.6 mg/kg p.o. in a rat zymosan radiant heat test and of 13.5 mg/kg p.o. in a rat Complete Freund's adjuvant RH test but was virtually inactive in an uninflamed radiant heat test. In limited studies, tolerance was not observed to the antihyperalgesic or antinociceptive effects of the compound. Unlike ibuprofen, JNJ-20788560 did not produce gastrointestinal (GI) erosion. Although morphine reduced GI motility at all doses tested and reached nearly full effect at the highest dose, JNJ-20788560 did not retard transit at the lowest dose and reached only 11% reduction at the highest dose administered. Unlike morphine, JNJ-20788560 did not exhibit respiratory depression (blood gas analysis), and no withdrawal signs were precipitated by the administration of opioid (mu or delta) antagonists. Coupled with the previously published lack of self-administration behavior of the compound by alfentanil-trained primates, these findings strongly recommend delta-opioid agonists such as JNJ-20788560 for the relief of inflammatory hyperalgesia.

Blockade of group II metabotropic glutamate receptors produces hyper-locomotion in cocaine pre-exposed rats by interactions with dopamine receptors.

It was previously reported that blockade of group II metabotropic glutamate receptors (mGluRs) produces hyper-locomotion in rats previously exposed to amphetamine, indicating that group II mGluRs are well positioned to modulate the expression of behavioral sensitization by amphetamine. The present study further examined the locomotor activating effects of specific blockade of these receptors after cocaine pre-exposures. First, rats were pre-exposed to seven daily injections of cocaine (15mg/kg, IP). When challenged the next day with an injection of either saline or the group II mGluR antagonist LY341495 (0.5, 1.0 or 2.5mg/kg, IP), they produced hyper-locomotor activity, measured by infrared beam interruptions, to LY341495 compared to saline in a dose-dependent manner. Second, rats were pre-exposed to either saline or seven daily injections of cocaine (15mg/kg, IP). Three weeks later, when they were challenged with an injection of either saline or LY341495 (1.0mg/kg, IP), only rats pre-exposed to cocaine produced hyper-locomotor activity to LY341495 compared to saline. These effects, however, were not present when dopamine D1 (SCH23390; 5 or 10microg/kg), but not D2 (eticlopride; 10 or 50microg/kg), receptor antagonist was pre-injected, indicating that this cocaine-induced hyper-locomotor activity to LY341495 may be mediated in dopamine D1 receptor-dependent manner. These results suggest that group II mGluRs may be adapted to interact with dopaminergic neuronal signaling in mediating the sensitized locomotor activity produced by repeated cocaine pre-exposures.

Inhibition of human CYP3A4, UGT1A6, and P-glycoprotein with halogenated xanthene food dyes and prevention by superoxide dismutase.

Synthetic food dyes are xenobiotics, and, after ingestion, portions of these dyes may be absorbed and metabolized by phase I and II drug-metabolizing enzymes, and excreted by transporters of phase III enzymes. In the previous report, it was shown that inhibition of UDP-glucuronosyltrasnferase 1A6 occurred following ingestion of phloxine, erythrosine, and rose bengal present in 12 permitted synthetic food dyes. In this report, the influence of dyes was examined on CYP3A4, a major phase I drug-metabolizing enzyme, and P-glycoprotein, a major transporter by synthetic food dyes. Human cytochrome P-450 (CYP) 3A4 and P-glycoprotein were inhibited by xanthene food dyes. The IC(50) values of these dyes to inhibit CYP3A4 and P-glycoprotein were the same as the level of inhibition of UGT1A6 produced by three haloganated xanthene food dyes in the previous report, except acid red, which inhibited only CYP3A4. Data suggest that inhibition by dyes is not enzyme specific but may be in a membrane-specific or protein-specific manner, such as conformational changes in protein. In the previous study, it was suggested that inhibition by dyes depended upon light irradiation due to generation of (1)O2 from these dyes. In this study, the influence of superoxide dismutase and catalase on inhibition by dyes was examined. Superoxide dismutase but not catalase was effective in preventing the inhibition of UGT1A6 by the dyes. Data suggest that superoxide anions, originating from dyes via light irradiation, may attack drug-metabolizing enzymes. It is possible that red cosmetics containing phloxine, erythrosine, or rose bengal react with proteins in skin and may lead to skin damage.

Phototoxicity mechanisms: chlorpromazine photosensitized damage to DNA and cell membranes.

Photosensitized damage to biological molecules is the initial process in phototoxic responses. It is now recognized that many phototoxic compounds can photosensitize damage to more than one type of biological substrate. The in vitro light-initiated reactions of phototoxic compounds with DNA, soluble proteins and membrane components can be classified by their molecular mechanisms: (1) those in which an excited state of the phototoxic compound (or an unstable species derived from it) reacts directly with the biological substrate and (2) those in which a molecule derived from the phototoxic compound (a photoproduct or an activated oxygen species) reacts with the biological substrate. This paper describes the mechanisms by which chlorpromazine photosensitizes damage to membranes, protein and DNA and compares them to the mechanisms of photosensitization by psoralens, porphyrins, dyes, and other molecules.

Phototoxic effects of Hypericum extract in cultures of human keratinocytes compared with those of psoralen.

Extracts of Hypericum perforatum (St. John's wort) are used in the treatment of depression. They contain the plant pigment hypericin and hypericin derivates. These compounds have light-dependent activities. In order to estimate the potential risk of phototoxic skin damage during antidepressive therapy, we investigated the phototoxic activity of hypericin extract using cultures of human keratinocytes and compared it with the effect of the well-known phototoxic agent psoralen. The absorbance spectrum of our Hypericum extract revealed maxima in the whole UV range and in parts of the visible range. We cultivated human keratinocytes in the presence of different Hypericum concentrations and irradiated the cells with 150 mJ/cm2 UVB, 1 J/cm2 UVA or 3 h with a white light of photon flux density 2.6 mumol m-2 s-1. The determination of the bromodeoxyuridine incorporation rate showed a concentration- and light-dependent decrease in DNA synthesis with high hypericin concentrations (> or = 50 micrograms/mL) combined with UVA or visible light radiation. In the case of UVB irradiation a clear phototoxic cell reaction was not detected. We found phototoxic effects even with 10 ng/mL psoralen using UVA with the same study design as in the case of the Hypericum extract. These results confirm the phototoxic activity of Hypericum extract on human keratinocytes. However, the blood levels that are to be expected during antidepressive therapy are presumably too low to induce phototoxic skin reactions.

Effectiveness and tolerance of the hypericum extract LI 160 in comparison with imipramine: randomized double-blind study with 135 outpatients.

In a double-blind comparative study, 135 depressed patients were treated in 20 centers. Inclusion diagnoses were typical depressions with single episode (296.2), several episodes (296.3), depressive neurosis (300.4), and adjustment disorder with depressed mood (309.0) in accordance with DSM-III-R. The dosage was 3 x 300 mg hypericum extract LI 160 or 3 x 25 mg imipramine daily. The treatment lasted for 6 weeks. Main assessment criteria were the Hamilton Depression Scale (HAMD), the Depression Scale according to von Zerssen (D-S) and the Clinical Global Impressions (CGI). In both treatment groups, a parallel reduction of the Hamilton score from 20.2 to 8.8 (LI 160, n = 67) or from 19.4 to 10.7 (imipramine, n = 68), and the transformed D-S point values from 39.6 to 27.2 (LI 160) and 39.0 to 29.2 (imipramine) were found. The analysis of CGI revealed comparable results in both treatment groups. Clinically relevant changes of the safety parameters were not found. In the LI 160 group fewer and milder side effects were found as compared to imipramine.

Effectiveness and tolerance of the hypericum extract LI 160 compared to maprotiline: a multicenter double-blind study.

A randomized, double-blind study examining the effectiveness and tolerance of a standardized hypericum preparation when compared to maprotiline was performed in a group of 102 patients with depression, in accordance with ICD-10, F 32.1. The study was conducted in the offices of neurology and psychiatry specialists. The patients received, over a period of 4 weeks, either 3 x 300 mg of the hypericum extract or 3 x 25 mg maprotiline pills of identical appearance. Effectiveness was determined using the Hamilton Depression Scale (HAMD), the Depression Scale according to von Zerssen (D-S), and the Clinical Global Impression Scale (CGI). The total score of the HAMD scale dropped during the 4 weeks of therapy in both treatment groups by about 50%. The mean values of the D-S scale and the CGI scale showed similar results, and after 4 weeks of therapy, no significant differences in either treatment group were noticed. The onset of the effects occurred up to the second week of treatment, but were observed earlier with maprotiline than with the hypericum extract. On the other hand, maprotiline treatment resulted in more cases of tiredness, mouth dryness, and heart complaints.

Benefits and risks of the hypericum extract LI 160: drug monitoring study with 3250 patients.

Effectiveness and acceptance of a 4-week treatment with hypericum extract LI 160 were investigated by 663 private practitioners. The results of the 3250 patients (76% women and 24% men), were recorded using data sheets. The age of the patients ranged from 20 to 90 years (mean 51 years). Of the patients, 49% were mildly depressed, 46% intermediate, and 3% severely depressed. In about 30% of the patients, the situation normalized or improved during the therapy. Undesired drug effects were reported in 79 (2.4%) patients and 48 (1.5%) discontinued the therapy. Most frequently noted side effects were gastrointestinal irritations (0.6%), allergic reactions (0.5%), tiredness (0.4%), and restlessness (0.3%).

Placebo-controlled double-blind study examining the effectiveness of an hypericum preparation in 105 mildly depressed patients.

One hundred and five outpatients with mild depressions of short duration were treated in a double-blind study with either 3 x 300 mg hypericum extract or placebo. The therapy phase was 4 weeks. The effectiveness was judged according to the Hamilton Depression Scale after 2 and 4 weeks. The values of the mean basic score in these periods fell from 15.8 to 9.6 or 7.2 in the active group, and in the placebo group, from 15.8 to 12.3 and 11.3. The differences between active and placebo groups were statistically significant with P < .05 and P < .01 achieved after 2 and 4 weeks, respectively. In the active group, 28 of 42 patients (67%) and, in the placebo group, 13 of 47 patients (28%) responded to treatment. Notable side effects were not found.

Effects of hypericum extract on the sleep EEG in older volunteers.

The effects of treatment with high doses (300 mg three times daily) of hypericum extract LI 160 on sleep quality and well-being were investigated over a 4-week period. The double-blind, placebo-controlled study was conducted with 12 older, healthy volunteers in a cross-over design, which included a 2-week wash-out phase between both treatment phases. A hypostatic influence of the REM sleep phases, which is typical for tricyclic antidepressants and MAO inhibitors, could not be shown for this phytopharmacon. Instead, LI 160 induced an increase of deep sleep during the total sleeping period. This could be shown consistently in the visual analysis of the sleeping phases 3 and 4, as well as in the automatic analysis of slow-wave EEG activities. The continuity of sleep was not improved by LI 160; this was also the case for the onset of the sleep, the intermittent wake-up phases, and total sleep duration.

St. John's Wort (Hypericum perforatum): clinical effects on depression and other conditions.

St. John's Wort (Hypericum perforatum), a perennial flowering plant, has been used medicinally for thousands of years, and has most recently been identified as an effective treatment for mild to moderate depression. Clinical studies on the use of this plant for depression have utilized liquid tinctures and standardized solid extracts (0.3% hypericin--300 mg three times a day). Severe depression may also respond to this botanical, although it appears a larger dose is needed (600 mg solid extract three times a day). Hypericum has been favorably compared to numerous antidepressant drugs, the studies having revealed equivalent results and a much more favorable incidence of side effects. Studies have also demonstrated its efficacy in treating seasonal affective disorder. In vitro investigations of Hypericum show antiviral activity, although there is evidence these promising results might not occur in vivo. Traditional actions and uses include enhancement of wound healing, as well as anti-inflammatory and analgesic activity.

St John's wort for depression--an overview and meta-analysis of randomised clinical trials.

OBJECTIVE: To investigate if extracts of Hypericum perforatum (St John's wort) are more effective than placebo in the treatment of depression, are as effective as standard antidepressive treatment, and have fewer side effects than standard antidepressant drugs. DESIGN: Systematic review and meta-analysis of trials revealed by searches. TRIALS: 23 randomised trials including a total of 1757 outpatients with mainly mild or moderately severe depressive disorders: 15 (14 testing single preparations and one a combination with other plant extracts) were placebo controlled, and eight (six testing single preparations and two combinations) compared hypericum with another drug treatment. MAIN OUTCOME MEASURES: A pooled estimate of the responder rate ratio (responder rate in treatment group/responder rate in control group), and numbers of patients reporting and dropping out for side effects. RESULTS: Hypericum extracts were significantly superior to placebo (ratio = 2.67; 95% confidence interval 1.78 to 4.01) and similarly effective as standard antidepressants (single preparations 1.10; 0.93 to 1.31, combinations 1.52; 0.78 to 2.94). There were two (0.8%) drop outs for side effects with hypericum and seven (3.0%) with standard antidepressant drugs. Side effects occurred in 50 (19.8%) patients on hypericum and 84 (52.8%) patients on standard antidepressants. CONCLUSION: There is evidence that extracts of hypericum are more effective than placebo for the treatment of mild to moderately severe depressive disorders. Further studies comparing extracts with standard antidepressants in well defined groups of patients and comparing different extracts and doses are needed.