2,488 research outputs found
Expression and function of transient receptor potential channels in the female bovine reproductive tract
© 2016 Elsevier Inc. The epithelium lining the oviduct is critical for early reproductive events, many of which are mediated via intracellular calcium ions. Despite this, little is known about the regulation of calcium homeostasis in the oviductal epithelium. Epithelial transient receptor potential channels (TRPCs) modulate calcium flux in other tissues, and their expression and functional regulation have therefore been examined using the bovine oviduct as a model for the human. The effects of FSH, LH, 17β-estradiol, and progesterone on TRPCs expression and intracellular calcium flux were determined. Transient receptor potential channels 1, 2, 3, 4, and 6 were expressed in the bovine reproductive tract, and their gene expression varied throughout the estrous cycle. In more detailed studies undertaken on TRPC1 and 6, we show that protein expression varied through the estrus cycle; specifically, 17β-estradiol, FSH, and LH individually and in combination upregulated TRPC1 and 6 expression in cultured bovine oviduct epithelial cells although progesterone antagonized these effects. Functional studies showed changes in calcium mobilization in bovine oviduct epithelial cells were dependent on TRPCs. In conclusion, TRPC1, 2, 3, 4, and 6 are present in the epithelium lining the bovine oviduct, and TRPC1 and 6 vary through the estrous cycle suggesting an important role in early reproductive function
Endocrinological effects of high-dose Hypericum perforatum extract WS 5570 in healthy subjects
In this single-blind study, the effects of acute oral administration of high-dose Hypericum perforatum extract WS 5570 on the cortisol ( COR), adrenocorticotropic hormone ( ACTH), growth hormone (GH), and prolactin (PRL) secretions were examined in 12 healthy male volunteers. In a randomized order, the subjects received placebo or WS 5570 at several dosages (600, 900, and 1,200 mg) at 08.00 h on 4 different days. After insertion of an intravenous catheter, blood samples were drawn 1 h prior to administration of placebo or WS 5570 ( 600, 900, or 1,200 mg), at the time of administration, and during 5 h thereafter at intervals of 30 min. The serum concentrations of COR, GH, and PRL as well as the plasma levels of ACTH were determined in each blood sample by means of double antibody radioimmunoassay, fluoroimmunoassay, and chemiluminescence immunometric assay methods. The area under the curve value was used as parameter for COR, ACTH, GH, and PRL responses. Repeated-measures Anova revealed a significant stimulatory effect of WS 5570 on the ACTH secretion, whereas COR and PRL secretions were not significantly influenced. Moreover, there was a stimulatory peak of GH release 240 min after challenge with WS 5570 in some but not all volunteers, without reaching statistical significance in comparison with placebo. Mean arterial blood pressure and heart rate remained unchanged after administration of WS 5570. Apparently, WS 5570 at the dosages given in this study inconsistently causes endocrinological effects in healthy subjects by influencing central neurotransmitters. Copyright (C) 2004 S. Karger AG, Basel
The antidepressant hyperforin increases the phosphorylation of CREB and the expression of TrkB in a tissue-specific manner.
International audienceHyperforin is one of the main bioactive compounds that underlie the antidepressant actions of the medicinal plant Hypericum perforatum (St. John's wort). However, the effects of a chronic hyperforin treatment on brain cells remains to be fully addressed. The following study was undertaken to further advance our understanding of the biological effects of this plant extract on neurons. Special attention was given to its impact on the brain-derived neurotrophic factor (BDNF) receptor TrkB and on adult hippocampal neurogenesis since they appear central to the mechanisms of action of antidepressants. The consequences of a chronic hyperforin treatment were investigated on cortical neurons in culture and on the brain of adult mice treated for 4 wk with a daily injection (i.p.) of hyperforin (4 mg/kg). Its effects on the expression of the cyclic adenosine monophosphate response element-binding protein (CREB), phospho-CREB (p-CREB), TrkB and phospho-TrkB (p-TrkB) were analysed by Western blot experiments and its impact on adult hippocampal neurogenesis was also investigated. Hyperforin stimulated the expression of TRPC6 channels and TrkB via SKF-96365-sensitive channels controlling a downstream signalling cascade involving Ca2+, protein kinase A, CREB and p-CREB. In vivo, hyperforin augmented the expression of TrkB in the cortex but not in the hippocampus where hippocampal neurogenesis remained unchanged. In conclusion, this plant extract acts on the cortical BDNF/TrkB pathway leaving adult hippocampal neurogenesis unaffected. This study provides new insights on the neuronal responses controlled by hyperforin. We propose that the cortex is an important brain structure targeted by hyperforin
Regiodivergent photocyclization of dearomatized acylphloroglucinols: asymmetric syntheses of (—)-nemorosone and (—)-6-epi-garcimultiflorone A
Regiodivergent photocyclization of dearomatized acylphloroglucinol substrates has been developed to produce type A polycyclic polyprenylated acylphloroglucinol (PPAP) derivatives using an excited-state intramolecular proton transfer (ESIPT) process. Using this strategy, we achieved the enantioselective total syntheses of the type A PPAPs (—)-nemorosone and (—)-6-epi-garcimultiflorone A. Diverse photocyclization substrates have been investigated leading to divergent photocyclization processes as a function of tether length. Photophysical studies were performed, and photocyclization mechanisms were proposed based on investigation of various substrates as well as deuterium-labeling experiments.R35 GM118173 - NIGMS NIH HHSAccepted manuscriptSupporting documentatio
Recommended from our members
Enantioselective Total Synthesis of Hyperforin
A modular, 18-step total synthesis of hyperforin is described. The natural product was quickly accessed using latent symmetry elements, whereby a group-selective, Lewis acid-catalyzed epoxide-opening cascade cyclization was used to furnish the bicyclo[3.3.1]nonane core and set two key quaternary stereocenters.Chemistry and Chemical Biolog
Quality Control of Hypericum perforatum L. Analytical challenges and recent progress
Objectives
The most widely applied qualitative and quantitative analytical methods in the quality control of Hypericum perforatum extracts will be reviewed, including routine analytical tools and most modern approaches.
Key findings
Biologically active components of H. perforatum are chemically diverse, therefore different chromatographic and detection methods are required for the comprehensive analysis of St. John’s wort extracts. Naphthodianthrones, phloroglucinols and flavonoids are the most widely analysed metabolites of this plant. For routine quality control, detection of major compounds belonging to these groups seem to be sufficient, however closer characterisation requires the detection of minor compounds as well.
Conclusions
TLC and HPTLC are basic methods in the routine analysis, whereas HPLC-DAD is the most widely applied method for quantitative analysis due to its versatility. LC-MS is gaining importance in pharmacokinetic studies due to its sensitivity. Modern approaches, such as DNA barcoding, NIRS and NMR metabolomics may offer new possibilities for the more detailed characterization of secondary metabolite profile of Hypericum perforatum extracts
Johanniskraut - von Inhaltsstoffen und anderen Unwägbarkeiten
Die Depression gehört zu den häufigsten Volkskrankheiten. Derzeit sind rund vier Millionen Deutsche an einer behandlungsbedürftigen Depression erkrankt. Die Erkrankung verläuft typischerweise in Form von Episoden, die Wochen bis Monate, manchmal auch Jahre anhalten können. Wenn die Erkrankung unbehandelt bleibt, kann sie wiederkehren und einen chronischen Verlauf nehmen. Rund 75 Prozent der Betroffenen erleiden nach einer Ersterkrankung innerhalb von fünf Jahren mindestens eine neue depressive Phase. Zudem werden mit steigender Episodenzahl die episodenfreien Zwischenzeiten immer kürzer. Es gilt heute als unstrittig, dass mehr als die Hälfte aller Depressionen nicht diagnostiziert und allenfalls ein Fünftel adäquat behandelt werden. Das verursacht nicht nur enorme Kosten für die Volkswirtschaft, sondern ist für die Betroffenen auch mit erheblichem Leid und Lebensgefahr verbunden
Arbuscular mycorrhizal fungi altered the hypericin, pseudohypericin, and hyperforin content in flowers of Hypericum perforatum grown under contrasting P availability in a highly organic substrate
St. John’s Wort (Hypericum perforatum) is a perennial herb able to produce water-soluble active ingredients (a.i.), mostly in flowers, with a wide range of medicinal and biotechnological uses. However, information about the ability of arbuscular mycorrhizal fungi (AMF) to affect its biomass accumulation, flower production, and concentration of a.i. under contrasting nutrient availability is still scarce. In the present experiment, we evaluated the role of AMF on growth, flower production, and concentration of bioactive secondary metabolites (hypericin, pseudohypericin, and hyperforin) of H. perforatum under contrasting P availability. AMF stimulated the production of aboveground biomass under low P conditions and increased the production of root biomass. AMF almost halved the number of flowers per plant by means of a reduction of the number of flower-bearing stems per plant under high P availability and through a lower number of flowers per stem in the low-P treatment. Flower hyperforin concentration was 17.5% lower in mycorrhizal than in non-mycorrhizal plants. On the contrary, pseudohypericin and hypericin concentrations increased by 166.8 and 279.2%, respectively, with AMF under low P availability, whereas no effect of AMF was found under high P availability. These results have implications for modulating the secondary metabolite production of H. perforatum. However, further studies are needed to evaluate the competition for photosynthates between AMF and flowers at different nutrient availabilities for both plant and AM fungus
The antidepressant effect of hypericum perforatum extract Ze 117 is associated with reduced possibilities of drug interactions than hypericum perforatum extract LI 160.
Hypericum perforatum (HP) is the most extensively investigated medicinal herbs with antidepressant effect. Differences showed by HP extracts in their antidepressant effect and their clinical consequence of HP-drug interactions have been related with HP extract different composition, particularly regarding to their primary ingredients hyperforin and hypericin content. Experimental data and clinical trials have shown that low-hyperforin-content HP has a comparable antidepressant efficacy in the treatment of mild/moderate depression (1) (2). However, hyperforin is responsible for CYP3A4 induction via activation of a nuclear steroid/pregnane and xenobiotic receptor (SXR/PXR) and hypericin is a P-glycoprotein inducing compound (3), which are the main origin of HP-drug interactions. Changes in cytochrome P-450 (CYP-450) activity could modulate the effect of different drugs. Some of the reported interactions are based on findings from in vitro studies but the clinical importance of which remain to be demonstrated. Two different hypericum extracts, Ze 117 and LI 160, which are differently composed, Ze 117 (0.15-0.25% hypericin, 0.5% hyperforin) and LI 160 (0.3% hypericin, 4-6% hyperforin) were checked regarding their antidepressant-like activity vs. classical antidepressants with and without liver CYP 450 enzyme activity modulation by cimetidine.
Experimental procedures followed the ECC Directives and were approved by local authorities. Male Wistar rats (n=6 per group, 6 months old, weight 314±25 g, Charles River-Spain) were injected (i.p. once a day) with Ze 117 (20 mg/kg, Zeller AG), LI 160 (20 mg/kg, Lichtwer Pharma AG), imipramine (IMI) (10.9 mg/kg, Novartis SL), fluoxetine (FLU) (5 mg/kg, Lilly and Dista) or saline (SAL), in presence and absence of cimetidine (CIM) (50 mg/kg, Rimsa) during 20 days. The forced swim test (4) was used for the evaluation of the antidepressant-like effect. The opend-field test was used for the evaluation of the motor activity. The total CYP 450 content of the liver was measure using spectrophotometry methods in liver microsomes. Results are expressed as mean±sem and were compared by Student t test and ANOVA test followed by Bonferroni post-test.
The drugs antidepressant effect (reduction of the immobility time) ranking order was: i) without cimetidine’s CYP-450 inhibition: IMI 109±33s >Ze 117 163±21s =FLU165±29s >LI 160 201±234s >SAL 224±17s, pLI 160 144±13s >FLU 171±21s >Ze 117 188±10 >SAL 219±20s, pLI 160 >Ze 117 >SAL, p<0.05). LI 160 significantly reduced the liver CYP-450 total content with respect to SAL (-43.3%, p<0.05) while Ze 117 had lower effect (-25.9%, p<0.05).
In conclusion, hypericum perforatum extract Ze 117 shows higher antidepressant effect and lower inhibitory effect of the total CYP 450 liver content than hypericum perforatum extract LI 160. Liver CYP 450 inhibition by cimetidine increased the antidepressant of LI 160 but did not modify the antidepressant effect of Ze 117.
(1)Fiebich BL, Knörle R, Appel K et al. (2011) Fitoterapia 82(3):474-480.
(2)Singer A, Schmidt M, Hauke W et al. (2011) Phytomedicine 18(8-9):739-742.
(3)Mannel M. (2004) Drug Saf 27(11):773-797.
(4)Castagné V, Moser P, Roux S et al. (2011) Curr Protoc Neurosci 55:8.10A.1-8.10A.14.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
- …
