Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We previously showed that a methanolic extract of St John's wort (SJW) (Hypericum) and hypericin, one of its active constituents, both have delayed regulation of genes that are involved in the control of the hypothalamic-pituitary-adrenal (HPA) axis. Hyperforin, another constituent of SJW, is active in vitro and has been proposed to be the active constituent for therapeutic efficacy in depression. We therefore examined if hyperforin has delayed effects on HPA axis control centers similar to those of Hypericum and hypericin. We used in situ hybridization histochemistry to examine in rats the effects of short-term (2 weeks) and long-term (8 weeks) oral administration of two hyperforin preparations, fluoxetine (positive control), and haloperidol (negative control) on the expression of genes involved in the regulation of the HPA axis. Fluoxetine (10 mg/kg) given daily for 8 weeks, but not 2 weeks, significantly decreased levels of corticotropin-releasing hormone (CRH) mRNA by 22% in the paraventricular nucleus (PVN) of the hypothalamus and tyrosine hydroxylase (TH) mRNA by 23% in the locus coeruleus. Fluoxetine increased levels of mineralocorticoid (MR) (17%), glucocorticoid (GR) (18%), and 5-HT(1A) receptor (21%) mRNAs in the hippocampus at 8, but not 2, weeks. Comparable to haloperidol (1 mg/kg), neither the hyperforin-rich CO(2) extract (27 mg/kg) nor hyperforin-trimethoxybenzoate (8 mg/kg) altered mRNA levels in brain structures relevant for HPA axis control at either time point. These data suggest that hyperforin and hyperforin derivatives are not involved in the regulation of genes that control HPA axis function.
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PMID:Hyperforin-containing extracts of St John's wort fail to alter gene transcription in brain areas involved in HPA axis control in a long-term treatment regimen in rats. 1286 94

The phloroglucinol derivative hyperforin has been recently shown to be a major antidepressant component in the extract of Hypericum perforatum. Experimental studies clearly demonstrated its activity in different behavioral models of depression. Moreover clinical studies linked the therapeutic efficacy of Hypericum extracts to their hyperforin content, in a dose-dependent manner. The molecular mechanism of action of hyperforin is still under investigation. Hyperforin has been shown to inhibit, like conventional antidepressants, the neuronal uptake of serotonin, norepinephrine and dopamine. However, hyperforin inhibits also the uptake of gamma-aminobutyric acid (GABA) and L-glutamate. The uptake inhibition by hyperforin does not involve specific binding sites at the transporter molecules; its mechanism of action seems to be related to sodium conductive pathways, leading to an elevation in intracellular Na(+) concentration. Other additional mechanisms of action of hyperforin, involving ionic conductances as well synaptosomal and vesicular function, have been suggested. In addition to its antidepressant activity, hyperforin has many other pharmacological effects in vivo (anxiolytic-like, cognition-enhancing effects) and in vitro (antioxidant, anticyclooxygenase-1, and anticarcinogenic effects). These effects could be of clinical importance. On the other hand, the role of hyperforin in the pharmacological interactions occurring during Hypericum extract therapy must be fully investigated. Hyperforin seems to be responsible for the induction of liver cytochrome oxidase enzymes and intestinal P-glycoprotein. Several pharmacokinetic studies performed in rats and humans demonstrated oral bioavailability of hyperforin from Hypericum extract. Only recently a new chromatographic method for detection of hyperforin in the brain tissue has been developed and validated. Taking into account the chemical instability of hyperforin, current efforts are directed to the synthesis of new neuroactive derivatives.
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PMID:Role of hyperforin in the pharmacological activities of St. John's Wort. 1549 71

Hypericum perforatum (St John's Wort [SJW]) counts among the most favourite herbal drugs, and is the only herbal alternative to classic synthetic antidepressants in the therapy of mild to moderate depression. Several clinical studies have been conducted to verify the effectiveness of ethanolic or methanolic extracts of SJW. Alcoholic SJW extracts are a mixture of substances with widely varying physical and chemical properties and activities. Hyperforin, a phloroglucinol derivative, is the main source of pharmacological effects caused by the consumption of alcoholic extracts of SJW in the therapy of depression. However, several studies indicate that flavone derivatives, e.g. rutin, and also the naphthodianthrones hypericin and pseudohypericin, take part in the antidepressant efficacy. In contrast to the amount of documentation concerning clinical efficacy, oral bioavailability and pharmacokinetic data about the active components are rather scarce. The hyperforin plasma concentration in humans was investigated in a small number of studies. The results of these studies indicate a relevant plasma concentration, comparable with that used in in vitro tests. Furthermore, hyperforin is the only ingredient of H. perforatum that could be determined in the brain of rodents after oral administration of alcoholic extracts. The plasma concentrations of the hypericins were, compared with hyperforin, only one-tenth and, until now, the hypericins could not be found in the brain after oral administration of alcoholic H. perforatum extracts or pure hypericin. Until now, the pharmacokinetic profile of the flavonoids in humans after oral administration of an alcoholic H. perforatum extract has been investigated in only one study. More data are available for rutin and the aglycone quercetin after administration of pure substances or other flavonoid sources.
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PMID:Hypericum perforatum: a 'modern' herbal antidepressant: pharmacokinetics of active ingredients. 1664 Apr 52

Extracts of the plant St John's wort, Hyperforin perforatum L., have been used for centuries in traditional medicine, notably for the treatment of depression. One of their main lipophilic components, a natural prenylated phloroglucinol termed hyperforin (HF), has been identified as the major molecule responsible for the antidepressant effects of this plant. Within the last few years, a number of studies have demonstrated that HF displays, in addition, several other biological properties of potential pharmacological interest. They include an antibacterial capacity and inhibitory effects on inflammatory mediators. It is worth noting that HF also promotes apoptosis of various cancer cells from solid tumors and hematological malignancies, including B-cell chronic lymphocytic leukemia. In addition, HF inhibits the capacity of migration and invasion of different tumor cells, as well as exhibiting antiangiogenic effects. Altogether, these properties qualify HF as a lead structure for the development of new therapeutic molecules in the treatment of various diseases, including some malignant tumors.
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PMID:Hyperforin, a new lead compound against the progression of cancer and leukemia? 1679 Dec 62

St John's wort (SJW) extracts, prepared from the aerial parts of Hypericum perforatum, contain numerous pharmacologically active ingredients, including naphthodianthrones (e.g., hypericin and its derivatives), phloroglucinols derivatives (e.g., hyperforin, which inhibits the reuptake of a number of neurotransmitters, including serotonin), and flavonoids. Such extracts are widely used for the treatment of mild-to-moderate depression. As a monotherapy, SJW has an encouraging safety profile. However, relevant and, in some case, life-threatening interactions have been reported, particularly with drugs which are substrate of cytochrome P450 and/or P-glycoprotein. Well-documented SJW interactions include (1) reduced blood cyclosporin concentration, as suggested by multiple case reports as well as by clinical trials, (2) serotonin syndrome or lethargy when SJW was given with serotonin reuptake inhibitors, (3) unwanted pregnancies in women while using oral contraceptives and SJW, and (4) reduced plasma drug concentration of antiretroviral (e.g., indinavir, nevirapine) and anticancer (i.e., irinotecan, imatinib) drugs. Hyperforin, which is believed to contribute to the antidepressant action of St John's wort, is also strongly suspected to be responsible of most of the described interactions.
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PMID:Herb-drug interactions with St John's wort (Hypericum perforatum): an update on clinical observations. 1985 15

St. John's Wort (SJW) has been used medicinally for over 5,000 years. Relatively recently, one of its phloroglucinol derivatives, hyperforin, has emerged as a compound of interest. Hyperforin first gained attention as the constituent of SJW responsible for its antidepressant effects. Since then, several of its neurobiological effects have been described, including neurotransmitter re-uptake inhibition, the ability to increase intracellular sodium and calcium levels, canonical transient receptor potential 6 (TRPC6) activation, N-methyl-D-aspartic acid (NMDA) receptor antagonism as well as antioxidant and anti-inflammatory properties. Until recently, its pharmacological actions outside of depression had not been investigated. However, hyperforin has been shown to have cognitive enhancing and memory facilitating properties. Importantly, it has been shown to have neuroprotective effects against Alzheimer's disease (AD) neuropathology, including the ability to disassemble amyloid-beta (Abeta) aggregates in vitro, decrease astrogliosis and microglia activation, as well as improve spatial memory in vivo. This review will examine some of the early studies involving hyperforin and its effects in the central nervous system (CNS), with an emphasis on its potential use in AD therapy. With further investigation, hyperforin could emerge to be a likely therapeutical candidate in the treatment of this disease.
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PMID:Neurobiological effects of Hyperforin and its potential in Alzheimer's disease therapy. 2001 41

St. John's wort has been found to be an effective and safe herbal treatment for depression in several clinical trials. However, the underlying mechanism of its therapeutic effects is unclear. Recent studies show that the loss and malfunction of oligodendrocytes are closely related to the neuropathological changes in depression, which can be reversed by antidepressant treatment. In this study, we evaluated the effects of hyperforin, a major active component of St. John's wort, on the proliferation, development and mitochondrial function of oligodendrocytes. The study results revealed that hyperforin promotes maturation of oligodendrocytes and increases mitochondrial function without affecting proliferation of an oligodendrocyte progenitor cell line and neural stem/progenitor cells. Hyperforin also prevented mitochondrial toxin-induced cytotoxicity in an oligodendrocyte progenitor cell line. These findings suggest that hyperforin may stimulate the development and function of oligodendrocytes, which could be a mechanism of its effect in depression. Future in vitro and in vivo studies are required to further characterize the mechanisms of hyperforin.
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PMID:Hyperforin promotes mitochondrial function and development of oligodendrocytes. 2184 57

The standardized extract of the St. John's wort plant (Hypericum perforatum) is commonly used to treat mild to moderate depression. Its active constituent is hyperforin, a phloroglucinol derivative that reduces the reuptake of serotonin and norepinephrine by increasing intracellular Na(+) concentration through the activation of nonselective cationic TRPC6 channels. TRPC6 channels are also Ca(2+) -permeable, resulting in intracellular Ca(2+) elevations. Indeed, hyperforin activates TRPC6-mediated currents and Ca(2+) transients in rat PC12 cells, which induce their differentiation, mimicking the neurotrophic effect of nerve growth factor. Here, we show that hyperforin modulates dendritic spine morphology in CA1 and CA3 pyramidal neurons of hippocampal slice cultures through the activation of TRPC6 channels. Hyperforin also evoked intracellular Ca(2+) transients and depolarizing inward currents sensitive to the TRPC channel blocker La(3+) , thus resembling the actions of the neurotrophin brain-derived neurotrophic factor (BDNF) in hippocampal pyramidal neurons. These results suggest that the antidepressant actions of St. John's wort are mediated by a mechanism similar to that engaged by BDNF.
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PMID:Hyperforin modulates dendritic spine morphology in hippocampal pyramidal neurons by activating Ca(2+) -permeable TRPC6 channels. 2281 87

Hyperforin is a natural phloroglucinol that has been know for the treatment of depression. Hyperforin displays also antibacterial, antiproliferant and antiangiogenic activity. Synthetic derivatives of hyperforin have also recently been reported to possess increased bioactivity. The clinical applications are limited by the hydrophobic characteristics and the instability of the molecule. In this review we discuss about some of the derivatives of hyperforin (aristoforin, tetrahydrohyperforin and octahydrohyperforin) that demonstrated promising antitumor activity. Among these, octahydrohyperforin also possesses antibacterial activity against both the planktonic and biofilm states of bacteria.
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PMID:Anticancer and Antibacterial Activity of Hyperforin and Its Derivatives. 2517 57

Hyperforin is a pharmacologically active component of the medicinal plant Hypericum perforatum (St. John's wort), recommended as a treatment for a range of ailments including mild to moderate depression. Part of its action has been attributed to TRPC6 channel activation. We found that hyperforin induces TRPC6-independent H(+) currents in HEK-293 cells, cortical microglia, chromaffin cells and lipid bilayers. The latter demonstrates that hyperforin itself acts as a protonophore. The protonophore activity of hyperforin causes cytosolic acidification, which strongly depends on the holding potential, and which fuels the plasma membrane sodium-proton exchanger. Thereby the free intracellular sodium concentration increases and the neurotransmitter uptake by Na(+) cotransport is inhibited. Additionally, hyperforin depletes and reduces loading of large dense core vesicles in chromaffin cells, which requires a pH gradient in order to accumulate monoamines. In summary the pharmacological actions of the "herbal Prozac" hyperforin are essentially determined by its protonophore properties shown here.
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PMID:Protonophore properties of hyperforin are essential for its pharmacological activity. 2551 Dec 54


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