Definitions

1. Hyperforin is a plant compound from Hypericum perforatum that inhibits tumor cell proliferation in vitro by induction of apoptosis.
2. Hyperforin is an extremely fragile compound that typically degrades rapidly.
3. Hyperforin is a substance belonging to a group of phenolic compounds known as acylphloroglucinols.
4. Hyperforin is a prenylated phloroglucinol believed to be the main active constituent responsible for its antidepressant effects.
5. Hyperforin is one of the principal constituents identified in St John's wort.

Hypericin

1. The characteristic metabolites of St John's wort are the photodynamic active plant pigment hypericin and the phloroglucin-derivative hyperforin.
2. The active components: hypericin and hyperforin, are clinically indicated to be effective in cases of mild to medium depression.

Hyperforin

1. Here, we report that hyperforin also acts as an angiogenesis inhibitor in vitro and in vivo.
2. At the end of the six-week trial, those taking the highest hyperforin dose showed the most positive results.
3. Hyperforin is confirmed to be a major neuroactive component of h.
4. No accumulation of hyperforin occurred with repeated dosing.
5. Here we describe a novel activity of hyperforin, namely its ability to inhibit the growth of tumour cells by induction of apoptosis.

Na

1. The effect of hyperforin was also associated with elevated [Na +] i.
2. Thus, we speculated that hyperforin works by elevating [Na +] i.

Serotonin Uptake

1. Fig. 1. Inhibition of [ 3 H]serotonin uptake into mouse cortex synaptosomes by hyperforin and monensin.
2. Figure 1 shows the concentration-dependent inhibition by hyperforin of [ 3 H]serotonin uptake into mouse brain synaptosomes.
3. Fig. 5. Top, effects of increasing concentrations of hyperforin on [ 3 H]serotonin uptake and [Na +] i in human platelets.

Concentration

1. Higher concentrations of hyperforin had no further effects (Fig.
2. Adhyperforin, which occurs in St. John's wort in lower concentrations than hyperforin, differs from the latter only by the presence of a single methyl group.

Hypericum Extracts

1. Thus, hyperforin has to be considered an important antidepressant constituent of hypericum extract.
2. Hyperforin represents the neurotransmitter reuptake inhibiting constituent of hypericum extract.
3. The data suggest hyperforin as the active principle of hypericum extracts in biochemical models of antidepressant activity.
4. In humans, hyperforin plasma levels of about 600 nM were seen after a single dose of 600 mg of hypericum extract (Biber et al., 1998).

Extract

1. Biber A, Fischer H, Römer A and Chatterjee SS (1998) Oral bioavailability of hyperforin from hypericum extracts in rats and human volunteers.
2. High quality, standardised, pharmaceutical grade hydroalcoholic extracts contain at least 3% of stable hyperforin (7).
3. The oral bioavailability of hyperforin in doses up to 30mg (ie 600mg St. John's wort extract) was high.

Did

1. Finally, I did an Abstract search for hyperforin and found nothing new.
2. By contrast, hyperforin did not increase the K m (Table 2), but slightly decreased K m.
3. Because hyperforin is such an important component of H. perforatum, I did a Keyword search for hyperforin.

Articles

1. Then I did a Topic search for hyperforin and found many articles, a lot of which I had already found before.
2. I also found several primary articles describing experiments performed with hyperforin and other constituents of St. John's Wort.

St John

1. One of the studies also shows that St. John's Wort with a higher hyperforin content is more effective.
2. Hyperforin content of vegetative parts of St. John's wort (after Reference 10).
3. Hyperforin and its homologue adhyperforin occur exclusively in the reproductive parts of St. John's wort (7).
4. Animal studies have shown that constituents other than hyperforin are responsible for a dopaminergic effect of an ethanolic St. John's wort extract (13).
5. The authors concluded that St. John's wort extracts with a high hyperforin content have a shielding effect on the central nervous system.

Monensin

1. Kinetic analyses of the effects of citalopram, hyperforin, and monensin on [ 3 H]serotonin uptake into mouse cortex synaptosomes.
2. Thus, monensin effects on synaptosomal uptake systems show considerable similarities to the properties of hyperforin.
3. Inhibitory effects of St. John's wort extracts and pure hyperforin on monoamine oxidase activity and synaptosomal uptake of neurotransmitters.

Dopamine

1. Scientists hypothesize that this is physical evidence that hyperforin is inhibiting the re-uptake of seratonin, noradrenaline and dopamine.
2. In contrast to hyperforin, neither hypericin nor the flavonoid kaempferol inhibited the synaptosomal uptake of serotonin, noradrenaline or dopamine (12).

Mm

1. At a hyperforin concentration leading to about 80% uptake inhibition, an elevation of [Na +] i by about 20 mM again was found.
2. Maximal elevation of [Na +] i by about 70 mM was seen at 50 µM hyperforin.

Human

1. In vitro, hyperforin blocked microvessel formation of human dermal microvascular endothelial cells (HDMEC) on a complex extracellular matrix.
2. As far as we know, this is the first evidence that hyperforin is also active at the human serotonin transporter.
3. Simultaneous determination of hypericin and hyperforin in human plasma with liquid chromatography-tandem mass spectrometry.

Apoptosis

1. Furthermore, hyperforin reduced proliferation of HDMEC in a dose-dependent manner, without displaying toxic effects or inducing apoptosis of the cells.
2. These findings suggest that hyperforin activates a mitochondria-mediated apoptosis pathway.

Inhibited

1. Hyperforin inhibited the activity of 5-LO with IC(50) values of about 1-2 micromolar.
2. The same study found that both hyperforin and the hyperforin-containing extract also inhibited serotonin-induced contractions in guinea pig ileum.

Antidepressive

1. Another source describes how hyperforin is a major antidepressive component of alcoholic hypericum extracts.
2. The discovery of hyperforin as the key antidepressive compound has, however, contributed to a better understanding of the mode of action of St. John's wort.

Containing

1. For topical use, creams that usually contain 1.5% hyperforin and transdermal patches containing 0.3% hypericin are marketed.
2. Both used two different St. John's wort extracts, containing 0.5% and 5.0% hyperforin, respectively.
3. Recently, a new compound containing a hyperforin and a sesquiterpene moiety was isolated from leaves and stems of St. John's wort (9).
4. Extraction with supercritical carbon dioxide can yield extracts containing more than 38.8% hyperforin, which is stable on prolonged storage (6).

Role

1. The role of hyperforin has been investigated in two double-blind, randomised, placebo-controlled trials.
2. They nearly all had a common theme, namely the role of a compound called hyperforin.

Platelets

1. Hyperforin could not interfere with COX-2 product formation and did not significantly inhibit 12- or 15-LO in platelets or leukocytes, respectively.

Antidepressant

1. Antidepressant activity of hypericum perforatum and hyperforin: the neglected possibility.

Proliferation

1. Furthermore, hyperforin reduced proliferation of HDMEC in a dose-dependent manner, without displaying toxic effects or inducing apoptosis of the cells.

Influx

1. Additionally, hyperforin induces barium influx in PC12 cells and this influx can be inhibited by SK&F 96365, LOE 908, Gd 3+ and La 3+.

Human Platelets

1. Moreover, La3+ and Gd3+ attenuate the effect of hyperforin on serotonin uptake in human platelets.

Categories

1. Antidepressant Effects
2. Tumour Cells
3. Human Platelets
4. Nature > Life > Death > Apoptosis
5. Glossaries > Glossary of Pharmacology Stubs /
6. Books about "Hyperforin" in Amazon.com
   

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