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PubMed2002

An in vitro and hydroponic growing system for hypericin, pseudohypericin, and hyperforin production of St. John's wort (Hypericum perforatum CV new stem).

While the interest in medicinal plants continues to grow, there is a lack of basic information with respect to efficient protocols for plant production. Recently, in vitro regeneration protocols have been developed to provide masses of sterile, consistent St. John's wort. The current study assessed the potential for acclimatization of in vitro grown St. John's wort plantlets to a nutrient film technique (NFT) hydroponic system in a controlled environment greenhouse. Quantitative analyses of hypericin, hyperforin and pseudohypericin in flower tissues were used as the parameters to assess the quality of the greenhouse-grown plants. The three bioactive compounds were found to be present in similar or higher amounts than previously reported values for field-grown plants. These data provide evidence that greenhouse hydroponic systems can be effectively used for the efficient production of St. John's wort and other medicinal plants.

Anthracenes↗
PubMed2003

Studies on the antioxidative activity of phloroglucinol derivatives isolated from hypericum species.

Twenty-one phloroglucinol derivatives, belonging to 8 different carbon skeletons, were tested for their ability to influence the oxidative burst of polymorphonuclear cells (PMNs) after stimulation with N-formyl-methionyl-leucyl-phenylalanine (FMLP) or opsonized zymosan (OZ). Results revealed a strong reduction of oxygen production by PMNs after stimulation with FMLP for the compounds ialibinone E ( 5), hyperguinone B ( 15) and hyperforin ( 21). The IC 50 values obtained were 2.5 microM ( 5), 3.3 microM ( 15) and 1.8 microM ( 21), respectively. Slight modifications of the substituents or variation of the stereochemistry resulted in a significant loss of activity. None of the active compounds showed antioxidative activity after stimulation with OZ. The influence of compounds 5, 15 and 21 on the production of oxygen radicals in an H 2 O 2 /horseradish peroxidase system was investigated and revealed potent activity only for compound 5 (IC 50 1 microM). The superoxide-scavenging properties of ialibinone E ( 5) and hyperguinone B ( 15) were additionally tested in a cytochrome c assay and only ialibinone E ( 5) was found to be significantly active at lower micromolar concentrations. Ialibinone E ( 5) was not active in a xanthine oxidase assay (urate formation) in concentrations up to 100 microM and its activity is therefore not attributable to the inhibition of this enzyme. It can be assumed that the activity of compounds 5 and 15 in the different cellular and enzymatic assays, is most likely caused by different and maybe specific mechanisms and cannot be explained by a radical scavenger activity alone. None of the active phloroglucinols showed cytotoxic effects against the PMNs.

Antioxidants↗
PubMed2003

Sub-chronic treatment effects of an extract of Hypericum perforatum (St. John's Wort, Li 160) on neuroendocrine responses to the 5-T2A agonist, DOI in the rat.

Clinical studies have demonstrated the antidepressant efficacy of LI 160 extracts, which is comparable to antidepressants such as imipramine. The study was undertaken to assess the sub-chronic effects of LI 160 extract on plasma corticosterone and prolactin (PRL) responses to the post-synaptic 5-HT 2A receptor agonist, 2,5-dimethoxy-4-iodophenyl-2-aminopropane (DOI), in the male rat. Results show that sub-chronic treatment with the LI 160 extract reduced corticosterone and PRL responses to DOI. LI 160 may modify brain 5-HT function in the rat, possibly by reducing the sensitivity of central 5-HT 2A receptors. This may be a result of decreased receptor expression, signal transduction or intracellular messengers. These findings could be relevant to the therapeutic efficacy of St. John's Wort.

Animals↗
PubMed2004

The significance of "nonsignificance" in randomized controlled studies: a discussion inspired by a double-blinded study on St. John's wort (Hypericum perforatum L.) for premenstrual symptoms.

OBJECTIVES: This study aimed to investigate the efficacy of St. John's wort extract (SJW) as a treatment for premenstrual symptoms. DESIGN: The study was a randomized, double-blinded, placebo-controlled trial, with two parallel treatment groups. After a no-treatment baseline cycle, volunteers were randomized to either SJW or placebo for a further two menstrual cycles. SETTINGS/LOCATION: A postal trial conducted from The University of Reading, Berkshire, England. SUBJECTS: One hundred and sixty-nine (169) normally menstruating women who experienced recurrent premenstrual symptoms were recruited onto the study. One hundred and twenty-five (125) completed the protocol and were included in the analysis. INTERVENTIONS: Six hundred milligrams (600) mg of SJW (standardized to contain 1800 microg of hypericin) or placebo (containing lactose and cellulose). OUTCOME MEASURE: A menstrual diary was used to assess changes in premenstrual symptoms. The anxiety-related subgroup of symptoms of this instrument was used as the primary outcome measure. RESULTS: After averaging the effects of treatment over both treatment cycles it was found that there was a trend for SJW to be superior to placebo. However, this finding was not statistically significant. CONCLUSION: The possibility that this nonsignificant finding resulted from insufficient statistical power in the study, rather than a lack of efficacy of SJW, is discussed. Following this discussion the recommendation is made that, in future, similar studies should be powered to detect a minimum clinically relevant difference between treatments.

Adult↗
PubMed2001

A systematic review and meta-analysis of Hypericum perforatum in depression: a comprehensive clinical review.

The herbal remedy St John's wort is widely used as an antidepressant but its efficacy has not been systematically investigated. Meta-analyses and systematic reviews of published trials strongly suggest St John's wort is more effective than placebo although comparative efficacy to standard antidepressants is less clearly established. We updated and expanded previous meta-analyses of St John's wort, scrutinised the validity of published reports and examined possible mechanisms of action. Twenty-two randomised controlled trials were identified. Meta-analysis showed St John's wort to be significantly more effective than placebo (relative risk (RR) 1.98 (95% CI 1.49-2.62)) but not significantly different in efficacy from active antidepressants (RR 1.0 (0.90-1.11)). A sub-analysis of six placebo-controlled trials and four active comparator trials satisfying stricter methodological criteria also suggested that St John's wort was more effective than placebo (RR 1.77 (1.16-2.70)) and of similar effectiveness to standard antidepressants (RR 1.04 (0.94-1.15)). There was no evidence of publication bias. Adverse effects occurred more frequently with standard antidepressants than with St John's wort. The mechanism of action of St John's wort remains unknown. Future research should include large scale, appropriately powered comparisons of St John's wort and standard antidepressants.

Anthracenes↗
PubMed1998

Is St. John's wort (Hypericum perforatum) an effective antidepressant?

SJW is a remarkably safe antidepressant with an apparently unique mode of action. Although it has demonstrated efficacy in mild and moderate depression when compared with placebo or tricyclic antidepressants, several research areas beg to be explored. Its effects should be compared with serotonin reuptake inhibitors. Studies in severely depressed patients are lacking, as are studies on its utility as a therapeutic adjunct to standard antidepressants.

Animals↗
PubMed2004

Effects of St. John's wort (Hypericum perforatum) on tacrolimus pharmacokinetics in healthy volunteers.

Tacrolimus is an immunosuppressant approved for the prevention of rejection following transplantation and is a substrate for CYP3A and P-glycoprotein. A pharmacokinetic interaction between St. John's wort (antidepressant herbal product and inducer of CYP3A and P-glycoprotein) and tacrolimus was evaluated in 10 healthy volunteers. The pharmacokinetics of tacrolimus were obtained from serial blood samples collected following single oral doses (0.1 mg/kg) prior to and during an 18-day concomitant St. John's wort dosing phase (300 mg orally three times daily). Coadministration of St. John's wort significantly decreased tacrolimus AUC (306.9 microg.h/L +/- 175.8 microg.h/L vs. 198.7 microg.h/L +/- 139.6 microg.h/L; p=0.004) and increased apparent oral clearance (349.0 mL/h/kg +/- 126.0 mL/h/kg vs. 586.4 mL/h/kg +/- 274.9 mL/h/kg; p=0.01) and apparent oral volume of distribution at steady state (11.5 L/kg +/- 4.3 L/kg vs. 17.6 L/kg +/- 9.6 L/kg; p=0.04). St. John's wort appears to induce tacrolimus metabolism, most likely through induction of CYP3A and P-glycoprotein.

Administration, Oral↗
PubMed2001

Selected physical and chemical properties of commercial Hypericum perforatum extracts relevant for formulated product quality and performance.

OBJECTIVE: The complex composition-activity relationship of botanicals such as St John's Wort (SJW) presents a major challenge to product development, manufacture, and establishment of appropriate quality and performance standards for the formulated products. As part of a larger study aimed at addressing that challenge, the goals of the present study are to (1) determine and compare the phytochemical profiles of 3 commercial SJW extracts; (2) assess the possible impact of humidity, temperature, and light on their stability; and (3) evaluate several physical properties important to the development of solid dosage forms for these extracts. METHODS: An adapted analytical method was developed and validated to determine phytochemical profiles and assess their stability. The extract physical properties measured were particle size (Malvern Mastersizer), flow (Carr's compressibility index; minimum orifice diameter), hygroscopicity (method of Callahan et al), and low-pressure compression physics (method of Heda et al). RESULTS: The phytochemical properties differed greatly among the extracts and were extremely sensitive to changes in storage conditions, with marked instability under conditions of elevated humidity. All extracts exhibited moderate to free-flow properties and were very hygroscopic. Compression properties varied among the extracts and differed from a common use excipient, microcrystalline cellulose. CONCLUSIONS: Three commercial sources of SJW extracts exhibited different physical and chemical properties. Standardization to 1 or 2 marker compounds does not ensure chemical equivalence nor necessarily equivalent pharmacological activity. Flow and compression properties appear suitable for automatic capsule-filling machines, but hygroscopicity and the moisture sensitivity of the phytochemical profile are concerns.

Chemistry, Pharmaceutical↗
PubMed2001

St John's wort (Hypericum perforatum L.): a review of its chemistry, pharmacology and clinical properties.

The chemical composition of St. John's wort has been well-studied. Documented pharmacological activities, including antidepressant, antiviral, and antibacterial effects, provide supporting evidence for several of the traditional uses stated for St John's wort. Many pharmacological activities appear to be attributable to hypericin and to the flavonoid constituents; hypericin is also reported to be responsible for the photosensitive reactions that have been documented for St. John's wort. With regard to the antidepressant effects of St John's wort, hyperforin, rather than hypericin as originally thought, has emerged as one of the major constituents responsible for antidepressant activity. Further research is required to determine which other constituents contribute to the antidepressant effect. Evidence from randomised controlled trials has confirmed the efficacy of St John's wort extracts over placebo in the treatment of mild-to-moderately severe depression. Other randomised controlled studies have provided some evidence that St John's wort extracts are as effective as some standard antidepressants in mild-to-moderate depression. There is still a need for further trials to assess the efficacy of St John's wort extracts, compared with that of standard antidepressants, particularly newer antidepressant agents, such as the selective serotonin reuptake inhibitors (recent comparative studies with fluoxetine and sertraline have been conducted). Also, there is a need for further studies in well-defined groups of patients, in different types of depression, and conducted over longer periods in order to determine long-term safety. St John's wort does appear to have a more favourable short-term safety profile than do standard antidepressants, a factor that is likely to be important in patients continuing to take medication. Concerns have been raised over interactions between St John's wort and certain prescribed medicines (including warfarin, ciclosporin, theophylline, digoxin, HIV protease inhibitors, anticonvulsants, selective serotonin reuptake inhibitors, triptans, oral contraceptives); advice is that patients taking these medicines should stop taking St John's wort, generally after seeking professional advice as dose adjustment of conventional treatment may be necessary.

Adult↗
PubMed2006

Cytoprotective effects of 5 benzophenones and a xanthone from Hypericum annulatum in models of epirubicin-induced cytotoxicity: SAR-analysis and mechanistic investigations.

A new benzophenone O-glucoside neoannulatophenonoside (1) together with the known pinocembrin-7-O-glucoside were isolated from the aerial parts of Hyperium annulatum Moris (Guttiferae). The former was identified as 3',5',6-trihydroxy-4-methoxybenzophenone-2-O-beta-D-glucopyranoside by means of chemical and physical evidence. The cytoprotective effects of the new compound together with the previously isolated from this species hypericophenonoside (2), annulatophenone (3), annulatophenonoside (4), acetylannulatophenonoside (5) and 1,3,7-trihydroxyxanthone (6) were evaluated in a model of epirubicin-induced cellular toxicity in K-562 cells. While the benzophenone O-glycosides 1, 2, 4 and 5 exerted substantial cytoprotective effects against the epirubicin cytotoxicity in K-562 cells the aglycones 3 and 6 lacked any significant cytoprotective activity. Biochemical investigations aimed at evaluating the free-radical scavenging activity of the tested compounds as well as their effects on the cellular glutathione stores were carried out as well, aiming at unravelling the mechanisms of cytoprotection. Finally, the ability of 1, 4 and 5 to ameliorate epirubicin-induced anticlonogenic effects on bone marrow cells colony forming units, in vitro were also evaluated. Taken together, the experimental data indicate that the benzophenone glycosides isolated from H. annulatum have a substantial cytoprotective potential against the toxic effects induced by epirubicin and necessitates further detailed pharmacological evaluation of these compounds as possible chemoprotective/radioprotective agents.

Animals↗
PubMed2003

St. John's wort (Hypericum perforatum) as a treatment for premenstrual dysphoric disorder: case report.

Premenstrual dysphoric disorder (PMDD), a menstruous dysfunction, is characterized by profoundly depressed mood, and studies have shown that antidepressants are effective for PMDD. The authors describe a case of PMDD who was initially treated with selective serotonin reuptake inhibitors. Due to intolerable gastrointestinal side effects with selective serotonin reuptake inhibitors, St. John's wort (900 mg/day) was substituted and much improvement in PMDD symptoms was noted for at least five-month follow-up. The authors propose that St. John's wort could be an alternative medication for PMDD, especially for patients experiencing intolerable side effects with selective serotonin reuptake inhibitors.

Adult↗