St John's Wort Extract Research Articles

Tissue Regeneration and Remodeling in Rat Models after Application of Hypericum perforatum L. Extract-Loaded Bigels.

The wound-healing effect of St. John's Wort (SJW) is mainly attributed to hyperforin (HP), but its low stability restricts its topical administration. This study investigates how "free" HP-rich SJW extract (incorporated into a bigel; B/SJW) and extract "protected" by nanostructured lipid carriers (also included in a biphasic semisolid; B/NLC-SJW) affect tissue regeneration in a rat skin excision wound model. Wound diameter, histological changes, and tissue gene expression levels of fibronectin (Fn), matrix metalloproteinase 8 (MMP8), and tumor necrosis factor-alpha (TNF-α) were employed to quantify the healing progress. A significant wound size reduction was achieved after applying both extract-containing semisolids, but after a 21-day application period, the smallest wound size was observed in the B/NLC-SJW-treated animals. However, the inflammatory response was affected more favorably by the bigel containing the "free" SJW extract, as evidenced by histological studies. Moreover, after the application of B/SJW, the expression of Fn, MMP8, and TNF-α was significantly higher than in the positive control. In conclusion, both bigel formulations exhibited beneficial effects on wound healing in rat skin, but B/SJW affected skin restoration processes in a comprehensive and more efficient way.

St. John's wort extract with a high hyperforin content does not induce P-glycoprotein activity at the human blood-brain barrier.

St. John's wort (SJW) extract, a herbal medicine with antidepressant effects, is a potent inducer of intestinal and/or hepatic cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp), which can cause clinically relevant drug interactions. It is currently not known whether SJW can also induce P-gp activity at the human blood-brain barrier (BBB), which may potentially lead to decreased brain exposure and efficacy of certain central nervous system (CNS)-targeted P-gp substrate drugs. In this study, we used a combination of positron emission tomography (PET) imaging and cocktail phenotyping to gain a comprehensive picture on the effect of SJW on central and peripheral P-gp and CYP activities. Before and after treatment of healthy volunteers (n = 10) with SJW extract with a high hyperforin content (3-6%) for 12-19 days (1800 mg/day), the activity of P-gp at the BBB was assessed by means of PET imaging with the P-gp substrate [11C]metoclopramide and the activity of peripheral P-gp and CYPs was assessed by administering a low-dose phenotyping cocktail (caffeine, omeprazole, dextromethorphan, and midazolam or fexofenadine). SJW significantly increased peripheral P-gp, CYP3A, and CYP2C19 activity. Conversely, no significant changes in the peripheral metabolism, brain distribution, and P-gp-mediated efflux of [11C]metoclopramide across the BBB were observed following the treatment with SJW extract. Our data suggest that SJW does not lead to significant P-gp induction at the human BBB despite its ability to induce peripheral P-gp and CYPs. Simultaneous intake of SJW with CNS-targeted P-gp substrate drugs is not expected to lead to P-gp-mediated drug interactions at the BBB.

St. John's wort formulations induce rat CYP3A23-3A1 independent of their hyperforin content.

The pregnane X receptor (PXR) is a ligand activated regulator of cytochrome P450 (CYP)3A enzymes. Among the ligands of human PXR is hyperforin, a constituent of St John's wort (SJW) extracts and potent inducer of human CYP3A4. It was the aim of this study to compare the effect of hyperforin and SJW formulations controlled for its content on CYP3A23-3A1 in rats. Hyperiplant® was used as it contains a high hyperforin content and Rebalance® because it is controlled for a low hyperforin content. In silico analysis revealed a weak hyperforin-rPXR binding affinity, which was further supported in cell-based reporter gene assays showing no hyperforin-mediated reporter activation in presence of rPXR. However, cellular exposure to Hyperiplant® and Rebalance® transactivated the CYP3A-reporter 3.8 fold and 2.8 fold, respectively, and they induced Cyp3a23-3a1 mRNA expression in rat hepatoma cells compared to control 48-fold and 18-fold, respectively. In Wistar rats treated for 10 days with 400 mg/kg of Hyperiplant® we observed 1.8-times the Cyp3a23-3a1 mRNA expression, a 2.6-fold higher CYP3A23-3A1 protein amount and a 1.6-fold increase in activity compared to control. For Rebalance® we only observed a 1.8-fold hepatic increase of CYP3A23-3A1 protein compared to control animals. Even though there are differing effects on rCyp3a23-3a1/CYP3A23-3A1 in rat liver reflecting the hyperforin content of the SJW extracts, the modulation is most likely not linked to an interaction of hyperforin with rPXR. Significance Statement Treatment with St John's wort (SJW) has been reported to affect CYP3A expression and activity in rats. Our comparative study further supports this finding but shows that the PXR-ligand hyperforin is not the driving force for changes in rat CYP3A23-3A1 expression and function in vivo and in vitro Importantly, CYP3A induction mimics findings in humans but our results suggest that another so far unknown constituent of SJW is responsible for the expression and function modifying effects in rat liver.

Effect of St. John's Wort (Hypericum perforatum L.) on Male Sexual and Reproductive Health: A Narrative Review.

Hypericum species are widely acknowledged for their biological attributes, with notable attention being paid to Hypericum perforatum, commonly known as St. John's wort (SJW) within the Hypericum section of the Hypericaceae family. This species is among the most thoroughly investigated herbal medicines, particularly in terms of its application in the management of mild to moderate depression. SJW is used to treat depression, menopausal symptoms, attention-deficit hyperactivity disorder (ADHD), somatic symptom disorder, obsessive-compulsive disorder, and skin conditions, such as wounds and muscle pain. However, the usefulness and effectiveness of SJW for male sexual and reproductive health (SRH) are not well known. To assess the current evidence in the literature on the effect of SJW on male SRH. This narrative review followed a predetermined protocol and used MEDLINE and PubMed to identify articles published in English on the effects of SJW on male SRH. The search used various keywords, such as "Hypericum Perforatum", "St. John's Wort", and terms related to sexual and reproductive health issues. Articles published between the inception of the database and August 2023 were included. We identified 12 articles published from 1999 to 2019, the majority of which were experimental and conducted on animals. These studies demonstrate variability in terms of design, sample size, type of SJW extract used, the dosage administered, and duration of treatment. Studies have indicated potential sexual dysfunction (SD) due to SJW, which includes reduced libido, delayed ejaculation, delayed orgasm, and erectile dysfunction. Additionally, reproductive toxicity has been suggested, as evidenced by spermicidal effects through the inhibition of sperm motility, abnormal spermatozoa, chromosomal aberrations, and DNA denaturation. Furthermore, some studies have reported potential adverse events during maternal exposure, inhibition of fertilization, and disruption of reproductive parameters. Our review suggests that the safety and efficacy of SJW in the treatment of human SRH remain unclear. Further comprehensive, well-designed studies with larger samples, longer exposure periods, and specific dosages are needed to clarify SJW's effects of SJW. Therefore, consultation with healthcare professionals before using herbal remedies or supplements is crucial.

Encapsulation of St. John's Wort extract in β-Cyclodextrin carrier: In-vitro antioxidant, antimicrobial and Caco-2 cell viability studies

St. John's wort (SJW) is a plant flowering species, and its extract shows antidepressant, anticancer, wound-healing, antibiotic, antiviral, antioxidant, anxiolytic and anti-inflammatory activities. However, SJW extract has low aqueous solubility and biological efficacy; it might be due to the presence of lipophilic components such as hyperforin and hypericin. To increase the aqueous solubility of SJW extract, in the present report an attempt has been made to prepare SJW extract/β-cyclodextrin inclusion complex (IC). The LCMS analysis of SJW extract showed the presence of hyperforin and hypericin components. Morphological investigation depicted the spherical shaped mono-disperse particles of 30 nm size and DLS confirmed hydrodynamic diameter around 100 nm. The encapsulation efficiency of IC was 76%, and 92% SJW components were released from IC in 13.3 h. Caco-2 cell viability study pointed towards improved safety profile of SJW extract after β-CD complex formation. Furthermore, synthesized IC showed higher antioxidant activity than native SJW extract. The prepared IC showed moderate antimicrobial activity for Escherichia coli (E. coli), Enterococcus faecalis (E. faecalis) and Bacillus cereus (B. cereus. The work would help to enhance the biological efficacy of SJW extract.

Hypericum perforatum L. extract exerts insulinotropic effects and inhibits gluconeogenesis in diabetic rats by regulating AMPK expression and PKCε concentration

Ethnopharmacological relevanceHypericum perforatum L., commonly known as St. John's Wort (SJW), represents one of the best-known and most thoroughly researched medicinal plant species. The ethnobotanical usage and bioactivities related to H. perforatum include treatment of skin diseases, wounds and burns, gastrointestinal problems, urogenital diseases and psychiatric disorders, particularly depression. In the last decade, many studies focused on the bioactive constituents responsible for the antihyperglycemic and antidiabetic activity of SJW extracts. However, the mechanism by which H. perforatum extract exhibits these properties is still unclear. Hence, the current study was designed to gain insight into the underlying biochemical and molecular mechanisms by which wildly growing H. perforatum exerts its antihyperglycemic and antidiabetic activities. Material and methodsPlant material of H. perforatum was harvested from a natural population in the Republic of North Macedonia during full flowering season. Methanol (80% v/v) was used to extract bioactive components from HH powder. The dissolved HH dry extract (in 0.3% CMC) was given daily as a single treatment (200 mg/kg bw) during 14 days both in healthy and streptozotocin-induced diabetic rats. As a positive control, we applied glibenclamide. The activity of key enzymes involved in carbohydrate methabolisam in the liver were assessed, along with substrate concentration, as well as AMPK mRNA levels, PKCε concentration, plasma insulin level and pancreatic PARP activity. ResultsCompared to diabetic rats, treatment of diabetic rats with HH extract resulted with decreased activity of hepatic enzymes glucose-6-phospatase and fructose-1,6-bisphosphatase, increased liver glycogen and glucose-6-phosphate content, which resulted with reduced blood glucose concentration up to normoglycaemia. Non-significant changes were observed in the activity of hexokinase, glycogen phosphorylase and glucose-6-phospahte dehydrogenase. HH-treatment also caused an increase in plasma insulin concentration and increase in pancreatic PARP activity. Finally, HH treatment of diabetic rats showed significant increase in AMPK expression and decrease of PKCε concentration. ConclusionWe present in vivo evidence that HH- extract exert insulinotropic effects and regulate endogenous glucose production mostly by suppressing liver gluconeogenesis. The HH-treatment did not effected glycogenolysys and glycolysis. Finally, we confirm the antihyperglycemic and antidiabetic effect of HH-extract and the mechanism of this effect involves amelioration of AMPK and PKCε changes in the liver.

St. John's wort extract STW3-VI affects the binding behaviour, signal transduction and lateral mobility of 5-HT2A receptors observed by single molecule detection and the use of a novel fluorescence-labeled ligand

Background5-HT2A receptors play an important role in the development and therapy of depression. St. John's wort (SJW) extracts are used in the treatment of depression. The effects of pre-treatment with SJW extract on the behaviour of 5-HT2A receptors in the plasma membrane have not been well described at the molecular level. MethodsIn this work, the influence of the SJW extract STW3-VI on 5-HT2A receptor internalization and calcium response under stimulating conditions are determined using different reporter cell lines. Influences on 5-HT2A receptor binding as well as on the lateral diffusion behaviour of receptor-ligand complexes (RLC) in the plasma membrane are investigated by fluorescence correlation spectroscopy (FCS) and single particle tracking (SPT) in real time on living cells. Therefore, a selective fluorescently labeled ligand was first developed. ResultsSTW3-VI pre-treatment inhibited both the 5-HT2A receptor internalization and the calcium response after agonistic stimulation with (±)-TCB-2, which suggests an inhibitory effect. Receptor binding studies using FCS surprisingly showed a dose-dependent increase in 5-HT2A receptor binding under STW3-VI. However, it is noticeable that there was a clear redistribution towards faster diffusing RLC, who possibly contribute less to signal transduction. The diffusive states of 5-HT2A receptors identified by SPT changed also under STW3-VI. Remarkably, there was a redistribution from faster diffusing to immobile RLC, while at the same time the transition probabilities for a receptor to change the diffusive state decreased clearly compared to control cells. This particular lateral diffusion behaviour likely characterizes 5-HT2A receptors with impaired signal transduction. ConclusionThe present data indicate a correlation between receptor status and lateral mobility, with STW3-VI apparently having an inhibitory effect on 5-HT2A receptor-mediated signaling in the cell models used here. Single-molecule techniques such as FCS and SPT provide important data that contribute to a better understanding of therapeutically relevant drug-target interactions and downstream regulatory processes.

Convergent gene clusters underpin hyperforin biosynthesis in St John's wort.

The meroterpenoid hyperforin is responsible for the antidepressant activity of St John's wort extracts, but the genes controlling its biosynthesis are unknown. Using genome mining and biochemical work, we characterize two biosynthetic gene clusters (BGCs) that encode the first three steps in the biosynthesis of hyperforin precursors. The findings of syntenic and phylogenetic analyses reveal the parallel assembly of the two BGCs. The syntenous BGC in Mesua ferrea indicates that the first cluster was assembled before the divergence of the Hypericaceae and Calophyllaceae families. The assembly of the second cluster is the result of a coalescence of genomic fragments after a major duplication event. The differences between the two BGCs - in terms of gene expression, response to methyl jasmonate, substrate specificity and subcellular localization of key enzymes - suggest that the presence of the two clusters could serve to generate separate pools of precursors. The parallel assembly of two BGCs with similar compositions in a single plant species is uncommon, and our work provides insights into how and when these gene clusters form. Our discovery helps to advance our understanding of the evolution of plant specialized metabolism and its genomic organization. Additionally, our results offer a foundation from which hyperforin biosynthesis can be more fully understood, and which can be used in future metabolic engineering applications.

Prescription of St John's Wort extracts: clinical risks due to differences in their hyperforin content

Prescription of St John's Wort extracts: clinical risks due to differences in their hyperforin content

Simultaneous determination of naphtodianthrones, emodin, skyrin and new bisanthrones in Hypericum perforatum L. in vitro shoot cultures

Hypericum perforatum L. (St John's wort) extracts are top-selling herbal medicines for the treatment of various ailments including mild to moderate depression across the world. One of the major bioactive compounds of these extracts is hypericin that is also considered as a lead molecule for drug development. Here, we report on the development of a robust method for the simultaneous quantification of hypericins (hypericin, pseudohypericin, protohypericin and protopseudohypericin), their presumed precursors (emodin and skyrin) and new skyrin derivatives (oxyskyrin, iridoskyrin, rubroskyrin and luteoskyrin). Compounds extracted from the in vitro shoot cultures of H. perforatum L. in ethanol, acetone, 80 % methanol, ethylacetate and dichloromethane were separated by ultra-performance liquid chromatography (UPLC), quantified by photo diode array/ fluorescence (PDA-FLR) and annotated by Q- Exactive Orbitrap mass spectrometer (UPLC-QE-MS). Analyses of the UPLC data revealed that ethanol is the best extractant for the efficient quantification of all target compounds, although all of them could also be extracted in acetone and 80 % methanol. The extractants as well as the method of detection proved to be important for the efficient quantification of naphtodianthrones. Our results are expected to significantly contribute to the dissection of the hypericin biosynthesis pathway and the quality control of Hypericum extracts in the pharmaceutical industry.

Inhibition of pancreatic lipase by the constituents in St. John's Wort: In vitro and in silico investigations

Herbal medicines are frequently used for the prevention and treatment of obesity and obesity-related disorders. Our preliminary screening showed that St. John's Wort (SJW) displayed potent inhibition on pancreatic lipase (PL), a key hydrolase responsible for lipid digestion and absorption in mammals. Herein, the inhibition potentials and inhibitory mechanism of SJW extract and its major constituents on PL were fully investigated by a set of in vitro and in silico studies. The results clearly demonstrated that the naphthodianthrones, biflavones and most of flavonoids in SJW displayed strong to moderate inhibition on PL. Among all tested natural compounds, two naphthodianthrones (hypericin and pseudohypericin) and one biflavone (I3,II8-biapigenin) isolated from SJW exhibited potent PL inhibition activity, with the IC50 values of <1 μM. Inhibition kinetics analyses showed that hypericin, pseudohypericin and I3,II8-biapigenin inhibited PL via a mixed manner, while molecular dynamics simulations revealed that three newly identified PL inhibitors could bind on PL at both the catalytic cavity and the interface between colipase and the C-terminal domain of PL. Collectively, our findings suggested that part of major constituents in SJW displayed potent PL inhibition activities, which could be used as lead compounds for the development of novel PL inhibitors.

Evaluation of the efficacy of Hypericum perforatum (St. John's wort) oil in the prevention of stricture due to esophageal corrosive burns.

The inflammatory response that follows the caustic burns results in fibrosis on the esophageal wall leading to esophageal stricture, dysphagia, and malnutrition. The controversy over the use of corticosteroids warrants alternative therapeutic interventions. We investigated the effect of extracts from St. John's wort (SJW) with known wound-healing activity on stricture formation in rat esophageal injury models. Five experimental groups were involved: sham group with no injury, control group with injury without treatment, and three different treatment groups (methylprednisolone, SJW extract, and combination of the two). Histopathological examination of esophageal damage and collagen accumulation, stenosis index, and tissue hydroxyproline levels were used to assess stricture and the effect of treatments. There was a significant weight loss in all groups except for those without injury and those treated with SJW extract, the latter gained weight albeit not significant. Stenosis index was increased in all groups compared to sham but not significantly in those treated with SJW extract. Histopathological and biochemical analyses produced mixed results. Some of the experimental indicators such as weight gain and stenosis index suggested the treatment of esophageal injury models using extracts of St. John's wort effective while other histopathological indicators show no significant benefit.

St. John's Wort accelerates the liver clearance of technetium-99-sestamibi in rats.

The intense liver uptake of technetium-99-sestamibi (Tc-MIBI) and photon scattering from the liver cause problems in quantitative perfusion interpretation. Hence, Tc-MIBI is a substrate for P-glycoprotein pump; variations in P-glycoprotein levels may affect liver clearance. Adult female Wistar rats were divided into seven main groups [control and St. John's Wort (SJW) treated] and each SJW-treated group included three subgroups that were killed at 15, 30, and 45 min after Tc-MIBI injection. Treated groups received an SJW extract suspension at two doses of 100 and 400 mg/kg once daily for 5, 10, and 14 days, respectively. Tc-MIBI was injected intravenously to all rats 24 h after the final treatment. The rats were anesthetized at the mentioned time after tracer injection, and heart and liver tissues were removed, weighed, and their radioactivity was counted. One rat from each group was selected randomly for myocardial perfusion imaging. A significant increase in liver clearance and heart-to-liver ratio was observed in all SJW-treated groups compared with the control, especially at 10 days after SJW treatment. The heart radioactivity decreased in SJW-receiving groups at 14 days after SJW treatment. This study showed that SJW extract accelerates the liver clearance of Tc-MIBI and significantly reduces photon scattering from the liver.

Mineralocorticoid receptor-related markers and outcome of major depression: focus on blood pressure and electrolytes.

A close association between vegetative regulation and affect is common knowledge. Recently, the role of aldosterone and the activity of its receptor [mineralocorticoid receptor (MR)] in the clinical outcome for treatment with standard antidepressants has been shown including low systolic blood pressure and a low concentration of plasma sodium (Na), both of which appear to be related to therapy resistance to standard antidepressants. We carried out a retrospective analysis of a double-blind placebo-controlled trial of St John's wort extract LI160 in 247 outpatients with major depression. The study did not show a difference between the treatment groups; therefore, a pooled dataset of the 6-week completer population of the trial was analyzed. The focus was on the moderating effect of blood pressure and electrolytes on clinical outcome (relative change in Montgomery-Asberg Depression Rating Scale). Low Na/K ratio and high K at screening predicted worse outcome after 6 weeks as measures with the Montgomery-Asberg Depression Rating Scale (P<0.01). Systolic blood pressure at the same time point did not influence the treatment outcome. In conclusion, signs of reduced peripheral MR sensitivity, as reflected by a lower plasma Na/K ratio and/or higher K concentration, predict worse outcome. This is in line with our recent data as well as neuroendocrine findings. The data indicate that widely collected biomarkers, which are related to MR activity, may be useful to identify patients, who are at risk of nonresponse to antidepressant treatment.

St John's wort extract influences membrane fluidity and composition of phosphatidylcholine and phosphatidylethanolamine in rat C6 glioblastoma cells

BackgroundChronic stress, an important factor in the development of depressive disorders, leads to an increased formation of cortisol, which causes a hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. In addition, cortisol mediates an adaptive effect on plasma membrane fluidity which may affect signal transduction of membrane-bound receptors and contribute to pathophysiological changes. MethodsMembrane fluidity was measured by fluorescence anisotropy using DPH (1,6-diphenyl-1,3,5-hexatriene) and TMA-DPH (1-(4-(trimethylamino)phenyl)-6-phenylhexa-1,3,5-triene). Changes in cellular content of phosphatidylcholine species was determined by pulse-chase experiments using deuterated choline and mass spectrometry. Single molecule tracking was used to examine the lateral mobility of β1-adrenoceptors and changes in cAMP formation were measured by ELISA. ResultsChronic exposure (6 – 8 days) of C6 cells to cortisol dose-dependently decreased DPH and TMA-DPH fluorescence anisotropy, reflecting increased membrane fluidity. In contrast, cells pretreated with St. John's wort extract Ze117 showed increased DPH and TMA-DPH fluorescence anisotropy values, indicating a membrane rigidification effect which was mediated at least by the constituents hypericin, hyperforin, quercetin, amentoflavone and biapigenin. The observed membrane fluidizing effect of cortisol could be reversed by cotreatment with Ze117. The membrane rigidification of Ze117 was in line with the in parallel observed decrease in the phosphatidylcholine/phosphatidylethanolamine ratio determined in whole cell lipid extracts. Interestingly, pulse-chase experiments demonstrated, that Ze117 inhibited the incorporation of choline-D9 in phosphatidylcholine species with saturated or monounsaturated fatty acids compared to control cells, while the synthesis of phosphatidylcholine species with polyunsaturated fatty acids was not affected. C6 cells whose membranes have become more rigid by Ze117 showed altered lateral mobility of β1-adrenoceptors as well as reduced cAMP formation after stimulation with the β1-adrenoceptor agonist dobutamine. ConclusionObviously, the signaling of β1-adrenoceptors depends on the nature of the membrane environment. It can therefore be assumed that Ze117 has a normalizing effect not only on the membrane fluidity of “stressed” cells, but also on lateral mobility and subsequently on the signal transduction of membrane-associated receptors.

Understanding drug interactions with St John's wort (Hypericum perforatum L.): impact of hyperforin content.

The aim of this study was to review herb-drug interaction studies with St John's wort (Hypericum perforatum L.) with a focus on the hyperforin content of the extracts used in these studies. PUBMED was systematically searched to identify studies describing pharmacokinetic interactions involving St John's wort. Data on study design and the St John's wort extract or product were gathered to extract hyperforin content and daily dose used in interaction studies. This analysis demonstrates that significant herb-drug interactions (resulting in a substantial change in systemic exposure) with St John's wort products were associated with hyperforin daily dosage. Products that had a daily dose of <1 mg hyperforin were less likely to be associated with major interaction for drugs that were CYP3A4 or p-glycoprotein substrates. Although a risk of interactions cannot be excluded even for low-dose hyperforin St. John's wort extracts, the use of products that result in a dose of not more than 1 mg hyperforin per day is recommended to minimise the risk of interactions. This review highlights that the significance of herb-drug interactions with St John's wort is influenced by the nature of the herbal medicines product, particularly the hyperforin content.

Neurotrophic, Cytoprotective, and Anti-inflammatory Effects of St. John's Wort Extract on Differentiated Mouse Hippocampal HT-22 Neurons.

Introduction: Since ancient times Hypericum perforatum L. named St. John's wort (SJW), has been used in the management of a wide range of applications, including nervous disorders. Development of mood disorders are due to alterations in glutamate metabolism, initiation of inflammatory pathways, and changes of the neuronal plasticity. Previous studies suggest that the glutamatergic system contributes to the pathophysiology of depression. Extracts of SJW have been recommended for the treatment of depression. The aim of the present in vitro study was to evaluate the action of STW3-VI, a special SJW extract in differentiated mouse hippocampal HT-22 neurons. We evaluated the stimulation of neurogenesis, the protective effect against glutamate or N-methyl-D-aspartate receptor induced-excitotoxicity and its anti-inflammatory properties in LPS-activated human macrophages.Results: After 48 h treatment, STW3-VI stimulated the neurite formation by 25% in comparison with the control and showed protective effects against glutamate- or NMDA-induced cytotoxicity by significantly increasing the viability about +25 or +50%. In conjunction with these effects, after pretreatment with STW3-VI, the intracellular reduced glutathione content was significantly 2.3-fold increased compared with the neurons incubated with glutamate alone. Additionally, pre-treatment of human macrophages with STW3-VI showed anti-inflammatory effects after 24 or 48 h concerning inhibition of LPS-induced TNF release by −47.3 and −53.8% (24 h) or −25.0 to −64.8% (48 h).Conclusions: Our data provide new evidence that STW3-VI protects hippocampal cells from NMDA- or glutamate-induced cytotoxicity. Moreover, our results indicate a morphological remodeling by increasing neurite outgrowth and activation of the anti-inflammatory defense by inhibition of the cytokine production in human macrophages after STW3-VI treatment. These protective, neurotrophic and anti-inflammatory properties may be beneficial in the treatment of depressive disorders.

A meta-analysis on the efficacy and safety of St John's wort extract in depression therapy in comparison with selective serotonin reuptake inhibitors in adults.

ObjectiveThe aim of the study was to investigate the efficacy and safety of St John’s wort extract and selective serotonin reuptake inhibitors (SSRIs) in the treatment of depression.MethodsDatabases were searched for studies comparing efficacy and/or safety of St John’s wort extract with SSRIs in depression from 1966 to April 2015. Stata software was used for statistical analysis.ResultsTwenty-seven studies met the study entry criteria. A total of 3,126 patients with depression were included. St John’s wort extract did not differ from SSRIs in clinical response, remission, and mean reduction in Hamilton Rating Scale for Depression score. St John’s wort extract had a significantly lower rate of adverse events compared to SSRIs (summary relative risk: 0.77; 95% confidence interval: 0.70, 0.84, P=0.00) and had fewer withdrawals due to adverse events. St John’s wort extract had superior safety in the management of patients with depression.ConclusionBoth St John’s wort extract and SSRIs are effective in treating mild-to-moderate depression. St John’s wort extract is safer than SSRIs.

St. John's Wort Attenuates Colorectal Carcinogenesis in Mice through Suppression of Inflammatory Signaling.

Despite widespread use as well as epidemiologic indications, there have been no investigations into the effect of St. John's wort (SJW) extract on colorectal carcinogenesis in vivo. This study reports a systematic evaluation of the impact of dietary supplementation of SJW extract on azoxymethane-induced colorectal carcinogenesis in mice. Mice were fed with either AIN-93G (control) diet or SJW extract-supplemented diet (SJW diet) prior to azoxymethane treatment. SJW diet was found to significantly improve the overall survival of azoxymethane-treated mice. Pretreatment with the SJW diet significantly reduced body weight loss as well as decrease of serum albumin and cholesterol levels associated with azoxymethane-induced colorectal tumorigenesis. SJW diet-fed mice showed a significant decrease in tumor multiplicity along with a decrease in incidence of large tumors and a trend toward decreased total tumor volume in a dose-dependent manner. A short-term study, which examined the effect of SJW prior to rectal bleeding, also showed decrease in colorectal polyps in SJW diet-fed mice. Nuclear factor kappa B (NF-κB) and extracellular signal-regulated kinase (ERK1/2) pathways were attenuated by SJW administration. SJW extract resulted in early and continuous attenuation of these pathways in the colon epithelium of SJW diet-fed mice under both short-term and long-term treatment regimens. In conclusion, this study demonstrated the chemopreventive potential of SJW extract against colorectal cancer through attenuation of proinflammatory processes.

Cerebral ABC Transporter-common Mechanisms May Modulate Neurodegenerative Diseases and Depression in Elderly Subjects

In elderly subjects, depression and dementia often coincide but the actual reason is currently unknown. Does a causal link exist or is it just a reactive effect of the knowledge to suffer from dementia? The ABC transporter superfamily may represent a causal link between these mental disorders. Since the transporters ABCB1 and ABCC1 have been discovered as major β-amyloid-exporting molecules at the blood-brain barrier and ABCC1 was found to be directly activated by St. John's wort (SJW), depression and dementia certainly share an important pathophysiologic link. It was recognized that herbal anti-depressant formulations made from SJW are at least as effective for the treatment of unipolar depression in old age as classical pharmacotherapy, while having fewer side effects (Cochrane reports, 2008). SJW is known to activate various metabolizing and transport systems in the body, with cytochrome P450 enzymes and ABC transporters being most important. Does the treatment of depression in elderly subjects using pharmacological compounds or phytomedical extracts target a mechanism that also accounts for peptide storage in Alzheimer's disease and perhaps other proteopathies of the brain? In this review we summarize recent data that point to a common mechanism and present the first promising causal treatment results of demented elderly subjects with distinct SJW extracts. Insufficient trans-barrier clearance may indeed present a common problem in all the proteopathies of the brain where toxic peptides are deposited in a location-specific manner. Thus, activation of efflux molecules holds promise for future treatment of this large group of devastating disorders.