Production of enterodiol from defatted flaxseeds through biotransformation by human intestinal bacteria.

BACKGROUND: The effects of enterolignans, e.g., enterodiol (END) and particularly its oxidation product, enterolactone (ENL), on prevention of hormone-dependent diseases, such as osteoporosis, cardiovascular diseases, hyperlipemia, breast cancer, colon cancer, prostate cancer and menopausal syndrome, have attracted much attention. To date, the main way to obtain END and ENL is chemical synthesis, which is expensive and inevitably leads to environmental pollution. To explore a more economic and eco-friendly production method, we explored biotransformation of enterolignans from precursors contained in defatted flaxseeds by human intestinal bacteria. RESULTS: We cultured fecal specimens from healthy young adults in media containing defatted flaxseeds and detected END from the culture supernatant. Following selection through successive subcultures of the fecal microbiota with defatted flaxseeds as the only carbon source, we obtained a bacterial consortium, designated as END-49, which contained the smallest number of bacterial types still capable of metabolizing defatted flaxseeds to produce END. Based on analysis with pulsed field gel electrophoresis, END-49 was found to consist of five genomically distinct bacterial lineages, designated Group I-V, with Group I strains dominating the culture. None of the individual Group I-V strains produced END, demonstrating that the biotransformation of substrates in defatted flaxseeds into END is a joint work by different members of the END-49 bacterial consortium. Interestingly, Group I strains produced secoisolariciresinol, an important intermediate of END production; 16S rRNA analysis of one Group I strain established its close relatedness with Klebsiella. Genomic analysis is under way to identify all members in END-49 involved in the biotransformation and the actual pathway leading to END-production. CONCLUSION: Biotransformation is a very economic, efficient and environmentally friendly way of mass-producing enterodiol from defatted flaxseeds.

[Antidepressant effect of acute administration with Jianyate Hao (JYTH) and its possible mechanism].

OBJECTIVE: Jianyate Hao (JYTH) , a traditional Chinese medicine formula, which has been used effectively to treat depression in the past ten years. The purpose of this study was to explore the antidepressant effect of acute administration with JYTH and its possible mechanism. METHOD: the animals behavioral despair models of depression, the tail suspension and forced swimming tests, were used to explore the antidepressant effects of JYTH. In addition, the locomotor activity test was used to detect the change of locomotor activity. The monoamine oxidase activity in the mouse brain was also determined by using fluorospectrophotometry. RESULT: JYTH (17.5, 35, 70 g x kg(-1), ig) could decrease the duration of immobility in both tail suspension and forced swimming tests, and the effect of JYTH (35 g x kg(-1) ig) was resembling imipramine (10 mg x kg(-1), ip) in relieving depression. And the effective doses (17.5, 35, 70 g x kg(-1), ig) did not alter locomotion activity. Moreover, JYTH (35 g x kg(-1), ig) was found to inhibit monoamine oxidase activity in the mouse brain. CONCLUSION: These findings suggest that JYTH exerts antidepressant effect in animals behavioral despair tests and the underlying mechamism may involve the inhibition monoamine oxidase activity in the mouse brain.

Curcumin reverses impaired hippocampal neurogenesis and increases serotonin receptor 1A mRNA and brain-derived neurotrophic factor expression in chronically stressed rats.

Curcuma longa is a major constituent of Xiaoyao-san, the traditional Chinese medicine, which has been used to effectively manage stress and depression-related disorders in China. As the active component of curcuma longa, curcumin possesses many therapeutic properties; we have previously described its antidepressant activity in our earlier studies using the chronic unpredictable stress model of depression in rats. Recent studies show that stress-induced damage to hippocampal neurons may contribute to the phathophysiology of depression. The aim of this study was to investigate the effects of curcumin on hippocampal neurogenesis in chronically stressed rats. We used an unpredictable chronic stress paradigm (20 days) to determine whether chronic curcumin treatment with the effective doses for behavioral responses (5, 10 and 20 mg/kg, p.o.), could alleviate or reverse the effects of stress on adult hippocampal neurogenesis. Our results suggested that curcumin administration (10 and 20 mg/kg, p.o.) increased hippocampal neurogenesis in chronically stressed rats, similar to classic antidepressant imipramine treatment (10 mg/kg, i.p.). Our results further demonstrated that these new cells mature and become neurons, as determined by triple labeling for BrdU and neuronal- or glial-specific markers. In addition, curcumin significantly prevented the stress-induced decrease in 5-HT(1A) mRNA and BDNF protein levels in the hippocampal subfields, two molecules involved in hippocampal neurogenesis. These results raise the possibility that increased cell proliferation and neuronal populations may be a mechanism by which curcumin treatment overcomes the stress-induced behavioral abnormalities and hippocampal neuronal damage. Moreover, curcumin treatment, via up-regulation of 5-HT(1A) receptors and BDNF, may reverse or protect hippocampal neurons from further damage in response to chronic stress, which may underlie the therapeutic actions of curcumin.

[Effects of jieyuwan on HPA axis and immune system in chronic stress models in rats].

OBJECTIVE: To observe the effects of jieyuwan on neuroendocrine-immune of chronic unpredictable stress rats, for identifing its mechanism of action. METHOD: Animals were randomly assigned to six groups: one non-stressed (control) group, one stressed group (CUS + vehicle) , three treatment groups (CUS + Jieyuwan 53, 106, 212 mg x kg(-1), respectively), and one group for imipramine (CUS + imipramine 10 mg x kg(-1)). We used the chronic unpredictable stress (CUS) test in rats to investigated the effects of chronic oral administration (21 days) of Jieyuwan and imipramine (ip) on the sucrose consumption, the relative weight of adrenal and thymus, the concentration of serum corticosterone, adrenocorticotropic hormone, TNF-alpha, IL-1beta measured by ELISA. RESULT: Our results showed that Sprague-Dawley rats subjected to CUS exhibited increased adrenal weight, reduction in thymus weight, less sucrose consumption, and synchronized with higher serum corticosterone, adrenocorticotropic hormone, TNF-alpha, IL-1beta concentration. Chronic treatment with Jieyuwan (53, 106, 212 mg x kg(-1), po, 21 days) could improve locomotion of stressed rat sucrose consumption, turn over the high levels of serum corticosterone, adrenocorticotropic hormone, TNF-alpha, IL-1beta concentration. CONCLUSION: The therapeutic actions of jieyuwan, in some degree, may be related with indirect or direct effects on HPA axis and immune system.

Curcumin reverses the effects of chronic stress on behavior, the HPA axis, BDNF expression and phosphorylation of CREB.

Curcuma longa is a major constituent of the traditional Chinese medicine Xiaoyao-san, which has been used to effectively manage stress and depression-related disorders in China. Curcumin is the active component of curcuma longa, and its antidepressant effects were described in our prior studies in mouse models of behavioral despair. We hypothesized that curcumin may also alleviate stress-induced depressive-like behaviors and hypothalamic-pituitary-adrenal (HPA) axis dysfunction. Thus in present study we assessed whether curcumin treatment (2.5, 5 and 10 mg/kg, p.o.) affects behavior in a chronic unpredictable stress model of depression in rats and examined what its molecular targets may be. We found that subjecting animals to the chronic stress protocol for 20days resulted in performance deficits in the shuttle-box task and several physiological effects, such as an abnormal adrenal gland weight to body weight (AG/B) ratio and increased thickness of the adrenal cortex as well as elevated serum corticosterone levels and reduced glucocorticoid receptor (GR) mRNA expression. These changes were reversed by chronic curcumin administration (5 or 10 mg/kg, p.o.). In addition, we also found that the chronic stress procedure induced a down-regulation of brain-derived neurotrophic factor (BDNF) protein levels and reduced the ratio of phosphorylated cAMP response element-binding protein (pCREB) to CREB levels (pCREB/CREB) in the hippocampus and frontal cortex of stressed rats. Furthermore, these stress-induced decreases in BDNF and pCREB/CREB were also blocked by chronic curcumin administration (5 or 10 mg/kg, p.o.). These results provide compelling evidence that the behavioral effects of curcumin in chronically stressed animals, and by extension humans, may be related to their modulating effects on the HPA axis and neurotrophin factor expressions.

The effects of curcumin on depressive-like behaviors in mice.

Curcuma longa is a major constituent of Xiaoyao-san, the traditional Chinese medicinal formula, which has been used effectively to treat depression-related diseases in China. There is no information available about the antidepressant activity of curcumin, the active component of curcuma longa. In the present study, we analyzed the effects of curcumin on depressive-like behaviors in mice, using two animal models of depression. Our results showed that curcumin treatment at 5 and 10 mg/kg (p.o.) significantly reduced the duration of immobility in both the tail suspension and forced swimming tests. These doses that affected the immobile response did not affect locomotor activity. In addition, the neurochemical assays showed that curcumin produced a marked increase of serotonin and noradrenaline levels at 10 mg/kg in both the frontal cortex and hippocampus. Dopamine levels were also increased in the frontal cortex and the striatum. Moreover, curcumin was found to inhibit monoamine oxidase activity in the mouse brain. These findings suggest that the antidepressant-like effects of curcumin may involve the central monoaminergic neurotransmitter systems.

Antidepressant effects of curcumin in the forced swim test and olfactory bulbectomy models of depression in rats.

Curcuma longa is a major constituent of Xiaoyao-san, the traditional Chinese medicinal formula, which has been used to effectively manage stress and depression-related disorders in China. Curcumin is the active component of curcuma longa, and we hypothesized that curcumin would have an influence on depressive-like behaviors. The purpose of the present study was to confirm the putative antidepressant effect of chronic administrations of curcumin (1.25, 2.5, 5 and 10 mg/kg, p.o.) in the forced swimming test and bilateral olfactory bulbectomy (OB) models of depression in rats. In the first study, chronic treatment with curcumin (14 days) reduced the immobility time in the forced swimming test. In the second experiment, curcumin reversed the OB-induced behavioral abnormalities such as hyperactivity in the open field, as well as deficits in step-down passive avoidance. In addition, OB-induced low levels of serotonin (5-HT), noradrenaline (NA), high 5-hydroxyindoleacetic acid (5-HIAA) and 4-dihydroxyphenylacetic acid (DOPAC) in the hippocampus were observed, and were completely reversed by curcumin administration. A slight decrease in 5-HT, NA and dopamine (DA) levels was found in the frontal cortex of OB rats which was also reversed by curcumin treatment. These results confirm the antidepressant effects of curcumin in the forced swim and the OB models of depression in rats, and suggest that these antidepressant effects may be mediated by actions in the central monoaminergic neurotransmitter systems.

Inhibitory effects of tetrandrine on the serum- and platelet-derived growth factor-BB-induced proliferation of rat aortic smooth muscle cells through inhibition of cell cycle progression, DNA synthesis, ERK1/2 activation and c-fos expression.

Tetrandrine (TET) is a well known naturally occurred nonspecific Ca(2+) channel blocker. It has long been used for the treatment of arrhythmia, hypertension, and occlusive cardiovascular disorders. The objective of the present study was to investigate the effect of TET on the proliferation of primary cultured rat aortic smooth muscle cells (RASMCs). TET significantly inhibited both 10% fetal bovine serum (FBS) and 50 ng/ml platelet-derived growth factor (PDGF)-BB-induced proliferation, [(3) H] ]thymidine incorporation into DNA, and p42/p44 mitogen-activated protein kinase (ERK1/2) phosphorylation at the concentration of 1.0 and 5.0 microM. Flow cytometry analysis of DNA content in synchronized cells revealed blocking of the FBS-inducible cell cycle progression by TET. In accordance with these findings, TET 5 microM caused a 48% decrease in the early elevation of c-fos expression induced after 10% FBS addition. Furthermore, in contrast to its distinguishable higher potency of Ca(2+) antagonistic activity, verapamil showed lower potent antiproliferative activities than TET. These results suggest that TET can exert antiproliferative effects against mitogenic stimuli for RASMCs in vitro by a mechanism that involves the MAPK pathway, altering cell cycle progression, and the inhibitory action cannot be limited to its Ca(2+) modulation.

Fangchinoline inhibits rat aortic vascular smooth muscle cell proliferation and cell cycle progression through inhibition of ERK1/2 activation and c-fos expression.

Fangchinoline (FAN; a plant alkaloid isolated from Stephania tetrandrae) is a nonspecific Ca(2+) channel blocker. The objective of the present study was to investigate the effect of FAN on the growth factor-induced proliferation of primary cultured rat aortic smooth muscle cells (RASMCs). FAN significantly inhibited both 5% fetal bovine serum (FBS)- and 50ng/mL platelet-derived growth factor (PDGF)-BB-induced proliferation, [3H]thymidine incorporation into DNA and phosphorylation of extracellular signal-regulated kinase 1/2. In accordance with these findings, FAN revealed blocking of the FBS-inducible progression through G(0)/G(1) to S phase of the cell cycle in synchronized cells and caused a 62% decrease in the early elevation of c-fos expression induced after 5% FBS addition. Furthermore, significant antiproliferative activity of FAN is observed at concentrations below those required to achieve significant inhibition of Ca(2+) channels by FAN. These results suggest that FAN reduced both FBS- and PDGF-BB-induced RASMCs proliferation by perturbing cell cycle progression. This antiproliferative effect of FAN is dependent on the MAP kinase pathway, but cannot be limited to its Ca(2+) modulation.

Tetrandrine, a bisbenzylisoquinoline alkaloid from Chinese herb Radix, augmented the hypnotic effect of pentobarbital through serotonergic system.

This is the first study of hypnotic activity of tetrandrine (a major component of Stephania tetrandrae) in mice by using synergism with pentobarbital as an index for the hypnotic effect. The results showed that tetrandrine potentiated pentobarbital (45 mg/kg, i.p.)-induced hypnosis significantly by reducing sleep latency and increasing sleeping time in a dose-dependent manner, and this effect was potentiated by 5-hydroxytryptophan (5-HTP). In the subhypnotic dosage of pentobarbital (28 mg/kg, i.p.)-treated mice, tetrandrine (60 and 30 mg/kg, p.o.) significantly increased the rate of sleep onset and also showed synergic effect with 5-HTP. Pretreatment of p-chlorophenylalanine (PCPA, 300 mg/kg, s.c.), an inhibitor of tryptophan hydroxylase, significantly decreased pentobarbital-induced sleeping time and tetrandrine abolished this effect. From these results, it should be presumed that serotonergic system may be involved in the augmentative effect of tetrandrine on pentobarbital-induced sleep.

The antidepressant effect of secoisolariciresinol, a lignan-type phytoestrogen constituent of flaxseed, on ovariectomized mice.

Secoisolariciresinol (SECO) is a natural lignan-type phytoestrogen constituent mainly found in flaxseed. It can be metabolized in vivo to mammalian lignans of enterodiol and enterolactone, which have been proven to be effective in relieving menopausal syndrome. Depression is one of the most common symptoms of menopausal syndrome, and is currently treated with estrogen replacement and antidepressant therapy. However, due to the serious side-effects of such agents, there are urgent needs for safer and more tolerable treatments. In this paper, using two classical depression models, the forced swimming test and the tail suspension test, we report the antidepressant effect of SECO on ovariectomized (OVX) mice by intragastric administration for 14 consecutive days at doses of 5, 10 and 20 mg/kg. The results showed that SECO (10 mg/kg) treatment could significantly reduce the duration of immobility of OVX mice in these two models compared with the control group (OVX mice + vehicle), which was similar to the positive control imipramine. In addition, SECO treatment could substantially increase brain monoamine (norepinephrine and dopamine) levels in OVX mice. The present studies showed that SECO can reverse depressive-like behavior and exhibit monoamine-enhancing effects.

Antidepressant-like effect of low molecular proanthocyanidin in mice: involvement of monoaminergic system.

Proanthocyanidin is a phenolic product present in plants which has antioxidant, antinociceptive and neuroprotective properties, without inducing significant toxicological effects. The present study tested the hypothesis that low molecular proanthocyanidin from grapes that has optimized bioavailability, would exert antidepressant-like activities in behavioral despair tests. The results suggested that oral administration proanthocyanidin at doses of 25 and 50mg/kg for 7days significantly reduced the duration of immobility in both the tail suspension and forced swimming tests. The doses that affected the immobile response did not affect locomotor activity. In addition, the neurochemical and neuropharmacological assays showed that proanthocyanidin produced a marked increase of 5-HT levels at 25 and 50mg/kg in three brain regions, the frontal cortex, hippocampus and hypothalamus. Noradrenaline and dopamine levels were also increased when higher dose of proanthocyanidin (50mg/kg) administration both in the frontal cortex and hippocampus. These effects were similar to those observed for the classical antidepressant imipramine (10mg/kg, i.p.). Moreover, Our study suggested that proanthocyanidin (12.5, 25 and 50mg/kg) dose dependently inhibited monoamine oxidase-A (MAO-A) activity, while MAO-B inhibitory activity was also found at higher doses (25 and 50mg/kg) after 7days administration. MAO-A selective inhibitor, moclobemide (20mg/kg, i.g.) produced MAO-A inhibition of 70.5% in the mouse brain. These findings suggest that the antidepressant-like effects of proanthocyanidin may involve the central monoaminergic neurotransmitter systems.

In vitro inhibitory effects of bergenin and norbergenin on bovine adrenal tyrosine hydroxylase.

The aqueous extract of Mallotus japonicus (Euphorbiaceae) showed an inhibitory effect on bovine adrenal tyrosine hydroxylase (TH), the rate-limiting enzyme in the biosynthesis of catecholamine. The present study was undertaken to investigate the effects of bergenin and norbergenin, constituents of the aqueous extract of Mallotus japonicus on bovine adrenal TH. Bergenin and norbergenin inhibited the TH activity by 29.0% and 53.4% at a concentration of 20 microg/mL, respectively, and exhibited noncompetitive inhibition of TH activity with the substrate l-tyrosine. The inhibition of TH activity and the inhibitory effect of norbergenin was more potent than that of bergenin. From these results, it is presumed that bergenin and norbergenin may be the active components of Mallotus japonicus in inhibiting TH, and these inhibitory effects may be partially responsible for the clinical use of Mallotus japonicus in treating peptic ulcer by reducing the availability of dopa/dopamine in vivo.