Anti-Toxoplasma gondii agent isolated from Orostachys malacophylla (Pallas) Fischer.

Botanical medicinal plants have aroused our interest to deal with Toxoplasmosis which can causes serious public health problems. Nipagic acid, gallic acid, ethyl gallate, phloretic acid, protocatechuic acid, methyl p-coumarate, arbutin, and homoprotocatechuic acid are first isolated from Orostachys malacophylla (Pallas) Fischer, their inhibition rate, survival rate, biochemical and viscera index are evaluated using gastric epithelia strain-1(GES-1). Among them, arbutin can effectively prolong the survival time of mice acutely infected with T. gondii, and exhibit the same curative effect as Spiramycin (Spi) group in terms of the glutathione (GSH) and malondialdehyde (MDA) content, alleviate hepatomegaly and splenomegaly. Structure-activity relationship (SAR) and molecular docking implies that phenolic hydroxyl group would be preferred for improvement of activity. In a summary, arbutin is a potential anti-T. gondii candidate for clinical application.

[Effect of Rehmanniae Radix on depression-like behavior and hippocampal monoamine neurotransmitters of chronic unpredictable mild stress model rats].

To investigate the effect of Rehmanniae Radix on depression-like behavior and monoamine neurotransmitters of chronic unpredictable mild stress(CUMS) model rats. CUMS combined with isolated feeding was used to induce the depression model of rats. The depression-like behavior of rats was evaluated by sucrose preference test, open field test, and forced swim test. Hematoxylin-Eosin(HE) staining was used to investigate the pathological changes of neurons in the CA1 and CA3 area of hippocampus. Ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS) was used to detect the contents of 5-hydroxytryptamine(5-HT), 5-hydroxyindoleacetic acid(5-HIAA), dopamine(DA), 3,4-dihydroxyphenylacetic acid(DOPAC), homovanillic acid(HVA), norepinephrine(NE), and 3-methoxy-4-hydroxyphenyl glycol(MHPG) in rats. Western blot was used to detect the protein expressions of tryptophan hydroxylase 2(TPH2), serotonin transporter(SERT), and monoamine oxidase A(MAO-A) in the hippocampus of rats. Compared with the normal group, depressive-like behavior of rats was obvious in the model group. The arrangements of neurons in the CA1 and CA3 area of hippocampus were loose and disorderly. The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in the hippocampal area were decreased(P<0.01). The protein expression of TPH2 was decreased(P<0.01), but those of SERT and MAO-A were increased(P<0.01). In the Rehmanniae Radix groups with 1.8 g·kg~(-1) and 7.2 g·kg~(-1), the depression-like behavior of CUMS rats and pathological changes of neurons in CA1, CA3 area of hippocampus were improved. The protein expression of TPH2(P<0.05, P<0.01) was increased, and those of SERT and MAO-A were down-regulated(P<0.05, P<0.01). The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in hippocampus were increased(P<0.05, P<0.01). The changes in DA, DOPAC, HVA, DA/(DOPAC +HVA), NE, DHPG, and NE/DHPG were not statistically significant. The results suggested that Rehmanniae Radix improved depression-like behavior of CUMS rats, and the mechanism might be related to the regulation of synthesis, transportation, and metabolism of 5-HT neurotransmitter in the hippocampus.

Cranberry Proanthocyanidin and Its Microbial Metabolite 3,4-Dihydroxyphenylacetic Acid, but Not 3-(4-Hydroxyphenyl)-Propionic Acid, Partially Reverse Pro-Inflammatory microRNA Responses in Human Intestinal Epithelial Cells.

SCOPE: The molecular basis underlying the anti-inflammatory and anticarcinogenic properties of cranberries is incompletely understood. The effects of a cranberry proanthocyanidin-rich extract (PAC) and two of its gut microbial metabolites, 3,4-dihydroxyphenylacetic acid (DHPAA) and 3-(4-hydroxyphenyl)-propionic acid (HPPA), on intestinal epithelial cells microRNA (miRNA) expression and their downstream pathways at homeostasis and in inflammatory conditions, are investigated. METHODS AND RESULTS: The expression of 799 miRNAs is quantitatively assessed in differentiated Caco-2BBe1 cells pre-treated with PAC, DHPAA, or HPPA and stimulated with interleukin (IL)-1ß or not. PAC, DHPAA, and HPPA generate subsets of shared and distinct miRNA responses. At homeostasis, miRNAs affected by the metabolites, but not PAC, targeted genes enriched in kinase, Wnt, and growth factor signaling, cell growth and proliferation, apoptosis, and specific cancer pathways. In an inflammatory environment, PAC and DHPAA, but not HPPA, reverses the expression of 16 and two IL-1ß-induced miRNAs, respectively, regulating inflammatory and cancer pathways. CONCLUSION: miRNA modulation is a novel mechanism for PAC bioactivity in the gut. The gut microbiota may be necessary to unlock these effects at homeostasis and partially in inflammation.

Buckwheat bioactive compounds, their derived phenolic metabolites and their health benefits.

SCOPE: Buckwheat (BW) consumption has been associated with a broad range of health benefits: antioxidant, anti-inflammatory and anticancer. These beneficial effects have been partially related to the presence of flavonoids. However, some of these compounds (i.e., rutin and quercetin) are metabolized in the gastrointestinal tract generating derived phenolic metabolites. In this study, we investigated the biological activity of rutin (Ru), quercetin (Q) an their derived phenolic metabolites 3,4-dihydroxyphenylacetic acid (3,4-DHPAA), 3-hydroxyphenylacetic acid (3-HPAA), and 4-hydroxy-3-methoxyphenylacetic acid (homovanillic acid, HVA). METHODS AND RESULTS: Q showed the highest antioxidant and reducing activity, and Ru the maximum chelating activity (85.33%). Antioxidant activity of 3,4-DHPAA was 5-fold higher than that of HVA, whereas their reducing activity was similar. The formation of methylglyoxal (MGO)-BSA and glucose-BSA (advanced glycation end products) was inhibited by Ru (98.5 and 92.7%), Q (95.6 and 89.1%) and 3,4-DHPPA (84.4.6 and 77.5%). Furthermore, Q (10-50 µM) and Ru (1-50 µM) downregulated the release of PGE2 , IL-8 and MCP-1, molecules involved in the inflammatory response, in IL1ß-inflamed myofibroblasts of colon CCD-18Co. CONCLUSION: This study suggests that BW phytochemicals and their phenolic metabolites may be responsible for the beneficial effects against chronic diseases attributed to BW consumption.

Phenolic acid concentrations in plasma and urine from men consuming green or black tea and potential chemopreventive properties for colon cancer.

SCOPE: Tea polyphenols are metabolized by the colonic microflora yielding phenolic metabolites, which may contribute to the health benefits of tea. We determined the serum and urine concentrations of phenolic acids, hippuric acid, and polyhydroxyphenyl-γ-valerolactones during green tea (GT) and black tea (BT) administration. The effects of (-)-epigallocatechin gallate (EGCG) and 3,4-dihydroxyphenylacetic acid (3,4-DHPAA) alone and in combination on bioavailability, intracellular metabolism, and antiproliferative activity were determined in HCT-116 colon cancer cells. METHODS AND RESULTS: The concentration of phenolic metabolites was quantified by HPLC with electrochemical detection and MS. Urine concentrations of 4-hydroxyphenylacetic acid (4-HPAA), 3-hydroxyphenylacetic acid (3-HPAA), and polyhydroxy-γ-valerolactones were increased significantly in men drinking GT compared to control. Urine concentration of 3-O-methylgallic acid (3OMGA) was significantly increased in men drinking BT compared to control. Serum 3,4-DHPAA was significantly increased after consumption of GT and BT and 4-HPAA after GT consumption. In vitro treatment of HCT-116 colon cancer cells with 3,4-DHPAA and EGCG exhibited an additive antiproliferative effect, while methylation of 3,4-DHPAA was significantly decreased. 3OMGA exhibited the strongest antiproliferative activity among the phenolic acids. CONCLUSION: The consumption of both, GT and BT, was associated with a significant increase in urinary and serum phenolic acids.

Oxytocin-induced yawning: sites of action in the brain and interaction with mesolimbic/mesocortical and incertohypothalamic dopaminergic neurons in male rats.

Oxytocin (80 ng) induces yawning when injected into the caudal part of the ventral tegmental area, the hippocampal ventral subiculum and the posteromedial nucleus of the amygdala of male rats. The behavioural response occurred concomitantly with an increase in the concentration of extracellular dopamine and its main metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) in the dialysate obtained from the shell of the nucleus accumbens and of the prelimbic medial prefrontal cortex by means of intracerebral microdialysis. Both oxytocin responses were significantly reduced by d(CH2)5Tyr(Me)²-Orn8-vasotocin, a selective oxytocin receptor antagonist, injected in the above brain areas 15 min before oxytocin. Similar results were obtained by activating central oxytocinergic neurons originating in the paraventricular nucleus of the hypothalamus and projecting to the ventral tegmental area, the hippocampus and the amygdala, with the dopamine agonist apomorphine given at a dose that induces yawning when injected into the paraventricular nucleus. Since oxytocin is considered a key regulator of emotional and social reward that enhances amygdala-dependent, socially reinforced learning and emotional empathy, mesolimbic and mesocortical dopamine neurons play a key role in motivation and reward, and yawning in mammals is considered a primitive, unconscious form of empathy, the present results support the hypothesis that oxytocinergic neurons originating in the paraventricular nucleus of the hypothalamus and projecting to the above brain areas and mesolimbic and mesocortical dopaminergic neurons participate in the complex neural circuits that play a role in the above mentioned functions.

The Ginkgo biloba extract EGb 761(R) and its main constituent flavonoids and ginkgolides increase extracellular dopamine levels in the rat prefrontal cortex.

BACKGROUND AND PURPOSE: Experimental and clinical data suggest that extracts of Ginkgo biloba improve cognitive function. However, the neurochemical correlates of these effects are not yet fully clarified. The purpose of this study was to examine the effects of acute and repeated oral administration of the standardized extract EGb 761((R)) on extracellular levels of dopamine, noradrenaline and serotonin (5-HT), and the dopamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the prefrontal cortex (PFC) and striatum of conscious rats. EXPERIMENTAL APPROACH: Monoamines and their metabolites were monitored by the use of microdialysis sampling and HPLC with electrochemical or fluorescence detection. KEY RESULTS: A single oral dose of EGb 761 (100 mg.kg(-1)) had no effect on monoamine levels. However, following chronic (100 mg.kg(-1)/14 days/once daily) treatment, the same dose significantly increased extracellular dopamine and noradrenaline levels, while 5-HT levels were unaffected. Chronic treatment with EGb 761 showed dose-dependent increases in frontocortical dopamine levels and, to a lesser extent, in the striatum. The extracellular levels of HVA and DOPAC were not affected by either acute or repeated doses. Treatment with the main constituents of EGb 761 revealed that the increase in dopamine levels was mostly caused by the flavonol glycosides and ginkgolide fractions, whereas bilobalide treatment was without effect. CONCLUSIONS AND IMPLICATIONS: The present results demonstrate that chronic but not acute treatment with EGb 761 increased dopaminergic transmission in the PFC. This finding may be one of the mechanisms underlying the reported effects of G. biloba in improving cognitive function.

The impact of the hormonal milieu and stress-associated hypothalamic dopaminergic activation on the rapid compensatory adrenal growth in cycling female rats.

OBJECTIVE: We sought to investigate the impact of emotional and surgical stress applied in two hormonally different estrous-cycle phases as well as the hypothalamic dopaminergic involvement on the rapid compensatory adrenal growth (CAG) and the individual adrenal growth (IAG) in rats. DESIGN: After surgery for left and sham adrenalectomy (Adx) carried out on either diestrus-2 (DE-2) or proestrus (PE), CAG and IAG were evaluated in PE or estrus (E), respectively. Hypothalamic dopaminergic activity was also assessed by measuring dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in DE-2, PE and E in controls and in PE and E in sham and left adrenalectomized rats. All groups experienced similar chronic emotional stress assessed by the emotional reactivity score recorded during vaginal screening. RESULTS: In controls, DOPAC levels in DE-2 were higher than in PE and E. In PE, following surgery in DE-2, DOPAC levels and DOPAC/DA ratio were increased compared to PE controls; CAG was not significant, while negative correlations of IAG and CAG with DOPAC/DA ratio were observed. In E, CAG and IAG were significant, while dopaminergic activity was not increased compared to E controls. CONCLUSIONS: The significant CAG and IAG following left Adx in PE but not in DE-2 suggest a pronounced positive impact of the hormonal milieu on this process. The profound attenuation of CAG and IAG in PE suggests a negative effect of stress-associated dopaminergic activation.

Evaluation of the influence of thermal oxidation on the phenolic composition and on the antioxidant activity of extra-virgin olive oils.

A comparison between the results obtained by using HPLC-UV, HPLC-MS, and CE-UV for characterizing the deterioration of extra-virgin olive oil during heating (180 degrees C) was investigated, taking into account phenolic compounds. The concentration of several compounds belonging to four families of phenols (simple phenols, lignans, complex phenols, and phenolic acids) was determined in the samples after the thermal treatment by all three techniques. Hydroxytyrosol, elenolic acid, decarboxymethyl oleuropein aglycon, and oleuropein aglycon reduced their concentration with the thermal treatment more quickly than other phenolic compounds present in olive oil. HYTY-Ac and Lig Agl were demonstrated to be quite resistant to this kind of treatment, and the behavior of lignans could be outstanding, as they belong to the family most resistant to thermal treatment. Several "unknown" compounds were determined in the phenolic profiles of the oils after the thermal treatment, and their presence was confirmed in refined olive oils. The oxidative stability index (OSI time) was reduced from 25 to 5 h after 3 h of heating, whereas the peroxide value showed a minimum after 1 h of heating.

Role of hypothalamic alpha-adrenoceptor activity in fructose-induced hypertension.

The aim of the present study was to investigate the effects of the alpha2-adrenoceptor antagonist yohimbine on blood pressure and heart rate (HR) regulation, as well as on adrenergic and serotoninergic neurotransmission, in fructose hypertensive (F) rats. The anterior hypothalamic area of control (C) and F rats was perfused with Ringer's solution containing 10 and 100 microg/mL yohimbine through a microdialysis concentric probe. The effects of yohimbine on mean arterial pressure (MAP) and HR, as well as on hypothalamic dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindole acetic acid (5-HIAA) levels, were measured according to perfusion time. Although intrahypothalamic perfusion of yohimbine increased blood pressure in C rats (DeltaMAP 9 +/- 1 and 11 +/- 2 mmHg for 10 and 100 microg/mL yohimbine, respectively; P < 0.05 vs Ringer's perfusion), the alpha-adrenoceptor antagonist did not modify MAP in F. Intrahypothalamic yohimbine had no effect on HR at either concentration tested. Intrahypothalamic perfusion of 10 and 100 microg/mL yohimbine increased DOPAC levels in C rats (135 +/- 6 and 130 +/- 5% of basal levels, respectively; both n = 6; P < 0.05 vs Ringer's perfusion), but not in F animals (115 +/- 6 and 102 +/- 6% of basal levels, respectively; both n = 6). In both C and F rats, yohimbine administration induced an increase in 5-HIAA dialysate levels. The results of the present study support the notion that alpha2-adrenoceptor tone of the anterior hypothalamus of normotensive rats, which contributes to normal blood pressure regulation, is not involved in the control of HR in either normotensive C or hypertensive F rats. The absence of changes in MAP after yohimbine perfusion in F rats suggests that the alpha2-adrenoceptor tone could be decreased in this group of rats and that this may be responsible for the maintenance of hypertension in this model. Intrahypothalamic perfusion of yohimbine increased DOPAC in the dialysate only in C rats, suggesting changes in presynaptic alpha2-adrenoceptor activity in fructose-overloaded rats. Conversely, increased 5-HIAA levels did not differ between C and F groups.

Of the major phenolic acids formed during human microbial fermentation of tea, citrus, and soy flavonoid supplements, only 3,4-dihydroxyphenylacetic acid has antiproliferative activity.

Dietary flavonoids are poorly absorbed from the gastrointestinal tract. Colonic bacteria convert flavonoids into smaller phenolic acids (PA), which can be absorbed into the circulation and may contribute to the chemopreventive activity of the parent compounds. The purpose of our study was to determine whether flavonoids from green and black tea (GT, BT), citrus fruit with rutin (CF+R) and soy (S) supplements exposed to the same conditions in a dynamic in vitro model of the colon (TIM-2) will form the same phenolic acid products of microbial metabolism. About 600 mg of flavonoids from GT, BT, CF+R and S extracts were infused at t = 0 and 12 h into the TIM-2. Samples from the lumen and dialysate were collected at t = 0,4,8,12,16,24 and 28h. The flavonoid and PA concentrations were measured by HPLC and GC-MS. GT, BT, and CF+R formed 3-methoxy-4-hydroxyphenylacetic acid (3M4HPAA), 4-hydroxyphenyl acetic acid (4HPAA), 3,4-dihydroxyphenylacetic acid (3,4DHPAA), and 3-(3-hydroxyphenyl) propionic acid (3,3HPPA). BT flavonoids were also metabolized to 2,4,6-trihydroxybenzoic acid (2,4,6THBA) and CF+R flavonoids to 3-(4-hydroxy-3-methoxyphenyl) propionic acid (3,4H3MPPA), 3-hydroxyphenyl acetic acid (3HPAA) and a small amount of hippuric acid. After S infusion, we found 3M4HPAA and 4HPAA only. Among these phenolic acids, only 3,4DHPAA exhibited antiproliferative activity in prostate and colon cancer cells. 3,4DHPAA was significantly (P < 0.005) more inhibitory in colon cancer cells (HCT116) compared with an immortalized normal intestinal epithelial cell line (IEC6). In summary, fermentation by intestinal microbes of GT, BT, C+R, and S flavonoids resulted in the conversion to the same major phenolic acids.

Antioxidative activity of 3,4-dihydroxyphenylacetic acid and caffeic acid in rat plasma.

The purpose of the present paper is to study and compare in vitro the inhibitory effect of 3,4-dihydroxyphenylacetic acid (DOPAC) and caffeic acid (CA) on lipid peroxidation in rat plasma. Rat plasma was oxidized at 37 degrees C by the radical initiators 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) or 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (MeO-AMVN). The consumption of endogenous alpha-tocopherol (alpha-TOH) and the accumulation of conjugated diene hydroperoxides were measured by high-performance liquid chromatography and by ultraviolet spectroscopy, respectively. Alpha-TOH was consumed at the same rate in the presence of 20 mM AAPH or 2 mM MeO-AMVN. DOPAC and CA suppressed the alpha-TOH consumption in a dose-dependent manner. A concentration of 50 microM of both phenolic acids was sufficient to induce a lag phase and to delay the rate of alpha-TOH consumption. The effect was more pronounced in rat plasma oxidation by AAPH than by MeO-AMVN. CA spared vitamin E more effectively than DOPAC in both oxidations. DOPAC and CA suppressed the formation of conjugated diene hydroperoxides. DOPAC and CA at concentration 50 microM suppressed alpha-TOH consumption during oxidation of soybean phosphatidylcholine (2.8 mM) multilamellar vesicles containing 15 microM alpha-TOH, in which the lipophilic initiator 2,2'-azobis (2,4-dimethylvaleronitrile) (6 mM) was incorporated. In conclusion, we demonstrated that DOPAC and CA in micromolar concentrations have antioxidant activity in rat plasma, a medium very close to the conditions in vivo, suggesting that supplementation with the phenolic acids will provide significant antioxidant protection.

Selective local action of angiotensin II on dopaminergic neurons in the rat hypothalamus in vivo.

Microdialysis was used to investigate whether angiotensin II modulates the basal and K+-induced release of endogenous noradrenaline, dopamine and their metabolites 3,4-dihydroxyphenylglycol (DOPEG) and 3,4-dihydroxyphenylacetic acid (DOPAC) from the anterior hypothalamus of the anaesthetized rat. The release of the amines was stimulated twice (ST1 and ST2) with either 50 mmol/l or 100 mmol/l K+. The release of each amine induced by K+ was reproducible and concentration-dependent. Angiotensin II when present in the perfusion fluid after ST1 at a concentration of 0.1 and 10 mumol/l (chosen after in vitro experiments had shown that the recovery of the peptide across the dialysis membrane was only 3.6%), had no significant effect on amine release. However, 10 mumol/l angiotensin II induced an immediate, significant increase in basal DOPAC outflow which reached a maximum of 89% in the 100 mmol/l K+ and 53% in the 50 mmol/l K+ experiments. No such effect was observed with DOPEG outflow. In a separate experimental series, addition of angiotensin II without a preceding K+ stimulation period did not significantly affect the outflow of the amines and metabolites. The results suggest that angiotensin II can selectively influence dopamine metabolism in the anterior hypothalamus in vivo but does not act locally to acutely facilitate the release of endogenous catecholamines from this brain area.