Flavonoids from Barnebydendron riedelii leaf extract mitigate thioacetamide-induced hepatic encephalopathy in rats: The interplay of NF-κB/IL-6 and Nrf2/HO-1 signaling pathways.

Phytochemical investigation of the butanol fraction (BUF) derived from the 70% aqueous methanolic leaf extract of Barnebydendron riedelii led to the isolation of three flavonoid glycosides; kaempferol-3-O-α-l-rhamnopyranosyl-(1 â†’ 6)-ß-d-glucopyranoside, quercetin-3-O-α-l-rhamnopyranosyl-(1 â†’ 6)-ß-d-galactopyranoside and quercetin-3-O-α-l-rhamnopyranosyl-(1 â†’ 6)-ß-d-glucopyranoside. Docking studies were fulfilled to validate the possible bio-properties of BUF toward nuclear factorkappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2). The protective role of BUF against behavioral, biochemical, molecular, histopathological and immunohistochemical alterations in thioacetamide (TAA)-induced hepatic encephalopathy in rats was investigated. The toxicological studies indicated that BUF was safe up to 2000 mg/kg bw. Prior to TAA intoxication, rats were orally treated with either BUF at multiple doses (70, 140 and 280 mg/kg bw) or lactulose (8 mL/kg bw) for 14 consecutive days. On the 13th and the 14th day, TAA (200 mg/kg bw/day) was intraperitoneally injected. The BUF significantly improved motor impairment, ameliorated cognitive deficits and attenuated TAA-induced hepatotoxicity. Moreover, BUF controlled the inflammatory processes by suppressing the hepatic inflammatory cytokine; interleukin-6 (IL-6) as well as its pro-inflammatory mediator; NF-κB supporting the molecular docking assessment. The brain neurotransmitters; dopamine, serotonin and noradrenaline, as well as ammonia levels were improved in BUF-treated TAA-intoxicated animals in a dose-dependent manner. Furthermore, BUF administration to TAA-intoxicated rats modulated the Nrf2 and heme oxygenase 1 (HO-1) genes expression in liver and brain tissues. The histological evaluation showed that pretreatment of TAA-intoxicated rats with BUF ameliorated the degenerative effects of TAA on liver and brain tissues as well as reduced the activation of cellular apoptotic marker; caspase-3 and glial fibrillary acidic protein (GFAP+) astrocytes. In conclusion, the observed hepato-neuroprotective effect of BUF is attributed to its flavonoidal content through its modulatory effects on of NF-κB/IL-6 and Nrf2/HO-1 signaling pathways.

LC-MS/MS combined with in vivo microdialysis sampling from conscious rat striatum for simultaneous determination of active constituents of Yuanhu- Baizhi herb pair and endogenous neurotransmitters: Application to pharmacokinetic and pharmacodynamic study.

The compatibility of Rhizoma Corydalis(Yuanhu,YH) and Radix Angelicae dahuricae (Baizhi,BZ) as a herb pair Yuanhu-Baizhi(YB) can produce synergistic analgesic effect. However, the underlying mechanism of this herb pair compatibility is not elucidated yet. A LC-MS/MS method combined with in vivo microdialysis sampling from awaken rats' striatum was developed to simultaneously quantitate three endogenous neurotransmitters, dopamine(DA), glutamate (Glu), and 5-hydroxytryptamine (5-HT), and nine components of Yuanhu-Baizhi herb pair in rats. The microdialysates were derivatizated with benzoyl chloride and analyzed on Agilent Poroshell 120EC-C18 column. The mobile phase consisted of aqueous solution with 0.05% formic acid and 2.0 mM ammonium formate (A), and acetonitrile (B) delivered at gradient elution. All the twelve analytes were quantified using an electrospray ionization tandem mass spectrometry in the selective reaction monitoring mode. The method was validated following FDA's guidance on bioanalytical validation. The standard curves were linear ( r2 > 0.991) over the corresponding concentration ranges. For three neurotransmitters, the intra-day and inter-day precision (RSD) were not greater than 14.9%, and the intra-day and inter-day accuracy (RE) ranged from -14.2∼ 7.2%. The LLOQ of 5-HT, DA and Glu were 0.50 nM, 0.50 nM and 20.00 nM, respectively. For nine components in Yuanhu-Baizhi herb pair, the intra-day and inter-day precision (RSD) were less than 15.0%, and the intra-day and inter-day accuracy (RE) ranged from -12.5 ∼14.8%. The novel developed method was applied to pharmacokinetic (PK) and pharmacodynamic (PD) study of Yuanhu-Baizhi herb pair in rats. The results showed that the pharmacokinetic behavior of nine components in the herb pair was significantly different with that of single herb, mainly referring to the bioavailability of five alkaloids from Yuanhu increased whereas that of four coumarins decreased in rat striatum. Pharmacodynamic study based on Glu, DA, and 5-HT revealed that the content of neurotransmitters varied when rats were administered Yuanhu-Baizhi herb pair or single herb. PD analysis results demonstrated the compatibility of Yuanhu and Baizhi has the synergistic effect and the effect of attenuation from the point of the neurotransmitters' view. In conclusion, the pharmacokinetic and pharmacodynamic study based on in vivo microdialysis sampling from awaken animals and LC-MS/MS quantitation is in favor of revealing the compatibility mechanism of herb pairs.

Neuromodulatory effects of ethyl acetate fraction of Zingiber officinale Roscoe extract in rats with lead-induced oxidative stress.

OBJECTIVE: This study investigated the ameliorative potential of Zingiber officinale Roscoe extract against lead-induced brain damage in rats. METHODS: Thirty male rats were divided into 5 groups of 6 rats each. Lead-acetate toxicity was induced by intraperitoneal injection (10 mg/kg body weight (b.w.)) in Groups B-E. Group A (control) and Group B (lead-acetate) were left untreated; vitamin C (200 mg/kg b.w.) was administered to Group C; ethyl acetate fraction from Z. officinale extract (200 and 100 mg/kg b.w.) was administered to Group D and E by oral gavage once daily for 7 days. Changes in the content of some key marker enzymes such as acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO), epinephrine, dopamine, Na+/K+-ATPase, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) as well as malonaldehyde (MDA) levels were determined in serum. RESULTS: Exposure to lead acetate resulted in a significant decrease (P < 0.05) in the activities of BChE, AChE, Na+/K+-ATPase, SOD, CAT and GPx with a corresponding increase in the levels of MDA, xanthine oxidase, epinephrine, dopamine and MAO relative to the control group. Levels of all disrupted parameters were alleviated by co-administration of Z. officinale fraction and by the standard drug, vitamin C. CONCLUSION: These results suggest that ethyl acetate fraction of Z. officinale extract attenuates lead-induced brain damage and might have therapeutic potential as a supplement that can be applied in lead poisoning.

Methanol extract of Nigella sativa seed induces changes in the levels of neurotransmitter amino acids in male rat brain regions.

CONTEXT: Nigella sativa L. (Ranunculaceae) (NS) has been used for medicinal and culinary purposes. Different parts of the plant are used to treat many disorders. OBJECTIVE: This study investigates the effects of NS methanol extract on brain neurotransmitter amino acid levels. MATERIALS AND METHODS: We measured the changes in aspartate, glutamate, glycine and γ-aminobutyric acid in five brain regions of male Wistar rats after methanol extract treatment. Animals were injected intraperitoneally with saline solution (controls) or NS methanol extract (equivalent of 2.5 g/kg body weight) and sacrificed 1 h later or after administering 1 daily dose for 8 days. The neurotransmitters were measured in the hypothalamus, cortex, striatum, hippocampus and thalamus by HPLC. RESULTS AND DISCUSSION: Results showed significant changes in amino acids compared to basal values. Glutamate increased significantly (16-36%) in the regions analyzed except the striatum. Aspartate in the hypothalamus (50 and 76%) and glycine in hippocampus (32 and 25%), thalamus (66 and 29%) and striatum (75 and 48%) also increased with the two treatment intervals. γ-Aminobutyric acid significantly increased in the hippocampus (38 and 32%) and thalamus (22 and 40%) but decreased in the cortex and hypothalamus although in striatum only after eight days of treatment (24%). CONCLUSION: Our results suggest that injected methanol extract modifies amino acid levels in the rat brain regions. These results could be of interest since some neurodegenerative diseases are related to amino acid level imbalances in the central nervous system, suggesting the prospect for therapeutic use of NS against these disorders.

Effect of fractionated extracts and isolated pure compounds of Spondias mombin (L. Anacardiaceae) leaves on novelty-induced rearing and grooming behaviours in mice.

This study attempted to elucidate the neurotransmitter systems involved in the neurophysiological properties of ethanolic extract, fractions and pure isolates of Spondias mombin leaves in mice (n = 6) after intraperitoneal (i.p.) route of administration.The crude ethanolic extract of Spondian mombin leaves was fractionated using the partitioning method to obtain the ethylacetate, butanolic and aqueous fractions. Open column chromatographic fractionation of the ethylacetate fraction yielded seven sub-fractions, out of which the pure coumaroyl, quercetin and gallic acid derivatives were obtained after purification on Sephadex LH 20. The ethanolic extract, butanolic fraction, ethylacetate subfractions and pure isolates of the Spondian mombin leaves were tested on novelty-induced rearing and grooming behaviours in mice with standard pharmacological tools using the open field method. The extract and its fractions decreased novelty-induced rearing in a dose-dependent manner. While the Coumaroyl derivative had no effect on novelty-induced rearing, it significantly reversed the inhibitory effect of yohimbine, propranolol and haloperidol on novelty-induced rearing. Quercetin significantly potentiated the inhibitory effect of yohimbine on novelty-induced rearing. Naloxone significantly potentiated the quercetin-induced suppression of novelty-induced rearing. Gallic acid derivative significantly potentiated the inhibitory effect of yohimbine on novelty-induced rearing. Naloxone, atropine and haloperidol pretreatments significantly potentiated gallic acid derivative-induced suppression of novelty-induced rearing.The extract and its fractions had biphasic effect on novelty-induced grooming in mice. Coumaroyl derivative significantly increased novelty-induced grooming, while quercetin and gallic acid derivative decreased novelty-induced grooming significantly. The three pure isolates significantly reversed the effects of yohimbine and atropine on the novelty-induced grooming in mice. Propranolol-induced increase in novelty-induced grooming was significantly reversed by coumaroyl and gallic acid derivatives. Pre-treatment with naloxone significantly increased the gallic acid derivative-induced suppression of novelty-induced grooming. Pre-treatment with haloperidol reversed the effect of coumaroyl derivative and potentiated the inhibitory effect of quercetin derivative and gallic acid derivative significantly. This study suggested that adrenergic and dopaminergic neuro-transmissions are strongly involved in the neural mechanisms of the effect of the three pure isolates derivative, while opioid neuro-transmission is strongly linked with the neural mechanism of behavioural effect of coumaroyl derivative.

Bioactivity guided isolation of antipsychotic constituents from the leaves of Rauwolfia tetraphylla L.

This study was undertaken to ascertain the antipsychotic properties of Rauwolfia tetraphylla L. leaves and to isolate and characterize the antipsychotic constituents. Among the MeOH extract and some alkaloidal fractions at different pHs, the alkaloidal CHCl(3) fraction at pH-9 (2C) showed the highest antipsychotic activity against dopaminergic (DA-D(2)) and serotonergic (5-HT(2A)) receptors in-vitro and amphetamine induced hyperactive mouse model in-vivo. The activity guided isolation of CHCl(3) fraction (2C) afforded six indole alkaloids: 10-methoxytetrahydroalstonine (1), isoreserpiline (2), an isomeric mixture of 11-demethoxyreserpiline (3) and 10-demethoxyreserpiline (4), α-yohimbine (5) and reserpiline (6). Given orally, alkaloids 3-6 showed significant antipsychotic activity in a dose dependent manner. None of the extract, alkaloidal fractions or alkaloids showed any extra pyramidal symptoms at the tested doses. It was also observed that MeOH extract was behaving similar to other clinically used novel atypical antipsychotics in having 5-HT(2A) occupancy greater than the DA-D(2) receptor at the tested doses. Further toxicity and safety evaluation studies of MeOH extracts of R. tetraphylla leaves at different doses (10, 100, 300 and 2000 mg/kg) on female Swiss albino mice showed that MeOH extract is non toxic. The isolated alkaloids, 3-6 could serve as a promising lead structure for drug development of treating psychotic conditions in human.

Actions of Artemisia vulgaris extracts and isolated sesquiterpene lactones against receptors mediating contraction of guinea pig ileum and trachea.

AIM OF THE STUDY: The present study evaluates the Philippine medicinal plant Artemisia vulgaris for antagonistic activity at selected biogenic amine receptors on smooth muscle of the airways and gastrointestinal tract in order to explain its traditional use in asthma and hyperactive gut. MATERIALS AND METHODS: The antagonistic activity of chloroform crude extract (AV-CHCl(3)) and methanol crude extract (AV-MeOH) of Artemisia vulgaris was studied against concentration-response curves for contractions of the guinea pig ileum and trachea to 5-hydroxytrptamine (5-HT(2) receptors), methacholine (M(3) muscarinic receptors), histamine (H(1) receptors) and ß-phenylethylamine (trace amine-associated receptors, TAAR1). RESULTS AND DISCUSSION: The Artemisia vulgaris chloroform (AV-CHCl(3)) and methanol (AV-MeOH) extract showed histamine H1 antagonism in the ileum and trachea. Further analysis of AV-CHCl(3) isolated two major components, yomogin and 1,2,3,4-diepoxy-11(13)-eudesmen-12,8-olide. Yomogin, a sesquiterpene lactone, exhibited a novel histamine H1 receptor antagonism in the ileum. CONCLUSION: The presence of a specific, competitive histamine receptor antagonist and smooth muscle relaxant activity in Artemisia vulgaris extracts on the smooth muscle in ileum and trachea explains its traditional use in the treatment of asthma and hyperactive gut.

Monoamine levels in rat striatum after acute intraperitoneal injection of strictosidinic acid isolated from Psychotria myriantha Mull. Arg. (Rubiaceae).

Strictosidinic acid 10mg/kg, isolated from Psychotria myriantha leaves, were administered intraperitoneally to Wistar male rats (n=5-6). After 60 minutes, striatum was dissected, homogenized and injected onto HPLC-ED chromatographic system. It was observed a 28.7% reduction in the 5-HT levels followed up by an increase of 5-HIAA levels (29.4%). Furthermore there was a decrease of 8.0% in DA levels and an increase in the levels of metabolites DOPAC (21.5%) and HVA (52.5%). The results indicate that strictosidinic acid has a promising effect in the central nervous system, justifying more studies about the central actions of Psychotria compounds.

Identification of SYWKQCAFNAVSCFamide: a broadly conserved crustacean C-type allatostatin-like peptide with both neuromodulatory and cardioactive properties.

The allatostatins comprise three structurally distinct peptide families that regulate juvenile hormone production by the insect corpora allata. A-type family members contain the C-terminal motif -YXFGLamide and have been found in species from numerous arthropod taxa. Members of the B-type family exhibit a -WX(6)Wamide C-terminus and, like the A-type peptides, appear to be broadly conserved within the Arthropoda. By contrast, members of the C-type family, typified by the unblocked C-terminus -PISCF, a pyroglutamine blocked N-terminus, and a disulfide bridge between two internal Cys residues, have only been found in holometabolous insects, i.e. lepidopterans and dipterans. Here, using transcriptomics, we have identified SYWKQCAFNAVSCFamide (disulfide bridging predicted between the two Cys residues), a known honeybee and water flea C-type-like peptide, from the American lobster Homarus americanus (infraorder Astacidea). Using matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS), a mass corresponding to that of SYWKQCAFNAVSCFamide was detected in the H. americanus brain, supporting the existence of this peptide and its theorized structure. Furthermore, SYWKQCAFNAVSCFamide was detected by MALDI-FTMS in neural tissues from five additional astacideans as well as 19 members of four other decapod infraorders (i.e. Achelata, Anomura, Brachyura and Thalassinidea), suggesting that it is a broadly conserved decapod peptide. In H. americanus, SYWKQCAFNAVSCFamide is capable of modulating the output of both the pyloric circuit of the stomatogastric nervous system and the heart. This is the first demonstration of bioactivity for this peptide in any species.

Neurotransmitters extraction by local intracerebral dialysis in anesthetized rats.

A new technique for in vivo neurotransmitter extraction was developed. Perfusion U shaped cannulae were chronically implanted in the caudate or the thalamus of rats. A segment of the cannula was a piece of dialysis tube of molecular weight cut off 1000. Measurable amounts of dopamine and norepinephrine were recovered from the perfusion fluid. Intraperitoneal amphetamine 10 mg/kg increased dopamine output from the caudate but not from the thalamus. The potential applications of this technique are discussed.