Protoberberine alkaloids: A review of the gastroprotective effects, pharmacokinetics, and toxicity.

BACKGROUND: Stomach diseases have become global health concerns. Protoberberine alkaloids (PBAs) are a group of quaternary isoquinoline alkaloids from abundant natural sources and have been shown to improve gastric disorders in preclinical and clinical studies. The finding that PBAs exhibit low oral bioavailability but potent pharmacological activity has attracted great interest. PURPOSE: This review aims to provide a systematic review of the molecular mechanisms of PBAs in the treatment of gastric disorders and to discuss the current understanding of the pharmacokinetics and toxicity of PBAs. METHODS: The articles related to PBAs were collected from the Web of Science, Pubmed, and China National Knowledge Infrastructure databases using relevant keywords. The collected articles were screened and categorized according to their research content to focus on the gastroprotective effects, pharmacokinetics, and toxicity of PBAs. RESULTS: Based on the results of preclinical studies, PBAs have demonstrated therapeutic effects on chronic atrophic gastritis and gastric cancer by activating interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (STAT6) pathway and suppressing transforming growth factor-beta 1 (TGF-ß1)/phosphoinositide 3-kinase (PI3K), Janus kinase-2 (JAK2)/signal transducers and activators of transcription 3 (STAT3), and mitogen-activated protein kinase (MAPK) pathways. The major PBAs exhibit similar pharmacokinetic properties, including rapid absorption, slow elimination, and low bioavailability. Notably, the natural organ-targeting property of PBAs may account for the finding of their low blood levels and high pharmacological activity. PBAs interact with other compounds, including conventional drugs and natural products, by modulation of metabolic enzymes and transporters. The potential tissue toxicity of PBAs should be emphasized due to their high tissue accumulation. CONCLUSION: This review highlights the gastroprotective effects, pharmacokinetics, and toxicity of PBAs and will contribute to the evaluation of drug properties and clinical translational studies of PBAs, accelerating their transfer from the laboratory to the bedside.

Dietary gallic acid as an antioxidant: A review of its food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions.

Gallic acid (GA), a dietary phenolic acid with potent antioxidant activity, is widely distributed in edible plants. GA has been applied in the food industry as an antimicrobial agent, food fresh-keeping agent, oil stabilizer, active food wrap material, and food processing stabilizer. GA is a potential dietary supplement due to its health benefits on various functional disorders associated with oxidative stress, including renal, neurological, hepatic, pulmonary, reproductive, and cardiovascular diseases. GA is rapidly absorbed and metabolized after oral administration, resulting in low bioavailability, which is susceptible to various factors, such as intestinal microbiota, transporters, and metabolism of galloyl derivatives. GA exhibits a tendency to distribute primarily to the kidney, liver, heart, and brain. A total of 37 metabolites of GA has been identified, and decarboxylation and dihydroxylation in phase I metabolism and sulfation, glucuronidation, and methylation in phase Ⅱ metabolism are considered the main in vivo biotransformation pathways of GA. Different types of nanocarriers, such as polymeric nanoparticles, dendrimers, and nanodots, have been successfully developed to enhance the health-promoting function of GA by increasing bioavailability. GA may induce drug interactions with conventional drugs, such as hydroxyurea, linagliptin, and diltiazem, due to its inhibitory effects on metabolic enzymes, including cytochrome P450 3A4 and 2D6, and transporters, including P-glycoprotein, breast cancer resistance protein, and organic anion-transporting polypeptide 1B3. In conclusion, in-depth studies of GA on food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions have laid the foundation for its comprehensive application as a food additive and dietary supplement.

Brazilin-Ce nanoparticles attenuate inflammation by de/anti-phosphorylation of IKKß.

Inflammation is associated with a series of diseases like cancer, cardiovascular disease and infection, and phosphorylation/dephosphorylation modification of proteins are important in inflammation regulation. Here we designed and synthesized a novel Brazilin-Ce nanoparticle (BX-Ce NPs) using Brazilin, which has been used for anti-inflammation in cardiovascular diseases but with narrow therapeutic window, and Cerium (IV), a lanthanide which has the general activity in catalyzing the hydrolysis of phosphoester bonds, to conferring de/anti-phosphorylation of IKKß. We found that BX-Ce NPs specifically bound to Asn225 and Lys428 of IKKß and inhibited its phosphorylation at Ser181, contributing to appreciably anti-inflammatory effect in cellulo (IC50 = 2.5 µM). In vivo mouse models of myocardial infarction and sepsis also showed that the BX-Ce NPs significantly ameliorated myocardial injury and improved survival in mice with experimental sepsis through downregulating phosphorylation of IKKß. These findings provided insights for developing metal nanoparticles for guided ion interfere therapy, particularly synergistically target de/anti-phosphorylation as promising therapeutic agents for inflammation and related diseases.

Sinapis Semen: A review on phytochemistry, pharmacology, toxicity, analytical methods and pharmacokinetics.

Sinapis Semen (SS), the dried mature seed of Sinapis alba L. and Brassica juncea (L.) Czern. et Coss., is one of the traditional Chinese medicinal materials with a wide range of pharmacological effects being used for asthma, cough and many other ailments. SS is also widely used in food agriculture, medicine and other industries in North America and South Asia. More recently, the research on SS has gradually intensified and increased. However, there is no systematic review of SS. In this review, through literature exploration and analysis, the research advance on phytochemistry, pharmacology, toxicity, analytical methods and pharmacokinetics of SS was aggregated initially. Total 144 compounds have been isolated and identified from SS. Among them, glucosinolates and their hydrolysates and volatile oils are the main active ingredients and important chemical classification markers. SS has a wide range of pharmacological effects, especially in cough suppressing, asthma calming, anti-inflammatory, neuroprotective, cardiovascular protective, inhibiting androgenic effects, anti-tumor, and skin permeation promoting effects. Sinapine and sinapic acid are the main active ingredients of SS for its medicinal effects. However, SS has a strong skin irritation, presumably related to the time of application, the method of processing, and original medicinal plants. This review will provide useful data for the follow-up research and safe and reasonable clinical application of SS.

The in vitro/in vivo metabolic pathways analysis of lobetyol, lobetyolin, and lobetyolinin, three polyacetylenes from Codonopsis Radix, by UHPLC-Q/TOF-MS and UHPLC-MS/MS.

Polyacetylenes, lobetyol, lobetyolin and lobetyolinin, are responsible for antitumor, antioxidant, anti-inflammatory, immunomodulatory activities of Codonopsis Radix. However, their metabolic pathways are still unknown. The study was purposed to investigate the metabolism of three polyacetylenes in vitro and in vivo by ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. Moreover, a rapid, sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometry method was developed for the simultaneous quantitative and semi-quantitative determination of lobetyol and its 12 metabolites to investigate the metabolic stability and metabolic phenotypes. A total of 47, 30 and 34 metabolites of lobetyol, lobetyolin and lobetyolinin were found in all samples. These metabolites are produced through extensive pathways, mainly involving oxidation, glucuronidation and glutathione conjugation. Lobetyol showed good metabolic stability in liver microsomes. The results of both recombinant human CYP enzymes and chemical inhibition experiments confirmed that CYP2C19, 1A1, 2C9, and 1A2 are the major isozymes mediating lobetyol metabolism.

Simultaneous determination of cordycepin and its metabolite 3'-deoxyinosine in rat whole blood by ultra-high-performance liquid chromatography coupled with Q Exactive hybrid quadrupole orbitrap high-resolution accurate mass spectrometry and its application to accurate pharmacokinetic studies.

Cordycepin from Cordyceps possesses excellent pharmacological properties, including anti-inflammation and anti-tumor effects, therefore representing a potential alternative medicine. However, doubts about the pharmacokinetic results of cordycepin had been raised in the previous study due to its rapid deamination. The organic solvent methanol was immediately added to terminate the degradation of cordycepin in anticoagulated blood samples and enable the accurate evaluation of pharmacokinetics in vivo. A sensitive and selective ultra-high-performance liquid chromatography coupled with Q Exactive hybrid quadrupole orbitrap high-resolution accurate mass spectrometry method was developed and validated to simultaneously determine cordycepin and its deamination metabolite 3'-deoxyinosine using 2-chloroadenosine as an internal standard in rat whole blood. The calibration curves of cordycepin and 3'-deoxyinosine showed excellent linearity within the concentration range of 1.05-10 000.00 ng/ml with acceptable accuracy, precision, selectivity, recovery, matrix effect, and stability. This method was successfully applied to the pharmacokinetic study of cordycepin and its metabolite in rat blood. The effect of the adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride on the pharmacokinetics of cordycepin was investigated. In summary, the reliable pharmacokinetic parameters of cordycepin and its deamination metabolite 3'-deoxyinosine in rat blood were successfully elucidated. Erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride considerably prolonged the half-life of cordycepin in vivo.

Biotransformation patterns of dictamnine in vitro/in vivo and its relative molecular mechanism of dictamnine-induced acute liver injury in mice.

Dictamnine (DIC), a typical furan-quinoline alkaloid, has a wide range of pharmacological and toxicological effects, such as anti-bacterial, antifungal, anti-cancer, and hepatoxicity. But the molecular mechanism of DIC-induced hepatoxicity in mice remains unclear. This study aimed to clarify the biotransformation patterns of DIC in vitro/in vivo and the relative molecular mechanism of DIC-induced hepatoxicity in mice. All metabolites of DIC were identified by comparing the blank and drug-containing urine, feces, plasma, and liver samples. The structure of epoxide intermediate derived from DIC was confirmed by trapping assay. Oxidative stress injury and inflammation have been confirmed to be involved in the toxicological process of DIC-induced hepatoxicity in mice by detecting the relative biochemical indexes. The results will help to develop a deeper understanding about the biotransformation patterns of DIC, structure of the epoxide intermediate, and the molecular mechanism of DIC-induced hepatoxicity in mice.

Pharmacokinetic studies of ginsenosides Rk1 and Rg5 in rats by UFLC-MS/MS.

A rapid ultra-fast liquid chromatography tandem mass spectrometry method was developed and validated to determine ginsenosides Rk1 and Rg5, a pair of isomers, in rat plasma, which was successfully applied to their pharmacokinetic studies. Two ginsenosides were given to male Sprague-Dawley rats via intragastrical and intravenous routes, respectively, and the impact of double bond position on the pharmacokinetic features of the two ginsenosides was elucidated in rats. Ginsenoside Rg3 was used as internal standard and ethyl acetate was applied to extract analytes and internal standard. Chromatographic separation was carried out on a reverse-phase UPLC HSS T3 column (100 × 2.1 mm, 1.8 µm). The flow rate was set to 0.4 ml/min. The fragmentation transition was m/z 765.4 → m/z 101.1 for two ginsenosides. The mobile phases were composed of 0.1% formic acid aqueous solution and acetonitrile. The linear range was 2-1,000 ng/ml for the two ginsenosides. Intra- and inter-day precisions were <11.67%, and accuracy fluctuated from -7.44 to 6.78%. The extraction recovery, matrix effect and stability were within acceptable levels. After treatment with ginsenosides Rk1 and Rg5, some differences were found in their pharmacokinetic profiles in rats. The maximum plasma drug concentration and the area under the plasma drug concentration-time curve of ginsenoside Rg5 were about 5 times bigger than those of ginsenoside Rk1 after oral administration, and 3 times higher after intravenous administration. The oral bioavailabilities of ginsenosides Rk1 and Rg5 were 0.67 and 0.97%, respectively. The results indicated that ∆20(22) -ginsenosides showed better pharmacokinetic features than ∆20(21) -ginsenosides with the same glycosylation.

Identification of lusianthridin metabolites in rat liver microsomes by liquid chromatography combined with electrospray ionization time-of-flight mass spectrometry.

Lusianthridin, a bioactive component isolated from Dendrobium venustum, has been demonstrated to have many biological properties such as antioxidant and anticancer activities. However, the metabolic profiles remain unknown. This study was carried out to investigate the metabolic profiles of lusianthridin in liver microsomes. Lusianthridin was co-incubated with liver microsomes in the presence of nicotinamide adenine dinucleotide phosphate and UDP-glucuronic acid or glutathione at 37°C for 1 h. The incubation samples were analyzed by liquid chromatography combined with electrospray ionization high-resolution mass spectrometry. The data were acquired and processed. The structures of the metabolites were proposed by comparing their accurate mass and MS2 spectra with those of the parent compound. A total of 15 metabolites were detected in vitro, including two phase I and 13 phase II metabolites. The phase I metabolic pathways were oxidation, demethylation and dehydrogenation. The phase II metabolic pathways referred to glucuronidation and glutathione conjugation. The present study provides an overview pertaining to the metabolic profiles of lusianthridin in vitro, which is indispensable for understanding the efficacy and safety of lusianthridin, as well as the herbal medicine D. venustum.

Pharmacokinetic, bioavailability, and metabolism studies of lusianthridin, a dihydrophenanthrene compound, in rats by liquid chromatography/electrospray ionization tandem mass spectrometry.

Lusianthridin was reported to possess many biological properties such as anti-oxidant and anti-cancer activities. However, its metabolic profiles and pharmacokinetics in vivo remain unknown. This study was carried out to investigate the metabolic profiles and pharmacokinetics of lusianthridin in rats. The metabolic profiles were obtained by an ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). A total of eighteen metabolites involved three phase I metabolites and fifteen phase II metabolites were detected and identified. The major metabolic pathways of lusianthridin were demethylation, oxidation, sulfation, glucuronidation and glutathione conjugation. In addition, a simple and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established for determination of lusianthridin in rat plasma. After extracted by protein precipitation, lusianthridin was quantitated in positive ion mode. The method was linear over the range of 0.5-500 ng/mL (r ≥ 0.995) with the LLOQ of 0.5 ng/mL. The intra- and inter- precision and accuracy, extraction recovery, matrix effect and stability were within the acceptable limits. The validated method was applied to the pre-clinical pharmacokinetic study of lusianthridin in rats. After oral administration, lusianthridin was quickly absorbed into plasma and reached the max concentration of 236.22 ng/mL at 22.00 min. The elimination half life of lusianthridin from plasma was approximately 83.05-104.47 min and the oral absolute bioavailability was calculated as 30.93 %.

Metabolites identification and reversible interconversion of chelerythrine and dihydrochelerythrine in vitro/in vivo in rats using ultra-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

Chelerythrine (CHE) and dihydrochelerythrine (DHCHE), two typical benzophenanthridine alkaloids, have a wide range of pharmacological activities, such as antibacterial, anti-tumour and antiparasitic activities. To date, the biological activities of CHE and DHCHE are well reported, but the biotransformation of CHE and DHCHE in vivo remains unknown. This study aims to clarify the metabolic pathway of CHE and DHCHE in rat liver microsomes (RLMs) in vitro and in vivo. An ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC/ESI-QTOF-MS) method was developed for metabolites identification of CHE and DHCHE. The urine, feces, bile, and plasma samples and RLMs samples were collected for analyzing the biotransformation pathway of CHE and DHCHE. The result showed that there is a phenomenon of mutual reversible interconversion between CHE and DHCHE in vivo and in vitro. The other biotransformation pathways of CHE and DHCHE including demethylation, hydroxylation, methylene dioxy cycle opening, and glucuronidation mainly occurred in the side chain of benzophenanthridine parent structure. Twenty-five phase I and eight phase II metabolites of CHE, twenty-two phase I and eight phase II metabolites of DHCHE were detected. The results will help to develop a deeper understanding of CHE and DHCHE in vivo process and provide some references for the biotransformation research of other benzophenanthridine alkaloids.

Rapid identification and pharmacokinetic studies of multiple active alkaloids in rat plasma through UPLC-Q-TOF-MS and UPLC-MS/MS after the oral administration of Zanthoxylum nitidum extract.

Zanthoxylum nitidum (Roxb.) DC. (ZN) belongs to the genus Zanthoxylum of Rutaceae and has various chemical ingredients and pharmacologic effects. Alkaloids are its main active constituents responsible for diverse pharmacologic effects, such as anti-tumor, anti-bacterial, anti-inflammatory, and analgesic activities. The chemical and pharmacological effects of ZN are well reported, but the in vivo pharmacokinetic profiles of its main active alkaloids are poorly investigated. This study aims to elucidate the absorbed constituents and pharmacokinetic behavior of main active ingredients in rat plasma after the oral administration of ZN extract. The absorbed constituents in rat plasma were qualitatively analyzed using ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Ultra-high-performance liquid chromatography with triple quadrupole mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination and pharmacokinetic studies of dihydrochelerythrine (DHCHE), nitidine chloride (NIT), chelerythrine (CHE), sanguinarine (SAN), liriodenine (LIR), skimmianine (SKI), γ-fagarine (FAG), and dictamnine (DIC) in rat plasma. Eighteen prototypes and metabolites were identified according to exact mass, characteristic diagnostic fragment ions, and reference standards. The established UPLC-MS/MS quantitative method met the requirements of FDA for biological analysis methods. Method validation showed that this method has good linearity (r ≥ 0.9910), precision (RSD ≤ 18.63 %), accuracy (88.11 %-117.50 %), and stability. The limit of detection (LOD) could reach 1 ng/mL, and the limit of quantitation could reach 2 ng/mL. The plasma drug concentration of benzophenanthridine alkaloids, such as NIT, CHE, and DHCHE, were still low even after dose differences were deducted. For the furan quinoline alkaloids (such as SKI, FAG, and DIC), only SKI showed high plasma drug concentration, although SKI content comprised only approximately 1/6 of benzophenanthridine alkaloids. This study is the first to simultaneously determine the above-mentioned active alkaloids in rat plasma and would contribute to the comprehensive understanding of in vivo pharmacokinetic behavior on active alkaloids in ZN extract.

A rapid assay to screen adenosine deaminase inhibitors from Ligustri Lucidi Fructus against metabolism of cordycepin utilizing ultra-high-performance liquid chromatography-tandem mass spectrometry.

Cordycepin has recently received increased attention owing to its extensive pharmacological activity. Adenosine deaminase (ADA) is widely distributed in mammalian blood and tissues; as a result, cordycepin is quickly metabolized upon entering into the body and converted into the inactive metabolite 3'-deoxyinosine, thus limiting its activity when administered alone. We herein present a novel ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for screening ADA inhibitors against the metabolism of cordycepin. Cordycepin and 3'-deoxyinosine were chosen as substrate and product, respectively. A proper separation was achieved for all analytes within 3 min. 3'-Deoxyinosine was quantified in the presence or absence of potential ADA inhibitors to evaluate ADA activity. The assay can simultaneously determine substrate and product, with the endogenous substance and ADA inhibitors added not interfering in its activity. After optimizing the enzymatic incubation and UHPLC-MS/MS conditions, Km and Vmax values for ADA deamination of cordycepin were 95.18 ± 7.85 µm and 363.90 ± 12.16 µmol/min/unit, respectively. Oleanolic acid and ursolic acid from Ligustri Lucidi Fructus were chosen as ADA inhibitors with half maximal inhibitory concentration values of 21.82 ± 0.39 and 18.41 ± 0.14 µm, respectively. A non-competitive inhibition model was constructed and this assay can be used to screen other potential ADA inhibitors quickly and accurately.

Ameliorative effect of deoxyvasicine on scopolamine-induced cognitive dysfunction by restoration of cholinergic function in mice.

BACKGROUND: Aerial parts of Peganum harmala Linn is used as a traditional medical herb for treatment of amnesia in Uighur medicine in China. Deoxyvasicine (DVAS) is one of the chief active ingredients in P. harmala, it possesses strong acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in vitro, but the therapeutic effect and mechanisms on amnesia in vivo are unclear. PURPOSE: The objective of this study was to investigate the improvement effect of DVAS from P. harmala in learning and memory deficits of scopolamine-induced mice and elucidate the underlying mechanisms involved. METHODS: Mice were pretreated with DVAS (5, 15 and 45 mg/kg) and huperzine-A (0.2 mg/kg) by gavage for 7 days, and subsequently were daily intraperitoneally injected with scopolamine (1 mg/kg) to induce learning and memory deficits and behavioral performance was assessed by Morris water maze. To further evaluate the potential mechanisms of DVAS in improving learning and memory capabilities, pathological change, levels of various biochemical markers and protein expressions related to cholinergic system, oxidative stress, and neuroinflammation were examined. RESULTS: The results showed that DVAS could alleviate learning and memory deficits in scopolamine-treated mice. DVAS could regulate cholinergic function by inhibiting AChE and activating choline acetyltransferase (ChAT) activities and protein expressions. DVAS could induce brain-derived neurotrophic factor and protect hippocampal pyramidal cells against neuronal damage. DVAS also enhanced antioxidant defense via increasing the antioxidant enzyme level and activity of glutathione peroxidase, and anti-inflammatory function through suppressing tumor necrosis factor-α. Additionally, DVAS could regulate the neurotransmitters by elevating acetylcholine, 5-hydroxytryptamine, γ-aminobutyric acid and reducing 5-hydroxyindole-3-acetic acid and glutamic acid. CONCLUSION: Results illustrated that DVAS may be a promising candidate compound against amnesia via restoration of cholinergic function, regulating neurotransmitters, attenuating neuroinflammation and oxidative stress.

Long-term diosbulbin B treatment induced liver fibrosis in mice.

Airpotato yam is a traditional Chinese medicine used for treating thyroid disease and cancer in China. Diosbulbin B (DB) is reported to be the main hepatotoxic compound isolated from Airpotato yam. A variety of reports have shown the acute liver injury induced by DB in vivo. However, whether long-term administration of DB will cause liver fibrosis in mice is unknown. This study aims to investigate the liver fibrosis induced by long-term DB treatment in mice. C57BL/6 mice were orally given with DB (25, 50 mg/kg) for 1 or 2 month, respectively. Liver hydroxyproline content, hepatic collagen deposition and immune cells infiltration were increased in mice treated with DB (50 mg/kg) for 2 months. Serum amounts of hyaluronic acid and laminin were increased in mice treated with DB for 1 or 2 months. DB (50 mg/kg) induced hepatic stellate cells (HSCs) activation when mice were treated with DB for 2 months. Liver mRNA expression of Col1a1, Col1a2, Col3a1, fibronectin (Fn1), vimentin (Vim) and fibroblast-specific protein 1 (FSP1) were all increased in DB-treated mice. Hepatic protein expression of Vim, FSP1 and collagen 1 (COL1) were increased in DB-treated mice. Additionally, DB induced nuclear factor κB (NFκB) activation and increased the expression of pro-inflammatory molecules including tumor necrosis factor (TNF)-α, interleukin (IL)-6, intercellular cell adhesion molecule-1 (ICAM-1) and inducible nitric oxide synthase (iNOS) in mice. In conclusion, long-term administration of DB induced liver fibrosis in mice. HSCs activation, epithelial-mesenchymal transition (EMT) and liver inflammation contributed to DB-induced liver fibrosis in mice.

Buyang Huanwu Decoction Attenuates Infiltration of Natural Killer Cells and Protects Against Ischemic Brain Injury.

BACKGROUND/AIMS: Natural killer (NK) cells are among the first immune cells that respond to an ischemic insult in human brains. The infiltrated NK cells damage blood-brain barrier (BBB) and exacerbate brain infarction. Buyang Huanwu Decoction (BHD), a classic Chinese traditional herbal prescription, has long been used for the treatment of ischemic stroke. The present study investigated whether BHD can prevent brain infiltration of NK cells, attenuate BBB disruption and improve ischemic outcomes. METHODS: Transient focal cerebral ischemia was induced in rats by a 60-minute middle cerebral artery occlusion, and BHD was orally administrated at the onset of reperfusion, 12 hours later, then twice daily. Assessed parameters on Day 3 after ischemia were: neurological and motor functional deficits through neurological deficit score and rotarod test, respectively; brain infarction through TTC staining; BBB integrity through Evans blue extravasation; matrix metalloproteinase-2/9 activities through gelatin zymography; tight junction protein, nuclear factor-kB (NF-kB) p65 and phospho-p65 levels through Western blotting; NK cell brain infiltration and CXCR3 levels on NK cells through flow cytometry; interferon-γ production through ELISA; CXCL10 mRNA levels through real-time PCR; CXCL10 expression and p65 nuclear translocation through immunofluorescence staining. RESULTS: BHD markedly reduced brain infarction, improved rotarod performance, and attenuated BBB breakdown. Concurrently, BHD attenuated the upregulation of matrix metalloproteinase-2/9 activities and the degradation of tight junction proteins in the ischemic brain. Infiltration of NK cells was observed in the ischemic hemisphere, and this infiltration was blunted by treatment with BHD. BHD suppressed brain ischemia-induced interferon-γ and chemokine CXCL10 production. Furthermore, BHD significantly reduced the expression of CXCR3 on brain-infiltrated NK cells. Strikingly, BHD did not affect NK cell levels or its CXCR3 expression in the spleen or peripheral blood after brain ischemia. The nuclear translocation of NF-kB p65 and phospho-p65 in the ischemic brain was inhibited by BHD. CONCLUSION: Our findings suggest that BHD prevents brain infiltration of NK cells, preserves BBB integrity and eventually improves ischemic outcomes. The inhibitory effects of BHD on NK cell brain invasion may involve its ability of suppressing NF-kB-associated CXCL10-CXCR3-mediated chemotaxis. Notably, BHD only suppresses NK cells and their CXCR3 expression in the ischemic brain, but not those in periphery.

Analogous ß-Carboline Alkaloids Harmaline and Harmine Ameliorate Scopolamine-Induced Cognition Dysfunction by Attenuating Acetylcholinesterase Activity, Oxidative Stress, and Inflammation in Mice.

The analogous ß-carboline alkaloids, harmaline (HAL) and harmine (HAR), possess a variety of biological properties, including acetylcholinesterase (AChE) inhibitory activity, antioxidant, anti-inflammatory, and many others, and have great potential for treating Alzheimer's disease (AD). However, studies have showed that the two compounds have similar structures and in vitro AChE inhibitory activities but with significant difference in bioavailability. The objective of this study was to comparatively investigate the effects of HAL and HAR in memory deficits of scopolamine-induced mice. In the present study, mice were pretreated with HAL (2, 5, and 10 mg/kg), HAR (10, 20, and 30 mg/kg) and donepezil (5 mg/kg) by intragastrically for 7 days, and were daily intraperitoneal injected with scopolamine (1 mg/kg) to induce memory deficits and then subjected to behavioral evaluation by Morris water maze. To further elucidate the underlying mechanisms of HAL and HAR in improving learning and memory, the levels of various biochemical factors and protein expressions related to cholinergic function, oxidative stress, and inflammation were examined. The results showed that HAL and HAR could effectively ameliorate memory deficits in scopolamine-induced mice. Both of them exhibited an enhancement in cholinergic function by inhibiting AChE and inducing choline acetyltransferase (ChAT) activities, and antioxidant defense via increasing the antioxidant enzymes activities of superoxide dismutase and glutathione peroxidase, and reducing maleic diadehyde production, and anti-inflammatory effects through suppressing myeloperoxidase, tumor necrosis factor α, and nitric oxide as well as modulation of critical neurotransmitters such as acetylcholine (ACh), choline (Ch), L-tryptophan (L-Trp), 5-hydroxytryptamine (5-HT), γ-aminobutyric acid (γ-GABA), and L-glutamic acid (L-Glu). Furthermore, the regulations of HAL on cholinergic function, inflammation, and neurotransmitters were more striking than those of HAR, and HAL manifested a comparable antioxidant capacity to HAR. Remarkably, the effective dosage of HAL (2 mg/kg) was far lower than that of HAR (20 mg/kg), which probably due to the evidently differences in the bioavailability and metabolic stability of the two analogs. Taken together, all these results revealed that HAL may be a promising candidate compound with better anti-amnesic effects and pharmacokinetic characteristics for the treatments of AD and related diseases.

Rapid, reliable, and sensitive detection of adenosine deaminase activity by UHPLC-Q-Orbitrap HRMS and its application to inhibitory activity evaluation of traditional Chinese medicines.

Adenosine deaminase (ADA), which is a key enzyme in the metabolism of purine nucleosides, plays important roles in diverse disorders, such as tuberculosis, diabetes, liver disorders, and cancer. Determination of the activities of ADA and its isoenzymes in body fluids has received considerable attention in the diagnosis and treatment of relative diseases. Ultraviolet spectroscopy with adenosine (AD) as a substrate is a classical approach for screening potential ADA inhibitors by measuring the decrease in substrate (AD) at 265 nm or increase in the product (inosine) at 248 nm. However, AD and inosine share a very close maximum absorption wavelength, and the reaction is uncertain and is frequently interfered by the background color of matrix compounds or plant extracts. Thus, the method usually yields false positive or negative results. In this study, a novel, rapid, sensitive, and accurate ultra-high-performance liquid chromatography-Q exactive hybrid quadrupole orbitrap high-resolution accurate mass spectrometric (UHPLC-Q-Orbitrap HRMS) method was developed for determining and screening ADA inhibitors by directly determining the deamination product of AD, inosine. A proper separation was achieved for inosine and chlormequat (internal standard) within 2 min via isocratic elution (0.1% formic acid:methanol = 85:15, v/v) at a flow rate of 0.3 mL min-1 on a Waters ACQUITY HSS T3 column (2.1 mm × 100 mm, 1.8 µm) following a simple precipitation of proteins. The intra- and inter-day precisions of the developed method were below 7.17% and 8.99%, respectively. The method exhibited advantages of small total reaction volume (60 µL), short running time (2 min), high sensitivity (lowest limit of quantification of 0.02 µM for inosine), and low cost (small enzyme consumption of 0.007 unit mL-1 for ADA and substrate of 3.74 µM for AD in individual inhibition), and no matrix effects (101.64%-107.12%). Stability results showed that all analytes were stable under the investigated conditions. The developed method was successfully applied to the detection of the inhibitory activity of ADA from traditional Chinese medicines.