Breviscapine: A Review on its Phytochemistry, Pharmacokinetics and Therapeutic Effects.

Breviscapine is one of the extracts of several flavonoids of Erigeron breviscapus. Scutellarin is the main active component of breviscapine, and the qualitative or quantitative criteria as well. Scutellarin and its analogs share a similar skeleton of the flavonoids. Breviscapine has been widely used in the treatment of cerebral infarction and its sequelae, cerebral thrombus, coronary heart disease (CHD), and angina pectoris. Breviscapine has a broad spectrum of pharmacological activities, such as increasing blood flow, improving microcirculation, dilating blood vessels, decreasing blood viscosity, promoting fibrinolysis, inhibiting platelet aggregation, and thrombosis formation, etc. In addition, breviscapine and its analogs have significant value for drug research and development because of the superiority of those significant bioactivities. Furthermore, an increasing number of pharmacokinetic studies have explored the mechanism of scutellarin and its analogs. To provide a comprehensive understanding of the current research on breviscapine, scutellarin, and the analogs, the structural features, distribution situation, preparation method, content determination method, clinical applications, pharmacological action as well as pharmacokinetics are summarized in the present review.

Evaluation of nutraceutical application of xylooligosaccharide enzymatically produced from cauliflower stalk for its value addition through a sustainable approach.

There is increasing attention on the exploration of waste feedstocks as economically viable substrates for the production of prebiotic oligosaccharides, especially xylooligosaccharides, as excellent candidates for the maintenance and promotion of gut microbiota. XOS, an emerging prebiotic that has several functional attributes and beneficial health effects, is mainly produced by different processes, especially enzymatic hydrolysis through the valorisation of xylan enriched lignocellulosic materials. The present study deals with the enzymatic production of xylooligosaccharide (XOS) from xylan rich cauliflower stalk, a novel source. Delignification with alkali (NaOH) was found to be more efficient than acid and autohydrolysis, resulting in a higher extraction yield of xylan (18.42%). Alkaline extraction for 120 minutes at 1.25 M alkali concentration produced maximum xylan yield. FTIR analysis of xylan extracted from cauliflower stalk by an alkaline (NaOH) pretreatment method showed typical absorption bands at 1729 cm-1 that correspond to acetyl groups exhibiting the typical xylan specific band. Enzymatic hydrolysis was carried out with indigenously produced crude endoxylanase obtained from Aspergillus niger MTCC 9687 and the effects of substrate concentration, enzyme concentration, pH, time and temperature were investigated. High resolution MS analysis showed the presence of xylobiose as the major XOS. The major 1H spectral signals of XOS liberated from enzymatically hydrolysed alkali extracted cauliflower stalk xylan showed the presence of ß-anomeric protons in the spectral region of 4.0-4.7 ppm. Prebiotic efficacy of cauliflower stalk derived XOS alone and synbiotic combinations with known probiotic strains (Lactiplantibacillus plantarum, Bifidobacterium bifidum, Lactobacillus delbrueckii ssp. Helveticus) were evaluated. Butyrate was found to be the major short chain fatty acid produced by XOS supplemented fermentation media. All the synbiotic combinations showed significantly higher antioxidant and antimicrobial activities and reduced the viability of human bone cancer MG-63 cells. The individual profiles of antimicrobial components of XOS were identified as dihydroxy benzoic acid and aspartic acid by HPLC coupled to a photodiode array detector.

Valorisation of walnut shell and pea pod as novel sources for the production of xylooligosaccharides.

According to the high interest in agro-industrial waste reutilisation, underutilised lignocellulosic materials, such as walnut shell (WS) and pea pod (PP), come in focus. The aim of this paper was to evaluate WS and PP as sources for the production of xylooligosaccharides (XOS). Hemicelluloses from WS and PP were recovered by combining varying parameters of delignification and alkaline extraction. At optimal recovery conditions, the fractions were further hydrolysed to XOS using GH11 endo-xylanase, by varying time and enzyme concentration. Xylose was predominant in the monomeric composition of the obtained hemicelluloses, building low-branched (arabino)glucuronoxylan, in WS exclusively, while in PP some xyloglucan as well. Delignification was essential for high recovery of total xylose from the materials, up to at least 70 %. High xylan conversions were obtained for 24 h hydrolysis, resulting in xylobiose and xylotriose when using low enzyme concentration, while in xylose and xylobiose with high enzyme concentration.

Scutellarin ameliorates high glucose-induced vascular endothelial cells injury by activating PINK1/Parkin-mediated mitophagy.

ETHNOPHARMACOLOGICAL RELEVANCE: Scutellarin (Scu) is one of the main active ingredients of Erigeron breviscapus (Vant.) Hand.-Mazz which has been used to treat cardiovascular disease including vascular dysfunction caused by diabetes. Scu also has a protective effect on vascular endothelial cells against hyperglycemia. However, molecular mechanisms underlying this effect are not clear. AIM OF THE STUDY: This aim of this study was to investigate the effect of Scu on human umbilical vein endothelial cells (HUVECs) injury induced by high glucose (HG), especially the regulation of PTEN-induced kinase 1 (PINK1)/Parkin-mediated mitophagy. MATERIALS AND METHODS: HUVECs were exposed to HG to induce vascular endothelial cells injury in vitro. Cell viability was assessed by MTT assay. The extent of cell apoptosis was measured by Hoechst staining and flow cytometry. Mitophagy was assayed by fluorescent immunostaining, transmission electron microscope and immunoblot. Besides, virtual docking was conducted to validate the interaction of PINK1 protein and Scu. RESULTS: We found that Scu significantly increased cell viability in HG-treated HUVECs. Scu reduces the expression of Bcl-2, Bax and cytochrome C (Cyt.c) to inhibit apoptosis through a mitochondria-dependent pathway. Meanwhile, Scu improved the overload of reactive oxygen species (ROS), superoxide dismutase (SOD) activity and SOD2 protein expression, and reversed the collapse of mitochondrial membrane potential. Besides, Scu increased autophagic flux, improved the expression of microtubule-associated protein 1 light chain 3 Ⅱ (LC3 II), Beclin 1 and autophagy-related gene 5 (Atg 5) and decreased the expression of Sequestosome1/P62 in HG-treated HUVECs. Furthermore, Scu improved the expressions of PINK1, Parkin, and Mitofusin2, which revealed the enhancement of mitophagy. Moreover, the beneficial effects of Scu on HG-induced low expression of Parkin, overproduction of ROS, and over expressions of P62, Cyt.c and Cleaved caspase-3 were weakened by PINK1 gene knockdown. Molecular docking suggested good interaction of Scu and PINK1 protein. CONCLUSION: These results suggest that Scu may protect vascular endothelial cells against hyperglycemia-induced injury by up-regulating mitophagy via PINK1/Parkin signal pathway.

PK-PD Correlation of Erigeron Breviscapus Injection in the Treatment of Cerebral Ischemia-Reperfusion Injury Model Rats.

By measuring the cerebral infarction rate and neurological behavioral score of rats in a sham operation group, an MCAO model control group and an Erigeron breviscapus injection treatment group, we explored the therapeutic effects of Erigeron breviscapus injection on brain tissue and neuroethological injury in rats. Plasma samples were collected at 18 time points after intravenous injection of Erigeron breviscapus. The levels of scutellarin, 4-caffeoylquinic acid, 5-caffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, chlorogenic acid and isochlorogenic acid B in rat plasma at the various time points were determined by an HPLC method, and drug concentration versus time plots were constructed to estimate the pharmacokinetic parameters. Finally, a PK-PD combined model was used to analyze the relationship between the blood concentration, time and therapeutic effects of the seven active components. The results of the pharmacodynamics studies showed that the cerebral infarction rate of rats in the Erigeron breviscapus injection group decreased significantly at 5 min, 10 min, 20 min, 6 h, 8 h, 18 h, 24 h, 32 h, 40 h and 48 h after cerebral ischemia. Abnormal neurological behavior scores were significantly reduced after 4 h of cerebral ischemia. The pharmacokinetics results showed that the seven chemical constituents in Erigeron breviscapus injection reached their highest detection value after 5 min of cerebral ischemia. The lowest detection values of scutellarin and isochlorogenic acid B appeared after 6 h of cerebral ischemia but could not be detected after 8 h. The lowest detection values of 5-caffeoylquinic acid and 4,5-dicaffeoylquinic acid were found in the third hour of cerebral ischemia but not after 4 h. The lowest detection values of 4-caffeoylquinic acid, 3,5-dicaffeoylquinic acid and chlorogenic acid were found during the second hour of cerebral ischemia but not at the third hour. However, at 18 h, 24 h, 32 h and 40 h of cerebral ischemia, the cerebral infarction rates of rats in the Erigeron breviscapus injection group were significantly reduced, with decreased values of 6.22%, 11.71%, 6.92% and 4.96%, respectively, and the effects were stronger than those after 5-20 min of cerebral ischemia. The decreased values reached their highest value after 24 h of cerebral ischemia. Our results show that the effects of Erigeron breviscapus injection on reducing the cerebral infarct rate in MCAO model rats are characterized by a fast onset and long maintenance time. The 5-min blood concentration in cerebral ischemia was the highest test value, and after this time, the cerebral infarction rate of MCAO rats began to decrease. However, the peak value of the effects lagged behind that of the plasma concentration. The maximum effective time for Erigeron breviscapus injection appeared 24 h after cerebral ischemia, which provides a reference for the screening of specific drugs for ischemic stroke, optimal dosing regimens and rational clinical drug use. Graphical Abstract.

Dengzhan Shengmai capsules and their active component scutellarin prevent cognitive decline in APP/PS1 mice by accelerating Aß aggregation and reducing oligomers formation.

There is currently no effective treatment to prevent the progress of Alzheimer's disease (AD). The traditional Chinese herbs Dengzhan Shengmai (DZSM) capsules and their active component scutellarin possess multiple effects and are clinically used for the treatment of cerebrovascular diseases. Scutellarin has been reported to affect Aß aggregation. However, the effects of DZSM capsules on AD remain unknown. Through in vivo experiments, our study proved that the alleviating effects of DZSM capsules on cognitive deficits of AD mice were due to the role of scutellarin, which up-regulated low toxic amyloid plaques and down-regulated highly toxic soluble Aß42 and Aß40 levels in cortex. In vitro, we confirmed scutellarin's role in accelerating transforming Aß42 monomers into high-molecular-mass aggregates by biochemical assays, which supported the results observed in drug-treated APP/PS1 mice. In detail, the 1:10 ratio of scutellarin/Aß42 mixtures promoted production of large ß-sheet-rich fibrils whereas the 1:1 ratio promoted production of protofibrils. In addition, the binding between scutellarin and Aß monomers was quantified by microscale thermophoresis test and the apparent dissociation constant (Kd) was 1284.4 ±â€¯238.8 µM. What's more, binding regions between scutellarin and Aß fibrils were predicted by computational docking models and scutellarin might bind parallel to the long axis of Aß42 fibrils targeting hydrophobic grooves at residues 35-36 or 39. In conclusion, DZSM capsules protected against cognitive defects of AD through scutellarin-mediated acceleration of Aß aggregation into fibrils or protofibrils and reduction of soluble Aß oligomers, thus suggesting potential clinical applications of DZSM capsules and scutellarin in the treatment of AD.

In Silico and In Vitro Anti-Helicobacter Pylori Effects of Combinations of Phytochemicals and Antibiotics.

Helicobacter pylori infection is a WHO class 1 carcinogenic factor of gastric adenocarcinoma. In the past decades, many studies have demonstrated the increasing trend of antibiotic resistance and pointed out the necessity of new effective treatment. This study was aimed at identifying phytochemicals that can inhibit H. pylori and possibly serve as adjuvant treatments. Here, in silico molecular docking and drug-like properties analyses were performed to identify potential inhibitors of urease, shikimate kinase and aspartate-semialdehyde dehydrogenase. These three enzymes are targets of the treatment of H. pylori. Susceptibility and synergistic testing were performed on the selected phytochemicals and the positive control antibiotic, amoxicillin. The in-silico study revealed that oroxindin, rosmarinic acid and verbascoside are inhibitors of urease, shikimate kinase and aspartate-semialdehyde dehydrogenase, respectively, in which, oroxindin has the highest potency against H. pylori, indicated by a minimum inhibitory concentration (MIC) value of 50 µg/mL. A combination of oroxindin and amoxicillin demonstrated additive effects against H. pylori, as indicated by a fractional inhibitory concentration (FIC) value of 0.75. This study identified phytochemicals that deserve further investigation for the development of adjuvant therapeutic agents to current antibiotics against H. pylori.

Pathogen-targeting glycovesicles as a therapy for salmonellosis.

Antibiotic therapy is usually not recommended for salmonellosis, as it is associated with prolonged fecal carriage without reducing symptom duration or severity. Here we show that antibiotics encapsulated in hydrogen sulfide (H2S)-responsive glycovesicles may be potentially useful for the treatment of salmonellosis. The antibiotics are released in the presence of Salmonella, which is known to produce H2S. This approach prevents the quick absorption of antibiotics into the bloodstream, allows localized targeting of the pathogen in the gut, and alleviates disease symptoms in a mouse infection model. In addition, it reduces antibiotic-induced changes in the gut microbiota, and increases the abundance of potentially beneficial lactobacilli due to the release of prebiotic xylooligosaccharide analogs.

Impact of in vitro gastrointestinal digestion on the chemical composition, bioactive properties, and cytotoxicity of Vitis vinifera L. cv. Syrah grape pomace extract.

Grape pomace (GP) is a major byproduct worldwide, and it is well known for its bioactive compounds, such as fibers and phenolic compounds, that are popular for their impact upon human health, including gastrointestinal health. The objective of this work was to evaluate the chemical composition and biological activities of an enzymatic GP extract, as well as to investigate how gastrointestinal digestion (GID) modulates these properties. GP extract was previously produced using an enzymatic cocktail with xylanase activity and was then exposed to simulated conditions of GID, characterized for its chemical composition, and screened for antimicrobial, prebiotic, and antioxidant activities. The safety of this ingredient after GID was also assessed. GP extract presented high contents of dietary fiber and other carbohydrates, including xylooligosaccharides, in addition to minerals and phenolic compounds. In vitro simulated GID revealed that xylobiose was resistant to gastric conditions, unlike phenolic compounds. The use of 2% (w/v) of this ingredient proved to be a potential carbon source that could be fermented by Lactobacillus and Bifidobacterium spp, even after digestion. The extract also exhibited strong antioxidant and antimicrobial activities against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa; however, after GID, the antioxidant capacity decreased, and the antimicrobial capacity was strongly reduced or lost. Furthermore, the extract safety was also guaranteed on Caco-2 intestinal cells. This novel and green GP extract proved to be composed of relevant bioactive molecules, including xylooligosaccharides, polyphenols, organic acids, and minerals, which provided different biological properties; it has potential applications in the food industry such that it can be used as an ingredient in the development of new functional foods.

Enzymatic production of xylooligosaccharides from Brazilian Syrah grape pomace flour: a green alternative to conventional methods for adding value to agricultural by- products.

BACKGROUND: The aim of this work was to determine the most favorable conditions for the production of xylooligosaccharides (XOS) from Brazilian Syrah grape pomace. Chemical processes were performed using a rotatable central composite design where the concentration of sulfuric acid or sodium hydroxide and the grape pomace flour/solvent mass ratio were the dependent variables. Enzymatic production was also evaluated using xylanase produced by Aspergillus niger 3T5B8 and Viscozyme® enzymatic commercial cocktail. RESULTS: Chemical extraction allowed to recover 21.8-74.6% and 5.2-96.3% of total XOS for acidic and alkaline processes respectively. Enzymatic production extracted up to 88.68 ± 0.12% of total XOS using xylanase and up to 84.09 ± 2.40% with Viscozyme® . CONCLUSION: The present study demonstrated different feasible methods to produce high-added-value molecules, i.e. XOS, from Syrah grape pomace flour, valorizing this major by-product. The use of enzymatic cocktails demonstrated to be an alternative to the conventional methods, allowing to obtain an eco-friendly and sustainable grape pomace extract. © 2018 Society of Chemical Industry.

Understanding the influence of carrageenan oligosaccharides and xylooligosaccharides on ice-crystal growth in peeled shrimp (Litopenaeus vannamei) during frozen storage.

Cryoprotective saccharides are widely accepted antifreeze additives that reduce thawing loss, maintain texture, and retard protein denaturation in frozen seafood. In this study, the inhibition effects of carrageenan oligosaccharides and xylooligosaccharides on ice-crystal growth in peeled whiteleg shrimp were investigated and compared with sodium pyrophosphate treatment during frozen storage, especially the interactions between oligosaccharide molecules and ice crystals. The tissue microstructural results demonstrated that the fibers of shrimp muscle tissues from carrageenan oligosaccharide- and xylooligosaccharide-treated groups were arranged in a more tighter manner than those with sodium pyrophosphate treatment after 8 weeks of storage, which indicated that soaking in oligosaccharide solutions prior to freezing markedly slowed the damage caused to muscle tissues by large ice crystals. Ice-growth inhibition might play an important role in the cryoprotection of frozen shrimp. Furthermore, molecular docking and molecular dynamics (MD) simulations confirmed that oligosaccharides were generally close to the ice surface and embedded in ice layers via hydrogen bonds or hydrophobic or electrostatic interactions. The oligosaccharide-basal ice complex (ice-crystal structure) was partially destroyed, and some dislocation and disaggregation were observed around the oligosaccharide molecules. Thus, the incorporated oligosaccharides suppressed the growth of ice crystals, providing protection from freeze-induced damage. Overall, by comparing the experimental results to those from the MD simulations, a significant positive correlation existed between the oligosaccharides and ice-growth inhibition in shrimp muscle. These findings help better understand the cryoprotective mechanisms of oligosaccharides in frozen shrimp, and these two oligosaccharides may be potentially used as ice-growth inhibitors in seafood to maintain better quality during frozen storage.

Herbal Compounds with Special Reference to Gastrodin as Potential Therapeutic Agents for Microglia Mediated Neuroinflammation.

BACKGROUND: Activated microglia play a pivotal role neurodegenerative diseases by producing a variety of proinflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukin- 1beta (IL-1ß) and nitric oxide (NO) that are toxic to neurons and oligodendrocytes. METHODS: In view of the above, suppression of microglia mediated neuroinflammation is deemed a therapeutic strategy for neurodegenerative diseases. Several potential Chinese herbal extracts have been reported to exert neuroprotective effects against neurodegenerative diseases targeting specifically at the activated microglia. In this connection, the phenolic glucoside gastrodin, a main constituent of the Chinese herbal medicine Gastrodia rhizoma, produced widely in the local community exhibits potential neuroprotective effects through suppression of neurotoxic proinflammatory mediators. RESULTS: Here, we first review the roles of activated microglia in different brain diseases. The effects of gastrodin on activated microglia are then considered. We have identified gastrodin as a putative therapeutic agent as it has been found to suppress microglial activation thus ameliorating neuroinflammation. More importantly, gastrodin downregulates the expression of renin angiotensin system (RAS) and production of proinflammatory mediators. Remarkably, gastrodin promotes Sirtuin 3 (Sirt3) up-regulation and nicotinamide adenine dinucleotide phosphate oxidase-2 (NOX-2) down-regulation after ischemichypoxia in activated microglia mediated by AT1 or AT2 receptors which are angiotensin II receptors subtypes, indicating a possible molecular link between RAS and Sirt3 survival genes. CONCLUSION: This review summarizes the beneficial effects of gastrodin acting on activated microglia along with other herbal compounds. Its efficacy in neuroprotection is consistent with some common herbal products in China.

Pharmacological Effects of Scutellarin, An Active Component of Genus Scutellaria and Erigeron: A Systematic Review.

Flavonoid compound scutellarin (Scu) is quite frequently met in the plant kingdom, particularly in the genus Scutellaria (Lamiaceae) and Erigeron (Asteraceae). The extract of the herb of Erigeron breviscapus, containing this component in high amount, has been used for many years in traditional Chinese medicine. In recent years, studies have made great progress on the usefulness of Scu for treating various diseases by testing its mechanism of action. They support the traditional use of Scu rich plant in heart and cerebral ischemia. Scu can potentially be applied in Alzheimer's disease, Helicobacter pylori infection, vascular complications of diabetes and as an inhibitor of certain carcinomas. Various methods were designed to improve its isolation from plant material, solubility, absorption and bioavailability. On the basis of recent studies, it is suggested that Scu could be a promising candidate for new natural drug and deserves particular attention in further research and development.

Scutellarin inhibits Hela cell growth and glycolysis by inhibiting the activity of pyruvate kinase M2.

Scutellarin, one of natural flavonoids, is widely and clinically used for treating many diseases in China. Recently, scutellarin has demonstrated a broad spectrum of anti-proliferative activities against multiple cancer cell lines. However, the molecular mechanism of action remains to be investigated. We herein report the design and synthesis of biotinylated scutellareins as probes, which can be applied to discover scutellarein interacting proteins. Finally, we show that scutellarin directly targets pyruvate kinase M2 (PKM2) and inhibits its cytosolic activity to decrease glycolytic metabolism; on the other hand, scutellarin may also participate in regulating cell cycle and apoptotic proteins by activating MEK/ERK/PIN1 signaling pathway to promote the nuclear translocation of PKM2.

Cytotoxic and chemosensitization effects of Scutellarin from traditional Chinese herb Scutellaria altissima L. in human prostate cancer cells.

Scutellaria altissima L. is a common traditional Chinese medicine used to treat inflammation in some countries. Scutellarin, an active major flavone glycoside isolated from the traditional Chinese medicine Scutellaria altissima L., has been shown to offer various beneficial biochemical effects on cerebrovascular diseases and inflammation. However, the antiproliferative effects of Scutellarin in prostate cancer and the underlying mechanism are not fully elucidated. In the present study, we aimed to ascertain whether Scutellarin inhibits cancer cell growth and to further explore the molecular mechanism. Scutellarin enhanced the sensitivity of prostate cancer cells to cisplatin. MTT assays revealed that cell viability was significantly decreased in the prostate cancer cells treated with Scutellarin. Flow cytometric analysis indicated that Scutellarin suppressed cell proliferation by promoting G2/M arrest and inducing apoptosis. We employed western blotting to delineate the underlying mechanisms involved in the G2/M arrest and apoptosis. Comet assay and γH2AX immunocytochemistry were used to detect levels of DNA damage in PC3 cells exposed to Scutellarin and/or cisplatin. Our data revealed that Scutellarin significantly induced prostate cancer cell apoptosis by activating the caspase cascade. An increase in the Bax/Bcl-2 ratio, depolarization of mitochondrial membrane potential and cell cycle arrest at G2/M phase were accompanied by the apoptosis induction. Additionally, Scutellarin altered the protein expression of cell cycle and apoptosis regulatory genes by downregulating Cdc2, cyclin B1 and Bcl-2 and upregulating caspase-3, caspase-9 and Bax in prostate cancer cells. Furthermore, Scutellarin sensitized PC3 cells to cisplastin treatment in a dose-dependent manner. Taken together, our data confirmed the cytotoxicity of Scutellarin against prostate cancer PC3 cells and provide new findings in regards to Scutellarin sensitizing prostate cancer cells to chemotherapy. Our findings suggest that Scutellarin has potential to be used as a novel antineoplastic therapeutic candidate for prostate cancer patients.

Scutellarin suppresses growth and causes apoptosis of human colorectal cancer cells by regulating the p53 pathway.

Scutellarin is a flavonoid isolated from a medicinal herb Scutellaria barbata D. Don and exerts therapeutic effects on cardiovascular diseases. However, it remains unclear whether Scutellarin exhibits anti­tumor actions on human colon cancer. The current study aimed to investigate whether Scutellarin produces antiproliferative and pro­apoptotic effects on HCT­116 human colon cancer cells and to elucidate the mechanisms involved. Human colon cancer cells were exposed to different concentrations of Scutellarin, and cellular growth and apoptosis were evaluated by MTT assay, terminal deoxynucleotidyl transferase­mediated dUTP nick end labeling (TUNEL) staining, western blot analysis and other assays. A cell viability assay demonstrated that Scutellarin treatment reduced the viability of HCT­116 cells in a dose­ and time­dependent manner. TUNEL staining demonstrated that Scutellarin also induced apoptotic changes in HCT­116 cells. The expression level of the anti­apoptotic protein, Bcl­2 apoptosis regulator (Bcl­2), was reduced by Scutellarin in HCT­116 cells, whereas the expression Bcl­2 associated X apoptosis regulator (Bax) and the activation of caspase­3 protein were increased by Scutellarin treatment. Further investigation revealed that Scutellarin significantly increased the phosphorylation of p53 protein in HCT­116 cells. Additionally, suppression of p53 using a specific inhibitor, pifithrin­α, abrogated the pro­apoptotic effects of Scutellarin in HCT­116 cells. Collectively, Scutellarin reduced the viability and induced apoptosis of human colon carcinoma cells, potentially by regulating p53 and Bcl­2/Bax expression. These data suggested that Scutellarin may be useful as a promising anti­tumor drug for treating colon cancer.

Pharmacokinetic Comparison of Scutellarin and Paeoniflorin in Sham-Operated and Middle Cerebral Artery Occlusion Ischemia and Reperfusion Injury Rats after Intravenous Administration of Xin-Shao Formula.

Xin-Shao formula is a folk remedy widely used in China to prevent and cure stroke. Cerebral ischemic reperfusion (I/R) injury often takes place during the treatment of stroke. Information about the pharmacokinetic behavior of the remedy under cerebral I/R injury conditions is lacking. The present study aimed to compare the pharmacokinetic properties of scutellarin and paeoniflorin, two major bioactive components of Xin-Shao formula, under physiological state in cerebral I/R injury rats. Neurobehavioral dysfunction was evaluated and cerebral infarcted volume was measured in middle cerebral artery occlusion I/R injury (MCAO) rats. Plasma samples were collected at various time points after a single dose (intravenous, i.v.) of Xin-Shao formula. The levels of plasma scutellarin and paeoniflorin at the designed time points were determined by a UPLC-MS/MS method, and drug concentration versus time plots were constructed to estimate pharmacokinetic parameters. Increase in terminal elimination half-life (t1/2z) and mean residence time (MRT(0-t)) of scutellarin as well as elevation in area under the plasma drug concentration-time curve from 0 h to the terminal time point (AUC(0-t)) and maximum plasma drug concentration (Cmax) of paeoniflorin, along with decreased clearance of paeoniflorin and scutellarin as well as reduced apparent volume of distribution (Vz) of paeoniflorin, were observed in MCAO rats, compared with those in sham-operated animals. The elimination of scutellarin and paeoniflorin were reduced in cerebral I/R injury reduced rats.

Separation of five compounds from leaves of Andrographis paniculata (Burm. f.) Nees by off-line two-dimensional high-speed counter-current chromatography combined with gradient and recycling elution.

An off-line two-dimensional high-speed counter-current chromatography method combined with gradient and recycling elution mode was established to isolate terpenoids and flavones from the leaves of Andrographis paniculata (Burm. f.) Nees. By using the solvent systems composed of n-hexane/ethyl acetate/methanol/water with different volume ratios, five compounds including roseooside, 5,4'-dihydroxyflavonoid-7-O-ß-d-pyranglucuronatebutylester, 7,8-dimethoxy-2'-hydroxy-5-O-ß-d-glucopyranosyloxyflavon, 14-deoxyandrographiside, and andrographolide were successfully isolated. Purities of these isolated compounds were all over 95% as determined by high-performance liquid chromatography. Their structures were identified by UV, mass spectrometry, and (1) H NMR spectroscopy. It has been demonstrated that the combination of off-line two-dimensional high-speed counter-current chromatography with different elution modes is an efficient technique to isolate compounds from complex natural product extracts.

Biological evaluation and molecular docking of baicalin and scutellarin as Helicobacter pylori urease inhibitors.

ETHNOPHARMACOLOGICAL RELEVANCE: Baicalin and scutellarin are the principal bioactive components of Scutellaria baicalensis Georgi which has extensively been incorporated into heat-clearing and detoxification formulas for the treatment of Helicobacter pylori-related gastrointestinal disorders in traditional Chinese medicine. However, the mechanism of action remained to be defined. AIM OF THE STUDY: To explore the inhibitory effect, kinetics and mechanism of Helicobacter pylori urease (the vital pathogenetic factor for Helicobacter pylori infection) inhibition by baicalin and scutellarin, for their therapeutic potential. MATERIALS AND METHODS: The ammonia formations, indicator of urease activity, were examined using modified spectrophotometric Berthelot (phenol-hypochlorite) method. The inhibitory effect of baicalin and scutellarin was characterized with IC50 values, compared to acetohydroxamic acid (AHA), a well known Helicobacter pylori urease inhibitor. Lineweaver-Burk and Dixon plots for the Helicobacter pylori urease inhibition of baicalin and scutellarin was constructed from the kinetic data. SH-blocking reagents and competitive active site Ni(2+) binding inhibitors were employed for mechanism study. Molecular docking technique was used to provide some information on binding conformations as well as confirm the inhibition mode. Moreover, cytotoxicity experiment using Gastric Epithelial Cells (GES-1) was evaluated. RESULTS: Baicalin and scutellarin effectively suppressed Helicobacter pylori urease in dose-dependent and time-independent manner with IC50 of 0.82±0.07 mM and 0.47±0.04 mM, respectively, compared to AHA (IC50=0.14±0.05 mM). Structure-activity relationship disclosed 4'-hydroxyl gave flavones an advantage to binding with Helicobacter pylori urease. Kinetic analysis revealed that the types of inhibition were non-competitive and reversible with inhibition constant Ki of 0.14±0.01 mM and 0.18±0.02 mM for baicalin and scutellarin, respectively. The mechanism of urease inhibition was considered to be blockage of the SH groups of Helicobacter pylori urease, since thiol reagents (L,D-dithiothreitol, L-cysteine and glutathione) abolished the inhibitory action and competitive active site Ni(2+) binding inhibitors (boric acid and sodium fluoride) carried invalid effect. Molecular docking study further supported the structure-activity analysis and indicated that baicalin and scutellarin interacted with the key residues Cys321 located on the mobile flap through S-H·π interaction, but did not interact with active site Ni(2+). Moreover, Baicalin (at 0.59-1.05 mM concentrations) and scutellarin (at 0.23-0.71 mM concentrations) did not exhibit significant cytotoxicity to GES-1. CONCLUSIONS: Baicalin and scutellarin were non-competitive inhibitors targeting sulfhydryl groups especially Cys321 around the active site of Helicobacter pylori urease, representing potential to be good candidate for future research as urease inhibitor for treatment of Helicobacter pylori infection. Furthermore, our work gave additional scientific support to the use of Scutellaria baicalensis in traditional Chinese medicine (TCM) to treat gastrointestinal disorders.

Biological Activities of xylooligosaccharides generated from garlic straw xylan by purified xylanase from Bacillus mojavensis UEB-FK.

A newly isolated Bacterium strain named UEB-FK was selected from Tunisian Sahara, exhibiting the highest clear zone on agar plates containing oat spelt xylan by staining with Congo red. On the basis of 16S rDNA sequence analysis, this strain was identified as Bacillus mojavensis. This strain produced extracellular xylanase. Xylanase from the strain was purified to homogeneity and had an apparent molecular weight of 14 kDa. The K m and V max values of the purified xylanase on oat spelt xylan were 3.85 mg/mL and 250.02 U/mg, respectively. The optimum pH and temperature for the enzyme were found to be 4.0 and 50 °C, respectively, and the enzyme exhibited significant heat stability. In addition, the enzyme was found to be stable in a wide range of pH (3-9). The main hydrolysis products yielded from garlic straw-extracted xylan were xylobiose and xylotriose. The antioxidant and antibacterial activities of xylan oligosaccharide (XOS) were investigated. As regards to the in vitro antioxidant activities, the XOS showed a important DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity (IC50 = 0.45 mg/mL) and a high ß-carotene bleaching (IC50 = 2.2 mg/mL). Furthermore, XOS had a high antimicrobial activity against Klebsiella pneumoniae, Enterococcus faecalis, Bacillus thuringiensis, and Pseudomonas aeruginosa.