Li-Yuan Kang

The anti-inflammatory activities of Tanshinone IIA, an active component of TCM, are mediated by estrogen receptor activation and inhibition of iNOS.

Tanshinone IIA (Tan IIA) is a major compound extracted from a traditional herbal medicine Salvia miltiorrhiza BUNGE, which is used to treat cardiovascular diseases, cerebrovascular diseases and postmenopausal syndrome. It has also been shown to possess anti-inflammatory activity. Since Tan IIA has a similar structure to that of 17beta-estradiol (E(2)), the present study was undertaken to characterize the estrogenic activity of Tan IIA and to demonstrate a functional role of this activity in RAW 264.7 cells. In transient transfection assay, Tan IIA (10 microM) increases ERE-luciferase activity in an estrogen receptor (ER) subtype-dependent manner when either ERalpha or ERbeta were co-expressed in Hela cells. In LPS-induced RAW 264.7 cells, Tan IIA exerts anti-inflammatory effects by inhibition of iNOS gene expression and NO production, as well as inhibition of inflammatory cytokine (IL-1beta, IL-6, and TNF-alpha) expression via ER-dependent pathway. Therefore, it could serve as a potential selective estrogen receptor modulator (SERM) to treat inflammation-associated neurodegenerative and cardiovascular diseases without increasing the risk of breast cancer.

Neuroprotection of Scutellarin is mediated by inhibition of microglial inflammatory activation

Inhibition of microglial over-reaction and the inflammatory processes may represent a therapeutic target to alleviate the progression of neurological diseases, such as neurodegenerative diseases and stroke. Scutellarin is the major active component of Erigeron breviscapus (Vant.) Hand-Mazz, a herbal medicine in treatment of cerebrovascular diseases for a long time in the Orient. In this study, we explored the mechanisms of neuroprotection by Scutellarin, particularly its anti-inflammatory effects in microglia. We observed that Scutellarin inhibited lipopolysaccharide (LPS)-induced production of proinflammatory mediators such as nitric oxide (NO), tumor necrosis factor α (TNFα), interleukin-1β (IL-1β) and reactive oxygen species (ROS), suppressed LPS-stimulated inducible nitric oxide synthase (iNOS), TNFα, and IL-1β mRNA expression in rat primary microglia or BV-2 mouse microglial cell line. Scutellarin inhibited LPS-induced nuclear translocation and DNA binding activity of nuclear factor κB (NF-κB). It repressed the LPS-induced c-Jun N-terminal kinase (JNK) and p38 phosphorylation without affecting the activity of extracellular signal regulated kinase (ERK) mitogen-activated protein kinase. Moreover, Scutellarin also inhibited interferon-γ (IFN-γ)-induced NO production, iNOS mRNA expression and transcription factor signal transducer and activator of transcription 1α (STAT1α) activation. Concomitantly, conditioned media from Scutellarin pretreated BV-2 cells significantly reduced neurotoxicity compared with conditioned media from LPS treated alone. Together, the present study reported the anti-inflammatory activity of Scutellarin in microglial cells along with their underlying molecular mechanisms, and suggested Scutellarin might have therapeutic potential for various microglia mediated neuroinflammation.

Characterization of in vivo antioxidant constituents and dual-standard quality assessment of Danhong injection

Antioxidants and oxidative stress play a critical role in cardiovascular diseases. Danhong injection (DHI) is a well prescribed cardiovascular medication in China, but its detailed chemical basis and mechanisms of action remain unknown. To prove the antioxidant activity of DHI, its free radical scavenging capacity (RSC) was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) spectrophotometric assay. The 50% radical scavenging activity value was 1:129.2 mL/mL, against 0.95 mM DPPH. To further identify the antioxidant compounds, modified thin-layer chromatography combined with DPPH bioautography assay was used. Compared with vitamin C, 11 of 16 available compounds displayed strong antioxidant activity, which were also detected in rat serum after intravenous administration of DHI by ultra-performance liquid chromatography-tandem mass spectrometry, except for hydroxysafflor yellow A. Therefore, 10 antioxidants remaining in the blood as key markers, and six other compounds as general markers, were employed to perform the quality control of DHI by ultra-performance liquid chromatography-ultraviolet detection after systematic methodological validation. The analytical results indicate a high correlation (r = 0.9) between the total content of those antioxidants remaining in blood and RSC of DHI among 10 batches. Further, the antioxidant profiling and chemical marker quantification as dual-standard quality assessment was successfully applied to evaluate Danshen and safflower injections.

Neuroprotective effects of scutellarin against hypoxic-ischemic-induced cerebral injury via augmentation of antioxidant defense capacity.

An increasing number of studies has indicated that hypoxic-ischemic-induced cerebral injury is partly mediated via oxidative stress. Recent researches have focused on searching for drug and herbal manipulations to protect against hypoxic-ischemic-induced oxidative cell damage. Scutellarin is a flavonoid derived from the Erigeron breviscapus (vant.) and has been reported to exhibit neuroprotective properties. However, its precise mechanism, particularly its antioxidation mechanism, remains elusive. In the present study, we investigated the neuroprotective effects of scutellarin on middle cerebral artery occlusion (MCAO)-induced brain damage in rats, and oxygen-glucose deprivation (OGD)-induced toxicity in primary culture of rat cortical neurons. In vivo, intraperitoneal injections of scutellarin (20 and 60 mg/kg) improved the neurological score and diminished the percentage of brain infarct volume. At the same time, scutellarin significantly increased superoxide dismutase (SOD), catalase (CAT) activities and glutathione (GSH) level in ischemic brain tissues, enhancing endogenous antioxidant activity. Moreover, pretreatment of scutellarin (25, 50 and 100 μM) protected neurons against lethal stimuli, decreased the percentage of apoptotic cells and inhibited reactive oxygen species (ROS) generation in OGD-induced primary cortical neurons in vitro. These results suggest that the preventive and therapeutic potential of scutellarin in cerebral injury patients is, at least in part, ascribed to augmentation of cellular antioxidant defense capacity.

Simultaneous determination of stilbenes, phenolic acids, flavonoids and anthraquinones in Radix polygoni multiflori by LC–MS/MS

A simple and sensitive method was developed for the simultaneous determination of stilbenes, phenolic acid, flavonoids and anthraquinones in Radix polygoni multiflori by liquid chromatography tandem mass spectrometry (LC-MS/MS). The separation was completed on an Eclipse Plus C(18) (50 mm × 3.0 mm, 1.8 μm) column using 0.05% (v/v) formic acid and acetonitrile as mobile phases. The correlation coefficients of all the calibration curves were higher than 0.9990. The recoveries ranged from 95.9% to 106%. Relative standard deviations of intra and inter-day precisions were lower than 6.51%. The validated method was successfully applied to quantify stilbenes, phenolic acid, flavonoids and anthraquinones, which provided a new basis for overall assessment on quality of Radix polygoni multiflori.

Caffeic acid ester fraction from Erigeron breviscapus inhibits microglial activation and provides neuroprotection

ObjectiveTo investigate the effects of caffeic acid ester fraction (Caf) from Erigeron breviscapus, mainly composed of dicaffeoylquinic acids (diCQAs), on microglial activation in vitro and focal cerebral ischemia in vivo.MethodsThe production of nitric oxide (NO), tumor necrosis factor α (TNF-α), and interleukin-1β (IL-1β) induced by lipopolysaccharide (LPS) treatment in rat primary cultured microglia were measured by Griess reaction or enzyme-linked immunosorbent assay. Cell viability of cortical neurons was measured using AlamarBlue reagent. The behavioral tests and the infarct area of brain were used to evaluate the damage to central nervous system in rat middle cerebral artery occlusion (MCAO) model of cerebral ischemia. Real time polymerase chain reaction was used to determine the expression of inducible nitric oxide synthase (iNOS), TNF-α and IL-1β mRNA in ischemic cerebral tissues.ResultsCaf inhibited the production of NO, TNF-α and IL-1β induced by LPS treatment in primary microglia in a dose-dependent manner. Exposure of cortical neurons to conditioned medium from Caf-treated microglia increased neuronal cell viability (P<0.01) compared with conditioned medium from LPS-treated alone. In MCAO rat model of cerebral ischemia, Caf could significantly improve neurobehavioural performance and reduce percentage infarct volume compared with the vehicle group (P<0.05). Caf could also significantly inhibit the up-regulation of iNOS, TNF-α, and IL-1β gene expressions in ischemic cerebral tissues.ConclusionCaf could suppress microglial activation, which may be one mechanism of its neuroprotective effect against ischemia.

Platelet activation, and antiplatelet targets and agents: current and novel strategies.

Platelets play a key role in thrombosis and haemostasis, which can be either beneficial or deleterious depending on the circumstances. Multiple factors, such as genetic polymorphisms, pathological state and lifestyle, are thought to be associated with platelet hyperreactivity. Platelet activation occurs through the complex process of transmembrane signalling, with a cascade of biochemical interactions leading to platelet activation. Transmembrane signalling involves many different molecules with different enzymatic activity and/or function. Based on the signalling pathways involved in platelet activation, there are four possible targets of antiplatelet drugs: (i) inhibition of agonist generation; (ii) receptor inhibition; (iii) G-protein inhibition; and (iv) inhibition of enzymatic cascades. However, both established and novel antiplatelet drugs have their own advantages and disadvantages. Because of the problems associated with the use of current antiplatelet drugs, such as resistance, optimal dosage and safety, future strategies for the development of new antiplatelet drugs and new treatment regimens may include consideration of the following: (i) a shift from single targets within the signalling cascade to multiple targets; (ii) a shift from therapy with a single drug to combination therapy; and (iii) investigating drugs in current clinical use for novel antiplatelet properties.

IQMNMR: Open source software using time-domain NMR data for automated identification and quantification of metabolites in batches

BackgroundOne of the most promising aspects of metabolomics is metabolic modeling and simulation. Central to such applications is automated high-throughput identification and quantification of metabolites. NMR spectroscopy is a reproducible, nondestructive, and nonselective method that has served as the foundation of metabolomics studies. However, the automated high-throughput identification and quantification of metabolites in NMR spectroscopy is limited by severe spectral overlap. Although numerous software programs have been developed for resolving overlapping resonances, as well as for identifying and quantifying metabolites, most of these programs are frequency-domain methods, considerably influenced by phase shifts and baseline distortions, and effective only in small-scale studies. Almost all these programs require multiple spectra for each application, and do not automatically identify and quantify metabolites in batches.ResultsWe created IQMNMR, an R package that integrates a relaxation algorithm, digital filter, and similarity search algorithm. It differs from existing software in that it is a time-domain method; it uses not only frequency to resolve overlapping resonances but also relaxation time constants; it requires only one NMR spectrum per application; is uninfluenced by phase shifts and baseline distortions; and most important, yields a batch of quantified metabolites.ConclusionsIQMNMR provides a solution that can automatically identify and quantify metabolites by one-dimensional proton NMR spectroscopy. Its time-domain nature, stability against phase shifts and baseline distortions, requirement for only one NMR spectrum, and capability to output a batch of quantified metabolites are of considerable significance to metabolic modeling and simulation.IQMNMR is available at http://cran.r-project.org/web/packages/IQMNMR/.