Cathy W. C. Bi

Cordysinocan, a polysaccharide isolated from cultured Cordyceps, activates immune responses in cultured T-lymphocytes and macrophages: signaling cascade and induction of cytokines.

Cordyceps sinensis, a well-known traditional Chinese medicine, possesses activities in anti-tumor, anti-oxidation and stimulating the immune response; however, the identity of active component(s) is not determined. A strain of Cordyceps sinensis, namely UST 2000, has been isolated. By using activity-guided purification, a novel polysaccharide of molecular weight approximately 82 kDa was isolated from the conditioned medium of cultured Cordyceps. The isolated exo-polysaccharide, namely cordysinocan, contains glucose, mannose, galactose in a ratio of 2.4:2:1. In cultured T-lymphocytes, application of cordysinocan induced the cell proliferation and the secretion of interleukin-2, interleukin-6 and interleukin-8. In addition, the phosphorylation of extracellular signal-regulated kinases (ERK) was induced transiently by the treatment of cordysinocan. Moreover, application of cordysinocan in cultured macrophages increased the phagocytosis activity and the enzymatic activity of acid phosphatase. These results therefore verify the important role of Cordyceps polysaccharide in triggering such immune responses.

Quality evaluation of Rhizoma Belamcandae (Belamcanda chinensis (L.) DC.) by using high-performance liquid chromatography coupled with diode array detector and mass spectrometry.

A high-performance liquid chromatography coupled with diode array detector and mass spectrometry (HPLC-DAD-MS) method was developed to evaluate the quality of Rhizoma Belamcandae (Belamcanda chinensis (L.) DC.) through establishing chromatographic fingerprint and simultaneous determination of seven phenolic compounds. The analysis was achieved on an Alltima C(18) analytical column (250 mm x 4.6 mm i.d. 5 microm) using linear gradient elution of acetonitrile-0.1% trifluoroacetic acid. The correlation coefficients of similarity were determined from the HPLC fingerprints, and they shared a close similarity. By using an online APCI-MS/MS, twenty phenols were identified. In addition, seven of these phenols including mangiferin, 7-O-methylmangiferin, tectoridin, resveratrol, tectorigenin, irigenin and irisflorentin were quantified by the validated HPLC-DAD method. These phenols are considered to be major constituents in Rhizoma Belamcandae, and are generally regarded as the index for quality assessment of this herb. This developed method by having a combination of chromatographic fingerprint and quantification analysis could be applied to the quality control of Rhizoma Belamcandae.

Flavonoids from Radix Astragali Induce the Expression of Erythropoietin in Cultured Cells: A Signaling Mediated via the Accumulation of Hypoxia-Inducible Factor-1α

Radix Astragali (RA) is commonly used as a health food supplement to reinforce the body vital energy. Flavonoids, including formononetin, ononin, calycosin, and calycosin-7-O-β-d-glucoside, are considered to be the major active ingredients within RA. Here, we provided different lines of evidence that the RA flavonoids stimulated the expression of erythropoietin (EPO), the central regulator of red blood cell mass, in cultured human embryonic kidney fibroblasts (HEK293T). A plasmid containing hypoxia response element (HRE), a critical regulator for EPO transcription, was tagged upstream of a firefly luciferase gene, namely, pHRE-Luc, which was being transfected into fibroblasts. The application of RA flavonoids onto the transfected cells induced the transcriptional activity of HRE. To account for the transcriptional activation after the treatment of flavonoids, the expression of hypoxia-inducible factor-1α (HIF-1α) was markedly increased: The increase was in both mRNA and protein levels. In addition, the degradation of HIF-1α was reduced under the effect of flavonoids. The regulation of HIF-1α therefore could account for the activation of EPO expression mediated by the RA flavonoids. The current results therefore reveal the function of this herb in enhancing hematopoietic functions.

Flavonoids Induce the Synthesis and Secretion of Neurotrophic Factors in Cultured Rat Astrocytes: A Signaling Response Mediated by Estrogen Receptor

Neurotrophic factors are playing vital roles in survival, growth, and function of neurons. Regulation of neurotrophic factors in the brain has been considered as one of the targets in developing drug or therapy against neuronal disorders. Flavonoids, a family of multifunctional natural compounds, are well known for their neuronal beneficial effects. Here, the effects of flavonoids on regulating neurotrophic factors were analyzed in cultured rat astrocytes. Astrocyte is a major secreting source of neurotrophic factors in the brain. Thirty-three flavonoids were screened in the cultures, and calycosin, isorhamnetin, luteolin, and genistein were identified to be highly active in inducing the synthesis and secretion of neurotrophic factors, including nerve growth factor (NGF), glial-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF). The inductions were in time- and dose-dependent manners. In cultured astrocytes, the phosphorylation of estrogen receptor was triggered by application of flavonoids. The phosphorylation was blocked by an inhibitor of estrogen receptor, which in parallel reduced the flavonoid-induced expression of neurotrophic factors. The results proposed the role of flavonoids in protecting brain diseases, and therefore these flavonoids could be developed for health food supplement for patients suffering from neurodegenerative diseases.

The expression of erythropoietin triggered by danggui buxue tang, a Chinese herbal decoction prepared from radix Astragali and radix Angelicae Sinensis, is mediated by the hypoxia-inducible factor in cultured HEK293T cells.

ETHNOPHARMACOLOGICAL EVIDENCE Danggui buxue tang (DBT), a Chinese medicinal decoction that is being commonly used as hematopoietic medicine to treating woman menopausal irregularity, contains two herbs: radix Astragali and radix Angelicae Sinensis. Pharmacological results indicate that DBT can stimulate the production of erythropoietin (EPO), a specific hematopoietic growth factor, in cultured cells. AIM OF THE STUDY In order to reveal the mechanism of DBTs hematopoietic function, this study investigated the activity of the DBT-induced EPO expression and the upstream regulatory cascade of EPO via hypoxia-induced signaling in cultured kidney fibroblasts (HEK293T). MATERIALS AND METHODS DBT-induced mRNA expressions were revealed by real-time PCR, while the change of protein expressions were analyzed by Western blotting. For the analysis of hypoxia-dependent signaling, a luciferase reporter was used to report the transcriptional activity of hypoxia response element (HRE). RESULTS The plasmid containing HRE, being transfected into HEK293T, was highly responsive to the challenge of DBT application. To account for the transcriptional activation of HRE, DBT treatment was shown to increase the mRNA and protein expressions of hypoxia-inducible factor-1α (HIF-1α). In addition, the activation of Raf/MEK/ERK signaling pathway by DBT could also enhance the translation of HIF-1α, suggesting the dual actions of DBT in stimulating the EPO expression in kidney cells. CONCLUSION Our study indicates that HIF pathway plays an essential role in directing DBT-induced EPO expression in kidney. These results provide one of the molecular mechanisms of this ancient herbal decoction for its hematopoietic function.

Galangin, a flavonol derived from Rhizoma Alpiniae Officinarum, inhibits acetylcholinesterase activity in vitro.

Acetylcholinesterase (AChE) inhibitors are widely used for the treatment of Alzheimers disease (AD). Several AChE inhibitors, e.g. rivastigmine, galantamine and huperzine are originating from plants, suggesting that herbs could potentially serve as sources for novel AChE inhibitors. Here, we searched potential AChE inhibitors from flavonoids, a group of naturally occurring compounds in plants or traditional Chinese medicines (TCM). Twenty-one flavonoids, covered different subclasses, were tested for their potential function in inhibiting AChE activity from the brain in vitro. Among all the tested flavonoids, galangin, a flavonol isolated from Rhizoma Alpiniae Officinarum, the rhizomes of Alpiniae officinarum (Hance.) showed an inhibitory effect on AChE activity with the highest inhibition by over 55% and an IC(50) of 120 microM and an enzyme-flavonoid inhibition constant (K(i)) of 74 microM. The results suggest that flavonoids could be potential candidates for further development of new drugs against AD.

Chemical and biological assessment of Angelicae Sinensis Radix after processing with wine: an orthogonal array design to reveal the optimized conditions.

The roots of Angelica sinensis [Angelica Sinensis Radix (ASR)] have been used as a common health food supplement for womens care for thousands of years in China. According to Asian tradition, ASR could be processed with the treatment of wine, which subsequently promoted the biological functions of ASR. By chemical and biological assessments, an orthogonal array design was employed here to determine the roles of three variable parameters in the processing of ASR, including oven temperature, baking time, and flipping frequency. The results suggested that oven temperature and baking time were two significant factors, while flipping frequency was a subordinate factor. The optimized condition of processing with wine therefore was considered to be heating in an oven at 80 °C for 90 min with flipping twice per hour. Under the optimized processing conditions, the solubilities of ferulic acid and Z-ligustilide from ASR were markedly increased and decreased, respectively. In parallel, the biological functions of processed ASR were enhanced in both anti-platelet aggregation and estrogenic activation; these increased functions could be a result of the altered levels of ferulic acid and Z-ligustilide in wine-processed ASR. Thus, the chemical and biological assessment of the processed ASR was in full accordance with the Chinese old tradition.

Trillin, a steroidal saponin isolated from the rhizomes of Dioscorea nipponica, exerts protective effects against hyperlipidemia and oxidative stress.

ETHNOPHARMACOLOGICAL EVIDENCE Numerous efforts have been conducted in searching for effective agents against cardiovascular diseases, in particular from herbal medicines. The rhizome of Dioscorea nipponica (Dioscoreae Nipponicae Rhizoma) is a traditional Chinese herb being prescribed to improve the blood circulation. Here, we identified a steroidal saponin trillin from Dioscorea nipponica, which showed robust anti-hyperlipidemic effects. MATERIALS AND METHODS Rats were induced for hyperlipidemia and subjected to the drug treatment. The anti-hyperlipidemic effects of trillin were evaluated by different biochemical assays. RESULTS In hyperlipidemic rat model, fed with high-fat diet, the blood levels of cholesterol, triglyceride, low density lipoprotein (LDL) and high density lipoprotein (HDL) were increased. The intra-peritoneal administration of trillin into those rats significantly improved the bleeding and blood coagulation time, and in parallel the treatment restored the levels of cholesterol, glyceride, LDL and HDL back to the normal condition. In addition, the administration of trillin in rats exerted beneficial effects in improving the levels of lipid peroxidation and superoxide dismutase activity. CONCLUSION This was the first time to reveal the anti-hyperlipidemic and anti-oxidative effects of trillin. These results would be important in developing food supplements for health improvements and therapeutic drugs against hyperlipidemia and cardiovascular diseases in future.

Modulation of protein adsorption, vascular cell selectivity and platelet adhesion by mussel-inspired surface functionalization

A mussel-inspired surface functionalization of the polydopamine (PDA) coating has been demonstrated to be a promising strategy to ensure the biocompatibility of various biomaterials. To explore the multifunctionality of the PDA coating for vascular stents and elucidate the mechanisms by which the PDA coating modulates vascular cell behavior, this study examined the protein adsorption, the responses of endothelial cells (ECs) and smooth muscle cells (SMCs), and platelet adhesion to various PDA-coated surfaces synthesized at varied initial dopamine concentrations. Our results indicate that various PDA coatings present distinct and varied functionalities. The quinone group on the PDA coating induces a substantially higher amount of protein adsorption, which subsequently plays a key role in promoting EC attachment and proliferation by regulating their focal adhesion and stress fiber formation. Meanwhile, the reactive phenolic hydroxyl group on the PDA coating potently inhibits SMC proliferation. In addition, the quinone-regulated fibrinogen adsorption to the PDA coating may increase platelet adhesion. Notably, the PDA coating synthesized at an initial dopamine concentration of 1.0 g L-1 shows the most favorable vascular cell selectivity. These findings shed light on the relationships between surface characteristics, protein adsorption, vascular cell behavior, and platelet adhesion of the PDA coating, which may guide better design of PDA application in vascular stents.

Estrogenic and Neuroprotective Properties of Scutellarin from Erigeron breviscapus: A Drug against Postmenopausal Symptoms and Alzheimer's Disease

Besides the classical hormonal effect, estrogen possesses neuroprotective effects in the brain, which leads to the searching of novel treatments for neurodegenerative diseases such as Alzheimers disease. Scutellarin is a major flavone derived from Herba Erigerontis, a Chinese medicine derived from Erigeron breviscapus, which has been shown here to possess both estrogenic and neuroprotective properties. Scutellarin showed the estrogenic effects by activating the estrogen responsive elements and phosphorylation of estrogen receptor alpha in cultured MCF-7 cells: the activation was in a dose-dependent manner. On the other hand, scutellarin inhibited the aggregation of beta-amyloid in vitro, and prevented the cell death mediated by beta-amyloid when applied to cultured neuronal PC12 cells. These results therefore suggested that Herba Erigerontis and its component scutellarin might have therapeutic effects against postmenopausal symptoms and Alzheimers disease.