Combination Treatment of Sorafenib and Bufalin Induces Apoptosis in NCI-H292 Human Lung Cancer Cells In Vitro.

BACKGROUND/AIM: Lung cancer notably contributes to tumor-associated mortality worldwide, and standard chemotherapy is used for lung cancer patients. However, its therapeutic efficacy remains unsatisfactory. This study aimed to evaluate the effects and molecular mechanisms of sorafenib and bufalin combination therapy on lung cancer cells in vitro. MATERIALS AND METHODS: NCI-H292 cells were treated with sorafenib, bufalin, and sorafenib in combination with bufalin. Cell viability, ROS production, Ca2+ release, and mitochondrial membrane potential were examined by flow cytometric assay. Annexin V/PI staining and chromatin condensation were examined by the apoptosis assays. Finally the molecular mechanism of apoptosis-associated protein expression was investigated by western blotting. RESULTS: NCI-H292 cells treated with sorafenib in combination with bufalin showed significantly decreased viability, enhanced cellular apoptosis, and DNA condensation when compared to that with sorafenib or bufalin alone. Moreover, the combination treatment exhibited higher reactive oxygen species (ROS) production and lower mitochondrial membrane potential (ΔΨm). The combined treatment resulted in higher expression of SOD but lower catalase compared to sorafenib treatment alone. Compared to sorafenib or bufalin treatment alone, the combination treatment resulted in lower Bcl-2 expression but higher Bax, Bad, APAF-1, caspase-3, and caspase-9. CONCLUSION: Sorafenib in combination with bufalin shows more potent cytotoxic effects and cell apoptosis than sorafenib or bufalin treatment alone in NCI-H292 cells. The combined treatment significantly enhanced apoptotic cell death in NCI-H292 lung cancer cells by activating ROS-, mitochondria-, and caspase-signaling pathways in vitro.

Deguelin Impairs Cell Adhesion, Migration and Invasion of Human Lung Cancer Cells through the NF-[Formula: see text]B Signaling Pathways.

Deguelin, a rotenoid, is isolated from a natural plant species, and has biological activities including antitumor function. In the present study, we investigated the effect of deguelin on the cell adhesion, migration and invasion of NCI-H292 human lung cancer cells in vitro. Cell viability was analyzed by using flow cytometer. Cell adhesion was determined by using the cell-matrix adhesion assay. Wound healing assay was used to examine cell migration. Cell migration and invasion were investigated using a Boyden chamber assay. The protein expression was measured by Western blotting and confocal laser microscopy. The electrophoretic mobility shift assay was used to measure NF-[Formula: see text]B p65 binding to DNA.We selected the concentrations of deguelin at 0, 0.5, 1.0, 1.5, 2.0 and 2.5[Formula: see text][Formula: see text]M and we found that those concentrations of deguelin did not induce significant cytotoxic effects on NCI-H292 cells. Thus, we selected those concentrations of deguelin for metastasis assay. We found that deguelin inhibited cell adhesion, migration and invasion in dose-dependent manners that was assayed by wound healing and transwell methods, respectively. Deguelin decreased the expression of MMP-2/-9, SOS 1, Rho A, p-AKT (Thr308), p-ERK1/2, p-p38, p-JNK, NF-[Formula: see text]B (p65) and uPA in NCI-H292 cells. Deguelin suppressed the expression of PI3K, SOS 1, NF-[Formula: see text]B (p65), but did not significantly affect PKC and Ras in the nuclei of NCI-H292 cells that were confirmed by confocal laser microscopy. We suggest that deguelin may be used as a novel anticancer metastasis of lung cancer in the future.

Gastro-Resistant Insulin Receptor-Binding Peptide from Momordica charantia Improved the Glucose Tolerance in Streptozotocin-Induced Diabetic Mice via Insulin Receptor Signaling Pathway.

Momordica charantia is a commonly used food and has been used for the management of diabetes. Our previous study has identified an insulin receptor (IR)-binding protein (mcIRBP) from Momordica charantia. Here we identified the gastro-resistant hypoglycemic bioactive peptides from protease-digested mcIRBP. By in vitro digestion and IR kinase activity assay, we found that a 9-amino-acid-residue peptide, mcIRBP-9, was a gastro-resistant peptide that enhanced IR kinase activities. mcIRBP-9 activated IR signaling transduction pathway, which resulted in the phosphorylation of IR, the translocation of glucose transporter 4, and the uptake of glucose in cells. Intraperitoneal and oral administration of mcIRBP-9 stimulated the glucose clearance by 30.91 ± 0.39% and 32.09 ± 0.38%, respectively, in streptozotocin-induced diabetic mice. Moreover, a pilot study showed that daily ingestion of mcIRBP-9 for 30 days decreased the fasting blood glucose levels and glycated hemoglobin (HbA1c) levels by 23.62 ± 6.14% and 24.06 ± 1.53%, respectively. In conclusion, mcIRBP-9 is a unique gastro-resistant bioactive peptide generated after the digestion of mcIRBP. Furthermore, oral administration of mcIRBP-9 improves both the glucose tolerance and the HbA1c levels in diabetic mice via targeting IR signaling transduction pathway.

Bufalin Inhibits NCI-H460 Human Lung Cancer Cell Metastasis In Vitro by Inhibiting MAPKs, MMPs, and NF-κB Pathways.

Bufalin, a component of Chan Su (a traditional Chinese medicine), has been known to have antitumor effects for thousands of years. In this study, we investigated its anti-metastasis effects on NCI-H460 lung cancer cells. Under sub-lethal concentrations (from 25 up to 100 nM), bufalin significantly inhibits the invasion and migration nature of NCI-H460 cells that were measured by Matrigel Cell Migration Assay and Invasion System. Bufalin also suppressed the enzymatic activity of matrix metalloproteinase (MMP)-9, which was examined by gelatin zymography methods. Western blotting revealed that bufalin depressed several key metastasis-related proteins, such as NF-κB, MMP-2, MMP-9, protein kinase C (PKC), phosphatidylinositol 3-kinase (PI3-K), phosphorylated Akt, growth factor receptor-bound protein 2 (GRB2), phosphorylated extracellular signal-regulated kinase (ERK), phosphorylated p38, and phosphorylated c-Jun NH2-terminal kinase (JNK). As evidenced by immunostaining and the electrophoretic mobility shift assay (EMSA), bufalin induced not only a decreased cytoplasmic NF-κB production, but also decreased its nuclear translocation. Several metastasis-related genes, including Rho-associated (Rho A), coiled-coil-containing protein kinase 1 (ROCK1), and focal adhesion kinase (FAK), were down-regulated after bufalin treatment. In conclusion, bufalin is effective in inhibiting the metastatic nature of NCI-H460 cells in low, sub-lethal concentrations. Such an effect involves many mechanisms including MMPs, mitogen-activated protein kinases (MAPKs) and NF-κB systems. Bufalin has a potential to evolve into an anti-metastasis drug for human lung cancer in the future.

Kaempferol induces DNA damage and inhibits DNA repair associated protein expressions in human promyelocytic leukemia HL-60 cells.

Numerous evidences have shown that plant flavonoids (naturally occurring substances) have been reported to have chemopreventive activities and protect against experimental carcinogenesis. Kaempferol, one of the flavonoids, is widely distributed in fruits and vegetables, and may have cancer chemopreventive properties. However, the precise underlying mechanism regarding induced DNA damage and suppressed DNA repair system are poorly understood. In this study, we investigated whether kaempferol induced DNA damage and affected DNA repair associated protein expression in human leukemia HL-60 cells in vitro. Percentages of viable cells were measured via a flow cytometry assay. DNA damage was examined by Comet assay and DAPI staining. DNA fragmentation (ladder) was examined by DNA gel electrophoresis. The changes of protein levels associated with DNA repair were examined by Western blotting. Results showed that kaempferol dose-dependently decreased the viable cells. Comet assay indicated that kaempferol induced DNA damage (Comet tail) in a dose-dependent manner and DAPI staining also showed increased doses of kaempferol which led to increased DNA condensation, these effects are all of dose-dependent manners. Western blotting indicated that kaempferol-decreased protein expression associated with DNA repair system, such as phosphate-ataxia-telangiectasia mutated (p-ATM), phosphate-ataxia-telangiectasia and Rad3-related (p-ATR), 14-3-3 proteins sigma (14-3-3σ), DNA-dependent serine/threonine protein kinase (DNA-PK), O(6)-methylguanine-DNA methyltransferase (MGMT), p53 and MDC1 protein expressions, but increased the protein expression of p-p53 and p-H2AX. Protein translocation was examined by confocal laser microscopy, and we found that kaempferol increased the levels of p-H2AX and p-p53 in HL-60 cells. Taken together, in the present study, we found that kaempferol induced DNA damage and suppressed DNA repair and inhibited DNA repair associated protein expression in HL-60 cells, which may be the factors for kaempferol induced cell death in vitro.

A novel glycated hemoglobin A1c-lowering traditional Chinese medicinal formula, identified by translational medicine study.

Diabetes is a chronic metabolic disorder that has a significant impact on the health care system. The reduction of glycated hemoglobin A1c is highly associated with the improvements of glycemic control and diabetic complications. In this study, we identified a traditional Chinese medicinal formula with a HbA1c-lowering potential from clinical evidences. By surveying 9,973 diabetic patients enrolled in Taiwan Diabetic Care Management Program, we found that Chu-Yeh-Shih-Kao-Tang (CYSKT) significantly reduced HbA1c values in diabetic patients. CYSKT reduced the levels of HbA1c and fasting blood glucose, and stimulated the blood glucose clearance in type 2 diabetic mice. CYSKT affected the expressions of genes associated with insulin signaling pathway, increased the amount of phosphorylated insulin receptor in cells and tissues, and stimulated the translocation of glucose transporter 4. Moreover, CYSKT affected the expressions of genes related to diabetic complications, improved the levels of renal function indexes, and increased the survival rate of diabetic mice. In conclusion, this was a translational medicine study that applied a "bedside-to-bench" approach to identify a novel HbA1c-lowering formula. Our findings suggested that oral administration of CYSKT affected insulin signaling pathway, decreased HbA1c and blood glucose levels, and consequently reduced mortality rate in type 2 diabetic mice.

Deer Antler Extract Improves Fatigue Effect through Altering the Expression of Genes Related to Muscle Strength in Skeletal Muscle of Mice.

Deer antler is a well-known traditional Chinese medicine used in Asian countries for the tonic and the improvement of aging symptoms. The present study was designed to investigate the antifatigue effect and mechanism of Formosan sambar deer tip antler extract (FSDTAE). The swimming times to exhaustion of mice administered FSDTAE (8.2 mg/day) for 28 days were apparently longer than those of the vehicle-treated mice in forced swim test. However, the indicators of fatigue, such as the reduction in glucose level and the increases in blood urea nitrogen and lactic acid levels, were not significantly inhibited by FSDTAE. Therefore, microarray analysis was further used to examine the anti-fatigue mechanism of FSDTAE. We selected genes with fold changes >2 or <-2 in skeletal muscle for pathway analysis. FSDTAE-affected genes were involved in 9 different signaling pathways, such as GnRH signaling pathway and insulin signaling pathway. All of the significantly expressed genes were classified into 8 different categories by their functions. The most enriched category was muscular system, and 6 upregulated genes, such as troponin I, troponin T1, cysteine and glycine-rich protein 2, myosin heavy polypeptide 7, tropomyosin 2, and myomesin family member 3, were responsible for the development and contraction of muscle. Real-time PCR analysis indicated that FSDTAE increased troponins mRNA expression in skeletal muscle. In conclusion, our findings suggested that FSDTAE might increase the muscle strength through the upregulation of genes responsible for muscle contraction and consequently exhibited the anti-fatigue effect in mice.

The suppressive activities of six sources of medicinal ferns known as gusuibu on heat-labile enterotoxin-induced diarrhea.

Diarrheal disease is one of the most important worldwide health problems. Enterotoxigenic Escherichia coli (ETEC) is the most frequently isolated enteropathogen in diarrheal diseases. In developing countries, a very large number of people, especially children, suffer from diarrhea. To combat this problem, World Health Organization has constituted the Diarrhea Diseases Control Program which guides studies on traditional medicinal practices and preventive measures. Gusuibu, a traditional folk medicine, has been claimed to heal certain types of diarrhea. However, so far no scientific study has been carried out on the anti-diarrheal mechanism of Gusiubu. The present study was performed to examine the suppressive activities of ethanol extracts of six sources of folk medicinal ferns used as Gusuibu on heat-labile enterotoxin (LT)-induced diarrhea. Inhibitory effects of six sources were evaluated on the ETEC LT subunit B (LTB) and monosialotetrahexosylganglioside (GMI) interaction by GM1-enzyme linked immunosorbent assay and patent mouse gut assay. Our results indicated that Drynaria fortunei had no anti-diarrheal effect, while, among the remaining five folk medicinal ferns, four belonging to family Davalliaceae had significant abilities on both the blocking of LTB and GM1 interaction and the inhibition of LT-induced diarrhea. In conclusion, these findings suggested the potential application of Gusuibu as an anti-diarrheal remedy.

Peroxisome proliferator-activated receptor activating hypoglycemic effect of Gardenia jasminoides Ellis aqueous extract and improvement of insulin sensitivity in steroid induced insulin resistant rats.

BACKGROUND: The active components of Gardenia (Gardenia jasminoides Ellis, GJ) exhibit a hypoglycemic effect by improving insulin secretion and lowering plasma lipids. In the present study, we fed a water extract of gardenia to steroid-induced insulin-resistant (SIIR) rats and observed changes in signaling proteins in order to elucidate the mechanisms of the insulin-sensitizing effect of GJ and evaluate its possibility as an insulin-sensitizing agent. METHODS: Normal Wistar rats were randomly divided into a control group (i.e., saline) and experimental groups (GJ 100 and 200 mg/kg). Blood samples were taken at 0, 30, and 60 min for plasma glucose assay in order to determine the optimal dose to induce the hypoglycemic effect. SIIR rats were then randomly divided into a control group (i.e., saline) and an experimental group (optimal dose of gardenia extract) to observe the insulin-sensitizing effect of the extract. Finally, western blot analysis was performed to detect intracellular signaling proteins to elucidate the mechanisms of the insulin-sensitization effect of GJ. RESULTS: The normal Wistar rats in the GJ 200 mg/kg group exhibited significant hypoglycemic activity. Meanwhile, the SIIR rats had higher plasma glucose levels than normal rats. There was no obvious change in insulin level, but the insulin sensitivity index and homeostasis model assessment index were significantly elevated. Meanwhile, a significant hypoglycemic effect was observed with GJ 200 mg/kg. In addition, intracellular signaling proteins including insulin receptor substrate-1 (IRS-1) and peroxisome proliferator-activated receptor (PPARγ) were elevated in muscle cells. CONCLUSIONS: The optimal dose of GJ aqueous extract of 200 mg/kg exerts a PPARγ-activating hypoglycemic effect and improves insulin resistance in SIIR rats. Therefore, it is a potential insulin-sensitizing agent in type 2 diabetes mellitus with insulin resistance.

Crude extract of Euphorbia formosana inhibits the migration and invasion of DU145 human prostate cancer cells: The role of matrix metalloproteinase-2/9 inhibition via the MAPK signaling pathway.

Prostate cancer is a common worldwide health problem in males with a poor prognosis due in part to tumor invasion and migration. The crude extract of Euphorbia formosana (CEEF) has been used for the treatment of numerous diseases, however, its effects on the migration and invasion of prostate cancer cells have yet to be examined. In the present study, we investigated the effects of CEEF on the migration and invasion of DU145 human prostate cancer cells in vitro. The wound healing assay and the Matrigel-uncoated migration assay were used to examine the migration of cancer cells. Western blotting was used to examine the levels of proteins associated with migration and invasion, and gelatin zymography was used to examine the secretion levels of matrix metalloproteinases-2 and -9 (MMP­2/9) from DU145 cells following exposure to CEEF. The results indicated that CEEF suppressed the migration and invasion of DU145 prostate cancer cells and that these effects are exerted in a concentration- and time-dependent manner. CEEF inhibited the ERK1/2, p38, JNK, SOS1, PKC, PI3K and MMP-2/9 protein expression in DU145 cells. The results demonstrated that CEEF suppressed the migration and invasion of DU145 cells through inhibition of the mitogen-activated protein kinase (MAPK) signaling pathway resulting in the inhibition of MMP-2/9 in DU145 human prostate cancer cells.

Identification of Escherichia coli enterotoxin inhibitors from traditional medicinal herbs by in silico, in vitro, and in vivo analyses.

ETHNOPHARMACOLOGICAL RELEVANCE: Glycyrrhiza uralensis has been used for the treatment of gastrointestinal disorders, such as diarrhea, in several ancient cultures. Glycyrrhizin is the principal component of liquorice and lots of pharmacological effects have been demonstrated. AIM OF THE STUDY: Heat-labile enterotoxin (LT), the virulence factor of enterotoxigenic Escherichia coli, induces diarrhea by initially binding to the GM1 on the surfaces of intestinal epithelial cells and consequently leading to the massive loss of fluid and ions from cells. Therefore, we evaluated the inhibitory effects of traditional medicinal herbs (TMH) on the B subunit of LT (LTB) and GM1 interaction. MATERIALS AND METHODS: The inhibitory effects of TMH on LTB-GM1 interaction were evaluated by GM1-enzyme-linked immunosorbent assay (ELISA). The likely active phytochemicals of these TMH were then predicted by in silico model (docking) and analyzed by in vitro (GM1-ELISA) and in vivo (patent mouse gut assay) models. RESULTS: We found that various TMH, which have been ethnomedically used for the treatment of diarrhea, inhibited the LTB-GM1 interaction. Docking data showed that triterpenoids were the most active phytochemicals and the oleanane-type triterpenoids presented better LTB-binding abilities than other types of triterpenoids. Moreover, by in vitro and in vivo models, we demonstrated that glycyrrhizin was the most effective oleanane-type triterpenoid that significantly suppressed both the LTB-binding ability (IC50=3.26+/-0.17 mM) and the LT-induced fluid accumulation in mice. CONCLUSIONS: We found an LT inhibitor, glycyrrhizin, from TMH by in silico, in vitro, and in vivo analyses.

Eriobotrya japonica leaf and its triterpenes inhibited lipopolysaccharide-induced cytokines and inducible enzyme production via the nuclear factor-kappaB signaling pathway in lung epithelial cells.

Pulmonary inflammation is a characteristic of many lung diseases. Increased levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and proinflammatory cytokines, such as interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and IL-8, have been correlated with lung inflammation. In this study, we used lipopolysaccharide (LPS) to induce iNOS, COX-2, and cytokines (TNF-alpha, IL-1beta, and IL-8) productions in human lung epithelial cells (A-549). Leaf of Eriobotrya japonica (Pi-Pa-Ye, PPY), a traditional Chinese medicine for the treatment of pulmonary inflammatory diseases, was capable of suppressing LPS-induced cytokine productions in a dose-dependent manner. Moreover, the suppression of PPY on the cytokine productions resulted from the inhibition of inhibitory kappaB-alpha phosphorylation and nuclear factor-kappaB (NF-kappaB) activation. Analysis of the anti-inflammatory effects of ursolic acid and oleanolic acid, the triterpene compounds present in PPY, showed that ursolic acid significantly inhibited LPS-induced IL-8 production, NF-kappaB activation, and iNOS mRNA expression, whereas oleanolic acid did not have these effects. In conclusion, our findings suggested the potential mechanisms of PPY and its active component, ursolic acid, in the treatment of pulmonary inflammation.

Inhibition of lipopolysaccharide-induced interleukin-1beta and tumor necrosis factor-alpha production by menthone through nuclear factor-kappaB signaling pathway in HaCat cells.

Menthone, the Chinese old remedy extracted from genus Mentha, has been widely used as a cooling agent, a counterirritant for pain relief, and for the treatment of pruritus. However, its detail mechanisms for interfering inflammatory reaction remain unknown. In this study, we found that menthone can suppress the lipopolysaccharide (LPS)-induced proinflammatory cytokines, interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), as well as nuclear factor kappaB (NF-kappaB) activity induced by LPS and other inflammatory agents, including 12-O-tetradecanoylphorbol-13-acetate, hydrogen peroxide, okadaic acid, and ceramide. Furthermore, our data also demonstrated that the translocation of NF-kappaB activated by LPS into the nucleus was suppressed by menthone, and I-kappaB and beta-transducin repeat containing protein (beta-TrCP) were both involved in this suppression. To sum up, this study has provided molecular evidence for menthone effect on the LPS-induced cytokine production, NF-kappaB activation, and the involvement of I-kappaB and beta-TrCP.

Relationship Between San-Huang-Xie-Xin-Tang and its herbal components on the gene expression profiles in HepG2 cells.

Traditional Chinese medicine (TCM) has been used for thousands of years. Most Chinese herbal formulae consist of several herbal components and have been used to treat various diseases. However, the mechanisms of most formulae and the relationship between formulae and their components remain to be elucidated. Here we analyzed the putative mechanism of San-Huang-Xie-Xin-Tang (SHXXT) and defined the relationship between SHXXT and its herbal components by microarray technique. HepG2 cells were treated with SHXXT or its components and the gene expression profiles were analyzed by DNA microarray. Gene set enrichment analysis indicated that SHXXT and its components displayed a unique anti-proliferation pattern via p53 signaling, p53 activated, and DNA damage signaling pathways in HepG2 cells. Network analysis showed that most genes were regulated by one molecule, p53. In addition, hierarchical clustering analysis showed that Rhizoma Coptis shared a similar gene expression profile with SHXXT. These findings may explain why Rhizoma Coptis is the principle herb that exerts the major effect in the herbal formula, SHXXT. Moreover, this is the first report to reveal the relationship between formulae and their herbal components in TCM by microarray and bioinformatics tools.

Ginger and its bioactive component inhibit enterotoxigenic Escherichia coli heat-labile enterotoxin-induced diarrhea in mice.

Ginger is one of the most commonly used fresh herbs and spices. Enterotoxigenic Escherichia coli heat-labile enterotoxin (LT)-induced diarrhea is the leading cause of infant death in developing countries. In this study, we demonstrated that ginger significantly blocked the binding of LT to cell-surface receptor G M1, resulting in the inhibition of fluid accumulation in the closed ileal loops of mice. Biological-activity-guided searching for active components showed that zingerone (vanillylacetone) was the likely active constituent responsible for the antidiarrheal efficacy of ginger. Further analysis of chemically synthesized zingerone derivatives revealed that compound 31 (2-[(4-methoxybenzyl)oxy]benzoic acid) significantly suppressed LT-induced diarrhea in mice via an excellent surface complementarity with the B subunits of LT. In conclusion, our findings provide evidence that ginger and its derivatives may be effective herbal supplements for the clinical treatment of enterotoxigenic Escherichia coli diarrhea.

Inhibition of Escherichia coli heat-labile enterotoxin-induced diarrhea by Chaenomeles speciosa.

Enterotoxigenic Escherichia coli (ETEC) is responsible for millions of deaths in developing countries. Heat-labile enterotoxin (LT), the virulence factor of ETEC, induces diarrhea by initially binding to the G(M1) on the surface of intestinal epithelial cells and consequently leading to the massive loss of fluid and ions from cells. Fruit of Chaenomeles (FC), the dried fruit of Chaenomeles speciosa, has been used for diarrhea in China. However, the anti-diarrheal mechanism of FC is still unclear. In this study, we demonstrated that FC extract (FCE) inhibited the LT-induced diarrhea in mice by blocking the binding of the B subunit of LT (LTB) to G(M1). The ethyl acetate (EA) soluble fraction was the most active fraction of FC that significantly abolished the LTB and G(M1) interaction. Furthermore, the oleanolic acid, ursolic acid, and betulinic acid from EA fraction, blocked the toxin binding effects, resulting in the suppression of LT-induced diarrhea. Moreover, by docking techniques, these compounds fitted LTB well via hydrogen bonds and hydrophobic contacts with amino acid residues of LTB. In conclusion, our findings suggested that oleanolic acid, ursolic acid, and betulinic acid were the active constituents from FC and might be considered as lead therapeutic agents in the treatment of LT-induced diarrhea.

Emodin blocks the SARS coronavirus spike protein and angiotensin-converting enzyme 2 interaction.

Severe acute respiratory syndrome (SARS) is an emerging infectious disease caused by a novel coronavirus (SARS-CoV). SARS-CoV spike (S) protein, a type I membrane-bound protein, is essential for the viral attachment to the host cell receptor angiotensin-converting enzyme 2 (ACE2). By screening 312 controlled Chinese medicinal herbs supervised by Committee on Chinese Medicine and Pharmacy at Taiwan, we identified that three widely used Chinese medicinal herbs of the family Polygonaceae inhibited the interaction of SARS-CoV S protein and ACE2. The IC(50) values for Radix et Rhizoma Rhei (the root tubers of Rheum officinale Baill.), Radix Polygoni multiflori (the root tubers of Polygonum multiflorum Thunb.), and Caulis Polygoni multiflori (the vines of P. multiflorum Thunb.) ranged from 1 to 10 microg/ml. Emodin, an anthraquinone compound derived from genus Rheum and Polygonum, significantly blocked the S protein and ACE2 interaction in a dose-dependent manner. It also inhibited the infectivity of S protein-pseudotyped retrovirus to Vero E6 cells. These findings suggested that emodin may be considered as a potential lead therapeutic agent in the treatment of SARS.

Gastrodia elata modulated activator protein 1 via c-Jun N-terminal kinase signaling pathway in kainic acid-induced epilepsy in rats.

Gastrodia elata (Orchidaceae) is a Chinese herb. Our previous study showed that Gastrodia elata is able to reduce epileptic seizures, oxygen free radicals, microglia activation, and apoptosis in kainic acid (KA)-treated rats. Activator protein 1 (AP-1) is involved in modulating the neuronal plasticity and apoptosis. Therefore, the aim of this study was to investigate the role of AP-1 in antiepileptic effect of Gastrodia elata. Gastrodia elata (0.5, 1.0g/kg) or valproic acid (VA, 250mg/kg) was administered orally in Sprague-Dawley rats for 1 week before and 2 weeks after intraperitoneal injection of KA. Protein levels of AP-1 were determined by measuring c-Jun and c-Fos proteins, and the mitogen-activated protein (MAP) kinases activations were determined by measuring the phosphorylations of extracellular signal-regulated kinases, p38, and c-Jun N-terminal kinases (JNKs) in the frontal cortex and the hippocampus of rat brain using Western blotting. These results indicated that pre-treatment with Gastrodia elata or VA activated JNK signal pathway and c-Jun expression, while post-treatment with Gastrodia elata or VA suppressed both the JNK signaling pathway and the c-Jun expression induced by KA. These findings suggested that Gastrodia elata regulated the AP-1 expression via the JNK signaling pathway in KA-induced epilepsy.

Anti-diarrheal effect of Galla Chinensis on the Escherichia coli heat-labile enterotoxin and ganglioside interaction.

Enterotoxigenic Escherichia coli (ETEC) is the most frequently isolated enteropathogen, accounting for approximately 210 million diarrhea episodes annually. ETEC-induced diarrhea is initiated by the binding of B subunit of heat-labile enterotoxin (LTB) to the ganglioside G(M1) on the surface of intestinal epithelial cell. Therefore, we evaluated the inhibitory effects of 297 Chinese medicinal herbs on the LTB and G(M1) interaction by G(M1)-enzyme-linked immunosorbent assay. Galla Chinensis extract (GCE) exhibited anti-LT-induced diarrheal effect in the patent mouse gut assay, with IC50 value of 4.7+/-1.3 mg/ml. GCE also inhibited the binding of LTB to G(M1), suggesting that GCE suppressed the LT-induced fluid accumulation by blocking the binding of LTB to G(M1). Furthermore, the ethyl acetate (EA) soluble fraction was the most active fraction of Galla Chinensis that inhibiting the binding of LTB to G(M1) with an IC50 value of 153.6+/-3.4 microg/ml. The major components of the EA fraction should be phenolic derivatives according to a thin-layer chromatography analysis. Gallic acid, the major component of EA fraction, blocked the binding of LTB to G(M1), resulting in the suppression of LT-induced diarrhea. In conclusion, these data suggested that Galla Chinensis and gallic acid might be potent drugs for the treatment of LT-induced diarrhea.