The Powdered Root of Eurycoma longifolia Jack Improves Beta-Cell Number and Pancreatic Islet Performance through PDX1 Induction and Shows Antihyperglycemic Activity in db/db Mice.

Non-insulin-dependent diabetes mellitus (NIDDM) is a common metabolic disorder worldwide. In addition to the chief feature of long-standing hyperglycemia, dyslipidemia, hyperinsulinemia, and a number of complications develop in parallel. It is believed that an adequate control of blood glucose levels can cause these complications to go into remission. This study was performed to evaluate the antidiabetic activity of Eurycoma longifolia Jack (EL) in vivo. The blood-glucose-lowering activity of EL was studied in db/db mice administered crude powdered EL root (25, 50, and 100 mg/kg) orally for eight weeks. At the end of the study, HbA1c, insulin, plasma lipid levels, and histopathology were performed. Powdered EL root showed significant antihyperglycemic activity along with the control of body weight. After eight weeks of treatment, both the blood cholesterol level and the glycogen deposit in hepatocytes were remarkably lower, whereas the secreting insulin level was elevated. An improvement in islet performance was manifested as an increase in beta-cell number and pancreatic and duodenal homeobox 1 (PDX1) expression. Neogenesis or formation of new islets from pancreatic duct epithelial cells seen in the EL-treated group was encouraging. This study confirms the antihyperglycemic activity of EL through PDX1-associated beta-cell expansion resulting in an enhancement of islet performance.

Glycemia Lowering Effect of an Aqueous Extract of Hedychium coronarium Leaves in Diabetic Rodent Models.

Hedychium coronarium has a long history of use worldwide as a food and in folk medicine. In this study, we aimed to investigate the effect of an aqueous extract of H. coronarium leaves (HC) on type 2 diabetes mellitus (T2DM). Two types of animal models were used in this study: Streptozotocin (STZ)-induced T2DM (Wistar rats; N = 8) and C57BKSdb/db mice (N = 5). After treatment with HC for 28 days, glucose tolerance improved in both of the diabetic animal models. As significant effects were shown after 14 days of treatment in the STZ-induced T2DM model, we carried out the experiments with it. After 28 days of treatment with HC, the levels of cholesterol, triglyceride, high-density lipoprotein, and low-density lipoprotein were significantly improved in the STZ-induced T2DM model. The lesions degree of islet ß-cells was decreased after the HC treatment. Although the insulin level increased moderately, the aldosterone level was significantly decreased in the HC-treated groups, suggesting that aldosterone might play an important role in this effect. In summary, HC is a natural product and it is worth exploring its effect on T2DM.

The fungus-derived retinoprotectant theissenolactone C improves glaucoma-like injury mediated by MMP-9 inhibition.

BACKGROUND: Elevated intraocular pressure (IOP) is a major risk factor for glaucoma that has been found to induce matrix metalloproteinase-9 (MMP-9) activation and result in eventual retinal dysfunction. Proinflammatory cytokines such as monocyte chemoattractant protein-1 (MCP-1) and interleukin-1ß (IL-1ß) were also found to be involved in disease progression by mediating MMP-9 production. We previously reported that fungal derivative theissenolactone C (LC53) could exert ocular protective effects by suppressing neuroinflammation in experimental uveitis. PURPOSE: The aim of this study was to investigate the retinoprotective effects of natural compound LC53 on the high IOP-induced ischemia/reperfusion (I/R)-injury model of glaucoma and its cellular mechanisms. METHODS: A high IOP-induced I/R-injury model was manipulated by normal saline injection into the anterior chamber of the rat eye. MCP-1-stimulated monocytes and IL-1ß-activated primary astrocytes were used to investigate the cellular mechanisms of LC53. Retinal function was evaluated with the scotopic threshold response (STR) and combined rod-cone response by electroretinography (ERG). As a positive control, rats were treated with memantine. MMP-9 gelatinolysis, mRNA expression and protein expression were analyzed by gelatin zymography, RT-PCR, and Western Blot, respectively. The phosphorylation levels of MAPKs and NF-κB p65 were tested by Western Blot. Additionally, the levels of inflammatory MCP-1 and IL-1ß were determined by ELISA. RESULTS: The present study revealed that LC53 preserved the retina functional deficiency assessed by scotopic threshold response (STR) and combined rod-cone response of ERG after high IOP-induced I/R injury. These retinal protective effects of LC53 were positively correlated with inhibitory activities in I/R injury-elicited ocular MMP-9 activation and expression. The increased level of MCP-1 was not affected, and the enhanced IL-1ß production was partially reduced by LC53 in the retina after I/R injury. According to cellular studies, LC53 significantly and concentration-dependently abrogated MMP-9 activation and expression in MCP-1-stimulated THP-1 monocytes. We found the inhibitory activities of LC53 were through the ERK- and NF-κB-dependent pathways. In addition, LC53 dramatically suppressed IL-1ß-induced MMP-9 activation and expression in primary astrocytes. The phosphorylation of 65-kD protein (p65) of NF-κB was substantially blocked by LC53 in IL-1ß-stimulated primary astrocytes. CONCLUSION: LC53 exerted a retinal protective effect through NF-κB inhibition and was highly potent against MMP-9 activities after high IOP-induced I/R injury, suggesting that LC53 would be a promising drug lead for glaucoma or related medical conditions attributed to retinal ischemia.

Novel Protective Effects of Cistanche Tubulosa Extract Against Low-Luminance Blue Light-Induced Degenerative Retinopathy.

BACKGROUND/AIMS: Blue light-emitting diode light (BLL)-induced phototoxicity plays an important role in ocular diseases and causes retinal degeneration and apoptosis in human retinal pigment epithelial (RPE) cells. Cistanche tubulosa extract (CTE) is a traditional Chinese medicine with many beneficial protective properties; however, few studies have examined the ocular protective roles of CTE. In this study, we investigated the mechanisms underlying the effects of CTE on BLL-induced apoptosis in vitro and in vivo. METHODS: RPE cells were applied in the current in vitro study and cell viability was determined by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis-related protein expression was determined by western blot analysis and immunofluorescence staining. Brown Norway rats were used to examine exposure to commercially available BLL in vivo. Hematoxylin and eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and western blot assays were used to examine retinal morphological deformation. RESULTS: CTE significantly inhibited hydrogen peroxide-, tert-butyl hydroperoxide-, sodium azide-, and BLL-induced RPE damage. Further, CTE reduced the expression of apoptotic markers such as cleaved caspase-3 and TUNEL staining after BLL exposure by inactivating apoptotic pathways, as shown via immunofluorescent staining. In addition, CTE inhibited the BLL-induced phosphorylation of c-Jun N-terminal kinase, extra signal-related kinases 1/2, and p38 in RPE cells. In vivo, the oral administration of CTE rescued 60-day periodic BLL exposure-induced decrements in retinal thickness and reduced the number of TUNEL-positive cells in the brown Norway rat model. CONCLUSION: CTE is a potential prophylactic agent against BLL-induced phototoxicity.

The Novel HDAC8 Inhibitor WK2-16 Attenuates Lipopolysaccharide-Activated Matrix Metalloproteinase-9 Expression in Human Monocytic Cells and Improves Hypercytokinemia In Vivo.

Dysregulated human monocytes/macrophages can synthesize and secrete matrix metalloproteinases (MMPs), which play important roles in the progression of sepsis. In this study, we investigated the effects and mechanism of a novel histone deacetylase (HDAC8) inhibitor, (E)-N-hydroxy-4-methoxy-2-(biphenyl-4-yl)cinnamide (WK2-16), on MMP-9 production and activation in stimulated human monocytic THP-1 cells. Our results demonstrated that the acetylation level of structural maintenance of chromosomes 3 (SMC3) was up-regulated by WK2-16 in THP-1 cells. Consistently, an in vitro enzyme study demonstrated that WK2-16 selectively inhibited HDAC8 activity. Moreover, the WK2-16 concentration dependently suppressed MMP-9-mediated gelatinolysis induced by tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS). Additionally, WK2-16 significantly inhibited both MMP-9 protein and mRNA expression without cellular toxicity. Nevertheless, WK2-16 suppressed the extracellular levels of interleukin (IL)-6 from LPS-stimulated THP-1 cells. For the signaling studies, WK2-16 had no effect on LPS/TLR4 downstream signaling pathways, such as the NF-κB and ERK/JNK/P38 MAPK pathways. On the other hand, WK2-16 enhanced the recruitment of acetylated Yin Yang 1 (YY1) with HDAC1. Finally, in vivo studies indicated that WK2-16 could reduce the serum levels of TNF-α and IL-6 in endotoxemic mice. These results suggested that HDAC8 inhibition might provide a novel therapeutic strategy of hypercytokinemia in sepsis.

The natural retinoprotectant chrysophanol attenuated photoreceptor cell apoptosis in an N-methyl-N-nitrosourea-induced mouse model of retinal degenaration.

Retinitis pigmentosa (RP) is an inherited photoreceptor-degenerative disease, and neuronal degeneration in RP is exacerbated by glial activation. Cassia seed (Jue-ming-zi) is a traditional herbal medicine commonly used to treat ocular diseases in Asia. In this report, we investigated the retina-protective effect of chrysophanol, an active component of Cassia seed, in an N-methyl-N-nitrosourea (MNU)-induced mouse model of RP. We determined that chrysophanol inhibited the functional and morphological features of MNU-induced retinal degeneration using scotopic electroretinography (ERG), optical coherence tomography (OCT), and immunohistochemistry analysis of R/G opsin and rhodopsin. Furthermore, TUNEL assays revealed that chrysophanol attenuated MNU-induced photoreceptor cell apoptosis and inhibited the expression of the apoptosis-associated proteins PARP, Bax, and caspase-3. In addition, chrysophanol ameliorated reactive gliosis, as demonstrated by a decrease in GFAP immunolabeling, and suppressed the activation of matrix metalloproteinase (MMP)-9-mediated gelatinolysis. In vitro studies indicated that chrysophanol inhibited lipopolysaccharide (LPS)-induced iNOS and COX-2 expression in the BV2 mouse microglia cell line and inhibited MMP-9 activation in primary microglia. Our results demonstrate that chrysophanol provided neuroprotective effects and inhibited glial activation, suggesting that chrysophanol might have therapeutic value for the treatment of human RP and other retinopathies.

The Involvement of Serotonin in the Hypoglycemic Effects Produced by Administration of the Aqueous Extract of Xylaria nigripes with Steroid-Induced Insulin-Resistant Rats.

Xylaria nigripes (XN) is a medicinal fungus with a high-economic value. The aim of this study was to explore the hypoglycemic effects and mechanisms of the XN aqueous extract in steroid-induced insulin-resistant (SIIR) rats. Significant hypoglycemic effects were observed 60 min after administration of XN aqueous extract. In normal Wistar, hypoglycemic effects were 21% (the plasma glucose level decreased from 128.6 ± 12.5 to 100.9 ± 10.7 mg/dL). In SIIR, hypoglycemic effects were 26% (the plasma glucose level decreased from 177.6 ± 12.5 to 133.3 ± 29.7 mg/dL) rats refer to their baseline. The signaling proteins for insulin-receptor substrate-1 and glucose transporter-4 increased 0.51-fold and 1.12-fold, respectively, as determined by Western blotting; the increase in the proteins was 13% and 9%, respectively, as determined by immunohistochemistry. The serotonin antagonist, α-p-chlorophenylalanine, effectively blocked the hypoglycemic effects and increased the signaling protein levels. After XN administration, none of the animals showed significant changes in plasma-free fatty acids in 60 min. In summary, the XN extract may have hypoglycemic effects in normal Wistar and SIIR rats that may have a serotonin-related hypoglycemic effect and enhance insulin sensitivity in the SIIR rats.

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.

Evaluation of Acute 13-Week Subchronic Toxicity and Genotoxicity of the Powdered Root of Tongkat Ali (Eurycoma longifolia Jack).

Tongkat Ali (Eurycoma longifolia) is an indigenous traditional herb in Southern Asia. Its powdered root has been processed to produce health supplements, but no detailed toxicology report is available. In this study, neither mutagenicity nor clastogenicity was noted, and acute oral LD50 was more than 6 g/kg b.w. After 4-week subacute and 13-week subchronic exposure paradigms (0, 0.6, 1.2, and 2 g/kg b.w./day), adverse effects attributable to test compound were not observed with respect to body weight, hematology, serum biochemistry, urinalysis, macropathology, or histopathology. However, the treatment significantly reduced prothrombin time, partial thromboplastin time, blood urea nitrogen, creatinine, aspartate aminotransferase, creatine phosphate kinase, lactate dehydrogenase, and cholesterol levels, especially in males (P < 0.05). These changes were judged as pharmacological effects, and they are beneficial to health. The calculated acceptable daily intake (ADI) was up to 1.2 g/adult/day. This information will be useful for product development and safety management.

Aqueous extracts of Cordyceps militaris (Ascomycetes) lower the levels of plasma glucose by activating the cholinergic nerve in streptozotocin-induced diabetic rats.

In our previous research, Cordyceps militaris (CM) had a hypoglycemic effect in normal rats. In this study we wanted to elucidate whether CM also had an effect on diabetic rats. Twelve rats with streptozotocin-induced diabetes were separated randomly into 2 groups. First, aqueous extracts of CM 10 mg/kg (CM group) or saline (control group) was fed to the rats; then the plasma glucose levels were assayed. Second, the signaling proteins IRS-1 and GLUT-4 collected from the muscle were detected. Finally, another 2 groups of rats were injected with atropine 0.1 mg/kg intraperitoneally just before the CM/saline feeding, and the assays mentioned above were repeated. Blood glucose decreased 7.2% in the CM group but only 1.5% in the control group (P < 0.05). The IRS-1 signal was 2.9-fold higher than actin in the CM group but only 0.8-fold higher in the control group (P < 0.005). In GLUT-4 signal, the difference was 1.7- vs. 0.6-fold, respectively, compared with actin (P < 0.05). However, atropine injection made CM-induced hypoglycemia or elevation of IRS-1 and GLUT-4 not significant. In conclusion, CM had a hypoglycemic effect in diabetic rats and atropine blocked it. Therefore, the cholinergic activation also was considered to be involved in the hypoglycemic effect of CM in rats with streptozotocin-induced diabetes.

Extracts of Cordyceps militaris lower blood glucose via the stimulation of cholinergic activation and insulin secretion in normal rats.

Previous studies have shown that Cordyceps militaris (CM) has a hypoglycemic effect, but the actual mechanism remains unclear. This study explored the hypoglycemic mechanism of aqueous extracts of CM in normal Wistar rats. First, the optimal dose of CM for lowering plasma glucose and insulin secretion was tested. Further, atropine and hemicholinium-3 (HC-3) were injected and a western blot was used to investigate insulin signaling. It was found that 10 mg/kg CM extracts had a stronger hypoglycemic effect than a higher dose (100 mg/kg); therefore, a dose of 10 mg/kg was used in subsequent experiments. In normal rats, CM extracts decreased plasma glucose by 21.0% and induced additional insulin secretion by 54.5% after 30 min. When atropine or HC-3 was injected, CM induced a hypoglycemic effect, but the enhancement of insulin secretion was blocked. By western blotting, significant increases in the insulin receptor substrate 1 (IRS-1) and glucose transporter 4 (GLUT-4) were observed after CM feeding. However, the elevation of these signaling proteins was abolished by atropine or HC-3. Taken together, these findings indicate that CM can lower plasma glucose via the stimulation of insulin secretion and cholinergic activation involved in the hypoglycemic mechanism of normal Wistar rats.

Suppression of matrix metalloproteinase-9 expression by andrographolide in human monocytic THP-1 cells via inhibition of NF-κB activation.

There is much evidence indicating that human leukemic cells and monocytes/macrophages synthesize, and secrete, several matrix metalloproteinases (MMPs), and participate in the degradation of extracellular matrix components in tissue lesions. In this study, we investigated the effects and mechanisms of andrographolide, extracted from the herb Andrographis paniculata, on human monocytic MMPs expression and activation. Andrographolide (1-50 µM) exhibited concentration-dependent inhibition of MMP-9 activation, induced by either tumor necrosis factor-α (TNF-α), or lipopolysaccharide (LPS), in THP-1cells. In addition, andrographolide did not present an inhibitory effect on MMP-9 enzymatic activity at a concentration of 50 µM. By contrast, enzyme-linked immunosorbent assay (ELISA) showed that andrographolide partially affect TIMP-1 levels. Western blot analysis showed that both TNF-α, and LPS stimulators attenuated MMP-9 protein expression in a concentration-dependent manner. Using reverse transcription polymerase chain reaction (RT-PCR), we found that andrographolide suppressed expression of MMP-9 messenger RNA. Furthermore, we also found that andrographolide could significantly inhibit the degradation of inhibitor-κB-α (IκB-α) induced by TNF-α. We used electrophoretic mobility shift assay and reporter gene detection to show that andrographolide also markedly inhibited NF-κB signaling, anti-translocation and anti-activation. In conclusion, we demonstrate that andrographolide attenuates MMP-9 expression, and its main mechanism might involve the NF-κB signal pathway. These results provide new opportunities for the development of new anti-inflammatory and leukemic therapies.

Zinc oxide nanoparticles-induced intercellular adhesion molecule 1 expression requires Rac1/Cdc42, mixed lineage kinase 3, and c-Jun N-terminal kinase activation in endothelial cells.

The explosive development of nanotechnology has caused an increase in unintended biohazards in humans and in the ecosystem. Similar to particulate matter, nanoparticles (NPs) are strongly correlated with the increase in incidences of cardiovascular diseases, yet the mechanisms behind this correlation remain unclear. Within the testing concentrations of 0.1-10 µg/ml, which did not cause a marked drop in cell viability, zinc oxide NPs (ZnO-NPs) induced intercellular adhesion molecule-1 (ICAM-1) messenger RNA, and protein expression in both concentration- and time-dependent manner in treated human umbilical vein endothelial cells (HUVECs). ZnO-NPs treatment cause the activation of Ras-related C3 botulinum toxin substrate 1 (Rac1)/cell division control protein 42 homolog (Cdc42) and protein accumulation of mixed lineage kinase 3 (MLK3), followed by c-Jun N-terminal kinase (JNK) and transcription factor c-Jun activation. Induction of ICAM-1 and phosphorylation of JNK and c-Jun could be inhibited by either JNK inhibitor SP600125 or Rac guanosine triphosphatase inhibitor NSC23766 pretreatment. In addition, pretreatment with NSC23766 significantly reduced MLK3 accumulation, suggesting the involvement of Rac1/Cdc42-MLK3-JNK-c-Jun signaling in the regulation of ZnO-NPs-induced ICAM-1 expression, whereas these signaling factors were not activated in zinc oxide microparticles (ZnO-MPs)-treated HUVECs. The increase of ICAM-1 expression on ZnO-NPs-treated HUVECs enables leukocytes to adhere and has been identified as an indicator of vascular inflammation. Our data are essential for safety evaluation of the clinical usage of ZnO-NPs in daily supplements, cosmetics, and biomedicines.

Shikonin inhibited mitogen-activated IL-4 and IL-5 production on EL-4 cells through downregulation of GATA-3 and c-Maf induction.

AIM: To investigate the effects of shikonin on phorbol myristate acetate (PMA) plus cyclic adenosine monophosphate (cAMP)-induced T helper (T(H)) 2 cell cytokine production, and the underlying mechanism. MAIN METHODS: We used activated EL-4 murine T-lymphoma cells, which produce interleukin (IL)-4 and IL-5, but not interferon (IFN)-γ, as T(H)2 cell-like cells and treated them with PMA+cAMP to investigate the effects of shikonin on T(H)2 cytokines, transcriptional factors, and the related mitogen-activated protein kinase (MAPK)/nuclear factor (NF)-κB signaling pathway. KEY FINDINGS: The data show that shikonin inhibited the PMA+cAMP-induced mRNA and protein expression of IL-4 and IL-5 via the downregulation of GATA-binding protein-3 (GATA-3) and c-musculoaponeurotic fibrosarcoma (Maf) but not T-box expressed in T cells (T-bet). Moreover, shikonin suppressed the phosphorylation of p38, inhibitor of κB (IκB) kinase (IKK)-ß and IκB-α, and the subsequent IκB-α degradation induced by PMA+cAMP; however, the PMA+cAMP-induced phosphorylation of extracellular signal-related kinase (ERK), which resulted in minor inhibition and phosphorylation of c-Jun N-terminal kinase (JNK), seemed to be unaffected by shikonin treatment. SIGNIFICANCE: This study suggests that downregulation of GATA-3 and c-Maf via the suppression of p38, IKK-ß and IκB-α phosphorylation might contribute to the inhibitory effect of shikonin on mitogen-induced IL-4 and IL-5 production in EL-4T cells. Furthermore, shikonin is a potential drug for treating allergic diseases.

Myrrh mediates haem oxygenase-1 expression to suppress the lipopolysaccharide-induced inflammatory response in RAW264.7 macrophages.

OBJECTIVES: To elucidate a novel anti-inflammatory mechanism of myrrh against lipopolysaccharide (LPS)-induced inflammation. METHODS: RAW264.7 macrophages were cultured in DMEM and then cells were treated with LPS or LPS plus a myrrh methanol extract (MME) for 24h. The culture medium was collected for determination of nitric oxide (NO), prostaglandin (PG)E(2) , interleukin (IL)-1ß, and tumour necrosis factor (TNF)-α, and cells were harvested by lysis buffer for Western blot analysis. KEY FINDINGS: Our data showed that treatment with the MME (1∼100µg/ml) did not cause cytotoxicity or activate haem oxygenase-1 (HO-1) protein synthesis in RAW264.7 macrophages. Furthermore, the MME inhibited LPS-stimulated NO, PGE(2) , IL-1ß and TNF-α release and inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 protein expression. Zn(II) protoporphyrin IX, a specific inhibitor of HO-1, blocked the inhibition of iNOS and COX-2 expression by the MME. CONCLUSIONS: These results suggest that among mechanisms of the anti-inflammatory response, the MME inhibited the production of NO, PGE(2) , IL-1ß and TNF-α by downregulating iNOS and COX-2 gene expression in macrophages and worked through the action of HO-1.

Electroacupuncture-induced cholinergic nerve activation enhances the hypoglycemic effect of exogenous insulin in a rat model of streptozotocin-induced diabetes.

The aim of this study is to explore the mechanisms by which electroacupuncture (EA) enhances the hypoglycemic effect of exogenous insulin in a streptozotocin- (STZ-) diabetic rats. Animals in the EA group were anesthetized and subjected to the insulin challenge test (ICT) and EA for 60 minutes. In the control group, rats were subjected to the same treatment with the exception of EA stimulation. Blood samples were drawn to measure changes in plasma glucose, free fatty acids (FFA), and insulin levels. Western blot was used to assay proteins involved in insulin signaling. Furthermore, atropine, hemicholinium-3 (HC-3), and Eserine were used to explore the relationship between EA and cholinergic nerve activation during ICT. EA augmented the blood glucose-lowering effects of EA by activating the cholinergic nerves in STZ rats that had been exposed to exogenous insulin. This phenomenon may be related to enhancement of insulin signaling rather than to changes in FFA concentration.

Aristolochic acid downregulates monocytic matrix metalloproteinase-9 by inhibiting nuclear factor-κB activation.

Aristolochic acid (AA)-associated nephropathy was described as being characterized by a rapid progressive enhancement of interstitial renal fibrosis. Renal tissue fibrosis occurs because of an imbalance of extracellular matrix (ECM) accumulation and matrix metalloproteinase (MMP) activation. Much evidence indicates that inflammatory renal disease including monocyte and mesangial interactions is linked to the development and progression of renal remodeling. In this study, we found that AA showed concentration-dependent inhibition of tumor necrosis factor (TNF)-α-induced MMP-9 activation with an IC(50) value of 6.4±0.5µM in human monocytic THP-1 cells. A similar effect was also noted with different ratios of AAs (types I and II). However, AA had no inhibitory effect on the intact enzymatic activity of MMP-9 at a concentration of 20µM. On the other hand, the level of tissue inhibitor of metalloproteinase (TIMP)-1 was not induced by AA, but it suppressed TNF-α-induced MMP-9 protein and messenger RNA expressions. AA also significantly inhibited TNF-α-induced IκBα degradation. Furthermore, an electrophoretic mobility shift assay and a reported gene study, respectively, revealed that AA inhibited TNF-α-induced NF-κB translocation and activation. In addition, compared to other NF-κB inhibitors, AA exerted significant inhibition of MMP-9 activation and monocyte chemotactic protein-1-directed invasion. From these results, we concluded that AA, a natural compound, inhibits TNF-α-induced MMP-9 in human monocytic cells possibly through the NF-κB signal pathway. These results also imply that AA may be involved in alteration of matrix homeostasis during renal fibrosis in vivo.

Electroacupuncture improves glucose tolerance through cholinergic nerve and nitric oxide synthase effects in rats.

The purpose of this investigation was to evaluate the effect and mechanisms of electroacupuncture (EA) at the bilateral Zusanli acupoints (ST-36) on glucose tolerance in normal rats. Intravenous glucose tolerance test (IVGTT) was performed to examine the effects of electroacupuncture (EA) on glucose tolerance in rats. The EA group underwent EA at the ST-36, with settings of 15 Hz, 10 mA, and 60 min; the control group underwent the same treatments, but without EA. Atropine, hemicholinium-3 (HC-3) or NG-nitro-L-arginine methyl ester (L-NAME) were injected into the rats alone or simultaneously and EA was performed to investigate differences in plasma glucose levels compared to the control group. Plasma samples were obtained for assaying plasma glucose and free fatty acid (FFA) levels. Western blot was done to determine the insulin signal protein and nNOS to exam the correlation between EA and improvement in glucose tolerance. The EA group had significantly lower plasma glucose levels compared to the control group. Plasma glucose levels differed significantly between the EA and control groups after the administration of L-NAME, atropine, or HC-3 treatments alone, but there were no significant differences in plasma glucose with combined treatment of L-NAME and atropine or L-NAME and HC-3. EA decreased FFA levels and enhanced insulin signal protein (IRS1) and nNOS activities in skeletal muscle during IVGTT. In summary, EA stimulated cholinergic nerves and nitric oxide synthase for lowering plasma FFA levels to improve glucose tolerance.

Shikonin inhibits maturation of bone marrow-derived dendritic cells and suppresses allergic airway inflammation in a murine model of asthma.

BACKGROUND AND PURPOSE: Shikonin exhibits a wide range of anti-inflammatory actions. Here, we assessed its effects on maturation of murine bone marrow-derived dendritic cells (BM-DCs) and on allergic reactions in a murine model of asthma. EXPERIMENTAL APPROACH: Cultured murine BM-DCs were used to investigate the effects of shikonin on expression of cell surface markers and their stimulation of T-cell proliferation and cytokine production. The therapeutic potential of shikonin was evaluated in a model of allergic airway disease. KEY RESULTS: Shikonin dose-dependently inhibited expression of major histocompatibility complex class II, CD80, CD86, CCR7 and OX40L on BM-DCs, induced by a mixture of ovalbumin (OVA; 100µg·mL(-1) ) and thymic stromal lymphopoietin (TSLP; 20ng·mL(-1) ). Shikonin-treated BM-DCs were poor stimulators of CD4(+) T lymphocyte and induced lower levels of interleukin (IL)-4, IL-5, IL-13 and tumour necrosis factor (TNF)-α release by responding T-cells. After intratracheal instillation of shikonin in OVA-immunized mice, OVA challenge induced lower IL-4, IL-5, IL-13, TNF-α and eotaxin release in bronchial alveolar lavage fluid, lower IL-4 and IL-5 production in lung cells and mediastinal lymph node cells and attenuated OVA-induced lung eosinophilia and airway hyperresponsiveness. CONCLUSION AND IMPLICATIONS: Shikonin effectively suppressed OVA + TSLP-induced BM-DC maturation in vitro and inhibited allergic inflammation and airway hyperresponsiveness in a murine model of asthma, showing good potential as a treatment for allergic asthma. Also, our model provides a novel platform for screening drugs for allergic diseases.

Anti-herpes simplex virus effects of berberine from Coptidis rhizoma, a major component of a Chinese herbal medicine, Ching-Wei-San.

Berberine is an alkaloid extracted from Coptidis rhizome. Among the individual herbal components of a Chinese herb medicine, Ching-Wei-San, Coptidis Rhizoma has the most potent antimicrobial activity. By high-pressure liquid chromatography, the quantitative analysis of berberine from 6.25-mg/mL (w/v) Coptidis rhizome extract or 50.00-mg/mL (w/v) Ching-Wei-San was determined to be 0.26 mg/mL. To explore the potential use of Ching-Wei-San against herpes simplex virus (HSV) infection, the cytotoxicity, anti-HSV-1 and anti-HSV-2 activity in Vero cells were assayed. The selectivity index of berberine was about 1.2-1.5 times higher than that of Coptidis rhizome extract and Ching-Wei-San. Moreover, the antiviral activities correspond to the content of berberine in the aqueous solution. Berberine may interfere with the viral replication cycle after virus penetration and no later than the viral DNA synthesis step, and its activities were not affected by the preparation processes. Berberine, the natural plants that contain this component, including Coptidis rhizome, and Ching-Wei-San have all shown anti-HSV effects.