Effect of the Chinese herb extract osthol on IL-4-induced eotaxin expression in BEAS-2B cells

Osthole enhances the immunosuppressive effects of bone marrow-derived mesenchymal stem cells by promoting the Fas/FasL system

Thanks to the advantages of easy harvesting and escape from immune rejection, autologous bone marrow-derived mesenchymal stem cells (BMSCs) are promising candidates for immunosuppressive therapy against inflammation and autoimmune diseases. However, the therapy is still challenging because the immunomodulatory properties of BMSCs are always impaired by immunopathogenesis in patients. Because of its reliable and extensive biological activities, osthole has received increased clinical attention. In this study, we found that BMSCs derived from osteoporosis donors were ineffective in cell therapy for experimental inflammatory colitis and osteoporosis. In vivo and in vitro tests showed that because of the down-regulation of Fas and FasL expression, the ability of osteoporotic BMSCs to induce T-cell apoptosis decreased. Through the application of osthole, we successfully restored the immunosuppressive ability of osteoporotic BMSCs and improved their treatment efficacy in experimental inflammatory colitis and osteoporosis. In addition, we found the immunomodulatory properties of BMSCs were enhanced after osthole pre-treatment. In this study, our data highlight a new approach of pharmacological modification (ie osthole) to improve the immune regulatory performance of BMSCs from a healthy or inflammatory microenvironment. The development of targeted strategies to enhance immunosuppressive therapy using BMSCs may be significantly improved by these findings.

Osthole Attenuates Macrophage Activation in Experimental Asthma by Inhibitingthe NF-ĸB/MIF Signaling Pathway

Inhibition of activated macrophages is an alternative therapeutic strategy for asthma. We investigated whether a coumarin compound, osthole, isolated from Cnidium monnieri (L.) Cuss, alleviated macrophage activation in vivo and in vitro. Osthole could reduce expression of a marker of activated macrophages, cluster of differentiation (CD)206, in an ovalbumin-challenge model of asthma in mice. Osthole could also inhibit infiltration of inflammatory cells, collagen deposition and production of proinflammatory cytokines [interleukin (IL)-1β, tumor necrosis factor-ɑ, macrophage migration inhibitory factor (MIF)] in asthmatic mice. In vitro, expression of phosphorylated-IĸBɑ, MIF and M2 cytokines (Ym-1, Fizz-1, arginase-1) in IL-4-induced macrophages decreased upon exposure to the NF-ĸB inhibitor MG-132. In our short hairpin (sh)RNA-MIF-knockdown model, reduced expression of M2 cytokines was detected in the IL-4 + shRNA-MIF group. Osthole could attenuate the proliferation and migration of an IL-4-induced rat alveolar macrophages line (NR8383). Osthole could reduce IL-4-induced translocation of nuclear factor-kappa B (NF-ĸB) in NR8383 cells. Collectively, our results suggest that osthole ameliorates macrophage activation in asthma by suppressing the NF-ĸB/MIF signaling pathway, and might be a potential agent for treating asthma.

Osthole Reduces Mouse IOP Associated With Ameliorating Extracellular Matrix Expression of Trabecular Meshwork Cell

Purpose

Elevation of IOP in POAG is thought to involve excessive accumulation of extracellular matrix in the trabecular meshwork (TM), leading to an increase in outflow resistance of the aqueous humor. Osthole, a coumarin derivative extracted from the fruit of a variety of plants, such as Cnidium monnieri, is reported to prevent profibrotic responses by inhibiting Smad signaling pathway activated by TGF-β in liver, kidney, and cardiac tissues. We tested if osthole can (1) inhibit TGF-β2–induced extracellular matrix expression in cultured human TM (HTM) cells, and (2) lower TGF-β2–induced ocular hypertension in the mouse.

Methods

Cultured HTM cells were treated with 5 ng/mL TGF-β2 for 48 hours, then with osthole for 24 hours. The expressions of fibronectin, collagen type IV, and laminin were assessed by quantitative PCR, Western blot, and immunocytochemistry. BALB/cJ mice were injected intravitreally with an adenoviral vector encoding a bioactive mutant of TGF-β2 (Ad.hTGF-β2^226/228) in one eye to induce ocular hypertension, with the uninjected contralateral or Ad.Empty-injected eye serving as controls. Mice were then treated with a daily intraperitoneal injection of 30 mg/kg osthole. Conscious mouse IOP values were measured using a TonoLab rebound tonometer.

Results

In cultured HTM cells, stimulation with TGF-β2 increased expressions of fibronectin, collagen IV, and laminin. These in vitro changes were significantly and completely mitigated by osthole (10 µM). Daily intraperitoneal injections of 30 mg/kg osthole, starting either at day 0 (same day as Ad.hTGF-β2226/228 injection) or at day 14, significantly decreased TGF-β2–induced ocular hypertension in the mouse. In contrast, osthole did not affect IOP of control eyes.

Conclusions

These results demonstrated that osthole is capable of reducing TGF-β2–induced extracellular matrix expression in cultured HTM cells. It also reduced TGF-β2–induced ocular hypertension in the mouse. These findings indicate that this natural product may be useful as a novel treatment for POAG.

Osthole attenuates ovalbumin‑induced lung inflammation via the inhibition of IL‑33/ST2 signaling in asthmatic mice

Asthma is a common chronic inflammatory airway disease. Recent studies have reported that interleukin (IL)-33 is a potential link between the airway epithelium and Th2-type inflammatory responses, which are closely related to the progression of asthma. The IL-33 receptor, ST2, is highly expressed in group 2 innate lymphoid cells (ILC2s), Th2 cells, mast cells, eosinophils and natural killer (NK) cells. Cnidii Fructus is a Chinese herb with a long history of use in the treatment of asthma in China. Osthole is one of the major components of Cnidii Fructus. The present study examined the anti-asthmatic effects of osthole in mice and aimed to elucidate the underlying mechanisms involving the IL-33/ST2 pathway. BALB/c mice were sensitized and challenged with ovalbumin and then treated with an intraperitoneal injection of osthole (25 and 50 mg/kg). Subsequently, the airway hyper-responsiveness (AHR) and inflammation of the lungs were evaluated. The amounts of IL-4, IL-5, IL-13, interferon (IFN)-γ and IL-33 in the bronchoalveolar lavage fluid (BALF) were measured by Luminex assay and their mRNA levels in the lungs were measured by reverse transcription-quantitative PCR. The histopathology of the lungs was performed with H&E, PAS and Masson's staining. The expression of ST2 in the lungs was evaluated by immunohistochemistry. The data demonstrated that osthole markedly reduced AHR and decreased the number of eosinophils and lymphocytes in BALF. It was also observed that osthole significantly inhibited the release of Th2-type cytokines (IL-4, IL-5 and IL-13) and upregulated the IFN-γ level in BALF. Moreover, osthole significantly attenuated the IL-33 and ST2 expression in the lungs of asthmatic mice. On the whole, osthole attenuated ovalbumin-induced lung inflammation through the inhibition of IL-33/ST2 signaling in an asthmatic mouse model. These results suggest that osthole is a promising target for the development of an asthma medication.

Coumarins as Modulators of the Keap1/Nrf2/ARE Signaling Pathway

The Keap1/Nrf2/ARE system is a central defensive mechanism against oxidative stress which plays a key role in the pathogenesis and progression of many diseases. Nrf2 is a redox-sensitive transcription factor controlling a variety of downstream antioxidant and cytodefensive genes. Nrf2 has a powerful anti-inflammatory activity mediated via modulating NF-κB. Therefore, pharmacological activation of Nrf2 is a promising therapeutic strategy for the treatment/prevention of several diseases that are underlined by both oxidative stress and inflammation. Coumarins are natural products with promising pharmacological activities, including antioxidant, anticancer, antimicrobial, and anti-inflammatory efficacies. Coumarins are found in many plants, fungi, and bacteria and have been widely used as complementary and alternative medicines. Some coumarins have shown an ability to activate Nrf2 signaling in different cells and animal models. The present review compiles the research findings of seventeen coumarin derivatives of plant origin (imperatorin, visnagin, urolithin B, urolithin A, scopoletin, esculin, esculetin, umbelliferone, fraxetin, fraxin, daphnetin, anomalin, wedelolactone, glycycoumarin, osthole, hydrangenol, and isoimperatorin) as antioxidant and anti-inflammatory agents, emphasizing the role of Nrf2 activation in their pharmacological activities. Additionally, molecular docking simulations were utilized to investigate the potential binding mode of these coumarins with Keap1 as a strategy to disrupt Keap1/Nrf2 protein-protein interaction and activate Nrf2 signaling.

Phytochemistry, Ethnopharmacology, Pharmacokinetics and Toxicology of Cnidium monnieri (L.) Cusson

Cnidium monnieri (L.) Cusson (CMC) is a traditional Chinese herbal medicine that has been widely grown and used in Asia. It is also known as "She chuang zi" in China (Chinese: ), "Jashoshi" in Japan, "Sasangia" in Korea, and "Xa sang tu" in Vietnam. This study aimed to provide an up-to-date review of its phytochemistry, ethnopharmacology, pharmacokinetics, and toxicology. All available information on CMC was collected from the Encyclopedia of Traditional Chinese Medicines, PubMed, EMBASE, ScienceDirect, Scopus, Web of Science, and China Network Knowledge Infrastructure. The updated chemical structures of the compounds are those ones without chemical ID numbers or references from the previous review. A total of 429 chemical constituents have been elucidated and 56 chemical structures have been firstly identified in CMC with traceable evidence. They can be categorized as coumarins, volatile constituents, liposoluble compounds, chromones, monoterpenoid glucosides, terpenoids, glycosides, glucides, and other compounds. CMC has demonstrated impressive potential for the management of various diseases in extensive preclinical research. Since most of the studies are overly concentrated on osthole, more research is needed to investigate other chemical constituents.

Osthole decreases collagen I/III contents and their ratio in TGF-β1-overexpressed mouse cardiac fibroblasts through regulating the TGF-β/Smad signaling pathway

The present study was designed to elucidate whether the mechanism by which osthole decreases collagenI/III contents and their ratio is regulating the TGF-β/Smad signaling pathway in TGF-β1-overexpressed mouse cardiac fibroblasts (CFs). These CFs were cultured and treated with different concentrations of osthole. Our results showed that the TGF-β1 expression in the CFs transfected with that the recombinant expression plasmids pcDNA3.1(+)-TGF-β1 was significantly enhanced. After the CFs were treated with 1.25-5 μg·mL^-1 of osthole for 24 h, the mRNA and protein expression levels of collagensIand III were reduced. The collagen I/III ratio was also reduced. The mRNA and protein expression levels of TGF-β1, TβRI, Smad2/3, P-Smad2/3, Smad4, and α-SMA were decreased, whereas the expression level of Smad7 was increased. These effects suggested that osthole could inhibit collagen I and III expression and reduce their ratio via the TGF-β/Smad signaling pathway in TGF-β1 overexpressed CFs. These effects of osthole may play beneficial roles in the prevention and treatment of myocardial fibrosis.

Osthole inhibits pancreatic cancer progression by directly exerting negative effects on cancer cells and attenuating tumor-infiltrating M2 macrophages

Pancreatic cancer has remained a major cause of cancer-related deaths. A hallmark of pancreatic cancer is extensive stromal reactions, resulting in a unique tumor microenvironment, especially the involvement of macrophages. These tumor-educated cells limit the efficacy of chemotherapy. Therefore, it is necessary to identify an effective treatment strategy. In this study, we aimed to explore the anti-tumor and immunomodulatory effects of osthole on pancreatic cancer. We found that osthole suppressed Panc 02 cell migration and proliferation and induced apoptosis as shown in vitro. Osthole also attenuated the development of pancreatic cancer in mice by inhibiting tumor-infiltrating M2 macrophages in our study. Additionally, osthole inhibited the polarization of primary bone marrow cells into M2 macrophages and inhibited the expression of MRC1, CCL22 and TGF-β in the M2 polarization process in vitro. Detection of the related signaling pathways revealed that osthole exerted immunomodulatory effects on M2 macrophages by down-regulating p-STAT6 and the p-ERK1/2-C/EBP β axis. These results indicated that osthole has effective anti-tumor and immunomodulatory effects on pancreatic cancer.

Immune Homeostasis: Effects of Chinese Herbal Formulae and Herb-Derived Compounds on Allergic Asthma in Different Experimental Models

Allergic asthma is thought to arise from an imbalance of immune regulation, which is characterized by the production of large quantities of IgE antibodies by B cells and a decrease of the interferon-γ/interleukin-4 (Th1/Th2) ratio. Certain immunomodulatory components and Chinese herbal formulae have been used in traditional herbal medicine for thousands of years. However, there are few studies performing evidence-based Chinese medicine (CM) research on the mechanisms and effificacy of these drugs in allergic asthma. This review aims to explore the roles of Chinese herbal formulae and herb-derived compounds in experimental research models of allergic asthma. We screened published modern CM research results on the experimental effects of Chinese herbal formulae and herb-derived bioactive compounds for allergic asthma and their possible underlying mechanisms in English language articles from the PubMed and the Google Scholar databases with the keywords allergic asthma, experimental model and Chinese herbal medicine. We found 22 Chinese herb species and 31 herb-derived anti-asthmatic compounds as well as 12 Chinese herbal formulae which showed a reduction of airway hyperresponsiveness, allergen-specifific immunoglobulin E, inflflammatory cell infifiltration and a regulation of Th1 and Th2 cytokines in vivo, in vitro and ex vivo, respectively. Chinese herbal formulae and herbderived bioactive compounds exhibit immunomodulatory, anti-inflflammatory and anti-asthma activities in different experimental models and their various mechanisms of action are being investigated in modern CM research with genomics, proteomics and metabolomics technologies, which will lead to a new era in the development of new drug discovery for allergic asthma in CM.

Osthole treatment ameliorates Th2-mediated allergic asthma and exerts immunomodulatory effects on dendritic cell maturation and function

Osthole, an active component of Chinese herbal medicines, reportedly possesses various pharmacological properties and has potential therapeutic applications. This study explored the anti-allergic effects of osthole in asthmatic mice and investigated the immunomodulatory actions of osthole on dendritic cells (DCs) and T cells. Herein, we show that oral administration of osthole to BALB/c mice after ovalbumin (OVA) sensitization ameliorated all of the cardinal features of T helper 2 (Th2)-mediated allergic asthma; namely, the production of OVA-specific immunoglobulin E, airway hyperresponsiveness, airway inflammation and the production of Th2-type cytokines including interleukin (IL)-4, IL-5 and IL-13. Surprisingly, IL-10 production was not inhibited and was even enhanced by osthole treatment. We observed a significant increase in the percentages of IL-10-producing DCs and forkhead box P3-positive regulatory T (Treg) cells in osthole-treated asthmatic mice. Additionally, in vitro analyses revealed that osthole-treated bone-marrow-derived DCs had a partial maturation phenotype, secreting large amounts of IL-10 and low levels of proinflammatory cytokines, such as IL-12, IL-6 and tumor necrosis factor-α, and displaying reduced levels of MHC class II surface molecules. These DCs displayed immunosuppressive capacity by directly inhibiting effector T-cell responses or inducing Treg cells. In addition, osthole directly inhibited the activated CD4+ T-cell proliferation and Th1/Th2-type cytokine production in this system. Collectively, these results suggest that DCs and T cells are potential target cells responsible for the action of osthole against allergic asthma.Cellular &Molecular Immunology advance online publication, 7 August 2017; doi:10.1038/cmi.2017.71.

Osthole pretreatment alleviates TNBS-induced colitis in mice via both cAMP/PKA-dependent and independent pathways

Osthole, a natural coumarin found in traditional Chinese medicinal plants, has shown multiple biological activities. In the present study, we investigated the preventive effects of osthole on inflammatory bowel disease (IBD). Colitis was induced in mice by infusing TNBS into the colonic lumen. Before TNBS treatment, the mice received osthole (100 mg·kg^-1·d^-1, ip) for 3 d. Pretreatment with osthole significantly ameliorated the clinical scores, colon length shortening, colonic histopathological changes and the expression of inflammatory mediators in TNBS-induced colitis. Pretreatment with osthole elevated serum cAMP levels; but treatment with the PKA inhibitor H89 (10 mg·kg^-1·d^-1, ip) did not abolish the beneficial effects of osthole on TNBS-induced colitis. In mouse peritoneal macrophages, pretreatment with osthole (50 μmol/L) significantly attenuated the LPS-induced elevation of cytokines at the mRNA level; inhibition of PKA completely reversed the inhibitory effects of osthole on IL-1β, IL-6, COX2, and MCP-1 but not on TNFα. In Raw264.7 cells, the p38 inhibitor SB203580 markedly suppressed LPS-induced upregulation of the cytokines, whereas the PKA inhibitors H89 or KT5720 did not abolish the inhibitory effects of SB203580. Moreover, in LPS-stimulated mouse peritoneal macrophages, SB203580 strongly inhibited the restored expression of IL-1β, IL-6, COX2, and MCP-1, which was achieved by abolishing the suppressive effects of osthole with the PKA inhibitors. Western blot analysis showed that osthole significantly suppressed the phosphorylation of p38, which was induced by TNBS in mice or by LPS in Raw264.7 cells. Inhibition of PKA partially reversed the suppressive effects of osthole on p38 phosphorylation in LPS-stimulated cells. Collectively, our results suggest that osthole is effective in the prevention of TNBS-induced colitis by reducing the expression of inflammatory mediators and attenuating p38 phosphorylation via both cAMP/PKA-dependent and independent pathways, among which the cAMP/PKA-independent pathway plays a major role.

Anti-asthmatic activity of osthole in an ovalbumin-induced asthma murine model

Osthole, an active coumarin extracted from the dried fruits of Cnidium monnieri (L.) Cusson, is known to possess a variety of pharmacological activities. In the present study, we investigated and illuminated the mechanisms underlying the protective effects of osthole in an experimental model of allergic asthma. Our results show that osthole treatment significantly reduced the OVA-induced increase in serum IgE and inflammatory cytokines (IL-4, IL-5, IL-13) in bronchoalveolar lavage fluid (BALF), and decreased the recruitment of inflammatory cells in BALF and the lung. It also effectively attenuated goblet cell hyperplasia and mucus overproduction in lung tissue. In addition, western blot analysis demonstrated that osthole blocked NF-κB activation, which may be associated with a reduction in inflammatory cytokine production. These data suggest that osthole attenuated OVA-induced allergic asthma inflammation by inhibiting NF-κB activation. The present study identified the molecular mechanisms of action of osthole, which support the potential pharmaceutical application of osthole treatment for asthma and other airway inflammation disorders.

Anti-inflammatory effects of Salvia plebeia R. Br extract in vitro and in ovalbumin-induced mouse model

BACKGROUND

Asthma is an increasing global health problem, and novel strategies to prevent or ameliorate the condition are needed. Here, the effects of 80 % ethanol extracts of Salvia plebeia R. Br. (SE) on an induced inflammatory response were investigated.

RESULTS

Salvia plebeia R. Br. inhibited production of pro-inflammatory cytokines, such as TNF-α and IL-6, as well as nitric oxide (NO) in LPS-stimulated RAW 264.7 cells. NO and pro-inflammatory cytokine production was suppressed more effectively by SE of the aerial parts (SE-A) than of the roots (SE-R) of S. plebeia. In BEAS-2B cells, both SE-A and SE-R inhibited the increase in production of the inflammatory cytokines IL-6 and IL-8. We also investigated the anti-asthmatic effects of SE in an ovalbumin (OVA)-induced BALB/c mouse model. SE-A treatment significantly reduced the number of airway eosinophils, IL-4 and IL-13 levels, mucus production, and inflammatory infiltration, as compared with the corresponding levels in the untreated, OVA-induced mice, and had similar effects to dexamethasone.

CONCLUSIONS

Salvia plebeia ethanol extract ameliorated the induced inflammatory response in RAW 264.7 and BEAS-2B cells, with more effective inhibition noted for SE-A than for SE-R. SE-A treatment was effective in improving the histopathological changes in the lungs of asthma model mice via modulation of eosinophils and Th2 cytokines. These results suggest that SE-A can be considered as a therapeutic agent that can potentially relieve asthma.

Herbal Medicines for Asthmatic Inflammation: From Basic Researches to Clinical Applications

Asthma is one of the most common chronic inflammatory disorders, associated with reversible airflow obstruction, airway hyperresponsiveness, and airway remodeling. This disease has a significant impact on individuals, their families, and society. Standardized therapeutics such as inhaled corticosteroid in combination with long acting β2 agonist have been applied for asthma control; however, complementary and alternative medicines, especially herbal medicines, are still widely used all over the world. A growing body of literature suggests that various herbals or related products might be effective in inhibiting asthmatic inflammation. In this review, we summarize recent advances about the mechanistic studies of herbal medicines on allergic airway inflammation in animal models and their potential application into clinic for asthma control.

The Immunoregulatory Effects of Traditional Chinese Medicine on Treatment of Asthma or Asthmatic Inflammation

Asthma is a chronic respiratory symptoms with variable airflow limitation and airway hyperresponsiveness (AHR), and causes high economic burden. Traditional Chinese medicine (TCM) has a long-lasting history of using herbal medicine in the treatment of various respiratory diseases including asthma. In the last several decades, an increasing number of herbs have been shown to be effective in the treatment of asthma in clinical trials or asthmatic inflammation in animal models. Literature about the effects of TCM on the immune system were searched in electronic databases such as PubMed, Google Scholar and Scopus from 2000 to 2014. 'TCM' and 'asthma' were used as keywords for the searches. Over 400 literatures were searched and the literatures about the immune system were selected and reviewed. We only reviewed literatures published in English. Accumulating evidence suggests that TCM can directly inhibit the activation and migration of inflammatory cells, regulate the balance of Th1/Th2 responses, and suppress allergic hyperreactivity through inducing regulatory T cells or attenuating the function of dendritic cells (DCs). These studies provided useful information to facilitate the use of TCM to treat asthma. This review was conducted to classify the findings based on their possible mechanisms of action reported.

Cnidium monnieri: A Review of Traditional Uses, Phytochemical and Ethnopharmacological Properties

Cnidium monnieri (L.) Cuss., an annual plant of the Umbelliferae species is one of the most widely used traditional herbal medicines and its fruits have been used to treat a variety of diseases in China, Vietnam, and Japan. The aim of this review is to provide an up-to-date and comprehensive analysis of the botany, traditional uses, phytochemistry, pharmacology, toxicity and contraindication of Cnidium monnieri (L.) Cuss. and to provide future directions of research on this plant. To date, 350 compounds have been isolated and identified from Cnidium monnieri (L.) Cuss., including the main active constituent, coumarins. In vitro and in vivo studies suggest that osthole and other coumarin compounds possess wide range of pharmacological properties for the treatment of female genitals, male impotence, frigidity, skin-related diseases, and exhibit strong antipruritic, anti-allergic, antidermatophytic, antibacterial, antifungal, anti-osteoporotic effects. Although coumarins have been identified as the main active constituents responsible for the observed pharmacological effects, the molecular mechanisms of their actions are still unknown. Therefore, further studies are still required to reveal the structure-activity relationship of these active constituents. In addition, toxicological and clinical studies are also required to provide further data for pharmaceutical use.

Osthole: A Review on Its Bioactivities, Pharmacological Properties, and Potential as Alternative Medicine

This paper reviews the latest understanding of biological and pharmacological properties of osthole (7-methoxy-8-(3-methyl-2-butenyl)-2H-1-benzopyran-2-one), a natural product found in several medicinal plants such as Cnidium monnieri and Angelica pubescens. In vitro and in vivo experimental results have revealed that osthole demonstrates multiple pharmacological actions including neuroprotective, osteogenic, immunomodulatory, anticancer, hepatoprotective, cardiovascular protective, and antimicrobial activities. In addition, pharmacokinetic studies showed osthole uptake and utilization are fast and efficient in body. Moreover, the mechanisms of multiple pharmacological activities of osthole are very likely related to the modulatory effect on cyclic adenosine monophosphate (cAMP) and cyclic adenosine monophosphate (cGMP) level, though some mechanisms remain unclear. This review aims to summarize the pharmacological properties of osthole and give an overview of the underlying mechanisms, which showcase its potential as a multitarget alternative medicine.

Osthole Attenuates Inflammatory Responses and Regulates the Expression of Inflammatory Mediators in HepG2 Cells Grown in Differentiated Medium from 3T3-L1 Preadipocytes

This study explored the anti-inflammatory mechanisms by which osthole acted on HepG2 cells cultured in a differentiated medium from cultured 3T3-L1 preadipocyte cells. HepG2 cells, a human liver cell line, were treated with various concentrations of osthole in differentiated media from cultured 3T3-L1 cells to evaluate proinflammatory cytokines, inflammatory mediators, and signaling pathways. We used enzyme-linked immunosorbent assay kits to determine the levels of proinflammatory cytokines, real-time polymerase chain reaction to assay the mRNA expression, and western blot to determine the expression of cyclooxygenase-2 (COX-2) and heme oxygenase-1 (HO-1) proteins. We also investigated inflammatory mechanism pathway members, including mitogen-activated protein kinase (MAPK) and nuclear transcription factor kappa-B (NF-κB). Osthole was able to suppress the levels of proinflammatory cytokines interleukin (IL)-1β and IL-6, as well as chemokines monocyte chemoattractant protein-1 and IL-8. In addition, COX-2 was suppressed and HO-1 expression was increased in a concentration-dependent manner. Osthole was also able to decrease IκB-α phosphorylation and suppress the phosphorylation of MAPKs. These results suggest that osthole has anti-inflammatory effects as demonstrated by the decreased proinflammatory cytokine and mediator production through suppression of the NF-κB and MAPK signaling pathways in HepG2 cells when they are incubated on the differentiated medium from 3T3-L1 cells.

Inhibitory activity of Socheongryong‑tang and its constituent components against the production of RANTES, eotaxin, eotaxin‑3 and MMP‑9 from BEAS‑2B cells

Socheongryeong‑tang (SCRT) is a herbal formula previously used to treat pulmonary diseases primarily caused by the common cold virus, including airway inflammation, asthma and allergy. The aim of the present study was to investigate the inhibitory effect of SCRT water extract and its 13 constituent components on chemokine and enzyme production in the human bronchial epithelium cell line BEAS‑2B when induced by tumor necrosis factor‑α and interleukin‑4. The chemokines examined included regulated on activation of normal T‑cell‑expressed‑and‑secreted (RANTES), eotaxin and eotaxin‑3. The SCRT water extract demonstrated a dose‑dependent inhibition of RANTES, eotaxin, eotaxin‑3 and matrix metalloproteinase‑9 (MMP‑9) in BEAS‑2B cells. The 13 constituent compounds of SCRT water extract were quantitatively determined, and it was found that gallic acid, 6‑gingerol and methyl eugenol produced the most potent inhibition of RANTES, eotaxin and eotaxin‑3 as well as MMP‑9 activity regardless of their concentration in SCRT water extract. Principal component analysis and hierarchical clustering analysis revealed that the inhibitory effect of these three compounds contributed to that of SCRT water extract. In conclusion, the results of the present study indicated that the inhibitory effects of SCRT on chemokine and enzyme production in BEAS‑2B cells was associated with three of its constituent compounds, gallic acid, 6‑gingerol and methyl eugenol. This therefore suggested the potential use of these compounds as anti‑inflammatory agents.

Osthole ameliorates renal ischemia-reperfusion injury by inhibiting inflammatory response

INTRODUCTION

Renal ischemia-reperfusion (I/R) injury is a primary cause of acute renal failure that results in high mortality. This study aimed to investigate the effect of osthole, a natural coumarin derivative, on renal I/R injury in a rat model.

MATERIALS AND METHODS

Rats were randomly allocated to the sham operation + vehicle, I/R + vehicle, and I/R + osthole groups. Renal I/R injury was induced by clamping the left renal artery for 45 min followed by 12 h of reperfusion and a contralateral nephrectomy. Osthole (40 mg/kg) was intraperitoneally injected 30 min before inducing I/R. Renal function and histological damage were determined subsequently. Myeloperoxidase activity, monocyte/macrophage infiltration, as well as tumor necrosis factor-α, IL-1β, and activated p38 mitogen-activated protein kinase expression in kidneys were also assessed.

RESULTS

Osthole treatment significantly ameliorated I/R-induced renal functional and morphological injuries. Moreover, osthole treatment attenuated myeloperoxidase activity, monocyte/macrophage infiltration, and tumor necrosis factor-α, IL-1β, and activated p38 mitogen-activated protein kinase expression in kidneys.

CONCLUSIONS

Osthole treatment ameliorates renal I/R injury by inhibiting inflammatory responses in kidneys. Thus, osthole may represent a novel practical strategy to prevent renal I/R injury.

Osthole attenuates focal inflammatory reaction following permanent middle cerebral artery occlusion in rats

Osthole, a main active constituent from Cnidium monnieri (L.) CUSSON, has been considered therapeutic agent in the treatment of ischemic stroke. This study was designed to investigate the effect of osthole on permanent middle cerebral artery occlusion (MCAO) in rats. Osthole was administrated by gavage to the normal and the MCAO rats. Rats were assessed for neurological deficit after 24 h following MCAO, then their brains were evaluated to determine the infarct area, and the mRNA and protein levels of some inflammatory factors were detected. It was found that MCAO animals pre-treated with osthole for 7 d showed significant improvement in all neurological tests compared with vehicle-treated MCAO groups. In addition, there was a significant decrease in infarct volume 24 h after occlusion in animals pre-treated with osthole versus the vehicle-treated MCAO group. MCAO also dramatically caused some inflammatory factors increase. However, pretreatment with osthole restored the mRNA and protein levels of these factors, including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) of ischemic penumbra cortices, suggesting that osthole possessed the function of preventing brain against ischemic damage, while no significant difference was found in any of normal groups with or without osthole. The present study demonstrated that osthole may be a novel neuroprotective therapy in the treatment of focal ischemic stroke.

Synthesis and anthelmintic activity of osthol analogs against Dactylogyrus intermedius in goldfish

In an attempt to develop novel anthelmintic agents, our previously isolated osthol was used as lead structures for further optimization. In our research, a series of coumarin analogs, prepared from 7-hydroxy coumarin or 7-hydroxy-4-methyl coumarin, have been evaluated for their anthelmintic activities. In all of the compounds, 6 and 7 were first synthesized, and their structures were identified based on NMR and MS values. Among the candidates, 8-allyl-7-allyloxycoumarin showed better anthelmintic activity than other compounds against Dactylogyrus infestation with EC(50) value of 1.81 mg/L. The quantitative structure-activity relationship (QSAR) of 16 osthol analogs with anthelmintic activity expressed as pEC(50) and toxicity to goldfish expressed pLC(50), such results can offer useful theoretical references for future experimental works.

Osthole regulates inflammatory mediator expression through modulating NF-κB, mitogen-activated protein kinases, protein kinase C, and reactive oxygen species

Osthole, a coumarin compound, has been reported to exhibit various biological activities; however the cellular mechanism of its immune modulating activity has not yet been fully addressed. In this study we isolated osthole from the seeds of Cnidium monnieri and demonstrated that osthole inhibited TNF-α, NO and COX-2 expression in LPS-stimulated macrophages, without reducing the expression of IL-6. Furthermore, the phosphorylation of p38, JNK1/2, PKC-α and PKC-ε induced by LPS was inhibited by osthole; however, the phosphorylation of ERK1/2 and PKC-δ was not reduced by osthole. Osthole also inhibited NF-κB activation and ROS release in LPS-stimulated macrophages. Our current results indicated that osthole is the major anti-inflammatory ingredient of Cnidium monnieri seed ethanol extract.

Osthole improves chronic cerebral hypoperfusion induced cognitive deficits and neuronal damage in hippocampus

This study is to investigate the effects of osthole on cognitive impairment and neuronal degeneration in hippocampus induced by chronic cerebral hypoperfusion in rats, as well as the potential mechanism. Permanent occlusion of bilateral common carotid arteries (2VO) induced severe cognitive deficits tested by the water maze task, along with oxidative stress and neuronal loss in hippocampus. Oral administration of osthole for 3 weeks markedly attenuated cognitive deficits and neuronal damage. Biochemical experiments revealed that osthole decreased the production of malondialdehyde (MDA) and significantly increased the activities of Glutathione Peroxidase (GPx) and Catalase. Western blot analyses indicated that osthole prevented the downregulation of bcl-2 expression and upregulation of bax expression, which resulted in decreasing bax/bcl-2 ratio in hippocampus of 2VO rats. Additionally, osthole effectively alleviated the activation of caspase-3 induced by permanent occlusion of bilateral common carotid arteries. The observed results in present study suggest that osthole exhibits therapeutic potential for vascular dementia, which is most likely related, at least in part, to its antioxidation and anti-apoptotic actions.

Homoisoflavonoid derivatives from the roots of Ophiopogon japonicus and their in vitro anti-inflammation activity

Three new homoisoflavonoids (1-3) were isolated from the roots of Ophiopogon japonicus (Liliaceae). The structures of new metabolites were determined on the basis of spectroscopic analyses including 2D NMR. The anti-inflammatory activities of new compounds (1-3) were investigated by their effects on the release of the inflammatory chemokine eotaxin, stimulated by IL-4 and the combination of IL-4 and TNF-alpha in BEAS-2B cells, which mimics the in vivo conditions in bronchial allergic asthma.

Dammarane-type glycosides from Gynostemma pentaphyllum and their effects on IL-4-induced eotaxin expression in human bronchial epithelial cells

Two new dammarane-type glycosides, 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-[beta-d-glucopyranosyl(1-->4)-beta-d-glucopyranosyl]-20-O-[beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranoside] (1) and 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-beta-d-glucopyranosyl-20-O-[beta-d-6-O-acetylglucopyranosyl-(1-->2)-beta-d-glucopyranoside] (2), were isolated from a MeOH extract of the leaves of Gynostemma pentaphyllum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The isolated compounds showed potential inhibitory effects on eotaxin expression in BEAS-2B bronchial epithelial cells.

Attenuation of experimental autoimmune encephalomyelitis in C57 BL/6 mice by osthole, a natural coumarin

Osthole, a natural coumarin, is known to have a variety of pharmacological and biochemical uses and is considered to have potential therapeutic applications. Here we examined the effects of osthole on the central nervous system demyelination in experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis and its mechanism(s). C57 BL/6 mice immunized with myelin oligodendrocyte glycoprotein 35-55 amino acid peptide were treated with osthole at day 7 post immunization (7 p.i., subclinical periods, early osthole treatment) and day 13 p.i. (clinical periods, late osthole treatment) respectively and both therapies continued throughout the study. The content of nerve growth factor (NGF) and interferon gamma (IFN-gamma) in the sera and brain of mice in vivo as well as the splenocytes culture supernatants in vitro were detected. The results showed that osthole retarded the disease process when the therapy was initiated at subclinical periods, attenuated the clinical severity of EAE mice when the therapy was initiated at both subclinical and clinical periods, ameliorated inflammation and demyelination and improved the outcomes of magnetic resonance imaging. In addition, osthole blocked the reduction of NGF and suppressed IFN-gamma increase in EAE mice. These results suggested that osthole might be a new pharmacological approach to treat multiple sclerosis.

Osthole, a potential antidiabetic agent, alleviates hyperglycemia in db/db mice

Osthole is an agent isolated from Cnidium monnieri (L.) Cusson and Angelica pubescens and has been used to treat several diseases, including metabolic syndromes. To investigate the hypoglycemic effects of osthole in diabetic db/db mice and the underlying mechanisms of these effects by in vitro assay, diabetic db/db mice and cell experiments were utilized to understand its possible effects. Osthole significantly activated both PPARalpha and PPARgamma in a dose-dependent manner based on the results of the transition transfection assay. The activation of PPARalpha and PPARgamma by osthole also resulted in an increase in the expression of PPAR target genes such as PPAR itself, adipose fatty acid-binding protein 2, acyl-CoA synthetases, and carnitine palmitoyltransferase-1A. In vitro results suggested that osthole might be a dual PPARalpha/gamma activator, but its chemical structure differed from that of the thiazolidinedione class of antidiabetic drugs. In addition, osthole markedly activated the AMP-activated protein kinase and its downstream acetyl CoA carboxylase molecules by increasing their phosphorylation levels. Finally, obese diabetic db/db mice were treated with osthole by different administered routes, and osthole was found to markedly reduce blood glucose level. Interestingly, osthole did not reduce the blood insulin or lipid levels, two phenomena that did occur in animals treated with insulin sensitizers like PPAR agonists. These results suggest that osthole can alleviate hyperglycemia and could be potentially developed into a novel drug for treatment of diabetes mellitus.