Establishment of quantitative analysis model for quality control indexes of Farfarae Flos based on NIRS / 中国药房

OBJECTIVE To establish a quantitative analysis model for the contents of tussilagone， moisture， ethanol-soluble extract and total ash in Farfarae Flos based on near-infrared spectroscopy （NIRS）， providing a new idea for the rapid quality evaluation of Farfarae Flos and its preparations. METHODS Referring to the 2020 edition of the Chinese Pharmacopoeia， the contents of the main quality control indexes tussilagone， moisture， ethanol-soluble extract and total ash in 130 batches of Farfarae Flos from 19 producing areas were determined by HPLC， drying method， hot dip method and ash assay， respectively. The NIRS data information of the medicinal herbs of Farfarae Flos was collected， and then NIRS combined with the partial least squares method was used to establish the individual quantitative analysis models of the above quality control indexes in the samples， and the predictive model of the NIRS content was obtained after sample validation with validation set. RESULTS The range for the contents of tussilagone， moisture， ethanol-soluble extract and total ash in 130 batches of Farfarae Flos were 0.051 4%-0.103 5%， 7.75%-10.93%， 20.17%-31.12%， and 7.68%-12.10%， respectively. The internal cross-validation coefficients of determination （R2） of the established models for the quantitative analysis of tussilagone， moisture， ethanol-soluble extract and total ash in Farfarae Flos were 0.985 8， 0.968 4， 0.973 4， 0.988 0， respectively； the root mean square errors of calibration （RMSEC） were 0.001 54， 0.187， 0.478， 0.127， respectively； the root mean square errors of prediction （RMSEP） were 0.001 81， 0.212， 0.543， 0.149， respectively； RMSEP/RMSEC were 1.175 3， 1.133 7， 1.136 0 and 1.173 2， respectively， which were all within a reasonable range （1＜RMSEP/RMSEC≤1.2）. The mean absolute errors between the true and model-predicted values of the above four quality control indexes in the validation set of samples were －0.000 36， 0.061 43， 0.144 00， and 0.010 43， respectively，and the mean predicted recoveries were 99.65%， 100.72%，100.66%， and 100.15%， respectively. CONCLUSIONS The established NIRS quantitative analysis model has high stability and reliable results， which can be used for the rapid batch prediction of the content of relevant quality control indexes in Farfarae Flos.

Tussilagone inhibits osteoclastogenesis by modulating mitochondrial function and ROS production involved Nrf2 activation.

Reactive Oxygen Species (ROS) play an essential role in the pathogenesis of osteoporosis mainly characterized by excessive osteoclasts (OCs) activity. OCs are rich in mitochondria for energy support, which is a major source of total ROS. Tussilagone (TSG), a natural Sesquiterpenes from the flower of Tussilago farfara, has plentiful beneficial pharmacological characteristics with anti-inflammatory and anti-oxidative activity, but its effects and mechanism in osteopathology are still unclear. In our study, we investigated the regulation of ROS generated from the mitochondria in OCs. We found that TSG inhibited OCs differentiation and bone resorption without any cytotoxicity. Mechanistically, TSG reduced RANKL-mediated total ROS level by down-regulating intracellular ROS production and mitochondrial function, leading to the suppression of NFATc1 transcription. We also found that nuclear factor erythroid 2-related factor 2 (Nrf2) could enhance ROS scavenging enzymes in response to RANKL-induced oxidative stress. Furthermore, TSG up-regulated the expression of Nrf2 by inhibiting its proteosomal degradation. Interestingly, Nrf2 deficiency reversed the suppressive effect of TSG on mitochondrial activity and ROS signaling in OCs. Consistent with this finding, TSG attenuated post-ovariectomy (OVX)- and lipopolysaccharide (LPS) induced bone loss by ameliorating osteoclastogenesis. Taken together, TSG has an anti-bone resorptive effect by modulating mitochondrial function and ROS production involved Nrf2 activation.

Tussilagone attenuates atherosclerosis through inhibiting MAPKs-mediated inflammation in macrophages.

Atherosclerosis is a common chronic inflammatory disease. Recent studies have highlighted the key role of macrophages and inflammation in process of atherosclerotic lesion formation. A natural product, tussilagone (TUS), has previously exhibited anti-inflammatory activities in other diseases. In this study, we explored the potential effects and mechanisms of TUS on the inflammatory atherosclerosis. Atherosclerosis was induced in ApoE-/- mice by feeding them with a high-fat diet (HFD) for 8 weeks, followed by administration of TUS (10, 20 mg ·kg-1·d-1, i.g.) for 8 weeks. We demonstrated that TUS alleviated inflammatory response and reduced atherosclerotic plaque areas in HFD-fed ApoE-/- mice. Pro-inflammatory factor and adhesion factors were inhibited by TUS treatment. In vitro, TUS suppressed foam cell formation and oxLDL-induced inflammatory response in MPMs. RNA-sequencing analysis indicated that MAPK pathway was related to the anti-inflammation and anti-atherosclerosis effects of TUS. We further confirmed that TUS inhibited MAPKs phosphorylation in plaque lesion of aortas and cultured macrophages. MAPK inhibition blocked oxLDL-induced inflammatory response and prevented the innately pharmacological effects of TUS. Our findings present a mechanistic explanation for the pharmacological effect of TUS against atherosclerosis and indicate TUS as a potentially therapeutic candidate for atherosclerosis.

Tussilagone ameliorates high-fat diet-induced hepatic steatosis by enhancing energy metabolism and antioxidant activity.

Non-alcoholic fatty liver disease (NAFLD) is a major health problem. However, no effective treatments are currently available. Thus, there is a critical need to develop novel drugs that can prevent and treat NAFLD with few side effects. In this study, Tussilagone (TUS), a natural sesquiterpene isolated from Tussilago farfara L, was explored in vitro and in vivo for its potential to treat NAFLD. Our results showed that in vitro TUS reduced oleic acid palmitate acid-induced triglyceride and cholesterol synthesis in HepG2 cells, reduced intracellular lipid droplet accumulation, improved glucose metabolism disorders and increased energy metabolism and reduced oxidative stress levels. In vivo, TUS significantly reduced fat accumulation and improved liver injury in high-fat diet (HFD)-induced mice. TUS treatment significantly increased liver mitochondrial counts and antioxidant levels compared to the HFD group of mice. In addition, TUS was found to reduce the expression of genes involved in lipid synthesis sterol regulatory element binding protein-1 (SREBP1), fatty acid synthase (FASN), and stearoy-CoA desaturase 1 (SCD1) in vitro and in vivo. Our results suggest that TUS may be helpful in the treatment of NAFLD, suggesting that TUS is a promising compound for the treatment of NAFLD. Our findings provided novel insights into the application of TUS in regulating lipid metabolism.

Tussilagone protects acute lung injury from PM2.5 via alleviating Hif-1α/NF-κB-mediated inflammatory response.

Environmental pollution, especially particulate matter in the air, is a serious threat to human health. Long-term inhalation of particulate matter with a diameter < 2.5 µm (PM2.5) induced irreversible respiratory and lung injury. However, it is not clear whether temporary exposure to massive PM2.5 would result in epithelial damage and lung injury. More importantly, it is urgent to clarify the mechanisms of PM2.5 cytotoxicity and develop a defensive and therapeutic approach. In this study, we demonstrated that temporary exposure with PM2.5 induced lung epithelial cell apoptosis via promoting cytokines expression and inflammatory factors secretion. The cytotoxicity of PM2.5 could be alleviated by tussilagone (TSL), which is a natural compound isolated from the flower buds of Tussilago farfara. The mechanism study indicated that PM2.5 promoted the protein level of Hif-1α by reducing its degradation mediated by PHD2 binding, which furtherly activated NF-κB signaling and inflammatory response. Meanwhile, TSL administration facilitated the interaction of the Hif-1α/PHD2 complex and restored the Hif-1α protein level increased by PM2.5. When PHD2 was inhibited in epithelial cells, the protective function of TSL on PM2.5 cytotoxicity was attenuated and the expression of cytokines was retrieved. Expectedly, the in vivo study also suggested that temporary PM2.5 exposure led to acute lung injury. TSL treatment could effectively relieve the damage and decrease the expression of inflammatory cytokines by repressing Hif-1α level and NF-κB activation. Our findings provide a new therapeutic strategy for air pollution-related respiratory diseases, and TSL would be a potential preventive medicine for PM2.5 cytotoxicity.

Extraction and determination of tussilagone from Farfarae Flos with online solid-phase extraction-high-performance liquid chromatography using a homemade monolithic cartridge doped with porous organic cage material.

A solid-phase extraction cartridge was fabricated using diallyl isophthalate as the monomer with the addition of porous organic cage material via in situ free-radical polymerization in a stainless-steel column. The resulting monolithic adsorbent exhibited a relatively uniform porous structure, a high specific surface area of 113.98 m2 /g, and multiple functional chemical groups according to the characterization results. An online solid-phase extraction-high-performance liquid chromatography procedure was fabricated to extract and determine tussilagone from Farfarae Flos. The results show that the complex sample matrices can be removed in the solid-phase extraction procedure. Simultaneously, tussilagone can remain, which can be subsequently switched to an octadecylsilane bonded analytical column. The methodological validation showed that the correlation coefficient was 0.9999 with a linear range of 0.6-200.0 µg/mL, the limit of detection was 0.2 µg/mL, the limit of quantification was 0.6 µg/mL, accuracy was 100.3-100.6%, and relative standard deviation of precision was ≤1.9%. The present monolithic cartridge exhibits good reusability of not more than 100 times. The real sample of Farfarae Flos was determined with a tussilagone content of 0.74 mg/g.

Antiplatelet Activity of Tussilagone via Inhibition of the GPVI Downstream Signaling Pathway in Platelets.

Tussilagone is a sesquiterpenoid extracted from Tussilago farfara and is used as an oriental medicine for asthma and bronchitis. Although previous studies have shown that tussilagone has an inhibitory effect on platelet aggregation, no studies have been performed to investigate its precise effect on platelets, and the underlying mechanism remains unclear. In the present study, we showed that tussilagone inhibited platelet aggregation induced by collagen, thrombin and ADP, as well as platelet release induced by collagen and thrombin, in mice. Tussilagone decreased P-selectin expression and αIIbß3 activation (JON/A binding) in activated platelets, which indicated that tussilagone inhibited platelet activation. Moreover, tussilagone suppressed platelet spreading on fibrinogen and clot retraction. The levels of phosphorylated Syk, PLCγ2, Akt, GSK3ß, and MAPK (ERK1/2 and P38) and molecules associated with GPVI downstream signaling were downregulated in the presence of tussilagone. In addition, tussilagone prolonged the occlusion time in a mouse model of FeCl3-induced carotid artery thrombosis and had no effect on mouse tail bleeding time. These results indicate that tussilagone inhibits platelet function in vitro and in vivo and that the underlying mechanism involves the Syk/PLCγ2-PKC/MAPK and PI3K-Akt-GSK3ß signaling pathways downstream of GPVI. This research suggests that tussilagone is a potential candidate antiplatelet drug for the prevention of thrombosis.

Tussilagone promotes osteoclast apoptosis and prevents estrogen deficiency-induced osteoporosis in mice.

Osteoporosis is a degenerative disease characterized by reduced bone mass, in which deregulated bone remodeling by osteoclasts and osteoblasts is a main pathogenesis. Although recently tussilagone, a major active component of flower buds of Tussilago farfara, has been shown to inhibit osteoclastogenesis, its effect on estrogen deficiency-induced osteoporosis remains unknown. This study examined the effect of tussilagone on bone loss in ovariectomized mice and further explored its impact on osteoclast apoptosis and osteoblast formation in addition to osteoclastogenesis. Tussilagone suppression of osteoclastogenesis was confirmed in bone marrow derived macrophages, which was observed with the 1/10 concentration of that of the previous study. As demonstrated by ApoPercentage dye staining and Western blotting, tussilagone enhanced apoptosis in differentiated osteoclasts by increasing estrogen receptor α and Fas ligand expression. On the contrary, either osteoblast differentiation or mineralization was not affected by tussilagone. Lastly, administering tussilagone to mice for 6 weeks prevented trabecular microarchitecture impairment in ovariectomized mice compared to vehicle control groups. These findings suggest that tussilagone or Tussilago farfara prevents osteoporotic bone loss by suppressing osteoclast differentiation and inducing osteoclast apoptosis, and that it may therefore offer a possible remedy against resorptive bone diseases.

Tussilagone Inhibits Osteoclastogenesis and Periprosthetic Osteolysis by Suppressing the NF-κB and P38 MAPK Signaling Pathways.

BACKGROUND: Aseptic prosthetic loosening is one of the main factors causing poor prognosis of limb function after joint replacement and requires troublesome revisional surgery. It is featured by wear particle-induced periprosthetic osteolysis mediated by excessive osteoclasts activated in inflammatory cell context. Some natural compounds show antiosteoclast traits with high cost-efficiency and few side effects. Tussilagone (TUS), which is the main functional extract from Tussilago farfara generally used for relieving cough, asthma, and eliminating phlegm in traditional medicine has been proven to appease several RAW264.7-mediated inflammatory diseases via suppressing osteoclast-related signaling cascades. However, whether and how TUS can improve aseptic prosthetic loosening via modulating osteoclast-mediated bone resorption still needs to be answered. METHODS: We established a murine calvarial osteolysis model to detect the preventative effect of TUS on osteolysis in vivo. Micro-CT scanning and histomorphometric analysis were used to determine the variation of bone resorption and osteoclastogenesis. The anti-osteoclast-differentiation and anti-bone-resorption bioactivities of TUS in vitro were investigated using bone slice resorption pit evaluation, and interference caused by cytotoxicity of TUS was excluded according to the CCK-8 assay results. Quantitative polymerase chain reaction (qPCR) analysis was applied to prove the decreased expression of osteoclast-specific genes after TUS treatment. The inhibitory effect of TUS on NF-κB and p38 MAPK signaling pathways was testified by Western blot and NF-κB-linked luciferase reporter gene assay. RESULTS: TUS better protected bones against osteolysis in murine calvarial osteolysis model with reduced osteoclasts than those in the control group. In vitro studies also showed that TUS exerted antiosteoclastogenesis and anti-bone-resorption effects in both bone marrow macrophages (BMMs) and RAW264.7 cells, as evidenced by the decline of osteoclast-specific genes according to qPCR. Western blotting revealed that TUS treatment inhibited IκBα degradation and p38 phosphorylation. CONCLUSIONS: Collectively, our studies proved for the first time that TUS inhibits osteoclastogenesis by suppressing the NF-κB and p38 MAPK signaling pathways, therefore serving as a potential natural compound to treat periprosthetic osteolysis-induced aseptic prosthetic loosening.

Tussilagone Reduces Tumorigenesis by Diminishing Inflammation in Experimental Colitis-Associated Colon Cancer.

BACKGROUND: Tussilagone, a major component of Tussilago farfara L., has anti-angiogenic and anti-inflammatory effects. However, the therapeutic and preventive activity of tussilagone in colitis-associated colon carcinogenesis is unknown. METHODS: We intended to investigate the therapeutic effects and the potential mechanism of action underlying the pharmacological activity of tussilagone on colitis-associated colon cancer induced in mice using azoxymethane (AOM)/dextran sulfate sodium (DSS). We injected BALB/c mice with AOM and administered 2% DSS in drinking water. The mice were given tussilagone (2.5 and 5 mg/kg body weight) and colon tissues was collected at 72 days. We used Western blotting, immunohistochemistry and real-time RT-PCR analyses to examine the tumorigenesis and inflammatory status of the colon. RESULTS: Tussilagone administration significantly reduced the formation of colonic tumors. In addition, tussilagone treatment markedly reduced the inflammatory mediators and increased heme oxygease-1 in protein and mRNA levels in colon tissues. Meanwhile, nuclear NF-κB-positive cells were elevated and nuclear Nrf2-positive cells were demised by tussilagone treatment in colon tissues. Tussilagone also reduced cell proliferation, induced apoptosis and decreased the ß-catenin expression. CONCLUSIONS: Tussilagone administration decreases the inflammation and proliferation induced by AOM/DSS and induced apoptosis in colon tissue. Overall, this study indicates the potential value of tussilagone in suppressing colon tumorigenesis.

Tussilagone inhibits allergic responses in OVA-induced allergic rhinitis guinea pigs and IgE-stimulated RBL-2H3 cells.

Farfarae Flos is the dried flower buds of Tussilago farfara L. which is widely used to treat allergic and inflammatory diseases in Chinese folk. Tussilagone (TSL), a sesquiterpene compound purified from Farfarae Flos, has been confirmed the main active component in the plant. However, its anti-allergic activity hasn't been reported yet. The purpose of this study is to investigate the anti-allergic effect of TSL in ovalbumin (OVA)-induced allergic rhinitis (AR) guinea pigs and immunoglobulin E (IgE)-stimulated RBL-2H3 cells. The AR symptoms such as nasal scratching, sneezing and runny nose were scored and the histological changes of nasal mucosa were observed by H&E staining. The levels of histamine, OVA-specific IgE, IL-6 and TNF-α in the serum were measured by ELISA. In IgE-stimulated RBL-2H3 cells, the phosphoryration of Lyn, Syk, Akt, NF-κB p65, ERK and p38 MAPK were investigated by western blot analysis. The results showed that intraperitoneal injection of TSL at doses of 25 and 50 mg/kg significantly alleviated the allergic symptoms and the histological changes of nasal mucosa in OVA-induced allergic rhinitis guinea pigs. Moreover, the levels of histamine, IgE and IL-6 in the serum decreased significantly (p < .05). In vitro, TSL suppressed the phosphorylation of Lyn, Syk, Akt, NF-κB p65, ERK and p38 MAPK in IgE-stimulated RBL-2H3 cells. These results indicate TSL has therapeutic effect on allergic rhinitis in guinea pigs. The anti-allergic mechanism may be through the inhibition of allergic and inflammatory related pathways in mast cells.

Effect of Different Drying Methods on the Chemical Composition of Farfarae Flos / 中国药学杂志

OBJECTIVE: To analyze the effect of different drying methods on the major compounds in Farfarae Flos(FF). METHODS: The content of moisture and tussilagone were determined, and the common peaks in the HPLC fingerprint were calculated and subjected to the principal component analysis. RESULTS: The results showed that the moisture content was the highest when the FF was dried in the shade, and the drying method showed little effect on the content of tussilagone. The results of the principal component analysis showed that the FF dried in the shade was different from those of FF being dried under heat. The relative content of major compounds were the highest for the FF dried in the shade. In addition, the caffeoyl quinic acids and flavonoids were greatly affected after heating, however the heat drying showed little effect on the sesquiterpenoids. Among the different drying temperature, 55 ℃ showed smallest effect on the main components in the FF. CONCLUSION: The components in FF can be protected when drying in the shade, which reveals the scientific basis for the traditional experience of drying. However, in order to facilitate the drying process on a large scale, and minimizing the effect of drying on the compounds in the FF, drying temperature of 55 ℃ is recommended.

Effect of adulteration on quality of Farfarae Flos / 中草药

Objective: For the adulteration phenomenon of Farfarae Flos, the chemical composition of the flower buds and the rachis, rhizome, and the roots were compared, to provide the basis for the quality control of Farfarae Flos. Methods: The content of tussilagone was determined by high performance liquid chromatography (HPLC) according to the Chinese Pharmacopeia. The HPLC based fingerprint was also generated, and the similarity and the relative contents of the common peaks between the flower buds and adulteration parts were calculated. The pearson correlation between the relative content of the major compounds and the flower buds ratio, as well as principal component analysis and clustering analysis were also performed. Results: The content of tussilagone and the peak areas of 13 common peaks in the HPLC fingerprint were significantly higher than those in the rachis, rhizome, and the roots, and positively correlated with the flower buds ratio. The results of the principal component analysis and clustering analysis showed that the flower buds showed distinct separation with those adulteration parts. In addition, the compounds within the caffeoyl quinic acids and flavonoids showed positive correlations with each other, and the correlations were also observed between different kinds of components. Conclusion: The major compounds of Farfarae Flos were mainly present in the flower buds, and the quality of Farfarae Flos will be greatly affected when there are more impurities such as pedicel, taproot and rhizome in the crude drugs. Currently, there is no impurity in the Chinese pharmacopeia for Farfarae Flos, and the limit of the impurities should be added to guarantee the quality of Farfarae Flos.

Tussilagone Suppresses Angiogenesis by Inhibiting the VEGFR2 Signaling Pathway.

Tussilagone (TSL) is a sesquiterpenoid isolated from Tussilago farfara, which has been used as a traditional medicine for the treatment of asthma and bronchitis. It also takes part in the anti-inflammatory and antioxidant effects, but its role in angiogenesis is unknown. Angiogenesis is a cancer feature that is essential for supplying oxygen and nutrients to all proliferating tumor cells. Here, we demonstrated that TSL significantly inhibited the proliferation, migration, invasion, and tube formation of primary human umbilical vascular endothelial cell (HUVEC) in vitro. Also, TSL inhibited vascular endothelial growth factor (VEGF)-induced angiogenesis revealed by Matrigel plug assay in vivo. At present, we observed that TSL inhibited the activity of VEGFR2 signal pathway induced by VEGF. These findings suggested that TSL may serve as a potential therapeutic target in the angiogenesis.

Study on Quality Standard for Tussilago farfara Formula Granules / 中国药房

OBJECTIVE： To provide reference for the establishment of quality standard of Tussilago farfara formula granules. METHODS： TLC method was used for qualitative identification of tussilagone in T. farfara formula granules. The content of tussilagone in T. farfara formula granule was determined by HPLC. The determination was performed on a Thermo ODS Hypersil C18 column with the mobile phase consisted of methanol-water （85 ∶ 15， V/V） at the flow rate of 1.0 mL/min. The detection wavelength was set at 220 nm， the column temperature was 25 ℃. Sample size was 20 μL.  RESULTS： TLC spots of tussilagone were clear and well-separated， without interference from negative control. The linear range of tussilagone was 1.39-27.75 μg/mL （r＝0.999 9）. The limits of quantification and detection were 0.153 87 and 0.051 42 μg/mL， respectively. RSDs of precision， stability and reproducibility tests were lower than 2％. The recoveries were 97.12％-103.96％ （RSD＝2.60％， n＝6）. CONCLUSIONS： The method is simple， accurate and reproducible， and suitable for quality control of T. farfara formula granules.

Tussilagone suppressed the production and gene expression of MUC5AC mucin via regulating nuclear factor-kappa B signaling pathway in airway epithelial cells.

In the present study, we investigated whether tussilagone, a natural product derived from Tussilago farfara, significantly affects the production and gene expression of airway MUC5AC mucin. Confluent NCI-H292 cells were pretreated with tussilagone for 30 min and then stimulated with EGF (epidermal growth factor) or PMA (phorbol 12-myristate 13-acetate) for 24 h or the indicated periods. The MUC5AC mucin gene expression was measured by RT-PCR. Production of MUC5AC mucin protein was measured by ELISA. To elucidate the action mechanism of tussilagone, effect of tussilagone on PMA-induced NF-κB signaling pathway was investigated by western blot analysis. Tussilagone significantly inhibited the production of MUC5AC mucin protein and down-regulated the expression of MUC5AC mucin gene, induced by EGF or PMA. Tussilagone inhibited PMA-induced activation (phosphorylation) of inhibitory kappa B kinase (IKK), and thus phosphorylation and degradation of inhibitory kappa Ba (IκBα). Tussilagone inhibited PMA-induced phosphorylation and nuclear translocation of nuclear factor kappa B (NF-κB) p65. This, in turn, led to the down-regulation of MUC5AC protein production in NCI-H292 cells. These results suggest that tussilagone can regulate the production and gene expression of mucin by acting on airway epithelial cells through regulation of NF-κB signaling pathway.

Tussilagone, a major active component in Tussilago farfara, ameliorates inflammatory responses in dextran sulphate sodium-induced murine colitis.

Inflammatory bowel disease (IBD) is a chronically relapsing inflammatory disorder of the gastrointestinal tract. Current IBD treatments are associated with poor tolerability and insufficient therapeutic efficacy, prompting the need for alternative therapeutic approaches. Recent advances suggest promising interventions based on a number of phytochemicals. Herein, we explored the beneficial effects of tussilagone, a major component of Tussilago farfara, in mice subjected to acute colitis induced by dextran sulfate sodium (DSS). Treatment with tussilagone resulted in a significant protective effect against DSS-induced acute colitis in mice via amelioration of weight loss, and attenuation of colonic inflammatory damage. Additionally, the expression of tumor necrosis factor-α and interleukin-6 and the activity of myeloperoxidase in colonic tissues were significantly reduced in tussilagone-treated mice. Furthermore, immunohistochemical analysis revealed that tussilagone treatment reduced the numbers of nuclear factor-kappa B (NF-κB) and increased the numbers of nuclear factor erythroid 2-related factor 2 (Nrf2) in nuclei of colonic tissues. Taken together, tussilagone treatment attenuated DSS-induced colitis in mice through inhibiting the activation of NF-κB and inducing Nrf2 pathways, indicating that tussilagone is a potent therapeutic candidate for treatment of intestinal inflammation.

Effects of Flower Buds Extract of Tussilago farfara on Focal Cerebral Ischemia in Rats and Inflammatory Response in BV2 Microglia.

OBJECTIVE: To investigate the effects of the flower buds extract of Tussilago farfara Linné (Farfarae Flos; FF) on focal cerebral ischemia through regulation of inflammatory responses in activated microglia. METHODS: Brain ischemia was induced in Sprague-Dawley rats by a transient middle cerebral artery occlusion (tMCAO) for 90 min and reperfusion for 24 h. Twenty rats were randomly divided into 4 groups (n=5 per group): normal, tMCAO-induced ischemic control, tMCAO plus FF extract 300 mg/kg-treated, and tMCAO plus MK-801 1 mg/kg-treated as reference drug. FF extract (300 mg/kg, p.o.) or MK-801 (1 mg/kg, i.p.) was administered after reperfusion. Brain infarction was measured by 2,3,5,-triphenyltetrazolium chloride staining. Neuronal damage was observed by haematoxylin eosin, Nissl staining and immunohistochemistry using anti-neuronal nuclei (NeuN), anti-glial fibrillary acidic protein (GFAP), and anti-CD11b/c (OX42) antibodies in ischemic brain. The expressions of inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF-α), and hypoxia-inducible factor-1a (HIF-1α) were determined by Western blot. BV2 microglial cells were treated with FF extract or its main bioactive compound, tussilagone with or without lipopolysaccharide (LPS). Nitric oxide (NO) production was measured in culture medium by Griess assay. The expressions of iNOS, COX-2 and pro-inflammatory cytokines mRNA were analyzed by reverse transcription-polymerase chain reaction. The expression of iNOS, and COX-2 proteins, the phosphorylation of ERK1/2, JNK, and p38 MAPK and the nuclear expression of NF-κB p65 in BV2 cells were determined by Western blot. RESULTS: FF extract significantly decreased brain infarctions in ischemic rats (P<0.01). The neuronal death and the microglia/astrocytes activation in ischemic brains were inhibited by FF extract. FF extract also suppressed iNOS, TNF-α, and HIF-1α expression in ischemic brains. FF extract (0.2 and 0.5 mg/mL, P<0.01) and tussilagone 20 and 50 µmol/L, P<0.01) significantly decreased LPS-induced NO production in BV2 microglia through downregulation of iNOS mRNA and protein expression. FF extract and tussilagone significantly inhibited LPS-induced expression of TNF-α, IL-1ß, and IL-6 mRNA, and also suppressed the phosphorylation of ERK1/2, JNK and p38 MAPK and the nuclear expression of NF-κB in a dose-dependent manner. CONCLUSIONS: FF extract has a neuroprotective effect in ischemic stroke by the decrease of brain infarction, and the inhibition of neuronal death and microglial activation-mediated inflammatory responses.

Effects of Flower Buds Extract of Tussilago farfara on Focal Cerebral Ischemia in Rats and Inflammatory Response in BV2 Microglia / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of the flower buds extract of Tussilago farfara Linné (Farfarae Flos; FF) on focal cerebral ischemia through regulation of inflammatory responses in activated microglia.</p><p><b>METHODS</b>Brain ischemia was induced in Sprague-Dawley rats by a transient middle cerebral artery occlusion (tMCAO) for 90 min and reperfusion for 24 h. Twenty rats were randomly divided into 4 groups (n=5 per group): normal, tMCAO-induced ischemic control, tMCAO plus FF extract 300 mg/kg-treated, and tMCAO plus MK-801 1 mg/kg-treated as reference drug. FF extract (300 mg/kg, p.o.) or MK-801 (1 mg/kg, i.p.) was administered after reperfusion. Brain infarction was measured by 2,3,5,-triphenyltetrazolium chloride staining. Neuronal damage was observed by haematoxylin eosin, Nissl staining and immunohistochemistry using anti-neuronal nuclei (NeuN), anti-glial fibrillary acidic protein (GFAP), and anti-CD11b/c (OX42) antibodies in ischemic brain. The expressions of inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF-α), and hypoxia-inducible factor-1a (HIF-1α) were determined by Western blot. BV2 microglial cells were treated with FF extract or its main bioactive compound, tussilagone with or without lipopolysaccharide (LPS). Nitric oxide (NO) production was measured in culture medium by Griess assay. The expressions of iNOS, COX-2 and pro-inflammatory cytokines mRNA were analyzed by reverse transcription-polymerase chain reaction. The expression of iNOS, and COX-2 proteins, the phosphorylation of ERK1/2, JNK, and p38 MAPK and the nuclear expression of NF-κB p65 in BV2 cells were determined by Western blot.</p><p><b>RESULTS</b>FF extract significantly decreased brain infarctions in ischemic rats (P<0.01). The neuronal death and the microglia/astrocytes activation in ischemic brains were inhibited by FF extract. FF extract also suppressed iNOS, TNF-α, and HIF-1α expression in ischemic brains. FF extract (0.2 and 0.5 mg/mL, P<0.01) and tussilagone 20 and 50 μmol/L, P<0.01) significantly decreased LPS-induced NO production in BV2 microglia through downregulation of iNOS mRNA and protein expression. FF extract and tussilagone significantly inhibited LPS-induced expression of TNF-α, IL-1β, and IL-6 mRNA, and also suppressed the phosphorylation of ERK1/2, JNK and p38 MAPK and the nuclear expression of NF-κB in a dose-dependent manner.</p><p><b>CONCLUSIONS</b>FF extract has a neuroprotective effect in ischemic stroke by the decrease of brain infarction, and the inhibition of neuronal death and microglial activation-mediated inflammatory responses.</p>

Tussilagone suppressed the production and gene expression of MUC5AC mucin via regulating nuclear factor-kappa B signaling pathway in airway epithelial cells

In the present study, we investigated whether tussilagone, a natural product derived from Tussilago farfara, significantly affects the production and gene expression of airway MUC5AC mucin. Confluent NCI-H292 cells were pretreated with tussilagone for 30 min and then stimulated with EGF (epidermal growth factor) or PMA (phorbol 12-myristate 13-acetate) for 24 h or the indicated periods. The MUC5AC mucin gene expression was measured by RT-PCR. Production of MUC5AC mucin protein was measured by ELISA. To elucidate the action mechanism of tussilagone, effect of tussilagone on PMA-induced NF-κB signaling pathway was investigated by western blot analysis. Tussilagone significantly inhibited the production of MUC5AC mucin protein and down-regulated the expression of MUC5AC mucin gene, induced by EGF or PMA. Tussilagone inhibited PMA-induced activation (phosphorylation) of inhibitory kappa B kinase (IKK), and thus phosphorylation and degradation of inhibitory kappa Ba (IκBα). Tussilagone inhibited PMA-induced phosphorylation and nuclear translocation of nuclear factor kappa B (NF-κB) p65. This, in turn, led to the down-regulation of MUC5AC protein production in NCI-H292 cells. These results suggest that tussilagone can regulate the production and gene expression of mucin by acting on airway epithelial cells through regulation of NF-κB signaling pathway.