Taraxasterol suppresses the growth of human liver cancer by upregulating Hint1 expression

Taraxasterol protects against acetaminophen-induced hepatotoxicity by reducing liver inflammatory response and ameliorating oxidative stress in mice

Acute liver failure is mainly caused by the overdose of acetaminophen (APAP) globally. The traditional Chinese medicinal (TCM) herb, Taraxacum, contains Taraxasterol (TAX) as one of the active components. It is a pentacyclic-triterpene compound isolated from this herb. Present work aimed to investigate the in vitro and in vivo protection effect of TAX in APAP-induced acute liver injury, and determine the potential regulatory mechamisms. The liver injury caused by APAP is attenuated by TAX, as shown by the alleviated pathological changes of mice liver and the reduced serological indexes. TAX evidently controlled the oxidative stress and liver inflammation in mice liver. In vitro studies found that TAX reversed the decrease in LO2 cell viability induced by APAP, and protected LO2 cells from APAP-induced injury. In addition, TAX reduced the secretion of inflammatory factors in RAW264.7 macrophages as induced via APAP. Besides, TAX inhibited oxidative stress in LO2 cells induced by APAP in vitro. Noteworthy, TAX enhanced protein and mRNA expressions of Nrf2 in vivo, and knockdown of Nrf2 by using adeno-associated virus (AAV)-Nrf2-KO attenuated inhibitory impact of TAX in acute liver injury induced by APAP. Also, AAV-NRF2-KO weakened the inhibitory impact of TAX against APAP-triggered liver inflammation and oxidative stress of mice liver. Moreover, TAX activated the Nrf2 signaling in APAP-induced LO2 cells, as shown by the increased nuclear Nrf2 expression together with downstream HO-1 expression in vitro. Inhibition of Nrf2 by using ML-385, anNrf2inhibitor, weakened the inhibitory effect of TAX against APAP-induced oxidative stress and cell injury in LO2 cells. Moreover, inhibition of Nrf2 attenuated anti-inflammatory effect of TAX for APAP-induced RAW264.7 cells. Collectively, TAX could protect against APAP-triggered hepatotoxicitythrough suppression of liver oxidative stress and inflammatory response in mice.

Anti-tumor effect of dandelion flavone on multiple myeloma cells and its mechanism

BACKGROUND

Multiple myeloma (MM) is a prevalent hematologic malignancy characterized by the uncontrolled proliferation of monoclonal plasma cells in the bone marrow and excessive monoclonal immunoglobulin production, leading to organ damage. Despite therapeutic advancements, recurrence and drug resistance remain significant challenges.

OBJECTIVE

This study investigates the effects of dandelion flavone (DF) on MM cell proliferation, migration, and invasion, aiming to elucidate the mechanisms involved in MM metastasis and to explore the potential of traditional Chinese medicine in MM therapy.

METHODS

DF's impact on myeloma cell viability was evaluated using the CCK-8 and colony formation assays. Cell mobility and invasiveness were assessed through wound healing and transwell assays, respectively. RT-PCR was employed to quantify mRNA levels of MMP-2, MMP-9, TIMP-1, and TIMP-2. Apoptotic rates and molecular markers were analyzed via flow cytometry and RT-PCR. The PI3K/AKT signaling pathway was studied using Western blot and ELISA, with IGF-1 and the PI3K inhibitor LY294002 used to validate the findings.

RESULTS

DF demonstrated dose-dependent inhibitory effects on MM cell proliferation, migration, and invasion. It reduced mRNA levels of MMP-2 and MMP-9 while increasing those of TIMP-1 and TIMP-2. Furthermore, DF enhanced the expression of pro-apoptotic proteins and inhibited M2 macrophage polarization by targeting key molecules and enzymes. The anti-myeloma activity of DF was mediated through the inhibition of the PI3K/AKT pathway, as evidenced by diminished phosphorylation and differential effects in the presence of IGF-1 and LY294002.

CONCLUSION

By modulating the PI3K/AKT pathway, DF effectively inhibits MM cell proliferation, migration, and invasion, and induces apoptosis, establishing a novel therapeutic strategy for MM based on traditional Chinese medicine.

The relationship between aflatoxin B1 with the induction of extrinsic/intrinsic pathways of apoptosis and the protective role of taraxasterol in TM3 leydig cell line

Aflatoxins B1 (AFB1) a dangerous type of aflatoxin, poses a serious threat to human health. Meanwhile, Taraxasterol, a bioactive compound in dandelion, exhibits strong anti-inflammatory and antioxidant activity. Therefore, the aim of this study was to investigate the impact of AFB1 on the intrinsic and extrinsic pathways of apoptosis, as well as evaluate the protective role of taraxasterol in the TM3 Leydig cell line. Cell viability was evaluated using an MTT assay, measuring the effects of 3.6 µM AFB1 and varying concentrations of taraxasterol. Expression levels of Caspase 3,8, and 9 were analyzed with RT-qPCR, and flow cytometry was used to assess cell cycle progression and apoptotic alterations. The findings of this study demonstrated that exposure to 3.6 µM of AFB1 resulted in an upregulation of Caspase 3 and Caspase 9 expression, indicating an activation of apoptotic pathways in TM3 cells. Additionally, the analysis of apoptosis revealed a significant increase in cellular apoptosis at this AFB1 concentration. However, when TM3 cells were exposed to 5 µM of taraxasterol, a downregulation of Caspase 3 and Caspase 9 expression was observed, suggesting a protective effect against apoptosis. Moreover, the apoptotic rate in TM3 cells was reduced in the presence of 5 µM of taraxasterol. Consequently, this study highlights the potential of taraxasterol as a protective agent against AFB1-induced apoptosis and suggest its potential application in regulating cell survival and apoptosis-related processes. Further investigations are necessary to elucidate the underlying mechanisms and evaluate the clinical implications of taraxasterol in the context of fertility disorders and other conditions associated with AFB1 exposure.

Taraxasterol enhanced bladder cancer cells radiosensitivity via inhibiting the COX-2/PGE2/JAK2/STAT3/MMP pathway

PURPOSE

Radiotherapy with bladder preservation is highly acceptable among patients bearing bladder cancer (BCa), but the occurrence of secondary tolerance (ARR) during treatment is one of the important reasons for the failure of clinical radiotherapy. COX-2 has been frequently reported to be highly expressed and associated with radio-resistance in various cancers. In this study, the feasibility of Taraxasterol (Tara) as a radiosensitizer was investigated, and the target effect of Tara on COX-2 and its underlying mechanism were explored.

METHODS AND MATERIALS

The toxicity of Tara toward BCa cells was detected with the MTT method and cells in response to IR or Tara + IR were compared by clone formation assay. Next, a small RNA interference system (siRNA) was employed to decrease endogenous COX-2 expression in BCa cells, and the stem cell-like features and motion abilities of BCa cells under different treatments were investigated using microsphere formation and transwell chamber assay, respectively. Meanwhile, the expression of a series of inflammation-related molecules and stem cell characteristic molecules was determined by qRT-PCR, western blot and ELISA method. In vivo studies, BCa cells were subcutaneously injected into the right flank of each male mouse. Those mice were then grouped and exposed to different treatment: Tara, IR, IR + Tara and untreated control. The volumes of each tumor were measured every two days and target proteins were detected with immunohistochemical (IHC) staining.

RESULTS

The results show that COX-2 decline, due to COX-2 knocking-down or Tara treatment, could greatly enhance BCa cells' radiosensitivity and significantly decrease their migration, invasion and microsphere formation abilities, companied with the reduce of JAK2, phos-STAT3, MMP2 and MMP9 expression. However, Tara could not further reduce the expression of an above molecule of cells in COX-2-deficient BCa cells. Correspondingly, Tara treatment could not further enhance those siCOX-2 BCa cells response to IR.

CONCLUSIONS

Our data support that Tara can improve the radiosensitivity of BCa cells by targeting COX-2/PGE2. The mechanism may involve regulating STAT3 phosphorylation, DNA damage response protein activation, and expression of MMP2/MMP9.

The Many Faces of Histidine Triad Nucleotide Binding Protein 1 (HINT1)

The histidine triad nucleotide binding protein 1 (HINT1) is a nucleoside phosphoramidase that has garnered interest due to its widespread expression and participation in a broad range of biological processes. Herein, we discuss the role of HINT1 as a regulator of several CNS functions, tumor suppressor, and mast cell activator via its interactions with multiple G-protein-coupled receptors and transcription factors. Importantly, altered HINT1 expression and mutation are connected to the progression of multiple disease states, including several neuropsychiatric disorders, peripheral neuropathy, and tumorigenesis. Additionally, due to its involvement in the activation of several clinically used phosphoramidate prodrugs, tremendous efforts have been made to better understand the interactions behind nucleoside binding and phosphoramidate hydrolysis by HINT1. We detail the substrate specificity and catalytic mechanism of HINT1 hydrolysis, while highlighting the structural biology behind these efforts. The aim of this review is to summarize the multitude of biological and pharmacological functions in which HINT1 participates while addressing the areas of need for future research.

Taraxasterol suppresses the proliferation and tumor growth of androgen-independent prostate cancer cells through the FGFR2-PI3K/AKT signaling pathway

Prostate cancer (PCa) is prevalent among older men and difficult to survive after metastasis. It is urgent to find new drugs and treatments. Several studies show that taraxasterol (TAX) has important anti-inflammatory, anti-oxidative and anti-tumor effects. However, the function and mechanisms of TAX in PCa remain unclear. Here, we found that TAX could significantly suppress the viability and growth of androgen-independent PCa cells and down-regulate the expression of c-Myc and cyclin D1 in vitro. Mechanistically, PI3K/AKT signaling pathway was weakened and the expression of FGFR2 was reduced after TAX treatment in androgen-independent PCa cells. Moreover, TAX evidently inhibited the tumor growth in nude mice and the expression of c-Myc, cyclin D1, p-AKT and FGFR2 were down-regulated in xenograft tumor. These results indicate that TAX suppresses the proliferation of androgen-independent PCa cells via inhibiting the activation of PI3K/AKT signaling pathway and the expression of FGFR2, which means TAX may be a novel anti-tumor agent for later PCa treatment.

Anti-metastatic effect of taraxasterol on prostate cancer cell lines

Background and purpose

Prostate cancer is the second cause of death among men. Nowadays, treating various cancers with medicinal plants is more common than other therapeutic agents due to their minor side effects. This study aimed to evaluate the effect of taraxasterol on the prostate cancer cell line.

Experimental approach

The prostate cancer cell line (PC3) was cultured in a nutrient medium. MTT method and trypan blue staining were used to evaluate the viability of cells in the presence of different concentrations of taraxasterol, and IC50 was calculated. Real-time PCR was used to measure the expression of MMP-9, MMP-2, uPA, uPAR, TIMP-2, and TIMP-1 genes. Gelatin zymography was used to determine MMP-9 and MMP-2 enzyme activity levels. Finally, the effect of taraxasterol on cell invasion, migration, and adhesion was investigated.

Findings/Results

Taraxasterol decreased the survival rate of PC3 cells at IC50 time-dependently (24, 48, and 72 h). Taraxasterol reduced the percentage of PC3 cell adhesion, invasion, and migration by 74, 56, and 76 percent, respectively. Real-time PCR results revealed that uPA, uPAR, MMP-9, and MMP-2 gene expressions decreased in the taraxasterol-treated groups, but TIMP-2 and TIMP-1 gene expressions increased significantly. Also, a significant decrease in the level of MMP-9 and MMP-2 enzymes was observed in the PC3 cell line treated with taraxasterol.

Conclusion and implications

The present study confirmed the therapeutic role of taraxasterol in preventing prostate cancer cell metastasis in the in-vitro study.

A cell transmembrane peptide chimeric M(27-39)-HTPP targeted therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent malignant tumor, with a growing incidence and death rate worldwide. The aims and challenges of treating HCC include targeting the tumor, entering the tumor tissue, inhibiting the spread and growth of tumor cells. M27-39 is a small peptide isolated from the antimicrobial peptide Musca domestica cecropin (MDC), whereas HTPP is a liver-targeting, cell-penetrating peptide obtained from the circumsporozoite protein (CSP) of Plasmodium parasites. In this study, M27-39 was modified by HTPP to form M(27-39)-HTPP, which targeted tumor penetration to treat HCC. Here, we revealed that M(27-39)-HTPP had a good ability to target and penetrate the tumor, effectively limit the proliferation, migration, and invasion, and induce the apoptosis in HCC. Notably, M(27-39)-HTPP demonstrated good biosecurity when administered at therapeutic doses. Accordingly, M(27-39)-HTPP could be used as a new, safe, and efficient therapeutic peptide for HCC.

The effects of taraxasterol on liver fibrosis revealed by RNA sequencing

Effective treatment of liver fibrosis remains a challenging medical problem. Taraxasterol (TAR) has anti-inflammatory, anti-tumor and hepatoprotective effects. Studies have shown that TAR has good biological activity against liver injury induced by various factors. However, the anti-fibrotic effect of TAR and its mechanism are never clarified. The purpose of this study was to investigate the effects of TAR in liver fibrosis and to reveal its possible mechanism by RNA sequencing. Our results suggested that TAR attenuated CCl₄-induced hepatocyte necrosis, inflammatory infiltration and ECM deposition. TAR inhibited the levels of ALT, AST, ALP, γ-GT, LN, HA, PC III and IV-C in serum and TNF-α, IL-6, IL-1β and MDA in liver. In addition, TAR increased the activities of SOD and GSH-Px in liver. RNA sequencing analysis of liver tissues revealed that CCl₄ and TAR significantly altered 4,155 genes and 2,675 genes, respectively. TAR reversed changes in ECM-related genes. More specifically, TAR mediated the expression of genes related to the activation of the Hippo pathway, while inhibiting the expression of genes related to the activation of HIF-1α, TGF-β/Smad, and Wnt pathways. In the validation experiments, the qRT-PCR results showed that the expression levels of Yap1, Tead3, Hif1α, Vegfa, Tgfβ1, Want3a, and Ctnnb1 mRNA were consistent with the RNA sequencing results. The Western blot results showed that TAR inhibited the levels of TGF-β1 and p-Smad2. In addition, the results in vitro were consistent with those in vivo. Therefore, we concluded that TAR improved CCl₄-induced liver fibrosis by regulating Hippo, HIF-1α, TGF-β/Smad and Wnt pathways.

Systematic review of ethnomedicine, phytochemistry, and pharmacology of Cyperi Rhizoma

Cyperi Rhizoma (CR) is the dry rhizome of Cyperus rotundus L., a Cyperaceae plant. It has a long history of clinical medication and is known as the “holy medicine” of gynecology. CR smells sweet and bitter. It has the effect of soothing the liver and relieving depression, regulating qi, regulating meridian and relieving pain. It can be used to treat liver qi stagnation, chest pain, spleen and stomach qi stagnation, hernia pain, irregular menstruation and other diseases. At present, the main chemical constituents isolated from CR are volatile oil, flavonoids and terpenes. Modern pharmacological studies have shown that CR has a wide range of pharmacological activities, including antidepressant, hypoglycemic, antioxidant, anti-inflammatory, antipyretic and analgesic effects. In this paper, the botany, traditional application, phytochemistry, pharmacological effects, processing and other aspects of CR are reviewed. At the same time, the shortcomings of current research of CR are discussed in depth, and the possible solutions are put forward in order to find a breakthrough point for future research of CR.

The phytochemical and pharmacological profile of taraxasterol

Taraxasterol is one of the bioactive triterpenoids found in dandelion, a member of the family Asteraceae. In the animal or cellular models of several ailments, including liver damage, gastritis, colitis, arthritis, pneumonia, tumors, and immune system diseases, taraxasterol has been shown to have significant preventive and therapeutic effects. This review aims to evaluate the current state of research and provide an overview of the possible applications of taraxasterol in various diseases. The reported phytochemical properties and pharmacological actions of taraxasterol, including anti-inflammatory, anti-oxidative, and anti-carcinogenic properties, and its potential molecular mechanisms in developing these diseases are highlighted. Finally, we further explored whether taraxasterol has protective effects on neuronal death in neurodegenerative diseases. In addition, more animal and clinical studies are also required on the metabolism, bioavailability, and safety of taraxasterol to support its applications in pharmaceuticals and medicine.

The potential of dandelion in the fight against gastrointestinal diseases: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Dandelion (Taraxacum officinale Weber ex F. H. Wigg.), as a garden weed grown globally, has long been consumed as a therapeutic herb. Its folkloric uses include treatments of digestive disorders (dyspepsia, anorexia, stomach disorders, gastritis and enteritis) and associate complex ailments involving uterine, liver and lung disorders.

AIM OF THE STUDY

The present study aims to critically assess the current state of research and summarize the potential roles of dandelion and its constituents in gastrointestinal (GI) -protective actions. A focus is placed on the reported bioactive components, pharmacological activities and modes of action (including molecular mechanisms and interactions among bioactive substances) of dandelion products/preparations and derived active constituents related to GI protection.

MATERIALS AND METHODS

The available information published prior to August 2021 was reviewed via SciFinder, Web of Science, Google Scholar, PubMed, Elsevier, Wiley On-line Library, and The Plant List. The search was based on the ethnomedical remedies, pharmacological activities, bioactive compounds of dandelion for GI protection, as well as the interactions of the components in dandelion with the gut microbiota or biological regulators, and with other ingested bioactive compounds. The key search words were "Taraxacum" and "dandelion".

RESULTS

T. coreanum Nakai, T. mongolicum and T. officinale are the most commonly used species for folkloric uses, with the whole plant, leaves and root of dandelion being used more frequently. GI-protective substances of dandelion include taraxasterol, taraxerol, caffeic acid, chicoric acid, chlorogenic acid, luteolin and its glucosides, polysaccharides, inulin, and β-sitosterol. Dandelion products and derived constituents exhibit pharmacological effects against GI disorders, mainly including dyspepsia, gastroesophageal reflux disease, gastritis, small intestinal ulcer, ulcerative colitis, liver diseases, gallstones, acute pancreatitis, and GI malignancy. The underlying molecular mechanisms may include immuno-inflammatory mechanisms, apoptosis mechanism, autophagy mechanism, and cholinergic mechanism, although interactions of dandelion's constituents with GI health-related biological entities (e.g., GI microbiota and associated biological modulators) or other ingested bioactive compounds shouldn't be ignored.

CONCLUSION

The review reveals some in vivo and in vitro studies on the potential of dandelion derived products as complementary and alternative medicines/therapeutics against GI disorders. The whole herb may alleviate some symptoms related GI immuno-inflammatory basing on the abundant anti-inflammatory and anti-oxide active substances. Dandelion root could be a nontoxic and effective anticancer alternative, owing to its abundant terpenoids and polysaccharides. However, research related to GI protective dandelion-derived products remains limited. Besides the need of identifying bioactive compounds/complexes in various dandelion species, more clinical studies are also required on the metabolism, bioavailability and safety of these substances to support their applications in food, medicine and pharmaceuticals.

Exploration and validation of Taraxacum mongolicum anti-cancer effect

Taraxacum mongolicum gained a lot of concern and was applied in 93 formulas in China due to its fame as a traditional Chinese medicine. The earliest recorded application of Taraxacum mongolicum was traced back to the Han dynasty. Generations of doctors boosted the usage and enriched the pharmacological mechanism. Clinical application of the Taraxacum mongolicum is flourishing as it treats multiple diseases. This study aims to explore the anti-cancer effect, retrieve the active ingredients and screen the key targets of Taraxacum mongolicum in cancer therapy. We collected and evaluated 10 key active compounds to investigate the anti-cancer effect via 69 significant targets and a variety of biological processes and pathways. Gene Ontology (GO) enrichment analysis uncovered targets associated with protein phosphorylation, cell proliferation and apoptotic processes via regulation of kinases, ATP and enzyme binding activities. Half of the top 20 enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were directly involved in cancer. Based on standard selection criteria, seven hub targets were obtained. These targets functioned through distinct patterns and pathways in realizing the anti-cancer effect. Molecular docking was conducted to validate the potential combination between compounds and hub targets to explore the pharmacological mechanism of key compounds in Taraxacum mongolicum against cancer. In summary, our findings indicate that the famous and widely used Chinese herb, Taraxacum mongolicum, shows good anti-cancer effect through its active compounds, targeted genes, and multiple involved biological processes. The results may provide a theoretical basis for subsequent experimental validation and drug development of Taraxacum mongolicum extract against cancer.

HBV induced the discharge of intrinsic antiviral miRNAs in HBV-replicating hepatocytes via extracellular vesicles to facilitate its replication

Hepatitis B virus (HBV), which can cause chronic hepatitis B, has sophisticated machinery to establish persistent infection. Here, we report a novel mechanism whereby HBV changed miRNA packaging into extracellular vesicles (EVs) to facilitate replication. Disruption of the miRNA machinery in hepatocytes enhanced HBV replication, indicating an intrinsic miRNA-mediated antiviral state. Interference with EV release only decreased HBV replication if there was normal miRNA biogenesis, suggesting a possible link between HBV replication and EV-associated miRNAs. Microarray and qPCR analyses revealed that HBV replication changed miRNA expression in EVs. EV incubation, transfection of miRNA mimics and inhibitors, and functional pathway and network analyses showed that EV miRNAs are associated with antiviral function, suggesting that to promote survival HBV coopts EVs to excrete anti-HBV intracellular miRNAs. These data suggest a novel mechanism by which HBV maintains its replication, which has therapeutic implications.

Cytochrome P450 Monooxygenase/Cytochrome P450 Reductase Bi-Enzymatic System Isolated From Ilex asprella for Regio-Specific Oxidation of Pentacyclic Triterpenoids

Ilex asprella is a plant from Aquifoliaceae. Its root is commonly used as folk medicinal materials in southern China. The chemical compositions of I. asprella are rich in pentacyclic triterpenoids, which show various biological activities and demonstrate a good prospect for drug development. The elucidation of biosynthesis mechanism of triterpenoids in I. asprella could lay important foundations for the production of these precious plant secondary metabolites by metabolic engineering. Our previous studies have revealed IaAO1 (a CYP716A210 homolog) responsible for the C-28 oxidation of α- and β-amyrin. Herein, we reported the identification of three more cytochrome P450 monooxygenase genes IaAO2 (a CYP716A212 homolog), IaAO4 (CYP714E88), IaAO5 (CYP93A220), and a cytochrome P450 reductase gene IaCPR by using Saccharomyces cerevisiae eukaryotic expression system and gas chromatography-mass spectrometry. Among them, the protein encoded by IaAO2 can catalyze the C-28 oxidation of α-amyrin and β-amyrin, IaAO4 can catalyze the C-23 oxidation of ursolic acid and oleanolic acid, while IaAO5 is responsible for the C-24 oxidation of β-amyrin. By introducing three genes IaAO1, IaAO4 and IaCPR into S. cerevisiae. We constructed an engineered yeast strain that can produce C-23 hydroxyl ursane-type triterpenoid derivatives. This study contributes to a thorough understanding of triterpenoid biosynthesis of medicinal plants and provides important tools for further metabolic engineering.

Reparative Effects of Dandelion Fermentation Broth on UVB-Induced Skin Inflammation

Objective

To evaluate the efficacy of the dandelion fermentation broth in repairing UVB-induced skin inflammation.

Methods

Detection of active ingredients in dandelion fermentation broth and water extract. The antioxidant capacity of dandelion fermentation broth was investigated by in vitro antioxidant experiments. The influence of the broth on the content of inflammatory factors interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-1β (IL-1β), and tumor necrosis factor (TNF-α), in human immortalized epidermal cells (HaCaT) is discussed on the basis of a UVB-induced HaCaT damage model. The effects of the broth on the contents of skin barrier-related proteins kallikrein-7 (KLK-7), filaggrin (FLG) and aquaporin (AQP3) in the UVB-induced damage and repair of the HaCaT mechanism are also comprehensively discussed. The effect of DF on the activation of MAPK pathway proteins was detected by PCR. A chicken embryo chorioallantoic membrane test is used to explore the safety of the dandelion fermentation broth.

Results

The results show that the dandelion fermentation broth is rich inTotal sugar, with good free radical scavenging ability and antioxidant effects; it can regulate the MAPK pathway, reduce the expression of inflammatory factors, adjust the skin barrier factors and good safety.

Conclusion

Dandelion fermentation broth exhibits repairing effect on UVB-induced skin inflammation.

Taraxasterol attenuates melanoma progression via inactivation of reactive oxygen species-mediated PI3K/Akt signaling pathway

Background: Taraxasterol (TX), a pentacyclic triterpene, is one of the main active constituents isolated from Taraxacum officinale. A growing number of studies have reported that TX exhibits a wide range of biological activities such as anti-oxidative, anti-inflammatory, and neuro-protective effects. Recently, TX has been demonstrated to be a potential drug candidate for treatment of some types of cancers. However, the specific role of TX in melanoma remains unclear.Purpose: In this study, we aimed at exploration of the effect of TX on melanoma cell viability, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) as well as the underlying mechanisms.Research design: A375 and SK-MEL-28 cells were treated with various concentrations of TX for different times. Cell viability was measured using CCK-8 assay. Cell apoptosis was determined by flow cytometry. Transwell assays were performed to measure cell migration and invasion. The expression of E-cadherin, α-catenin, N-cadherin, vimentin, p-PI3K, PI3K, p-Akt and Akt was detected using western blot.Results: The study showed that TX induced A375 and SK-MEL-28 cell apoptosis. Furthermore, exposure to TX inhibited A375 and SK-MEL-28 cell migration and invasion. Besides, the EMT process was reversed in A375 and SK-MEL-28 cells after TX treatment. We also observed that TX reduced the protein expression of p-PI3K and p-Akt; thus, inhibiting activity of the PI3K/Akt pathway in A375 and SK-MEL-28 cells. In addition, TX treatment increased the levels of reactive oxygen species (ROS) in A375 and SK-MEL-28 cells, and treatment with the ROS scavenger NAC significantly rescued TX-induced down-regulation of p-PI3K and p-Akt in A375 and SK-MEL-28 cells.Conclusions: In conclusion, our study demonstrated that TX induced ROS accumulation followed by inactivation of the PI3K/Akt pathway and subsequently attenuated melanoma progression, suggesting that TX may be a potential candidate for treatment of melanoma.

Taraxasterol mitigates Con A-induced hepatitis in mice by suppressing interleukin-2 expression and its signaling in T lymphocytes

Discovery of anti-inflammatory drugs that can suppress T lymphocyte activation and proliferation by inhibiting TCR/CD3 and IL-2/IL-2R signaling is still needed in clinic, though rapamycin and other related reagents have made great success. Taraxasterol (TAS) is an active ingredient of dandelion, an anti-inflammatory medicinal herb with low in vivo toxicity that has long been used in China. Yet the action mechanism of TAS on lymphocytes remains elusive. The anti-inflammatory effects of TAS were evaluated in C57BL/6 mouse primary lymphocytes stimulated with concanavalin A (Con A) in vitro and in mouse model of Con A-induced acute hepatitis in vivo. Our results showed that TAS significantly suppressed Con A-induced acute hepatitis in a mouse model, reducing the hepatic necrosis areas, the release of aminotransferases, and the production of IL-2 and other inflammatory cytokines. Supporting this, in vitro study also showed that TAS reduced the production of IL-2 and the expression of IL-2 receptor subunit α (CD25) upon the stimulation of Con A, which was likely mediated by suppressing NF-κB activation. The downstream pathways of IL-2/IL-2R signaling, including the activation of PI3K/PDK1/mTOR, STAT3 and STAT5, were also suppressed by TAS. Consistently, Con A-induced T cell proliferation was also inhibited by TAS in vitro. Our data indicate that TAS can suppress both T lymphocyte activation and cell proliferation by down-regulating IL-2 expression and its signaling pathway thereby ameliorating Con A-induced acute hepatitis, highlighting TAS as a potential drug candidate for treating inflammatory diseases including autoimmune hepatitis.

Taraxasterol suppresses cell proliferation and boosts cell apoptosis via inhibiting GPD2-mediated glycolysis in gastric cancer

Gastric cancer (GC) is the most common malignant tumor of digestive tract. Taraxasterol (TAX), a kind of phytosterol, has been proved to exert anti-tumor functions in GC. Herein, the current work was carried out to identify the biological role of TAX and molecular mechanisms underlying TAX in the progression of GC. In the present study, CCK-8 assay, Colony formation assay, EDU staining and TUNEL staining were performed to evaluate the malignant behaviors of GC cells. Levels of proliferation and apoptosis-associated proteins were assessed using western blotting analysis. Besides, GPD2 expression in GC cells was presented on CCLE database and the interaction between TAX and GPD2 was obtained from STRING database. The glucose uptake, lactate production, LDH activity, ATP and expressions of glycolysis-associated enzymes were measured to evaluate glycolysis level. Results of the present research revealed that TAX suppressed the proliferative and clone-forming abilities of GC cells and boosted the apoptosis of GC cells. TAX reduced GPD2 expression in GC cells. Furthermore, overexpression of GPD2 reversed the inhibitory effects of TAX on the proliferative and clone-forming abilities of GC cells as well as abolished the promoting effects of TAX on the apoptosis of GC cells. Besides, upregulation of GPD2 abrogated the inhibition of TAX on glycolysis. To conclude, TAX could suppress GC progression via inhibiting GPD2-mediated glycolysis, which helps to develop a promising molecular target for GC therapies.

Taraxasterol inhibits TGF-β1-induced epithelial-to-mesenchymal transition in papillary thyroid cancer cells through regulating the Wnt/β-catenin signaling

Taraxasterol (TAR) is a kind of active compound extracted from dandelion and its molecular structure resembles steroid hormones. Recently, TAR has been reported to show an anti-tumor activity. However, the specific role of TAR in papillary thyroid cancer (PTC) has not been clarified. In this study, we investigated the effect of TAR on PTC cell migration, invasion and epithelial-to-mesenchymal transition (EMT) induced by TGF-β1. PTC cells were exposed to TGF-β1 (5 ng/mL) and then treated with different concentrations of TAR. We found that TAR showed no obvious cytotoxicity below 10 μg/mL but notably reduced migration and invasion of TGF-β1-treated PTC cells. Moreover, TAR treatment decreased MMP-2 and MMP-9 levels, and obviously affected the expression of EMT markers. We also observed that Wnt3a and β-catenin levels were significantly increased in TGF-β1-treated PTC cells while TAR inhibited these effects in a concentration-dependent manner. Additionally, activation of the Wnt pathway by LiCl attenuated the suppressive effect of TAR on TGF-β1-induced migration, invasion and EMT in PTC cells. Taken together, we highlighted that TAR could significantly suppress TGF-β1-regulated migration and invasion by reversing the EMT process via the Wnt/β-catenin pathway, suggesting that TAR may be a potential anti-cancer agent for PTC treatment.

Network pharmacology-based identification of the antitumor effects of taraxasterol in gastric cancer

Taraxasterol (TAX), a pentacyclic triterpene, has been reported to exhibit potent antitumor activity. However, the effects and molecular mechanisms of TAX in gastric cancer (GC) remain undocumented. A network pharmacology approach was applied to identify the collective targets of TAX and GC. Nude mice were subcutaneously injected with MKN-28 cells to establish GC subcutaneous xenograft model, which were treated with TAX for 16 days. Tumor volume was then examined every other day. The pathological scoring was assessed by using hematoxylin and eosin (H&E) staining, and the expression levels of Ki-67 and the target genes of TAX were confirmed by immunohistochemistry analysis. Five collective targets of TAX and GC were identified, such as epidermal growth factor receptor (EGFR), matrix metalloproteinase 2 (MMP2), B-Raf proto-oncogene, serine/threonine kinase (BRAF), fibroblast growth factor receptor 2 (FGFR2), and AKT serine/threonine kinase 1 (AKT1). Further investigations showed that, TAX administration repressed xenograft tumor growth and decreased Ki-67 levels, followed by the downregulation of EGFR and AKT1 expression in xenograft tumor tissues as compared with the untreated group. Our findings demonstrated that TAX inhibited the growth of GC by inhibition of EGFR/AKT1 signaling and might provide a novel therapeutic strategy for treatment of GC.

Taraxasterol acetate targets RNF31 to inhibit RNF31/p53 axis-driven cell proliferation in colorectal cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. Several studies have suggested that taraxasterol acetate (TA) can inhibit the growth of tumor cells. However, to date, it remains unclear how TA inhibits cell growth and how RNF31 functions as an oncogene. We examined the expression of RNF31 in CRC tissue samples via immunohistochemistry and elucidated the function of RNF31 in CRC cells by constructing a cell model with RNF31 depletion. A cycloheximide (CHX)-chase analysis and immunofluorescence assays were conducted to demonstrate that TA can promote RNF31 degradation by activating autophagy. We used the PharmMapper website to predict targets of TA and identified RNF31. CHX-chase experiments showed that TA could facilitate RNF31 degradation, which was inhibited by the administration of chloroquine. Immunofluorescence assays showed that RNF31 protein was colocalized with LC3I/II and p62, suggesting that TA promoted RNF31 degradation by activating autophagy. We also found that CRC patients with RNF31 overexpression had poorer survival than those with low RNF31 expression. The results of the CHX-chase experiment showed that depletion of RNF31 alleviated p53 degradation, which was inhibited by MG132. A series of co-immunoprecipitation (Co-IP) assays revealed that RNF31 interacts with p53 and promotes p53 ubiquitination and degradation. A Co-IP assay performed with a truncated RNF31 plasmid showed that the PUB domain interacts with p53. Moreover, the PUB domain is the key structure in the induction of p53 ubiquitination. Our findings reveal a key role of RNF31 in CRC cell growth and indicate a mechanism through which TA inhibits cell growth.

Inhibition of NLRP3 Inflammasome Activation and Pyroptosis in Macrophages by Taraxasterol Is Associated With Its Regulation on mTOR Signaling

Taraxasterol (TAS) is an active ingredient of Dandelion (Taraxacum mongolicum Hand. -Mazz.), a medicinal plant that has long been used in China for treatment of inflammatory disorders. But the underlying mechanism for its therapeutic effects on inflammatory disorders is not completely clear. Inflammasome activation is a critical step of innate immune response to infection and aseptic inflammation. Among the various types of inflammasome sensors that has been reported, NLR family pyrin domain containing 3 (NLRP3) is implicated in various inflammatory diseases and therefore has been most extensively studied. In this study, we aimed to explore whether TAS could influence NLPR3 inflammasome activation in macrophages. The results showed that TAS dose-dependently suppressed the activation of caspase-1 in lipopolysaccharide (LPS)-primed murine primary macrophages upon nigericin treatment, resulting in reduced mature interleukin-1β (IL-1β) release and gasdermin D (GSDMD) cleavage. TAS greatly reduced ASC speck formation upon the stimulation of nigericin or extracellular ATP. Consistent with reduced cleavage of GSDMD, nigericin-induced pyroptosis was alleviated by TAS. Interestingly, TAS time-dependently suppressed the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) and mTORC2 signaling induced by LPS priming. Like TAS, both INK-128 (inhibiting both mTORC1 and mTORC2) and rapamycin (inhibiting mTORC1 only) also inhibited NLRP3 inflammasome activation, though their effects on mTOR signaling were different. Moreover, TAS treatment alleviated mitochondrial damage by nigericin and improved mouse survival from bacterial infection, accompanied by reduced IL-1β levels in vivo. Collectively, by inhibiting the NLRP3 inflammasome activation, TAS displayed anti-inflammatory effects likely through regulation of the mTOR signaling in macrophages, highlighting a potential action mechanism for the anti-inflammatory activity of Dandelion in treating inflammation-related disorders, which warrants further clinical investigation.

Comparative Proteomic Study Shows the Expression of Hint-1 in Pituitary Adenomas

Pituitary adenomas (PAs) can be unpredictable and aggressive tumors. No reliable markers of their biological behavior have been found. Here, a proteomic analysis was applied to identify proteins in the expression profile between invasive and non-invasive PAs to search for possible biomarkers. A histopathological and immunohistochemical (adenohypophyseal hormones, Ki-67, p53, CD34, VEGF, Flk1 antibodies) analysis was done; a proteomic map was evaluated in 64 out of 128 tumors. There were 107 (84%) invasive and 21 (16%) non-invasive PAs; 80.5% belonged to III and IV grades of the Hardy–Vezina classification. Invasive PAs (n = 56) showed 105 ± 43 spots; 86 ± 32 spots in non-invasive PAs (n = 8) were observed. The 13 most prominent spots were selected and 11 proteins related to neoplastic process in different types of tumors were identified. Hint1 (Histidine triad nucleotide-binding protein 1) high expression in invasive PA was found (11.8 ± 1.4, p = 0.005), especially at high index (>10; p = 0.0002). High Hint1 expression was found in invasive VEGF positive PA (13.8 ± 2.3, p = 0.005) and in Flk1 positive PA (14.04 ± 2.28, p = 0.006). Hint1 is related to human tumorigenesis by its interaction with signaling pathways and transcription factors. It could be related to invasive behavior in PAs. This is the first report on Hint expression in PAs. More analysis is needed to find out the possible role of Hint in these tumors.

Plants of the Spontaneous Flora with Beneficial Action in the Management of Diabetes, Hepatic Disorders, and Cardiovascular Disease

The current pharmacological agents advised for the management of diabetes as well as cardiovascular and hepatic diseases are subject to numerous studies for safety and efficacy. Therefore, it is worth looking into alternative therapeutic aids such as natural products of medicinal plants. By a broad review of in vitro and in vivo studies on the various dandelion, chicory, and mulberry extracts, this work highlights their bioactive compounds and therapeutic action when used as a prevention and management aid in public health such as diabetes, cardiovascular disease, and hepatic disorders like non-alcoholic steatohepatitis. Natural products of dandelion leaves and root extracts can suppress the development of liver cancer, decrease insulin resistance, and suppress total triglyceride and cholesterol levels. Recent studies on mulberry leaves extracts indicated that they could decrease palmitic acid-induced lipotoxicity, increase total cholesterol and bile acid excretion, improve superoxide dismutase expression, and improve insulin resistance. Chicory root extracts boost satiety, reverse insulin resistance, and augment lipid metabolism thanks to their contents in chicoric acid, chlorogenic acid, and polysaccharides. Taraxacum officinale L., Morus nigra L., and Cichorium intybus L. present hepatoprotective, anti-inflammatory, antioxidant, hypolipidemic, and hypoglycemic activities and are shown to be advantageous in the management of obesity, dyslipidemia, Type 2 diabetes, and non-alcoholic fatty liver diseases. These plants are commonly available in the European spontaneous flora and more attention could be paid to their natural products.

Protective effect of taraxasterol on ischemia/reperfusion-induced acute kidney injury via inhibition of oxidative stress, inflammation, and apoptosis

Ischemia/reperfusion injury (IRI), the most common cause of acute kidney injury (AKI), is correlated with oxidative stress and subsequent inflammation. Taraxasterol, a natural product, has been shown to exert anti-oxidative and anti-inflammatory effects. However, the role of taraxasterol in renal IRI remains unknown. In this study, mice were subjected to 30 min of bilateral renal ischemia-reperfusion to induce AKI. Cellular hypoxia/reoxygenation (H/R) was used to mimic IRI in vitro. Western blotting, immunochemistry, immunofluorescence, TUNEL staining, ELISA, and flow cytometry were performed to evaluate kidney damage, oxidative stress, inflammation, and apoptosis in vivo and in vitro. Treatment with taraxasterol attenuated the following in a dose-dependent manner: tubular damage; infiltration of F4/80-positive macrophages; renal interstitial fibrosis; myeloperoxidase (MPO) activity; and expression of the inflammatory cytokines tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and monocyte chemoattractant protein-1 (MCP-1). Moreover, taraxasterol treatment remarkably ameliorated apoptosis in the kidney by decreasing Bax expression and conserving Bcl2. Notably, MitoSOX assay revealed that treatment with taraxasterol suppressed the production of mitochondrial reactive oxygen species. Furthermore, taraxasterol suppressed phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) of the mitogen-activated protein kinase (MAPK) signaling pathways in vivo and in vitro. In conclusion, these findings indicate that taraxasterol has a protective effect on IRI-induced AKI via inhibition of oxidative stress, inflammation, and apoptosis.

Hint1 Overexpression Inhibits the Cell Cycle and Induces Cell Apoptosis in Human Osteosarcoma Cells

Background

New evidence suggests that histidine triad nucleotide-binding protein 1 (Hint1) exerts a tumor suppressor effect in various human tumors, such as colorectal cancer and gastric cancer. However, it has not been reported whether Hint1 is involved in the occurrence and development of osteosarcoma (OS).

Materials and Methods

The present study investigated the role of Hint1 in human OS cells by using cell lines, including 143B, U2OS, KHOS-240S, Saos-2 and MG-63. Cell proliferation and apoptosis were detected by flow cytometry.

Results

The present result revealed that Hint1 is downregulated in these cell lines. The overexpression of Hint1 by adenovirus transfection in 143B and MG63 cell lines suppressed the proliferation and cell cycle, and increased the cell apoptosis. Mechanically, it was found that Hint1 downregulated the cyclin D1 expression via FOXO1 inhibition. Furthermore, FOXO1 overexpression in the 143B and MG63 cell lines significantly blurred the effects of Hint1 on cellular proliferation and apoptosis.

Conclusion

The present study indicates that Hint1 inhibits the development of OS by regulating FoxO1-cyclin D1, suggesting that Hint1 may be a new method for the treatment of OS.

Comparative peptidome profiling reveals critical roles for peptides in the pathology of pancreatic cancer

BACKGROUNDS/AIMS

Pancreatic cancer is a digestive system tumour disease with a notably poor prognosis and a 5-year survival rate of less than 10 %. In recent years, peptide drugs have shown great clinical value in antitumour applications. We aim to identify differentially expressed peptides by using peptidomics techniques to explore the mechanisms involved in the development and pathology of pancreatic cancer.

METHODS

We performed peptidomic analysis of pancreatic cancer and paired paracancerous tissues by using ITRAQ labelling technology and conducted in-depth bioinformatics analysis and functional studies on differentially expressed peptides.

RESULTS

A total of 2,881 peptides were identified, of which 133 were differentially expressed (116 were upregulated and 17 were downregulated). By using GO analysis, the differentially expressed peptides were found to be closely related to the tumour microenvironment and extracellular matrix. KEGG enrichment analysis revealed that precursor proteins were closely related to the T2DM and RAS signalling pathways. The endogenous peptide P1DG can significantly inhibit the proliferation, migration and invasion of pancreatic cancer cells.

CONCLUSION

P1DG and its precursor GAPDH may be closely related to the proliferation, migration and invasion of pancreatic cancer. Peptidomics can aid in understanding the pathogenesis of pancreatic cancer more comprehensively.

The enzymes OSC1 and CYP716A263 produce a high variety of triterpenoids in the latex of Taraxacum koksaghyz

Only very little is known about the resin composition of natural rubber from the dandelion species Taraxacum koksaghyz, thus its full characterization could provide new insights into how the isoprenoid end-products influence the physical properties of natural rubber, and this resin might be a good source of highly diverse triterpenoids. Here, we present a comprehensive analysis of the triterpenoid composition in an acetone extract and identified 13 triterpenes and triterpenoids also including the so far unknown pentacyclic compounds lup-19(21)-en-3-ol (1) and its ketone lup-19(21)-en-3-one (2). We purified single triterpenes from the acetone extract by developing a two-step HPLC system that is adapted to the structural differences of the described triterpenoids. Furthermore, we isolated six different oxidosqualene cyclases (OSCs) and two P450 enzymes, and we functionally characterized TkOSC1 and CYP716A263 in Nicotiana benthamiana and Saccharomyces cerevisiae in detail. TkOSC1 is a multifunctional OSC that was capable of synthesizing at least four of the latex-predominant pentacyclic triterpenes (taraxasterol, α-, β-amyrin and lup-19(21)-en-3-ol) while CYP716A263 oxidized pentacyclic triterpenes at the C-3 position. The identified enzymes responsible for biosynthesis and modification of pentacyclic triterpenes in T. koksaghyz latex may represent excellent tools for bioengineering approaches to produce pentacyclic triterpenes heterologously.

Role of Liver X Receptor in Mastitis Therapy and Regulation of Milk Fat Synthesis

Mastitis is important disease that causes huge economic losses in the dairy industry. In recent years, antibiotic therapy has become the primary treatment for mastitis, however, due to drug residue in milk and food safety factors, we lack safe and effective drugs for treating mastitis. Therefore, new targets and drugs are urgently needed to control mastitis. LXRα, one of the main members of the nuclear receptor superfamily, is reported to play important roles in metabolism, infection and immunity. Activation of LXRα could inhibit LPS-induced mastitis. Furthermore, LXRα is reported to enhance milk fat production, thus, LXRα may serve as a new target for mastitis therapy and regulation of milk fat synthesis. This review summarizes the effects of LXRα in regulating milk fat synthesis and treatment of mastitis and highlights the potential agonists involved in both issues.

Orthodontic compressive force modulates Ets-1/Tks5 pathway to promote the formation of circumferential invadopodia and the fusion of osteoclast precursors

During orthodontic treatment a mechanical force is applied to the teeth. However, it remains unclear how mechanical force promotes the maturation and fusion of osteoclast precursors into osteoclasts. In this study, we aimed to explore the mechanism by which orthodontic compressive force promotes osteoclast maturation. We used a RAW264.7 macrophage-like cell line derived from Balb/c mice as the experimental model. We found that compressive force promoted the maturation of osteoclasts based on tartrate-resistant acid phosphatase staining and the formation of invadopodia based on immunstaining of Tks5 and F-actin. Moreover, we found that compressive force upregulated the expression of Ets-1 and Tks5 and promoted the activation of Ets-1 in RAW264.7 cells. Furthermore, we identified Tks5 as a transcription target of Ets-1 in RAW264.7 cells and demonstrated that Ets-1 mediates the effects of compressive force on Tks5 upregulation, invadopodia formation and cell fusion in osteoclasts. In conclusion, Ets-1 is upregulated by compressive force and it is essential to transducing the mechanical signal to promote invadopodia formation and osteoclast fusion. Our findings provide novel insight into the mechanism underlying osteoclast maturation and fusion during orthodontic treatment.