Pristimerin inhibits angiogenesis in adjuvant-induced arthritic rats by suppressing VEGFR2 signaling pathways

Pristimerin exhibits anti-cancer activity by inducing ER stress and AKT/GSK3β pathway through increasing intracellular ROS production in human esophageal cancer cells

Pristimerin (Pris), a bioactive triterpenoid compound extracted from the Celastraceae and Hippocrateaceae families, has been reported to exhibit an anti-cancer property on various cancers. However, the effects of Pris on esophageal cancer are poorly investigated. This current study sought to explore the activity and underlying mechanism of Pris against human esophageal squamous cell carcinoma (ESCC) cells. We demonstrated that Pris showed cytotoxicity in TE-1 and TE-10 ESCC cell lines, and significantly inhibited cell viability in a concentration dependent manner. Pris induced G0/G1 phase arrest and triggered apoptosis. It was also observed that the intracellular ROS level was remarkedly increased by Pris treatment. Besides, the function of Pris mediating the activation of ER stress and the inhibition of AKT/GSK3β signaling pathway in TE-1 and TE-10 cells was further confirmed, which resulted in cell growth inhibition. And moreover, we revealed that all of the above pathways were regulated through ROS generation. In conclusion, our findings suggested that Pris might be considered as a novel natural compound for the developing anti-cancer drug candidate for human esophageal cancer.

Mechanistic insights into anti-inflammatory and immunosuppressive effects of plant secondary metabolites and their therapeutic potential for rheumatoid arthritis

The anti-inflammatory and immunosuppressive activities of plant secondary metabolites are due to their diverse mechanisms of action against multifarious molecular targets such as modulation of the complex immune system associated with rheumatoid arthritis (RA). This review discussed and critically analyzed the potent anti-inflammatory and immunosuppressive effects of several phytochemicals and their underlying mechanisms in association with RA in experimental studies, including preliminary clinical studies of some of them. A wide range of phytochemicals including phenols, flavonoids, chalcones, xanthones, terpenoids, alkaloids, and glycosides have shown significant immunosuppressive and anti-inflammatory activities in experimental RA models and a few have undergone clinical trials for their efficacy and safety in reducing RA symptoms and improve patient outcomes. These phytochemicals have potential as safer alternatives to the existing drugs in the management of RA, which possess a wide range of serious side effects. Sufficient preclinical studies on safety and efficacy of these phytochemicals must be performed prior to proper clinical studies. Further studies are needed to address the barriers that have so far limited their human use before the therapeutic potential of these plant-based chemicals as anti-arthritic agents in the treatment of RA is fully realized.

The protective effect of natural medicines in rheumatoid arthritis via inhibit angiogenesis

Rheumatoid arthritis is a chronic immunological disease leading to the progressive bone and joint destruction. Angiogenesis, accompanied by synovial hyperplasia and inflammation underlies joint destruction. Delaying or even blocking synovial angiogenesis has emerged as an important target of RA treatment. Natural medicines has a long history of treating RA, and numerous reports have suggested that natural medicines have a strong inhibitory activity on synovial angiogenesis, thereby improving the progression of RA. Natural medicines could regulate the following signaling pathways: HIF/VEGF/ANG, PI3K/Akt pathway, MAPKs pathway, NF-κB pathway, PPARγ pathway, JAK2/STAT3 pathway, etc., thereby inhibiting angiogenesis. Tripterygium wilfordii Hook. f. (TwHF), sinomenine, and total glucoside of Paeonia lactiflora Pall. Are currently the most representative of all natural products worthy of development and utilization. In this paper, the main factors affecting angiogenesis were discussed and different types of natural medicines that inhibit angiogenesis were systematically summarized. Their specific anti-angiogenesis mechanisms are also reviewed which aiming to provide new perspective and options for the management of RA by targeting angiogenesis.

Anticancer Potential and Molecular Targets of Pristimerin in Human Malignancies

The growing global burden of malignant tumors with increasing incidence and mortality rates underscores the urgent need for more effective and less toxic therapeutic options. Herbal compounds are being increasingly studied for their potential to meet these needs due to their reduced side effects and significant efficacy. Pristimerin (PS), a triterpenoid from the quinone formamide class derived from the Celastraceae and Hippocrateaceae families, has emerged as a potent anticancer agent. It exhibits broad-spectrum anti-tumor activity across various cancers such as breast, pancreatic, prostate, glioblastoma, colorectal, cervical, and lung cancers. PS modulates several key cellular processes, including apoptosis, autophagy, cell migration and invasion, angiogenesis, and resistance to chemotherapy, targeting crucial signaling pathways such as those involving NF-κB, p53, and STAT3, among others. The main objective of this review is to provide a comprehensive synthesis of the current literature on PS, emphasizing its mechanisms of action and molecular targets with the utmost clarity. It discusses the comparative advantages of PS over current cancer therapies and explores the implications for future research and clinical applications. By delineating the specific pathways and targets affected by PS, this review seeks to offer valuable insights and directions for future research in this field. The information gathered in this review could pave the way for the successful development of PS into a clinically applicable anticancer therapy.

UPLC-LTQ-Orbitrap-Based Cell Metabolomics and Network Pharmacology Analysis to Reveal the Potential Antiarthritic Effects of Pristimerin: In Vitro, In Silico and In Vivo Study

Rheumatoid arthritis (RA) is characterized by systemic inflammation and synovial hyperplasia. Pristimerin, a natural triterpenoid isolated from plants belonging to the Celastraceae and Hippocrateaceae families, has been reported to exhibit anti-inflammation and anti-proliferation activities. Our study aims to reveal the antiarthritic effects of pristimerin and explore its potential mechanism using in vitro, in silico, and in vivo methods. In the present study, pristimerin treatment led to a dose-dependent decrease in cell viability and migration in TNF-α stimulated human rheumatoid arthritis fibroblast-like synoviocytes MH7A. Moreover, UPLC-LTQ-Orbitrap-based cell metabolomics analysis demonstrated that phospholipid biosynthesis, fatty acid biosynthesis, glutathione metabolism and amino acid metabolic pathways were involved in TNF-α induced MH7A cells after pristimerin treatment. In addition, the adjuvant–induced arthritis (AIA) rat model was employed, and the results exhibited that pristimerin could effectively relieve arthritis symptoms and histopathological damage as well as reduce serum levels of TNF-α, NO and synovial expressions of p-Akt and p-Erk in AIA rats. Furthermore, network pharmacology analysis was performed to visualize crucial protein targets of pristimerin for RA treatment, which showed that the effects were mediated through the MAPK/Erk1/2, PI3K/Akt pathways and directing binding with TNF-α. Taken together, our study not only offered new insights into the biochemical mechanism of natural compounds for RA treatment, but also provided a strategy that integrated in vitro, in silico and in vivo studies to facilitate screening of new anti-RA drugs.

Geniposide alleviates VEGF-induced angiogenesis by inhibiting VEGFR2/PKC/ERK1/2-mediated SphK1 translocation

BACKGROUND

Rheumatoid arthritis (RA) is an angiogenesis-dependent disease caused by the imbalance of pro- and anti-angiogenic factors. More effective strategies to block synovial angiogenesis in RA should be studied. Geniposide (GE), a natural product isolated from the fruit of Gardenia jasminoides Ellis (GJ), is reported to have anti-inflammatory, anti-angiogenic and other pharmacological effects. However, the underlying mechanism through which GE affects synovial angiogenesis in RA remains unclear.

PURPOSE

In this research, we aimed to elucidate the effect and potential mechanisms of GE on angiogenesis in RA.

MATERIALS AND METHODS

Synovial angiogenesis in patients with RA and a rat model of adjuvant arthritis (AA) was detected by hematoxylin and eosin (HE) staining, immunohistochemistry (IHC), and western blottiing. The biological functions of vascular endothelial cells (VECs) and sphingosine kinase 1 (SphK1) translocation were checked by CCK-8, EdU, Transwell, tube formation, co-immunoprecipitation assays, and laser scanning confocal microscopy. The effect of the SphK1 gene on angiogenesis was assessed by transfection of SphK1-siRNA in cells and mices. The effect of GE on VEGF-induced angiogenesis was measured by Matrigel plug assay in a mouse model of AA.

RESULTS

GE effectively inhibited synovial angiogenesis and alleviated the disease process. SphK1, as a new regulatory molecule, has a potentially important relationship in regulating VEGF/VEGFR2 and S1P/S1PR1 signals. SphK1 translocation was activated via the VEGFR2/PKC/ERK1/2 pathway and was closely linked to the biological function of VECs. GE significantly reduced SphK1 translocation, thereby ameliorating the abnormal biological function of VECs. Furthermore, after transfection of SphK1 siRNA in VECs and C57BL/6 mice, silencing SphK1 caused effectively attenuation of VEGF-induced VEC biological functions and angiogenesis. In vivo, the Matrigel plug experiment indicated that GE significantly inhibited pericyte coverage, basement membrane formation, vascular permeability, and fibrinogen deposition.

CONCLUSIONS

Our findings suggest that GE inhibited VEGF-induced VEC biological functions and angiogenesis by reducing SphK1 translocation. Generally, studies have revealed that GE down-regulated VEGFR2/PKC/ERK1/2-mediated SphK1 translocation and inhibited S1P/S1PR1 signaling activation, thereby alleviating VEGF-stimulated angiogenesis. The above evidences indicated that angiogenesis inhibition may provide a new direction for RA treatment.

Novel Angiogenic Regulators and Anti-Angiogenesis Drugs Targeting Angiogenesis Signaling Pathways: Perspectives for Targeting Angiogenesis in Lung Cancer

Lung cancer growth is dependent on angiogenesis. In recent years, angiogenesis inhibitors have attracted more and more attention as potential lung cancer treatments. Current anti-angiogenic drugs targeting VEGF or receptor tyrosine kinases mainly inhibit tumor growth by reducing angiogenesis and blocking the energy supply of lung cancer cells. However, these drugs have limited efficiency, raising concerns about limited scope of action and mechanisms of patient resistance to existing drugs. Therefore, current basic research on angiogenic regulators has focused more on screening carcinogenic/anticancer genes, miRNAs, lncRNAs, proteins and other biomolecules capable of regulating the expression of specific targets in angiogenesis signaling pathways. In addition, new uses for existing drugs and new drug delivery systems have received increasing attention. In our article, we analyze the application status and research hotspots of angiogenesis inhibitors in lung cancer treatment as a reference for subsequent mechanistic research and drug development.

Pristimerin induces apoptosis and tumor inhibition of oral squamous cell carcinoma through activating ROS-dependent ER stress/Noxa pathway

BACKGROUND

Pristimerin (Pri), a natural quinone methide triterpenoid isolated from Celastraceae and Hippocrateaceae, exhibits potent antitumor activity against various cancers. However, the mechanism of apoptosis induction by Pri in oral squamous cell carcinoma (OSCC) and its anti-OSCC effect in vivo has not been widely studied.

PURPOSE

This study aimed to investigate the anti-OSCC activities of Pri in vitro and in vivo and addressed the potential mechanisms of Pri-induced apoptosis.

METHODS

The effects of Pri on OSCC cells were analyzed by cell viability, colony formation and flow cytometry assays. Western blotting and qRT-PCR assays were chosen to detect the expression of proteins and genes. The anti-OSCC efficacy of Pri in vivo was evaluated by CAL-27 xenografts.

RESULTS

We showed that Pri inhibited the proliferation of human OSCC cell lines. Additionally, Pri induced apoptosis by upregulating Noxa expression. Furthermore, Pri treatment triggered excessive endoplasmic reticulum (ER) stress activation and subsequently induced c-Jun N-terminal kinase (JNK) signaling. ROS scavengers and ER stress inhibitors significantly attenuated Pri-induced OSCC cell apoptosis. Finally, Pri suppressed tumor growth in CAL-27 xenografts, accompanied ER stress activation and cell apoptosis.

CONCLUSION

These results reveal that Pri suppressed tumor growth and triggered cell apoptosis through ER stress activation in OSCC cells and xenografts, suggesting that Pri may serve as a therapeutic agent for OSCC.

Bioactive fractions and compound of Ardisia crispa roots exhibit anti-arthritic properties mediated via angiogenesis inhibition in vitro

Background

Ardisia crispa (Thunb.) A.DC (Primulaceae), is a medicinal herb traditionally used by Asian people as remedies to cure inflammatory related diseases, including rheumatism. The plant roots possess various pharmacological activities including antipyretic, anti-inflammation and antitumor. Previous phytochemical studies of the plant roots have identified long chain alkyl-1,4-benzoquinones as major constituents, together with other phytochemicals. Hexane fraction of the plant roots (ACRH), was previously reported with anti-angiogenic and anti-arthritic properties, while its effect on their anti-arthritic in vitro, is yet unrevealed. Considering the significance of angiogenesis inhibition in developing new anti-arthritic agent, thus we investigated the anti-arthritic potential of Ardisia crispa roots by suppressing angiogenesis, in vitro.

Methods

Ardisia crispa roots hexane extract (ACRH) was prepared from the plant roots using absolute n-hexane. ACRH was fractionated into quinone-rich fraction (QRF) and further isolated to yield benzoquinonoid compound (BQ), respectively. In vitro experiments using VEGF-induced human umbilical vein endothelial cells (HUVECs) and IL-1β-induced human fibroblast-like synoviocytes for rheumatoid arthritis (HFLS-RA) were performed to evaluate the effects of these samples on VEGF-induced HUVECs proliferation and tube formation, and towards IL-1β-induced HFLS-RA proliferation, invasion, and apoptosis, respectively. Therapeutic concentrations (0.05, 0.5, and 5 μg/mL) tested in this study were predetermined based on the IC₅₀ values obtained from the MTT assay.

Results

ACRH, QRF, and BQ exerted concentration-independent antiproliferative effects on VEGF-induced HUVECs and IL-1β-induced HFLS-RA, with IC₅₀ values at 1.09 ± 0.18, 3.85 ± 0.26, and 1.34 ± 0.16 μg/mL in HUVECs; and 3.60 ± 1.38, 4.47 ± 0.34, and 1.09 ± 0.09 μg/mL in HFLS-RA, respectively. Anti-angiogenic properties of these samples were verified via significant inhibition on VEGF-induced HUVECs tube formation, in a concentration-independent manner. The invasiveness of IL-1β-induced HFLS-RA was also significantly inhibited in a concentration-independent manner by all samples. ACRH and BQ, but not QRF, significantly enhanced the apoptosis of IL-1β-induced HFLS-RA elicited at their highest concentration (5 μg/mL) (P < 0.05).

Conclusions

These findings highlight the bioactive fractions and compound from Ardisia crispa roots as potential anti-arthritic agents by inhibiting both HUVECs and HFLS-RA’s cellular functions in vitro, possibly mediated via their anti-angiogenic effects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03341-y.

Quinone-rich fraction of Ardisia crispa (Thunb.) A. DC roots alters angiogenic cascade in collagen-induced arthritis

Rheumatoid arthritis (RA) is a chronic joint disorder, of which, excessive angiogenesis is the well-established factor contributing to synovitis and joint destruction. Ardisia crispa (Primulaceae) is a medicinal herb with evidenced anti-angiogenic properties, attributed to 2-methoxy-6-undecyl-1,4-benzoquinone (BQ) found in its roots. However, it is still unclear how BQ is able to inhibit angiogenesis in RA. Hence, we investigated the anti-arthritic potential of quinone-rich fraction (QRF) separated from Ardisia crispa roots hexane extract (ACRH) by targeting angiogenesis on collagen-induced arthritis (CIA) in rats. The QRF was priorly identified by quantifying the BQ content in the fraction using GC-MS. Male Sprague-Dawley rats (n = 6) were initially immunised with type II collagen (150 µg) subcutaneously at the base of the tail on day 0. QRF (3, 10, and 30 mg/kg/day) and celecoxib (5 mg/kg/day) were orally administered for 13 consecutive days starting from day 14 post-induction, except for the vehicle and arthritic controls. QRF at all dosages moderately ameliorated the arthritic scores, ankle swelling, and hind paw oedema with no significant (p > 0.05) modulation on the bodyweights and organ weights (i.e., liver, kidney, and spleen). Treatment with QRF at 3, 10, and 30 mg/kg, significantly (p < 0.05) attenuated VEGF-A, PI3K, AKT, NF-κB, p38, STAT3, and STAT5 proteins and markedly restored the increased synovial microvessel densities (MVD) to the normal level in arthritic rats in a dose-independent manner. In conclusion, QRF conferred the anti-arthritic effect via angiogenesis inhibition in vivo, credited to the BQ content and synergism, at least in part, by other phytoconstituents.

Cellular and Molecular Mechanisms of Pristimerin in Cancer Therapy: Recent Advances

Seeking an efficient and safe approach to eliminate tumors is a common goal of medical fields. Over these years, traditional Chinese medicine has attracted growing attention in cancer treatment due to its long history. Pristimerin is a naturally occurring quinone methide triterpenoid used in traditional Chinese medicine to treat various cancers. Recent studies have identified alterations in cellular events and molecular signaling targets of cancer cells under pristimerin treatment. Pristimerin induces cell cycle arrest, apoptosis, and autophagy to exhibit anti-proliferation effects against tumors. Pristimerin also inhibits the invasion, migration, and metastasis of tumor cells via affecting cell adhesion, cytoskeleton, epithelial-mesenchymal transition, cancer stem cells, and angiogenesis. Molecular factors and pathways are associated with the anti-cancer activities of pristimerin. Furthermore, pristimerin reverses multidrug resistance of cancer cells and exerts synergizing effects with other chemotherapeutic drugs. This review aims to discuss the anti-cancer potentials of pristimerin, emphasizing multi-targeted biological and molecular regulations in cancers. Further investigations and clinical trials are warranted to understand the advantages and disadvantages of pristimerin treatment much better.

Pristimerin Suppresses RANKL-Induced Osteoclastogenesis and Ameliorates Ovariectomy-Induced Bone Loss

Osteoporosis is characterized by bone loss and destruction of trabecular architecture, which greatly increases the burden on the healthcare system. Excessive activation of osteoclasts is an important cause of osteoporosis, and suppression of osteoclastogenesis is helpful for the treatment of osteoporosis. Pristimerin, a natural compound, possesses numerous pharmacological effects via inactivating the NF-κB and MAPK pathways, which are closely related to osteoclastogenesis process. However, the relationship between Pristimerin and osteoclastogenesis requires further investigation. In this research, we examined the effect of Pristimerin on osteoclastogenesis and investigated the related mechanisms. Our results showed Pristimerin inhibited RANKL-induced osteoclast differentiation and osteoclastic bone resorption in vitro, with decreased expression of osteoclastogenesis-related markers including c-Fos, NFATc1, TRAP, Cathepsin K, and MMP-9 at both mRNA and protein levels. Furthermore, Pristimerin suppressed NF-κB and MAPK signaling pathways, reduced reactive oxygen species (ROS) production and activated the nuclear factor erythroid 2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) signaling during osteoclastogenesis. Our in vivo experiments showed that Pristimerin remarkably ameliorated ovariectomy-induced bone loss, reduced serum levels of TNF-α, IL-1β, IL-6, and RANKL, and increased serum level of osteoprotegerin (OPG). Therefore, our research indicated that Pristimerin is a potential chemical for the treatment of osteoporosis.

Anti-angiogenic activity of ShengMaBieJia decoction in vitro and in acute myeloid leukaemia tumour-bearing mouse models

Context: ShengMaBieJia decoction (SMBJD) is used to treat solid and hematological tumours; however, its anti-angiogenesis activity remains unclear.Objective: This study verified the anti-angiogenic effects of SMBJD in vitro and in tumour-bearing acute myeloid leukaemia (AML) mouse models.Materials and methods: In vivo, the chicken chorioallantoic membrane (CAM) and BALB/c null mouse xenograft models were treated with SMBJD (0, 2, 4, and 8 mg/mL) for 48 h and for 2 weeks, respectively. Anti-angiogenic activity was assessed according to microvessel density (MVD) and immunohistochemistry (IHC) targeting CD31 and VEGFR2. In vitro, proliferation viability, migratory activity and tube formation were measured. Western blots and polymerase chain reaction (PCR) assays were used to examine the levels of PI3K, Akt, and VEGF.Results: HPLC analyses revealed the active constituents of SMBJD such as liquiritin, cimifugin, ferulic, isoferulic, and glycyrrhizic acids. In vitro, SMBJD treatment decreased cellular migration, chemotaxis, and tube formation at non-cytotoxic concentrations (2, 4, and 8 mg/mL) in a time- and dose-dependent manner. The dosage of less than IC₂₀ is considered safe. In vivo, CAM models exhibited a decrease in MVD, and the tissues of xenografted mice possessed reduced CD31 and VEGFR2 expression. Conditioned media (CM) from AML cells (HL60 and NB4 cells) treated with non-cytotoxic doses of SMBJD inhibited chemotactic migration and tube formation in vitro. Both CM (HL60) and CM (NB4) exhibited downregulated expression of PI3K, Akt, and VEGF.Discussion and conclusions: SMBJD inhibited angiogenesis in AML through the PI3K/AKT pathway, which might be combined with targeted therapy to provide more effective treatment.

Pristimerin Suppresses Trophoblast Cell Epithelial-Mesenchymal Transition via miR-542-5p/EGFR Axis

Background

Ectopic pregnancy (EP) is an ectopic embryo implantation occurred outside the uterine cavity. Nowadays, more attention have garnered in fast and effective treatment with less side effects. Pristimerin is known as the clinical application for anti-cancer, and the effect on EP therapy is still unclear.

Materials and Methods

Trophoblast cell line HTR-8/SVneo was used; then, we performed cell counting kit-8 assay, wound healing assay, flow cytometry and real-time polymerase chain reaction analysis (RT-PCR) to detect the cell viability, migration ability, apoptosis and epithelial–mesenchymal transition (EMT) under pristimerin treatment. In addition, public bioinformatic database was used to discover the connection between molecular and genes. Finally, we used miRNA transfection and RT-PCR techniques to determine the underlying molecular mechanism.

Results

We revealed that pristimerin inhibited trophoblast cells proliferation, migration and EMT, while induced trophoblast cell apoptosis. Furthermore, expression of miR-542-5p, AGO2 and EGFR was suppressed in HTR-8/SVneo cells post pristimerin treatment, and miR-542-5p silence showed the same effect. Combing pristimerin treatment and miR-542-5p silence showed a synergistic action.

Conclusion

Pristimerin could be an effective treatment to block embryo implantation by miR-542-5p and EGFR down-regulation.

Pristimerin Inhibits MMP-9 Expression and Cell Migration Through Attenuating NOX/ROS-Dependent NF-κB Activation in Rat Brain Astrocytes Challenged with LPS

Purpose

Neuroinflammation plays a crucial role in neurodegenerative diseases. Matrix metalloproteinases (MMPs) are a landmark of neuroinflammation. Lipopolysaccharide (LPS) has been demonstrated to induce MMP-9 expression. The mechanisms underlying LPS-induced MMP-9 expression have not been completely elucidated in astrocytes. Nuclear factor-kappaB (NF-κB) is well known as one of the crucial transcription factors in MMP-9 induction. Moreover, reactive oxygen species (ROS) could be an important mediator of neuroinflammation. Here, we differentiated whether ROS and NF-κB contributed to LPS-mediated MMP-9 expression in rat brain astrocytes (RBA-1). Besides, pristimerin has been revealed to possess antioxidant and anti-inflammatory effects. We also evaluated the effects of pristimerin on LPS-induced inflammatory responses.

Methods

RBA-1 cells were used for analyses. Pharmacological inhibitors and siRNAs were used to evaluate the signaling pathway. Western blotting and gelatin zymography were conducted to evaluate protein and MMP-9 expression, respectively. Real-time PCR was for mRNA expression. Wound healing assay was for cell migration. 2',7'-dichlorodihydrofluorescein diacetate (H₂DCF-DA) and dihydroethidium (DHE) staining were for ROS generation. Immunofluorescence staining was conducted to assess NF-κB p65. Promoter-reporter gene assay and chromatin immunoprecipitation (ChIP) assay were used to detect promoter activity and the association of nuclear proteins with the promoter.

Results

Our results showed that the increased level of ROS generation was attenuated by edaravone (a ROS scavenger), apocynin (APO; an inhibitor of p47^Phox), diphenyleneiodonium (DPI; an inhibitor of NOX), and pristimerin in RBA-1 cells exposed to LPS. Besides, pretreatment with APO, DPI, edaravone, Bay11-7082, and pristimerin also inhibited the phosphorylation, nuclear translocation, promoter binding activity of NF-κB p65 as well as upregulation of MMP-9 expression-mediated cell migration in RBA-1 cells challenged with LPS.

Conclusion

These results suggested that LPS enhances the upregulation of MMP-9 through nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX)/ROS-dependent NF-κB activity. These results also provide new insights into the mechanisms by which pristimerin attenuates LPS-mediated MMP-9 expression and neuroinflammatory responses.

Identification of a novel tumor angiogenesis inhibitor targeting Shh/Gli1 signaling pathway in Non-small cell lung cancer

Although angiogenesis inhibitors targeting VEGF/VEGFR2 have been applied for tumor therapy, the outcomes are still unsatisfactory. Thus, it is urgent to develop novel angiogenesis inhibitor for cancer therapy from new perspectives. Identification of novel angiogenesis inhibitor from natural products is believed to be one of most promising strategy. In this study, we showed that pristimerin, an active agent isolated from traditional Chinese herbal medicine Celastrus aculeatus Merr, was a novel tumor angiogenesis inhibitor that targeting sonic hedgehog (Shh)/glioma associated oncogene 1 (Gli1) signaling pathway in non-small cell lung cancer (NSCLC). We showed that pristimerin affected both the early- and late-stage of angiogenesis, suggesting by that pristimerin inhibited Shh-induced endothelial cells proliferation, migration, invasion as well as pericytes recruitment to the endothelial tubes, which is critical for the new blood vessel maturation. It also suppressed tube formation, vessel sprouts formation and neovascularization in chicken embryo chorioallantoic membrane (CAM). Moreover, it significantly decreased microvessel density (MVD) and pericyte coverage in NCI-H1299 xenografts, resulting in tumor growth inhibition. Further research revealed that pristimerin suppressed tumor angiogenesis by inhibiting the nucleus distribution of Gli1, leading to inactivation of Shh/Gli1 and its downstream signaling pathway. Taken together, our study showed that pristimerin was a promising novel anti-angiogenic agent for the NSCLC therapy and targeting Shh/Gli1 signaling pathway was an effective approach to suppress tumor angiogenesis.

Attenuation of pristimerin on TNF-α-induced endothelial inflammation

OBJECTIVE

Pristimerin is known to have anti-cancer and anti-inflammatory activities; however, its therapeutic mechanism has not been described. In this study, to investigate the therapeutic mechanism of pristimerin, we examined the effect of pristimerin on TNF-α-induced endothelial inflammatory response both in vitro and in vivo.

METHODS

Leukocyte-endothelium Adhesion Assay was use to evaluate the endothelial cell-monocyte interaction. Western blotting was used to confirm protein expression. NF-κB p65 nuclear translocation in endothelial cells was detected using immunofluorescent microscopy. In vivo leukocyte infiltration was evaluated using acute lung inflammation model.

RESULTS

Pristimerin profoundly inhibited TNF-α-induced adhesion of monocytes to human endothelial cells and the leukocyte transmigration. Pristimerin dramatically inhibited the expression of TNF-α-induced endothelial adhesion molecules (intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1)) and the pro-inflammatory cytokine (IL-6, IL-8 and monocyte chemoattractant protein-1 (MCP-1)). Pristimerin suppressed the penetration of the leukocyte in the acute lung injury mice model. Furthermore, pristimerin also suppressed the TNF-α-activated Nuclear factor kappa B (NF-κB) activation.

CONCLUSIONS

Pristimerin has the anti-inflammatory properties in endothelial cells, at least in part, through the suppression of NF-κB activation, which may have a potential therapeutic effects for inflammatory vascular diseases.

Downregulation of Hypoxia-Inducible Factor-1α by RNA Interference Alleviates the Development of Collagen-Induced Arthritis in Rats

Rheumatoid arthritis (RA) is the most common type of autoimmune arthritis. Hypoxia-inducible factor-1α (HIF-1α) as a transcription factor in response to hypoxia suggests that it could be a potential therapeutic target for the treatment of RA. In this study, we assessed whether the HIF pathway blockade attenuates the manifestations of RA in the collagen-induced arthritis (CIA) rat model. We constructed a short hairpin RNA (shRNA) lentiviral expression vector targeting HIF-1α (pLVX-shRNA-HIF-1α) and to achieve HIF-1α RNA interference. Quantitative RT-PCR, immunofluorescence staining, and western blot were used to detect the expressions of HIF-1α, vascular endothelial growth factor (VEGF), phsopho (p)-p65, and p-IКBɑ mRNA and protein, respectively. Micro-computed tomography was used to investigate joint morphology at different time points after CIA induction. Moreover, enzyme-linked immunosorbent assay (ELISA) was used to monitor the expression of inflammatory cytokines. In vitro analyses revealed that pLVX-shRNA-HIF-1α effectively inhibited the expression of HIF-1α and VEGF and led to the activation of p-65 and p-IКBɑ, as well as decreased proinflammatory cytokine expression in cell culture. Inhibition of HIF-1α in rats decreased signs of a systemic inflammatory condition, together with decreased pathological changes of RA. Moreover, downregulation of HIF-1α expression markedly reduced the synovitis and angiogenesis. In conclusion, we have shown that pharmacological inhibition of HIF-1 may improve the clinical manifestations of RA.

Traditional uses, secondary metabolites, and pharmacology of Celastrus species - a review

ETHNOPHARMACOLOGICAL RELEVANCE

Plants of genus Celastrus (Celastraceae) have been widely used in traditional Chinese medicine (TCM) and Indian medicine to treat cognitive dysfunction, epilepsy, insomnia, rheumatism, gout, and dyspepsia for thousands of years.

AIM OF STUDY

We critically summarized the current evidence on the botanic characterization and distribution, ethnopharmacology, secondary metabolites, pharmacological activities, qualitative and quantitative analysis, and toxicology of Celastrus species to provide perspectives for developing more attractive pharmaceuticals of plant origin.

MATERIALS AND METHODS

The relevant information on Celastrus species was gathered from worldwide accepted scientific databases via electronic search (Web of Science, SciFinder, PubMed, Elsevier, SpringerLink, Wiley Online, China Knowledge Resource Integrated, and Google Scholar). Information was also obtained from the literature and books as well as PhD and MSc dissertations. Plant names were validated by "The Plant List" (www.theplantlist.org).

RESULTS

Comprehensive analysis of the above mentioned databases and other sources confirmed that ethnomedical uses of plants of Celastrus genus had been recorded in China, India, and other countries in Southern Asia. The phytochemical investigation revealed the presence of β-dihydroagarofuranoids, diterpenoids, triterpenoids, tetraterpenes, phenylpropanoids, alkaloids, flavonoids, lignans, and others. The crude extracts and isolated constituents have exhibited a wide range of in vitro and in vivo pharmacological effects, including antitumor, cytotoxic, insecticidal, antimicrobial, anti-rheumatoid arthritis (RA), anti-inflammatory, anti-ageing and antioxidative, and neuroprotective activities.

CONCLUSION

Plants of genus Celastrus have been confirmed to show a strong potential for therapeutic and health-maintaining effects, in light of their long traditional use and the phytochemical and pharmacological studies summarized here. Currently, pharmacological studies of this genus mainly focus on Celastrus paniculatus Willd. and Celastrus orbiculatus Thunb. Therefore, more pharmacological investigations should be implemented to support traditional uses of other medicinal plants of the genus Celastrus. Moreover, studies on the toxicity, bioavailability, and pharmacokinetics, in addition to clinical trials, are indispensable for assessing the safety and efficacy of the secondary metabolites or extracts obtained from plants belonging to this genus.

Herbal compounds for rheumatoid arthritis: Literatures review and cheminformatics prediction

Rheumatoid arthritis (RA) is a systemic disease characterized by autoimmunity, joint inflammation, and cartilage destruction, which affects 0.5-1% of the population. Many compounds from herbal medicines show the potentials to treat RA. On this basis, the compounds with good pharmacokinetic behaviors and drug-likeness properties will be further studied and developed. Therefore, the herbal compounds with anti-RA activities were reviewed in this paper, and the cheminformatics tools were used to predict their drug-likeness properties and pharmacokinetic parameters. A total of 90 herbal compounds were analyzed, which were reported to be effective on RA models through anti-inflammation, chondroprotection, immunoregulation, antiangiogenesis, and antioxidation. Most of the herbal compounds have good drug-likeness properties. Most of the compounds can be an alternative and valuable source for anti-RA drug discovery.

Therapeutic effects of polysaccharides from Anoectochilus roxburghii on type II collagen-induced arthritis in rats

Anoectochilus roxburghii, a famous Chinese herbal medicine, has been commonly used for the treatment of liver disease, diabetes, and rheumatoid arthritis. Our study aimed to investigate the anti-rheumatoid arthritis effects of A. roxburghii polysaccharides (ARP), using the rat's model of type II collagen-induced arthritis (CIA). ARP was prepared by alcohol sedimentation and structurally characterized based on combined chemical, chromatographic and spectroscopic methods. High Performance Size Exclusion Chromatography-Multiangle Laser Light Scattering-Refrative Index (HPSEC-MALLS-RI) analysis revealed that ARP includes two peaks, and the weight-average molecular weight (Mw) of the principal one was estimated as 5.90 kDa with a relative content of 98.2%. Pharmacological results exhibited that ARP significantly decreased the arthritis index and ameliorated the inflammatory cell infiltration and the synovial tissue destruction in CIA rats. Additionally, ARP possessed significant NO production inhibitory effects and antioxidant activity. Further anti-inflammatory mechanism investigations indicated that ARP significantly inhibited the activation of nuclear factor κB (NF-κB) pathway by suppressing the phosphorylation of IκB and p65, which subsequently down-regulated the mRNA expressions of IL-1β and IL-6 in LPS-stimulated RAW 264.7 cells. These findings suggested that ARP has great potential in the development of functional foods and dietary supplements for the treatment of rheumatoid arthritis.

Implications of Angiogenesis Involvement in Arthritis

Angiogenesis, the growth of new blood vessels, is essential in the pathogenesis of joint inflammatory disorders such as rheumatoid arthritis (RA) and osteoarthritis (OA), facilitating the invasion of inflammatory cells and increase in local pain receptors that contribute to structural damage and pain. The angiogenic process is perpetuated by various mediators such as growth factors, primarily vascular endothelial growth factor (VEGF) and hypoxia-inducible factors (HIFs), as well as proinflammatory cytokines, various chemokines, matrix components, cell adhesion molecules, proteases, and others. Despite the development of potent, well-tolerated nonbiologic (conventional) and biologic disease-modifying agents that have greatly improved outcomes for patients with RA, many remain resistant to these therapies, are only partial responders, or cannot tolerate biologics. The only approved therapies for OA include symptom-modifying agents, such as analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), steroids, and hyaluronic acid. None of the available treatments slow the disease progression, restore the original structure or enable a return to function of the damaged joint. Moreover, a number of safety concerns surround current therapies for RA and OA. New treatments are needed that not only target inflamed joints and control articular inflammation in RA and OA, but also selectively inhibit synovial angiogenesis, while preventing healthy tissue damage. This narrative review of the literature in PubMed focuses on the evidence illustrating the therapeutic benefits of modulating angiogenic activity in experimental RA and OA. This evidence points to new treatment targets in these diseases.

Pristimerin as a Novel Hepatoprotective Agent Against Experimental Autoimmune Hepatitis

Pristimerin (Pris) is bioactive natural quinonoid triterpene that has anti-inflammatory and anti-cancer activities. Meanwhile, its effect against hepatitis needs to be elucidated. This investigation aimed to evaluate the ability of Pris to protect against autoimmune hepatitis (AIH). A mouse model of AIH was established using single concanavalin A (Con A) intravenous injection. Mice were treated with Pris at two different doses (0.4 and 0.8 mg/kg) for 5 days prior to Con A challenge. Markers of hepatic injury, oxidative, inflammatory, and apoptotic damage were estimated. Results have revealed that Pris pretreatment ameliorated Con A-induced hepatic damage. There was decrease in the elevated serum indices of hepatic damage (ALT, AST, ALP, and LDH) and improvement of the histopathological picture of the liver. Pris effectively decreased Con A-induced neutrophil infiltration into the hepatic tissue as presented by amelioration of the level and immuno-expression of myeloperoxidase (MPO). Additionally, Pris attenuated Con A-induced increase in CD4+ T-cells in hepatic tissue. Lipid peroxidation was significantly depressed simultaneously with enhancement of the antioxidant capacity in Pris pretreated animals. Pris also enhanced nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA expression and its binding capacity. In addition, Pris increased mRNA expression of heme-oxygenase-1 (HO-1) and restored its normal level. Furthermore, Pris decreased the level and immuno-expression of nuclear factor kappa-B (NF-κB) as well as the downstream inflammatory cascade (TNF-α, IL-6, and IL-1β). Finally, Pris showed inhibitory effect on Con A-induced apoptotic alteration in liver as it decreased the mRNA expression and levels the apoptotic markers (Bax and caspase-3) and increased mRNA expression and level of the anti-apoptotic protein (Bcl2). In conclusion, this study demonstrates the potent hepatoprotective efficacy of Pris against Con A-induced hepatitis which may be related to anti-oxidative, anti-inflammatory, and anti-apoptotic pathways. Pris could serve as a new candidate for the management of hepatitis.

Wu-Tou Decoction Inhibits Angiogenesis in Experimental Arthritis by Targeting VEGFR2 Signaling Pathway

Wu-tou decoction (WTD) is a classic traditional Chinese medicine formula and has been extensively used for the treatment of rheumatoid arthritis (RA). Previous reports indicate that WTD possesses anti-inflammatory and antinociceptive activities, and inhibits the development of arthritic joints and disease severity of collagen-induced arthritis (CIA) or adjuvant-induced rats; however, its action on angiogenesis of RA has not been clarified. This study aims to determine the anti-angiogenic activity of WTD in CIA rats and in various angiogenesis models. Our data showed that WTD (0.95, 1.9, and 3.8 g/kg) markedly reduced the immature blood vessels in synovial membrane tissues of inflamed joints from CIA rats. It also inhibited in vivo angiogenesis in chick embryo and VEGF₁₆₅-induced microvessel sprout formation ex vivo. Meanwhile, WTD suppressed VEGF₁₆₅-/MH7A-induced migration, invasion, adhesion, and tube formation of human umbilical vein endothelial cells (HUVECs). Moreover, WTD significantly reduced the expression of angiogenic activators, including vascular endothelial growth factor (VEGF), VEGFR2, interleukin (IL)-1β, IL-17, transforming growth factor-β, platelet-derived growth factor, placenta growth factor, angiopoietin (Ang) I and Ang II in synovium of CIA rats, and/or in HUVECs. More interestingly, WTD blocked the autophosphorylation of VEGF₁₆₅-induced VEGFR2 and consequently downregulated the signaling pathways of activated AKT, ERK1/2, JNK, and p38 in VEGF₁₆₅-induced HUVECs. These findings suggest for the first time that WTD possesses the anti-angiogenic effect in RA in vivo, ex vivo, and in vitro by interrupting the targeting of VEGFR2 activation.

Effect of Qianghuo Erhuang Decoction on T Regulatory and T Helper 17 Cells in Treatment of Adjuvant-induced Arthritis in Rats

QianghuoErhuang Decoction (QED) is an effective recipe in treating rheumatoid arthritis. The present study aimed to explore the effects of QED on Treg and Th17 in adjuvant arthritis (AA) model. The study included 6 group rats: normal control group, AA group, AA + methotrexate (MTX) group, AA + high, moderate, and low dose QED groups. The arthritis score was significantly decreased in the MTX and high-dose QED groups compared with the AA group on days 24 and 28 (P < 0.01), respectively. The synovial tissue inflammation was attenuated by histological observation, and the proliferation of splenocytes was significantly inhibited in MTX and high-dose QED groups (P < 0.01). High-dose QED can up-regulated the percentage of Treg cells (P < 0.01) and down-regulated the percentage of Th17 cells (P < 0.05). Notably, the serum levels of IL-6, IL-17 and TNF-α were significantly decreased, while TGF-β levels were apparently elevated compared with AA group (P < 0.05, P < 0.01). Interestingly, moderate and low-dose QED had no such similar effects. In summary, high-dose QED had a therapeutic effect against adjuvant arthritis and regulated the related cytokine levels in serum. The underlying mechanism might be mediated via restoration of the imbalance in CD4⁺ T lymphocyte subsets, Treg/Th17.

Pristimerin Inhibits LPS-Triggered Neurotoxicity in BV-2 Microglia Cells Through Modulating IRAK1/TRAF6/TAK1-Mediated NF-κB and AP-1 Signaling Pathways In Vitro

Microglia plays a prominent role in the brain's inflammatory response to injury or infection by migrating to affected locations and secreting inflammatory molecules. However, hyperactivated microglial is neurotoxic and plays critical roles in the pathogenesis of neurodegenerative diseases. Pristimerin, a naturally occurring triterpenoid, possesses antitumor, antioxidant, and anti-inflammatory activities. However, the effect and the molecular mechanism of pristimerin against lipopolysaccharide (LPS)-induced neurotoxicity in microglia remain to be revealed. In the present study, using BV-2 microglial cultures, we investigated whether pristimerin modifies neurotoxicity after LPS stimulation and which intracellular pathways are involved in the effect of pristimerin. Here we show that pristimerin markedly suppressed the release of Regulated on Activation, Normal T Expressed and Secreted (RANTES), transforming growth factor-β1 (TGF-β1), IL-6, tumor necrosis factor-α (TNF-α), and nitric oxide (NO). Pristimerin also significantly inhibited migration of BV-2 microglia and alleviated the death of neuron-like PC12 cell induced by the conditioned medium from LPS-activated BV-2 microglial cells. Moreover, pristimerin reduced the expression and interaction of TNF Receptor-Associated Factor 6 (TRAF6) and Interleukin-1 Receptor-Associated Kinases (IRAK1), limiting TGF-beta activating kinase 1 (TAK1) activation, and resulting in an inhibition of IKKα/β/NF-κB and MKK7/JNK/AP-1 signaling pathway in LPS-activated BV-2 microglia. Taken together, the anti-neurotoxicity action of pristimerin is mediated through the inhibition of TRAF6/IRAK1/TAK1 interaction as well as the related pathways: IKKα/β/NF-κB and MKK7/JNK/AP-1 signaling pathways. These findings may suggest that pristimerin might serve as a new therapeutic agent for treating hyperactivated microglial induced neurodegenerative diseases.

Pristimerin effectively inhibits the malignant phenotypes of uveal melanoma cells by targeting NF‑κB pathway

Uveal melanoma (UM) is a highly aggressive intraocular malignancy that lacks any effective targeted-therapy. Neither survival nor prognosis has been improved for the past decades in patients with metastatic UM. NF‑κB pathway is reported to be abnormally activated in UM. However, the role of NF‑κB pathway as a potential therapeutical target in UM remains unclear. Here, the effect of pristimerin, a potent inhibitor of NF‑κB pathway, on UM cells in terms of growth, apoptosis, motility, invasion and cancer stem-like cells (CSCs) was evaluated in vitro. We showed that pristimerin suppressed tumor necrosis factor α (TNFα)-induced IκBα phosphorylation, translocation of p65, and expression of NF‑κB-dependent genes. Moreover, pristimerin decreased cell viability and clonogenic ability of UM cells. A synergistic effect was observed in the treatment of pristimerin combined with vinblastine, a frontline therapeutic agent, in UM. Pristimerin led to a significant increase in the Annexin V+ cell population as measured by flow cytometry. We also observed that pristimerin impaired the abilities of migration and invasion in UM cells. Furthermore, pristimerin eliminated the ALDH+ cells and weakened serial re-plating ability of melanosphere. Collectively, pristimerin shows remarkable anticancer activities in UM cells through inactivating NF‑κB pathway, revealing that pristimerin may be a promising therapeutic agent in UM.

Improved in vitro angiogenic behavior on anodized titanium dioxide nanotubes

Background

Neovascularization over dental implants is an imperative requisite to achieve successful osseointegration onto implanted materials. The aim of this study was to investigate the effects on in vitro angiogenesis of anodized 70 nm diameter TiO₂ nanotubes (NTs) on Ti6Al4V alloy synthesized and disinfected by means of a novel, facile, antibacterial and cost-effective method using super oxidized water (SOW). We also evaluated the role of the surface roughness and chemical composition of materials of materials on angiogenesis.

Methods

The Ti6Al4V alloy and a commercially pure Ti were anodized using a solution constituted by SOW and fluoride as electrolyte. An acid-etched Ti6Al4V was evaluated to compare the effect of micro-surface roughness. Mirror-polished materials were used as control. Morphology, roughness, chemistry and wettability were assessed by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy (EDX) and using a professional digital camera. Bovine coronary artery endothelial cells (BCAECs) were seeded over the experimental surfaces for several incubation times. Cellular adhesion, proliferation and monolayer formation were evaluated by means of SEM. BCAEC viability, actin stress fibers and vinculin cellular organization, as well as the angiogenic receptors vascular endothelial growth factor 2 (VEGFR2) and endothelial nitric oxide synthase (eNOS) were measured using fluorescence microscopy.

Results

The anodization process significantly increased the roughness, wettability and thickness of the oxidized coating. EDX analysis demonstrated an increased oxygen (O) and decreased carbon (C) content on the NTs of both materials. Endothelial behavior was solidly supported and improved by the NTs (without significant differences between Ti and alloy), showing that endothelial viability, adhesion, proliferation, actin arrangement with vinculin expression and monolayer development were evidently stimulated on the nanostructured surface, also leading to increased activation of VEGFR2 and eNOS on Ti6Al4V-NTs compared to the control Ti6Al4V alloy. Although the rougher alloy promoted BCAECs viability and proliferation, filopodia formation was poor.

Conclusion

The in vitro results suggest that 70 nm diameter NTs manufactured by anodization and cleaned using SOW promotes in vitro endothelial activity, which may improve in vivo angiogenesis supporting a faster clinical osseointegration process.