Brusatol improves the efficacy of an anti-mouse-PD-1 antibody via inhibiting programmed cell death 1 ligand 1 expression in a murine head and neck squamous cell carcinoma model.

OBJECTIVE: Combing PD-1/PD-L1 immune checkpoint inhibitors with natural products has exhibited better efficacy than monotherapy. Hence, the purpose of this research was to examine the anti-cancer effects of brusatol, a natural quassinoid-terpenoid derived from Brucea javanica, when used in conjunction with an anti-mouse-PD-1 antibody in a murine head and neck squamous cell carcinoma (HNSCC) model and elucidate underlying mechanisms. DESIGN: A murine HNSCC model and an SCC-15 cell xenograft nude mouse model were established to investigate the anti-cancer effects of brusatol and anti-PD-1 antibody. Mechanistic studies were performed using immunohistochemistry. Cell proliferation, migration, colony formation, and invasion were evaluated by MTT, migration, colony formation, and transwell invasion assays. PD-L1 levels in oral squamous cell carcinoma (OSCC) cells were assessed through qRT-PCR, flow cytometry, and western blotting assays. The impact of brusatol on Jurkat T cell function was assessed by an OSCC/Jurkat co-culture assay. RESULTS: Brusatol improved tumor suppression by anti-PD-1 antibody in HNSCC mouse models. Mechanistic studies revealed brusatol inhibited tumor cell growth and angiogenesis, induced apoptosis, increased T lymphocyte infiltration, and reduced PD-L1 expression in tumors. Furthermore, in vitro assays confirmed brusatol inhibited PD-L1 expression in OSCC cells and suppressed cell migration, colony formation, and invasion. Co-culture assays indicated that brusatol's PD-L1 inhibition enhanced Jurkat T cell-mediated OSCC cell death and reversed the inhibitory effect induced by OSCC cells. CONCLUSIONS: Brusatol improves anti-PD-1 antibody efficacy by targeting PD-L1, suggesting its potential as an adjuvant in anti-PD-1 immunotherapy.

Brusatol induces ferroptosis to inhibit hepatocellular carcinoma progression by targeting ATF3.

Ferroptosis is a novel form of programmed cell death that is triggered by iron-dependent lipid peroxidation. Brusatol (BRU), a natural nuclear factor erythroid 2-related factor 2 inhibitor, exhibits potent anticancer effects in various types of cancer. However, the exact mechanism of BRU in the treatment of hepatocellular carcinoma (HCC) remains unknown. The anticancer effects of BRU in HCC were detected using cell counting kit-8 and colony formation assays and a xenograft model. RNA sequencing (RNA-seq) and bioinformatics analyses of HCC cells were utilized to elucidate the mechanism underlying the effects of BRU in HCC. The levels of reactive oxygen species (ROS), glutathione (GSH), malondialdehyde (MDA), and Fe2+ were measured using assay kits. The expression of activating transcription factor 3 (ATF3) was tested using RT-qPCR, western blotting, and immunofluorescence staining. The role of ATF3 in BRU-induced ferroptosis was examined using siATF3. BRU significantly inhibited HCC cell proliferation, both in vitro and in vivo. BRU activated the ferroptosis signaling pathway and increased ATF3 expression. Furthermore, ATF3 knockdown impeded BRU-induced ferroptosis. BRU suppressed HCC growth through ATF3-mediated ferroptosis, supporting BRU as a promising therapeutic agent for HCC.

Brusatol alleviates pancreatic carcinogenesis via targeting NLRP3 in transgenic Krastm4Tyj Trp53tm1Brn Tg (Pdx1-cre/Esr1*) #Dam mice.

BACKGROUND: Pancreatic cancer (PanCa), ranked as the 4th leading cause of cancer-related death worldwide, exhibits an dismal 5-year survival rate of less than 5 %. Chronic pancreatitis (CP) is a known major risk factor for PanCa. Brusatol (BRT) possesses a wide range of biological functions, including the inhibition of PanCa proliferation. However, its efficacy in halting the progression from CP to pancreatic carcinogenesis remains unexplored. METHODS: We assess the effects of BRT against pancreatic carcinogenesis from CP using an experimentally induced CP model with cerulein, and further evaluate the therapeutic efficacy of BRT on PanCa by employing Krastm4TyjTrp53tm1BrnTg (Pdx1-cre/Esr1*) #Dam/J (KPC) mouse model. RESULTS: Our finding demonstrated that BRT mitigated the severity of cerulein-induced pancreatitis, reduced pancreatic fibrosis and decreased the expression of α-smooth muscle actin (α-SMA), which is a biomarker for pancreatic fibrosis. In addition, BRT exerted effects against cerulein-induced pancreatitis via inactivation of NLRP3 inflammasome. Moreover, BRT significantly inhibited tumor growth and impeded cancer progression. CONCLUSIONS: The observed effect of BRT on impeding pancreatic carcinogenesis through targeting NLRP3 inflammasome suggests its good potential as a potential agent for treatment of PanCa.

Modulators of the Nrf2 Signaling Pathway Enhance the Cytotoxic Effect of Standard Chemotherapeutic Drugs on Organoids of Metastatic Colorectal Cancer.

The activity of known modulators of the Nrf2 signaling pathway (bardoxolone and brusatol) was studied on cultures of tumor organoids of metastatic colorectal cancer previously obtained from three patients. The effect of modulators was studied both as monotherapy and in combination with standard chemotherapy drugs used to treat colorectal cancer. The Nrf2 inhibitor brusatol and the Nrf2 activator bardoxolone have antitumor activity. Moreover, bardoxolone and brusatol also significantly enhance the effect of the chemotherapy drugs 5-fluorouracil, oxaliplatin, and irinotecan metabolite SN-38. Thus, bardoxolone and brusatol can be considered promising candidates for further preclinical and clinical studies in the treatment of colorectal cancer.

The Experimental and In Silico-Based Evaluation of NRF2 Modulators, Sulforaphane and Brusatol, on the Transcriptome of Immortalized Bovine Mammary Alveolar Cells.

Changes during the production cycle of dairy cattle can leave these animals susceptible to oxidative stress and reduced antioxidant health. In particular, the periparturient period, when dairy cows must rapidly adapt to the sudden metabolic demands of lactation, is a period when the production of damaging free radicals can overwhelm the natural antioxidant systems, potentially leading to tissue damage and reduced milk production. Central to the protection against free radical damage and antioxidant defense is the transcription factor NRF2, which activates an array of genes associated with antioxidant functions and cell survival. The objective of this study was to evaluate the effect that two natural NRF2 modulators, the NRF2 agonist sulforaphane (SFN) and the antagonist brusatol (BRU), have on the transcriptome of immortalized bovine mammary alveolar cells (MACT) using both the RT-qPCR of putative NRF2 target genes, as well as RNA sequencing approaches. The treatment of cells with SFN resulted in the activation of many putative NRF2 target genes and the upregulation of genes associated with pathways involved in cell survival, metabolism, and antioxidant function while suppressing the expression of genes related to cellular senescence and DNA repair. In contrast, the treatment of cells with BRU resulted in the upregulation of genes associated with inflammation, cellular stress, and apoptosis while suppressing the transcription of genes involved in various metabolic processes. The analysis also revealed several novel putative NRF2 target genes in bovine. In conclusion, these data indicate that the treatment of cells with SFN and BRU may be effective at modulating the NRF2 transcriptional network, but additional effects associated with cellular stress and metabolism may complicate the effectiveness of these compounds to improve antioxidant health in dairy cattle via nutrigenomic approaches.

Brusatol hinders the progression of bladder cancer by Chac1/Nrf2/SLC7A11 pathway.

Bladder cancer is a common tumor that impacts the urinary system and marked by a significant fatality rate and an unfavorable prognosis. Promising antineoplastic properties are exhibited by brusatol, which is obtained from the dried ripe fruit of Brucea javanica. The present study aimed to evaluate the influence of brusatol on the progression of bladder cancer and uncover the molecular mechanism involved. We used Cell Counting Kit-8, colony formation and EdU assays to detect cell numbers, viability and proliferation. We used transwell migration assay to detect cell migration ability. The mechanism of brusatol inhibition of bladder cancer proliferation was studied by flow cytometry and western blotting. It was revealed that brusatol could reduce the viability and proliferation of T24 and 5637 cells. The transwell migration assay revealed that brusatol was able to attenuate the migration of T24 and 5637 cells. We found that treatment with brusatol increased the levels of reactive oxygen species, malondialdehyde and Fe2+, thereby further promoting ferroptosis in T24 and 5637 cells. In addition, treatment with RSL3 (an agonistor of ferroptosis) ferrostatin-1 (a selective inhibitor of ferroptosis) enhanced or reversed the brusatol-induced inhibition. In vivo, treatment with brusatol significantly suppressed the tumor growth in nude mice. Mechanistically, brusatol induced ferroptosis by upregulating the expression of ChaC glutathione-specific gamma-glutamylcyclotransferase (Chac1) and decreasing the expression of SLC7A11 and Nrf2 in T24 and 5637 cells. To summarize, the findings of this research demonstrated that brusatol hindered the growth of bladder cancer and triggered ferroptosis via the Chac1/Nrf2/SLC7A11 pathway.

Brusatol's anticancer activity and its molecular mechanism: a research update.

OBJECTIVE: Brusatol (BT) is a quassinoid compound extracted from Brucea javanica that is a traditional Chinese herbal medicine. Brusatol possesses biological and medical activity, including antitumor, antileukemia, anti-inflammatory, antitrypanosomal, antimalarial, and antitobacco mosaic virus activity. To summarize and discuss the antitumor effects of BT and its mechanisms of actions, we compiled this review by combining the extensive relevant literature and our previous studies. METHODS: We searched and retrieved the papers that reported the pharmacological effects of BT and the mechanism of BT antitumor activity from PubMed until July 2023. KEY FINDINGS: Numerous studies have shown that BT is a unique nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor that acts on various signaling pathways and has good antitumor properties. Brusatol shows great potential in cancer therapy by inhibiting cell proliferation, blocking the cell cycle, promoting tumor cell differentiation, accelerating tumor cell apoptosis, inducing autophagy, suppressing angiogenesis, inhibiting tumor invasion and metastasis, and reversing multidrug resistance. CONCLUSION: This review summarizes recent updates on the antitumor activity and molecular mechanisms of BT and provides references for future development and clinical translation of BT and its derivatives as antitumor drugs.

NRF2 activation in BON­1 neuroendocrine cancer cells reduces the cytotoxic effects of a novel Ruthenium(II)­curcumin compound: A pilot study.

Gastroenteropancreatic neuroendocrine neoplasms (GEP­NEN) are a group of rare tumors whose specific pathogenetic mechanisms of resistance to therapies have not been completely revealed yet. Chemotherapy is the main therapeutic approach in patients with GEP­NEN, however, novel combination regimens and targeted therapy are continuously explored. In the present study, the anticancer effect of a novel Ruthenium (Ru)(II)­Bisdemethoxycurcumin (Ru­bdcurc) compound was evaluated in BON­1 cell line, one of the few cell lines derived from GEP­NEN, largely used in experimental research of this type of tumors. The experimental data revealed that the Ru­bdcurc compound induced cell death in a dose­dependent manner, in vitro. Biochemical studies demonstrated that, in response to the lower dose of treatment, BON­1 cells activated the nuclear factor erythroid 2­related factor 2 (NRF2) pathway with induction of some of its targets including catalase and p62 as well as of the antiapoptotic marker Bcl2, all acting as chemoresistance mechanisms. NRF2 induction associated also with increased expression of endogenous p53 which is reported to be dysfunctional in BON­1 cells and to inhibit apoptosis. Genetic or pharmacologic targeting of NRF2 inhibited the activation of the NRF2 pathway, as well as of endogenous dysfunctional p53, in response to the lower dose of Ru­bdcurc, increasing the cell death. To assess the interplay between NRF2 and dysfunctional p53, genetic targeting of p53 showed reduced activation of the NRF2 pathway in response to the lower dose of Ru­bdcurc, increasing the cell death. These findings identified for the first time a possible dysfunctional p53/NRF2 interplay in BON­1 cell line that can be a novel key determinant in cell resistance to cytotoxic agents to be evaluated also in GEP­NEN.

Preparation, Optimization, and In-Vitro Evaluation of Brusatol- and Docetaxel-Loaded Nanoparticles for the Treatment of Prostate Cancer.

Challenges to docetaxel use in prostate cancer treatment include several resistance mechanisms as well as toxicity. To overcome these challenges and to improve the therapeutic efficacy in heterogeneous prostate cancer, the use of multiple agents that can destroy different subpopulations of the tumor is required. Brusatol, a multitarget inhibitor, has been shown to exhibit potent anticancer activity and play an important role in drug response and chemoresistance. Thus, the combination of brusatol and docetaxel in a nanoparticle platform for the treatment of prostate cancer is expected to produce synergistic effects. In this study, we reported the development of polymeric nanoparticles for the delivery of brusatol and docetaxel in the treatment of prostate cancer. The one-factor-at-a-time method was used to screen for formulation and process variables that impacted particle size. Subsequently, factors that had modifiable effects on particle size were evaluated using a 24 full factorial statistical experimental design followed by the optimization of drug loading. The optimization of blank nanoparticles gave a formulation with a mean size of 169.1 nm ± 4.8 nm, in agreement with the predicted size of 168.333 nm. Transmission electron microscopy showed smooth spherical nanoparticles. The drug release profile showed that the encapsulated drugs were released over 24 h. Combination index data showed a synergistic interaction between the drugs. Cell cycle analysis and the evaluation of caspase activity showed differences in PC-3 and LNCaP prostate cancer cell responses to the agents. Additionally, immunoblots showed differences in survivin expression in LNCaP cells after treatment with the different agents and formulations for 24 h and 72 h. Therefore, the nanoparticles are potentially suitable for the treatment of advanced prostate cancer.

Interaction Between Bruceoside B and Intestinal Flora and Its Inhibitory Effect on Human Lung Cancer A549 Cells / 中国实验方剂学杂志

ObjectiveTo explore the interaction between bruceoside B and gut microbiota and the inhibitory activity of its metabolites on human lung cancer A549 cells， and to explore the value of bruceoside B in the treatment of non-small cell lung cancer（NSCLC）. MethodBruceoside B was co-incubated with the human gut microbiota under anoxic conditions in vitro， and ultra high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS） was used to analyze the metabolic transformation products. Cell counting kit-8（CCK-8） assay was performed to determine the effects of bruceoside B and its metabolites on the proliferation of human lung cancer A549 cells and the half inhibitory concentration（IC50） was calculated. Five healthy male rats were gavaged with bruceoside B（2 mg·kg-1） for 7 days after adaptive feeding. The feces of rats were collected before and after administration. 16S rRNA sequencing was used to assess gut microbiota. ResultBruceoside B was mainly metabolized to brusatol by human gut microbiota， the IC50 of bruceoside B and the conversion product to A549 cells were 1 755.50， 19.57 μmol·L-1， respectively， and the conversion product had a better activity at inhibiting A549 cells proliferation than bruceoside B. Additionally， The results of intestinal flora analysis showed no significant differences in α diversity and β diversity of gut microbiota after administration. In terms of species abundance， at the phylum level， bruceoside B decreased the relative abundance of Actinobacteriota and Proteobacteria， increased the relative abundance of Firmicutes， Patescibacteria and Cyanobacteria. At the genus level， bruceoside B decreased the relative abundance of Staphylococcus， Aerococcus and Psychrobacter， increased the relative abundance of Romboutsia， Lactobacillus， Clostridium sensu stricto 1， Norank-f-norank-o-Clostridia-UCG-014， Turicibacter， Allobaculum and Candidatus Saccharimonas. The results of functional prediction showed that the gut microbiota functional compositions were relatively stable. ConclusionBruceoside B can be deglycosylated by intestinal flora and converted into brusatol， with a significant increase in antitumor activity. The administration of bruceoside B will not cause significant changes in the structure and function of the intestinal flora， resulting in intestinal microecological balance disorders， and the administration appears to be beneficial to the intestinal flora of NSCLC patients.

Effects of different concentrations of brusatol on silicosis fibrosis in mice / 环境与职业医学

Background Silicosis is a diffuse fibrosis of the lungs caused by long-term inhalation of free silicon dioxide (SiO2). It has a complex pathogenesis and lacks effective treatment. Brusatol (Bru) has a variety of biological activities, and its role in silicosis fibrosis is unclear yet. Objective To investigate the effects of different concentrations of Bru on SiO2-induced silicosis fibrosis in mice. Methods Thirty male C57BL/6J mice were randomly divided into five groups: a control group, a silica group, and three Bru intervention groups with low, medium, and high doses (1, 2, and 4 mg·kg−1), with 6 mice in each group. Except the control group, the remaining groups were established as SiO2-induced silicosis mouse models by using a single tracheal infusion of 50 μL 60 mg·mL−1 SiO2 suspension. The control group was dosed with equal amount of saline. The Bru intervention groups were injected intraperitoneally with Bru for 5 consecutive days and then injected every other day. After 28 d of exposure, the mice were executed and lung tissues were collected. The lung coefficient of the mice was measured, and the pathological changes of the lung tissues were observed after hematoxylin-eosin (HE) and Masson staining. The levels of apoptotic protein Cleaved-caspase 3, fibrosis-related protein α-smooth muscle actin (α-SMA), type I collagen (Col-I), autophagy-associated protein Beclin1, microtubule-associated protein 1 light chain 3 (LC3), Sequestosome 1 (p62/SQSTM1), Kelch like ECH-associated protein-1 (Keap1), and nuclear factor erythroid 2 related factor 2 (Nrf2) were detected by Western blot. The mRNA levels of Caspase 3, α-SMA, and Col-I were measured by realtime fluorescence-based quantitative PCR. Results Compared with the control group, the lung coefficient of mice in the silica group was significantly increased (P < 0.01); the lung tissues of the silicosis mice showed damaged alveolar walls, along with infiltration of inflammatory cells, fibrous nodules, and collagen deposition; furthermore, the protein and mRNA levels of Cleaved-caspase 3, α-SMA, and Col-I were significantly increased (P < 0.01); the expression levels of Beclin1, LC3-II/I, p62, and Nrf2 were increased, while that of Keap1 was decreased (P < 0.05). The interventions with low and medium doses of Bru reduced lung coefficient (P < 0.05) and protected against pathological damage and collagen deposition in the lung tissues of the silicosis mice; the protein and mRNA expression levels of Cleaved-caspase 3, α-SMA, and Col-I were significantly decreased in the low and medium dose groups (P < 0.05, P < 0.01), the expression levels of Beclin1, LC3-II/I, p62, and Nrf2 were also decreased (P < 0.05, P < 0.01), and the expression level of Keap1 was increased in the medium dose group (P < 0.05). However, compared with the silica group, the differences in lung coefficient, pathological damage, and protein and mRNA expression levels of Cleaved-caspase 3, α-SMA, and Col-I in the Bru high dose group were not statistically significant (P > 0.05). In addition, the high dose of Bru decreased Beclin1, LC3-II/I, and Nrf2 expression levels (P < 0.01), did not change p62 protein expression level (P > 0.05), while increased Keap1 protein level (P < 0.01). Conclusion Low and medium doses of Bru might regulate autophagy through the Keap1-Nrf2 pathway, ameliorate autophagic degradation impairment, reduce pulmonary coefficient, attenuate apoptosis, and delay the progression of fibrosis in SiO2-induced silicosis mice.

Research of proliferation inhibition and apoptosis promotion mechanism of brusatol on H1299 cells / 中国药理学通报

Aim To preliminarily investigate the effect of brusatol(BRU), the monomer components fromChinese medicines on H1299 cells and its mechanisms.Methods CCK-8 and EdU staining experiment were used to detect the effect of BRU on cell prolifera-tion.Clone formation experiment was performed to measure the effect of drugs on cell clone formation.Hoechst33258 staining experiment and flow cytometry were employed to observe the cell apoptosis.Western blot assay was used to detect the protein expression levels of Bcl-xL, Bax, Bcl-2, cleaved-caspase-3, caspase-3, Gadd45α, PI3K, p-PI3K, Akt, p-Akt and NF-κB-p65.Results CCK-8 assay revealed that the inhibitory effect of H1299 cells gradually increased with the rising of BRU concentration and action time.Compared with control group, the EdU incorporation rate of the BRU treatment group decreased significantly.Treated with different concentrations of BRU for 24 h, the clone formation rate was significantly reduced in a concentration-dependent manner.Hoechst33258 experiment and flow cytometry showed that BRU could induce apoptosis in H1299 cell nucleus and increase its apoptotic rate.Western blot results revealed that BRU could significantly up-regulate the protein levels of Bax, cleaved-caspase-3, Gadd45α, and significantly down-regulate the expression of Bcl-xL, Bcl-2, caspase-3.In addition, BRU could significantly decrease the expression level of p-PI3K, p-Akt, NF-κB-p65 in cell nucleus.Conclusions BRU can inhibit the proliferation and induce apoptosis of H1299 cells in a concentration and time-dependent manner.The mechanism may be related to the inhibition of PI3K/Akt signaling pathway and the nuclear shuttle of NF-κB-p65.

Brusatol: A potential anti-tumor quassinoid from Brucea javanica / 中草药·英文版

Brusatol, a triterpene lactone compound mainly from Brucea javanica, sensitizes a broad spectrum of cancer cells. It is known as a specific inhibitor of nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway. In this review, we provide a comprehensive overview on the antitumor effect and molecular mechanisms of brusatol in vitro and in vivo. This review also covers pharmacokinetics studies, modification of dosages forms of brusatol. Increasing evidences have validated the value of brusatol as a chemotherapeutic agent in cancers, which may contribute to drug development and clinical application.

The inhibitory effects of Brusatol on mouse early embryonic development and its molecular mechanism / 医学研究生学报

Objective Up to now, the role of Brucea in early embryonic development of mice and its mechanism is still unclear.This paper aims to explore the role of Brusatol in mouse early embryonic development and its possible mechanism.Methods 100 kunming rats of clean grade(80 female rats and 20 male rats) were divided into 6 group: negative control group(no DMSO)、blank control group(culture in fresh CM with equal DMSO)、20nmol/L brusatol treated group、50nmol/L brusatol treated group、100nmol/L brusatol treated group、200nmol/L brusatol treated group(A solution of Brusatol was diluted in CM to concentrations of 20, 50, 100 or 200nmol/L.).Each group used an average of 20 embryos each time, repeated 4 times.Fertilized eggs after cultured 24h, 48h,72h, 96h were respectively 2-cell stage, 4-cell stage,morula and blastocyst stage..The embryo development rate was observed in the culture medium and the optimal concentration was selected, the embryos were collected to analysis the subcellular localization of the Nrf2 by immunofluorescence.The mRNA expression level of Cyclin B, CDK1 and the protein expression of Nrf2 were detected by Q-PCR and western blot respectively.Results In 4-cell stage, the embryo development rates of 20、50、100nmol/L brusatol treated groups[(75.0±2.8)%、(30.4±7.5)%、(4.2±5.9)%] significantly reduced compared with the negative control group[(93.0±2.8)%]、blank control group[(90.9±1.2)%].In morula stage, compared with blastocyst rates of negative control group、blank control group [(83.5±2.1)%、(84.2±1.2)%], 50nmol/L brusatol treated group[(19.3±13.1)%] decreased obviously [(79.00±0.06)% vs 100%, P<0.05].In the cellular immunofluorescence assay, the expression of Nrf2 protein in 50nmol/L brusatol treated group was lower than blank control group(P<0.05).We further found that 50nmol/L brusatol treated group decreased more mRNA levels of Cyclin B[(59.5±9.2)%] and CDK1[(56.0±1.4)%] than blank control group(100%) in G2/M phase(P<0.05).Conclusion In this study, Brusatol mainly affects the cell cycle transformation from G2 to M phase dependent on Cyclin B-CDK1, further inhibiting the development of the embryo through down-regulating Nrf2.

Brusatol inhibits the invasion behavior of rheumatoid arthritis fibroblast-like synoviocytes through regulating mechanical properties of cytoskeleton / 医用生物力学

Objective To investigate the effects of brusatol on mechanical properties of the cytoskeleton as well as the invasion behavior of rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS). Methods Cytoskeleton staining method was used to determine the regulatory effects of brusatol on mechanical properties of the RA FLS cytoskeleton. Transwell chamber assay was used to detect the effects of brusatol on the cytoskeleton and invasion behavior of RA FLS. The effects of brusatol on the expression of matrix metalloproteinase-2/3 (MMP-2/3) of RA FLS were measured by zymography and Western blotting methods. Results Cytoskeleton staining and microscope observation showed that brusatol could significantly reduce the formation number of RA FLS pseudopodia, thus inhibited cell movement ability via regulating mechanical properties of cytoskeleton. The invasion behavior of RA FLS was inhibited by brusatol, and brusatol could down-regulate the expression of MMP-2/3. Conclusions Brusatol plays an important role in regulating mechanical properties of cytoskeleton and inhibiting the invasion behavior of RA FLS. Meanwhile, brusatol can inhibit the invasion behavior of RA FLS through down-regulating the expression of MMP-2/3. The research findings provide the corresponding experimental basis for further development of new drugs for RA treatment.