Abietane Diterpenoids from the Bark of Cryptomeria japonica and Their Antifungal Activities against Wood Decay Fungi.

Phytochemical investigation of the bark of Cryptomeria japonica led to the isolation of five new abietane diterpenoids, 5-epi-12-hydroxy-6-nor-5,6-secoabieta-8,11,13-trien-7,5-olide (1), 12-hydroxy-6ß-methoxy-6,7-secoabieta-8,11,13-trien-7,6-olide (2), 6ß,12-dihydroxy-7,8-secoabieta-8,11,13-trien-7,8-olide (4), 5,12-dihydroxy-7,8-secoabieta-8,11,13-trien-7,8-olide (5), and 5α,8-epoxy-12-hydroxy-7,8-secoabieta-8,11,13-trien-7-al (6), together with one known abietane diterpenoid, obtuanhydride (3). Their structures were elucidated by analysis of spectroscopic data and comparison with the spectral data of known analogs. At the concentration of 100 µg/mL, compounds 4, 5, and 6 inhibited antifungal activities against wood decay fungi activity by 18.7, 37.2, and 46.7%, respectively.

Caffeic acid ethanolamide induces antifibrosis, anti-inflammatory, and antioxidant effects protects against bleomycin-induced pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive interstitial lung disease; its cause is unknown, and it leads to notable health problems. Currently, only two drugs are recommended for IPF treatment. Although these drugs can mitigate lung function decline, neither can improve nor stabilize IPF or the symptoms perceived by patients. Therefore, the development of novel treatment options for pulmonary fibrosis is required. The present study investigated the effects of a novel compound, caffeic acid ethanolamide (CAEA), on human pulmonary fibroblasts and evaluated its potential to mitigate bleomycin-induced pulmonary fibrosis in mice. CAEA inhibited TGF-ß-induced α-SMA and collagen expression in human pulmonary fibroblasts, indicating that CAEA prevents fibroblasts from differentiating into myofibroblasts following TGF-ß exposure. In animal studies, CAEA treatment efficiently suppressed immune cell infiltration and the elevation of TNF-α and IL-6 in bronchoalveolar lavage fluid in mice with bleomycin-induced pulmonary fibrosis. Additionally, CAEA exerted antioxidant effects by recovering the enzymatic activities of oxidant scavengers. CAEA directly inhibited activation of TGF-ß receptors and protected against bleomycin-induced pulmonary fibrosis through inhibition of the TGF-ß/SMAD/CTGF signaling pathway. The protective effect of CAEA was comparable to that of pirfenidone, a clinically available drug. Our findings support the potential of CAEA as a viable method for preventing the progression of pulmonary fibrosis.

Anti-Lymphangiogenic Terpenoids from the Heartwood of Taiwan Juniper, Juniperus chinensis var. tsukusiensis.

To look in-depth into the phytochemical and pharmacological properties of Taiwan juniper, this study investigated the chemical profiles and anti-lymphangiogenic activity of Juniperus chinensis var. tsukusiensis. In this study, four new sesquiterpenes, 12-acetoxywiddrol (1), cedrol-13-al (2), α-corocalen-15-oic acid (3), 1,3,5-bisaoltrien-10-hydroperoxy-11-ol (4), one new diterpene, 1ß,2ß-epoxy-9α-hydroxy-8(14),11-totaradiene-3,13-dione (5), and thirty-three known terpenoids were successfully isolated from the heartwood of J. chinensis var. tsukusiensis. The structures of all isolates were determined through the analysis of physical data (including appearance, UV, IR, and optical rotation) and spectroscopic data (including 1D, 2D NMR, and HRESIMS). Thirty-four compounds were evaluated for their anti-lymphangiogenic effects in human lymphatic endothelial cells (LECs). Among them, totarolone (6) displayed the most potent anti-lymphangiogenic activity by suppressing cell growth (IC50 = 6 ± 1 µM) of LECs. Moreover, 3ß-hydroxytotarol (7), 7-oxototarol (8), and 1-oxo-3ß-hydroxytotarol (9) showed moderate growth-inhibitory effects on LECs with IC50 values of 29 ± 1, 28 ± 1, and 45 ± 2 µM, respectively. Totarolone (6) also induced a significant concentration-dependent inhibition of LEC tube formation (IC50 = 9.3 ± 2.5 µM) without cytotoxicity. The structure-activity relationship discussion of aromatic totarane-type diterpenes against lymphangiogenesis of LECs is also included in this study. Altogether, our findings unveiled the promising potential of J. chinensis var. tsukusiensis in developing therapeutics targeting tumor lymphangiogenesis.

Caffeic Acid Phenethyl Ester and Caffeamide Derivatives Suppress Oral Squamous Cell Carcinoma Cells.

Caffeic acid phenethyl ester (CAPE) contains antibiotic and anticancer activities. Therefore, we aimed to investigate the anticancer properties and mechanisms of CAPE and caffeamide derivatives in the oral squamous cell carcinoma cell (OSCC) lines SAS and OECM-1. The anti-OSCC effects of CAPE and the caffeamide derivatives (26G, 36C, 36H, 36K, and 36M) were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Cell cycle and total reactive oxygen species (ROS) production were analyzed using flow cytometry. The relative protein expression of malignant phenotypes was determined via Western blot analysis. The results showed that 26G and 36M were more cytotoxic than the other compounds in SAS cells. After 26G or 36M treatment for 48 h, cell cycle S phase or G2/M phase arrest was induced, and cellular ROS increased at 24 h, and then decreased at 48 h in both cell lines. The expression levels of cell cycle regulatory and anti-ROS proteins were downregulated. In addition, 26G or 36M treatment inhibited malignant phenotypes through mTOR-ULK1-P62-LC3 autophagic signaling activated by ROS generation. These results showed that 26G and 36M induce cancer cell death by activating autophagy signaling, which is correlated with altered cellular oxidative stress.

Antidiabetic and Immunoregulatory Activities of Extract of Phyllanthus emblica L. in NOD with Spontaneous and Cyclophosphamide-Accelerated Diabetic Mice.

Oil-Gan, also known as emblica, is the fruit of the genus Phyllanthus emblica L. The fruits are high in nutrients and display excellent health care functions and development values. The primary aim of this study was to investigate the activities of ethyl acetate extract from Phyllanthus emblica L. (EPE) on type 1 diabetes mellitus (T1D) and immunoregulatory activities in non-obese diabetes (NOD) mice with spontaneous and cyclophosphamide (Cyp)-accelerated diabetes. EPE was vehicle-administered to spontaneous NOD (S-NOD) mice or Cyp-accelerated NOD (Cyp-NOD) mice once daily at a dose of 400 mg/kg body weight for 15 or 4 weeks, respectively. At the end, blood samples were collected for biological analyses, organ tissues were dissected for analyses of histology and immunofluorescence (IF) staining (including expressions of Bcl and Bax), the expression levels of targeted genes by Western blotting and forkhead box P3 (Foxp3), and helper T lymphocyte 1 (Th1)/Th2/Th17/Treg regulatory T cell (Treg) cell distribution by flow cytometry. Our results showed that EPE-treated NOD mice or Cyp-accelerated NOD mice display a decrease in levels of blood glucose and HbA1c, but an increase in blood insulin levels. EPE treatment decreased blood levels of IFN-γ and tumor necrosis α (TNF-α) by Th1 cells, and reduced interleukin (IL)-1ß and IL-6 by Th17 cells, but increased IL-4, IL-10, and transforming growth factor-ß1 (TGF-ß1) by Th2 cells in both of the two mice models by enzyme-linked immunosorbent assay (ELISA) analysis. Flow cytometric data showed that EPE-treated Cyp-NOD mice had decreased the CD4+ subsets T cell distribution of CD4+IL-17 and CD4+ interferon gamma (IFN-γ), but increased the CD4+ subsets T cell distribution of CD4+IL-4 and CD4+Foxp3. Furthermore, EPE-treated Cyp-NOD mice had decreased the percentage per 10,000 cells of CD4+IL-17 and CD4+IFNγ, and increased CD4+IL-4 and CD4+Foxp3 compared with the Cyp-NOD Con group (p < 0.001, p < 0.05, p < 0.05, and p < 0.05, respectively). For target gene expression levels in the pancreas, EPE-treated mice had reduced expression levels of inflammatory cytokines, including IFN-γ and TNF-α by Th1 cells, but increased expression levels of IL-4, IL-10, and TGF-1ß by Th2 cells in both two mice models. Histological examination of the pancreas revealed that EPE-treated mice had not only increased pancreatic insulin-expressing ß cells (brown), and but also enhanced the percentage of Bcl-2 (green)/Bax (red) by IF staining analyses of islets compared with the S-NOD Con and the Cyp-NOD Con mice, implying that EPE displayed the protective effects of pancreas ß cells. EPE-treated mice showed an increase in the average immunoreactive system (IRS) score on insulin within the pancreas, and an enhancement in the numbers of the pancreatic islets. EPE displayed an improvement in the pancreas IRS scores and a decrease in proinflammatory cytokines. Moreover, EPE exerted blood-glucose-lowering effects by regulating IL-17 expressions. Collectively, these results implied that EPE inhibits the development of autoimmune diabetes by regulating cytokine expression. Our results demonstrated that EPE has a therapeutic potential in the preventive effects of T1D and immunoregulation as a supplementary.

A novel caffeic acid derivative prevents angiotensin II-induced cardiac remodeling.

Differentiation of cardiac fibroblasts into myofibroblasts is a critical event in the progression of cardiac fibrosis that causes pathological cardiac remodeling. Cardiac fibrosis is a hallmark of heart disease and is associated with a stiff myocardium and heart failure. This study investigated the effect of caffeic acid ethanolamide (CAEA), a novel caffeic acid derivative, on cardiac remodeling. Angiotensin (Ang) II was used to induce cardiac remodeling both in cell and animal studies. Treating cardiac fibroblast with CAEA in Ang II-exposed cell cultures reduced the expression of fibrotic marker α-smooth muscle actin (α-SMA) and collagen and the production of superoxide, indicating that CAEA inhibited the differentiation of fibroblast into myofibroblast after Ang II exposure. CAEA protects against Ang II-induced cardiac fibrosis and dysfunction in vivo, characterized by the alleviation of collagen accumulation and the recovery of ejection fraction. In addition, CAEA decreased Ang II-induced transforming growth factor-ß (TGF-ß) expression and reduced NOX4 expression and oxidative stress in a SMAD-dependent pathway. CAEA participated in the regulation of Ang II-induced TGF-ß/SMAD/NOX4 signaling to prevent the differentiation of fibroblast into myofibroblast and thus exerted a cardioprotective effect. Our data support the administration of CAEA as a viable method for preventing the progression of Ang II-induced cardiac remodeling.

Synthesis and Structure-Activity Relationship of Salvinal Derivatives as Potent Microtubule Inhibitors.

Salvinal is a natural lignan isolated from the roots of Salvia mitorrhiza Bunge (Danshen). Previous studies have demonstrated its anti-proliferative activity in both drug-sensitive and -resistant cancer cell lines, with IC50 values ranging from 4-17 µM. In this study, a series of salvinal derivatives was synthesized and evaluated for the structure-activity relationship. Among the twenty-four salvinal derivatives, six compounds showed better anticancer activity than salvinal. Compound 25 displayed excellent anticancer activity, with IC50 values of 0.13-0.14 µM against KB, KB-Vin10 (overexpress MDR/Pgp), and KB-7D (overexpress MRP) human carcinoma cell lines. Based on our in vitro microtubule depolymerization assay, compound 25 showed depolymerization activity in a dose-dependent manner. Our findings indicate that compound 25 is a promising anticancer agent with depolymerization activity that has potential for the management of malignance.

Osthole Antagonizes Microglial Activation in an NRF2-Dependent Manner.

Microglia are neuroglia in the brain with an innate immune function and participate in the progress of neurodegenerative diseases. Osthole (OST) is a coumarin derivative extracted from Cnidium monnieri and bears a microglia-antagonizing ability. However, the underlying mechanism of the antagonism is not clear. The lipopolysaccharides-induced microglial BV2 cell line and amyloid-overexpressing fruit fly were used as models to study OST treatment. We found that OST treatment is sufficient to evoke NRF2 cascade under an LPS-induced inflammatory environment, and silencing NRF2 is sufficient to abolish the process. Moreover, we found that OST is sufficient to antagonize microglial activation in both LPS-induced BV2 cells and Aß-overexpressing fruit flies, and silencing NRF2 abolishes OST's antagonism. Furthermore, OST treatment rescued survival, climbing, and the learning ability of Aß-overexpressing fruit flies and relieved oxidative stress. In conclusion, we proved that OST antagonizes microglial activation induced by either LPS or Aß and that NRF2 is necessary for OST's antagonism.

Two new chromones and a new coumarin from the fruit of Cnidium monnieri (L.) Cusson.

Two new chromones named cnidimol G (1) and cnidimol H (2), one new coumarin, 7-methoxy-8-(3-methoxy-3-methyl-2-oxobutyl)coumarin (3), and twenty known compounds were isolated from MeOH extract of the fruit of Cnidium monnieri (L.) Cusson. The structures of compounds were elucidated by extensive spectroscopic analyses including 1 D and 2 D NMR, HRESIMS, IR and UV. Anti-inflammatory activity of the selected isolated compounds were evaluated. Compounds 1 and 8 exhibited inhibitory activities against nitric oxide production.

Chemical Constituents and Anti-Angiogenic Principles from a Marine Algicolous Penicillium sumatraense SC29.

In this study, a marine brown alga Sargassum cristaefolium-derived fungal strain, Penicillium sumatraense SC29, was isolated and identified. Column chromatography of the extracts from liquid fermented products of the fungal strain was carried out and led to the isolation of six compounds. Their structures were elucidated by spectroscopic analysis and supported by single-crystal X-ray diffraction as four previously undescribed (R)-3-hydroxybutyric acid and glycolic acid derivatives, namely penisterines A (1) and C-E (3-5) and penisterine A methyl ether (2), isolated for the first time from natural resources, along with (R)-3-hydroxybutyric acid (6). Of these compounds identified, penisterine E (5) was a unique 6/6/6-tricyclic ether with an acetal and two hemiketal functionalities. All the isolates were subjected to in vitro anti-angiogenic assays using a human endothelial progenitor cell (EPCs) platform. Among these, penisterine D (4) inhibited EPC growth, migration, and tube formation without any cytotoxic effect. Further, in in vivo bioassays, the percentages of angiogenesis of compound 3 on Tg (fli1:EGFP) transgenic zebrafish were 54% and 37% as the treated concentration increased from 10.2 to 20.4 µg/mL, respectively, and the percentages of angiogenesis of compound 4 were 52% and 41% as the treated concentration increased from 8.6 to 17.2 µg/mL, respectively. The anti-angiogenic activity of penisterine D (4) makes it an attractive candidate for further preclinical investigation.

Fermented Taiwanofungus camphoratus Extract Ameliorates Psoriasis-Associated Response in HaCaT Cells via Modulating NF-𝜠B and mTOR Pathways.

Psoriasis is a chronic autoimmune disease, and until now, it remains an incurable disease. Therefore, the development of new drugs or agents that ameliorate the disease will have marketing potential. Taiwanofungus camphoratus (TC) is a specific fungus in Taiwan. It is demonstrated to have anticancer, anti-inflammation, and hepatoprotective effects. However, the effects of TC fermented extract on psoriasis are under investigation. In this research, we studied the ability of TC on antioxidative activity and the efficacy of TC on interleukin-17 (IL-17A)-induced intracellular oxidative stress, inflammation-relative, and proliferation-relative protein expression in human keratinocytes. The results of a DPPH radical scavenging assay, reducing power assay, and hydroxyl peroxide inhibition assay indicated that TC has a potent antioxidant ability. Furthermore, TC could reduce IL-17A-induced intracellular ROS generation and restore the NADPH level. In the investigation of pathogenesis, we discovered TC could regulate inflammatory and cell proliferation pathways via p-IKKα/p-p65 and p-mTOR/p-p70S6k signaling pathways in human keratinocytes. In conclusion, TC showed characteristics such as antioxidant, anti-inflammatory, and anti-psoriatic-associated responses. It is expected to be developed as a candidate for oxidative-stress-induced skin disorders or psoriasis treatment.

Naturally Occurring Bicoumarin Compound Daphnoretin Inhibits Growth and Induces Megakaryocytic Differentiation in Human Chronic Myeloid Leukemia Cells.

Daphnoretin extracted from the stem and roots of Wikstroemia indica (L.) C.A. Mey has been shown to possess antiviral and antitumor activities. Herein, we hypothesized that daphnoretin might induce megakaryocytic differentiation, thereby inhibiting the proliferation of cells and serving as a differentiation therapy agent for chronic myeloid leukemia (CML). Daphnoretin-treated K562 and HEL cells were examined for growth inhibition, cell morphology, and megakaryocyte-specific markers. Potential mechanisms of megakaryocytic differentiation of daphnoretin-treated K562 cells were evaluated. The results showed that daphnoretin inhibited the growth of K562 and HEL cells in a dose- and time-dependent manner. Flow cytometry analyses revealed that daphnoretin treatment slightly increased the proportion of sub-G1 and polyploid cells compared to that of dimethyl sulfoxide (DMSO)-treated control cells. Morphological examination showed that daphnoretin-treated K562 and HEL cells exhibited enlarged contours and multinucleation as megakaryocytic characteristics compared to DMSO-treated control cells. Daphnoretin treatment also dramatically enhanced the expression of megakaryocytic markers CD61 and CD41. Under optimal megakaryocytic differentiation conditions, daphnoretin increased the phosphorylation of STAT3 but not STAT5. In summary, daphnoretin inhibited cell growth and induced megakaryocytic differentiation in K562 and HEL cells. The efficacy of daphnoretin in vivo and in patients with CML may need further investigations for validation.

Correction: Chen et al. Secondary Metabolites with Anti-Inflammatory from the Roots of Cimicifuga taiwanensis. Molecules 2022, 27, 1657.

The authors wish to make the following changes to their paper [...].

Correction: Wu et al. Secondary Metabolites with Antimicrobial Activities from Chamaecyparisobtusa var. formosana. Molecules 2022, 27, 429.

The authors wish to make the following changes to their paper [...].

Correction: Cheng et al. Novel Antifungal Dimers from the Roots of Taiwania cryptomerioides. Molecules 2022, 27, 437.

The authors wish to make the following changes to their paper [...].

Anti-Inflammatory Constituents of Antrodia camphorata on RAW 264.7 Cells Induced by Polyinosinic-Polycytidylic Acid.

Antrodia camphorata is an endemic mushroom in Taiwan. This study was designed to screen anti-inflammatory compounds from the methanolic extract of the mycelium of A. camphorata on nitric oxide (NO) production in RAW 264.7 cells induced by polyinosinic-polycytidylic acid (poly I:C), a synthetic analog of double-stranded RNA (dsRNA) known to be present in viral infection. A combination of bioactivity-guided isolation with an NMR-based identification led to the isolation of 4-acetylantroquinonol B (1), along with seven compounds. The structure of new compounds (4 and 5) was elucidated by spectroscopic experiments, including MS, IR, and NMR analysis. The anti-inflammatory activity of all isolated compounds was assessed at non-cytotoxic concentrations. 4-Acetylantroquinonol B (1) was the most potent compound against poly I:C-induced NO production in RAW 264.7 cells with an IC50 value of 0.57 ± 0.06 µM.

Tyrosinase Inhibitors Derived from Chemical Constituents of Dianella ensifolia.

Dianella ensifolia is a perennial herb with thickened rhizome and is widely distributed in tropical and subtropical regions of Asia, Australia, and the Pacific islands. This plant has the potential to be used as a source of herbal medicine. This study investigated further phytochemistry and tyrosinase inhibitory effect of some constituents isolated from D. ensifolia. Four new flavans, (2S)-4'-hydroxy-6,7-dimethoxyflavan (1), (2S)-3',4'-dihydroxy-7-methoxy-8-methylflavan (2), (2S)-2'-hydroxy-7-methoxyflavan (3), and (2S,1'S)-4-hydroxy-4-(7-methoxy-8-methylchroman-2-yl)-cyclohex-2-enone (4), together with 67 known compounds, including 10 flavans (5−14), 5 flavanones (15−19), 3 flavone (20−22), 5 chalcones (23−27), 3 chromones (28−30), 15 aromatics (31−45), 7 phenylpropanoids (46−52), one lignan (53), 7 steroids (54−60), one monoterpene (61), one diterpene (62), 4 triterpenes (63−66), a carotenoid (67), 2 alkaloids (68 and 69), and 2 fatty acids (70 and 71) were isolated from D. ensifolia. Their structures were elucidated on the basis of physical and spectroscopic data analyses. Moreover, compounds 1−4, 8, 10−15, 20, 21, and 41 were evaluated for their mushroom tyrosinase inhibitory effect. Compounds 11 and 14 strongly inhibited mushroom tyrosinase activity with IC50 values of 8.6 and 14.5 µM, respectively.

Chemical constituents and their anti-neuroinflammatory activities from the bark of Taiwan incense cedar, Calocedrus formosana.

One undescribed C40 terpenoid, calomacroquinoic acid; four undescribed diterpenes, 5α,6α-epoxy-7α-hydroxyferruginol, 15-ethoxysugiol, 7-methoxy-6,7-secoabieta-8,11,13-triene-6,12-diol, and ethyl 7,8-secoabieta-11,14-dioxo-7-ate; two compounds isolated from Nature for the first time, 6ß,7α-dihydroxyferruginol and 12-O-methyltaxochinon; and six known compounds were successfully identified from the bark of Taiwan incense cedar Calocedrus formosana. Structures of all isolates were elucidated by physical data (appearance, ultraviolet, infrared, specific rotation, and X-ray) and spectroscopic data (1D and 2D nuclear magnetic resonance, and high-resolution electron ionization mass spectrometry). The biosynthetic pathway of calomacroquinoic acid is also described in the current study. Nitric oxide production in lipopolysaccharide (LPS)-stimulated BV-2 microglia cells was inhibited by 6,7-dehydroferruginol, 7α,11-dihydroxy-12-methoxy-8,11,13-abietriene, and trans-communic acid. Altogether, the bark of C. formosana possessed several potential natural therapeutics against inflammation-related neuronal diseases.

N-Octyl Caffeamide, a Caffeic Acid Amide Derivative, Prevents Progression of Diabetes and Hepatic Steatosis in High-Fat Diet Induced Obese Mice.

The underlying pathological mechanisms of diabetes are complicated and varied in diabetic patients, which may lead to the current medications often failing to maintain glycemic control in the long term. Thus, the discovery of diverse new compounds for developing medicines to treat diabetes and its complications are urgently needed. Polyphenols are metabolites of plants and have been employed in the prevention and treatment of a variety of diseases. Caffeic acid phenethyl ester (CAPE) is a category of compounds structurally similar to polyphenols. In this study, we aimed to investigate the antidiabetic activity and potential molecular mechanisms of a novel synthetic CAPE derivative N-octyl caffeamide (36M) using high-fat (HF) diet induced obese mouse models. Our results demonstrate that 36M prevented the progression of diabetes in the HF diet fed obese mice via increasing phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and inhibiting expression of protein tyrosine phosphatase 1B (PTP1B). We also found that 36M could prevent hepatic lipid storage in the HF diet fed mice via inhibition of fatty acid synthase and lipid droplet proteins, including perilipins and Fsp27. In conclusion, 36M is a potential candidate compound that can be developed as AMPK inhibitor and PTP1B inhibitor for treating diabetes and hepatic steatosis.

Antcin K inhibits VCAM-1-dependent monocyte adhesion in human rheumatoid arthritis synovial fibroblasts.

Background: Antcin K, an extract of Antrodia cinnamomea (a medicinal mushroom endemic to Taiwan commonly used in Chinese medicine preparations), inhibits proinflammatory cytokine production and angiogenesis in human rheumatoid arthritis synovial fibroblasts (RASFs), major players in RA disease. Antcin K also inhibits disease activity in mice with collagen-induced arthritis (CIA). Up until now, the effects of Antcin K upon cell adhesion molecules (CAMs) were unknown. Methods: RA and healthy synovial tissue samples (n = 10 in each group) were retrieved from the Gene Expression Omnibus (GEO) database (accession code: GDS5401) to compare CAM and monocyte marker expressions. In addition, synovial tissue samples from six RA patients and six patients undergoing arthroscopy for trauma/joint derangement (healthy controls) were subjected to immunohistochemical (IHC) analysis. mRNA and protein expression levels were analyzed in RASFs using RT-qPCR (Reverse transcription-quantitative polymerase chain reaction) and Western blot. RASFs were incubated with Antcin K and examined for monocyte adherence by fluorescence microscopy. Ankle joint tissue specimens from a CIA mouse model and healthy controls were stained with hematoxylin and eosin (H&E) and Safranin-O/Fast Green to examine histological changes and evidence of bone loss. IHC analysis determined levels of vascular cell adhesion molecule 1 (VCAM-1) and CD11b in CIA ankle tissue and clinical synovial tissue. Results: Levels of VCAM-1 expression were higher in the GEO database specimens and the study's clinical samples of RA synovial tissue compared with the healthy specimens. Antcin K dose-dependently inhibited VCAM-1 expression and monocyte adhesion in RASFs. Antcin K also significantly inhibited levels of VCAM-1 and monocyte CD11b expression in CIA tissue. These effects appeared to be mediated by MEK1/2-ERK, p38, and AP-1 signaling. Conclusions: Antcin K seems promising for the treatment of RA and deserves further investigations.