Salvianolic acid B inhibits IL-1β-induced inflammatory cytokine production in human osteoarthritis chondrocytes and has a protective effect in a mouse osteoarthritis model

Osteoarthritis (OA) is a chronic progressive disease that has complicated mechanisms that involve inflammation and cartilage degradation. In this study, we investigated the anti-inflammatory action of Salvianolic acid B (Sal B) in both human OA chondrocytes and a mouse OA model that was induced by destabilization of the medial meniscus. In vitro, chondrocytes were pretreated with Sal B (0, 25, 50, 100 μM) for 2 h, then incubated with IL-1β (10 ng/mL) for 24 h. NO production was determined by Griess method and PGE2 was assessed by ELISA. The expression of INOS, COX-2, MMP-13, ADAMTS-5 and NF-κB-related signaling molecules were tested by Western blotting. Immunofluorescence staining was used to detect P65 nuclear translocation. In vivo, the mouse OA model received intraperitoneal-injection of either Sal B (25 mg/kg) or saline every other day. Hematoxylin and Eosin, as well as Safranin-O-Fast green staining, were utilized to evaluate the severity of cartilage lesions up to 8 weeks following the surgery. Sal B inhibited the over-production of NO and PGE2, while the elevated expression of INOS, COX-2, MMP-13 and ADAMTS-5 were reversed by Sal B in IL-1β-induced chondrocytes. In addition, IL-1β significantly induced phosphorylation of NF-κB signaling, and this phosphorylation response was blocked by Sal B. Immunofluorescence staining demonstrated that Sal B could suppress IL-1β-induced p65 nuclear translocation. In vivo, the cartilage in Sal B-treated mice exhibited less cartilage degradation and lower OARSI scores. Taken together, Sal B possesses great potential value as a therapeutic agent for OA treatment.     

Fisetin inhibits IL-1β-induced inflammatory response in human osteoarthritis chondrocytes through activating SIRT1 and attenuates the progression of osteoarthritis in mice

Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage degradation and inflammation. Fisetin, a polyphenol extracted from fruits and vegetables, has been reported to have anti-inflammatory effects. Our study aimed to investigate the effect of fisetin on OA both in vitro and in vivo. In vitro, chondrocytes were pretreated with fisetin alone or fisetin combined with sirtinol (an inhibitor of SIRT1) for 2 h before IL-1β stimulation. Production of NO, PGE2, TNF-α and IL-6 were evaluated by the Griess reaction and ELISAs. The mRNA (COX-2, iNOS, MMP-3, MMP-13, ADAMTS-5, Sox-9, aggrecan and collagen-II) and protein expression (COX-2, iNOS, MMP-3, MMP-13, ADAMTS-5 and SIRT1) were measured by qRT-PCR and Western blot respectively. Immunofluorescence was used to assess the expression of collagen-II and SIRT1. SIRT1 activity was quantified with SIRT1 fluorometric assay kit. The in vivo effect of fisetin was evaluated by gavage in mice OA models induced by destabilization of the medial meniscus (DMM). We found that fisetin inhibited IL-1β-induced expression of NO, PGE2, TNF-α, IL-6, COX-2, iNOS, MMP-3, MMP-13, ADAMTS-5. Besides, fisetin remarkably decreased IL-1β-induced degradation of Sox-9, aggrecan and collagen-II. Furthermore, fisetin significantly inhibited IL-1β-induced SIRT1 decrease and inactivation. However, the inhibitory effect of fisetin was obvious abolished by sirtinol, suggesting that fisetin exerts anti-inflammatory effects through activating SIRT1. In vivo, fisetin-treated mice exhibited less cartilage destruction and lower OARSI scores. Moreover, fisetin reduced subchondral bone plate thickness and alleviated synovitis. Taken together, these findings indicate that fisetin may be a potential agent in the treatment of OA.     

Effects of platycodin D on IL-1β-induced inflammatory response in human osteoarthritis chondrocytes

Platycodin D (PYD), a major saponin derived and isolated from the roots of Platycodon grandiflorum, has been reported to have anti-inflammatory and anti-tumor effects. The present study aimed to investigate the effects of PYD on IL-1β-stimulated human osteoarthritis chondrocytes. Chondrocytes were treated with PYD 1 h before IL-1β treatment. The levels of MMP1, MMP13, IL-8, RANTES, PGE2, and NO were measured in this study. The expression of LXRα, NF-κB, and IκBα were detected by western blot analysis. The results showed that PYD significantly inhibited IL-1β-induced MMP1, MMP13, IL-8, RANTES, PGE2, and NO production. PYD also suppressed IL-1β-induced NF-κB activation. Furthermore, the expression of LXRα was up-regulated by PYD in a dose-dependent manner. In addition, LXRα siRNA inhibited the effects of PYD on MMP1, MMP13, PGE2, and NO production in human osteoarthritis chondrocytes. In conclusion, these results suggested that PYD attenuated IL-1β-induced inflammatory response in osteoarthritis chondrocyte by activating LXRα.     

Cryptotanshinone protects against IL-1β-induced inflammation in human osteoarthritis chondrocytes and ameliorates the progression of osteoarthritis in mice

Osteoarthritis (OA) is a common degenerative disease characterized by progressive erosion of articular cartilage, subchondral bone sclerosis and synovitis. Cryptotanshinone (CTS), an active component extracted from the root of Salvia miltiorrhiza Bunge, has been shown to have potent anti-inflammatory effects. However, its effects on OA have not been clearly elucidated. This study aimed to assess the effect of CTS on human OA chondrocytes and mice OA models. Human OA chondrocytes were pretreated with CTS (5, 10 and 20 μM) for 2 h and subsequently stimulated with IL-1β for 24 h. Production of NO, PGE2, IL-6, TNF-α was evaluated by the Griess reaction and ELISA. The protein expression of COX-2, iNOs, MMP-3, MMP13, COX-2, ADAMTS-5, JNK, p-JNK, ERK, p-ERK, p38, p-p38, p-IKKα/β, p65, p-p65, IκB-α, and p-IκB-α was tested by Western blot. In vivo, the severity of OA was determined by histological analysis. We found that CTS significantly inhibited the IL-1β-induced production of NO and PGE2; expression of COX-2, iNOS, MMP-3, MMP-13, and ADAMTS-5. Furthermore, CTS in dramatically suppressed IL-1β-stimulated NF-κB and MAPK activation. Immunofluorescence staining demonstrated that CTS could suppress IL-1β-induced phosphorylation of p65 nuclear translocation. In vivo, treatment of CTS prevented the destruction of cartilage and the thickening of subchondral bone in mice OA models. These results indicate that the therapeutic effect of CTS on OA is accomplished through the inhibition of both NF-κB and MAPK signaling pathways. Our findings provide the evidence to develop CTS as a potential therapeutic agent f or patients with OA.     

Protectin DX attenuates IL-1β-induced inflammation via the AMPK/NF-κB pathway in chondrocytes and ameliorates osteoarthritis progression in a rat model

Protectin DX (PDX) has been reported to have extensive anti-inflammatory effects. However, it is unknown whether PDX acts as an anti-inflammatory agent in the context of osteoarthritis (OA). This study aimed to evaluate the anti-inflammatory activity of PDX in vitro and in vivo in a model of OA. Primary rat chondrocytes were preincubated with PDX 1 h prior to IL-1β treatment for 24 h. We found that PDX was nontoxic, and pretreatment with PDX increased cell viability in IL-1β-induced chondrocytes. Preincubation with PDX also efficiently inhibited the degradation of type II collagen dose-dependently. Additionally, the expression of MMP-3, MMP-13, ADAMTS4, iNOS, COX-2, NO, and PGE2 decreased after IL-1β stimulation when cells were preincubated with PDX. Moreover, PDX inhibited the increase in phosphorylated NF-κB p65 and IκBα upon IL-1β stimulation, and the negative effects of IL-1β on chondrocytes were partially blocked by treatment with pyrrolidine dithiocarbamate (PDTC), a selective NF-κB inhibitor. In addition, we found that PDX increased AMPK phosphorylation in IL-1β-mediated chondrocytes. The phosphorylation of AMPK could be inhibited by compound C, a classic AMPK inhibitor. Compound C also remarkably reversed the decrease in p65 phosphorylation and MMP-13 expression caused by PDX. Furthermore, nuclear translocation of NF-κB was visible by immunofluorescence after PDX-induced AMPK activation. Additionally, we verified that PDX ameliorated cartilage degradation in monosodium iodoacetate (MIA)-induced OA rats through histological evaluation and ELISA of TNF-α in the serum and intra-articular lavage fluid. In conclusion, we have shown that PDX suppresses inflammation in chondrocytes in vitro and in vivo, likely through the AMPK/NF-κB signaling pathway. Our results suggest that PDX could be a useful novel therapeutic agent for OA treatment.     

Protective effects of paeonol on inflammatory response in IL-1β-induced human fibroblast-like synoviocytes and rheumatoid arthritis progression via modulating NF-κB pathway

Various investigations have demonstrated that human fibroblast-like synoviocytes rheumatoid arthritis (HFLS-RA) take part in the chronic inflammatory responses and RA progression. Inhibition of synovium activation and inflammatory processes may represent a therapeutic target to alleviate RA. Paeonol, a major natural product, has many biological and pharmacological activities. However, its protective effects against RA considering HFLS-RA have not been explored. In this study, anti-inflammatory effects of paeonol were detected in interleukin-1β (IL-1β)-treated HFLS-RA. Our results demonstrated that paeonol had no effect on cell survival and IL-1β-induced proliferation in HFLS-RA. Pretreatment with paeonol significantly suppressed the production of pro-inflammatory TNF-α, IL-6 and IL-1β, and the expressions of matrix metalloproteinase-1/-3 in vitro and in vivo. Mice treated with paeonol (10 mg/kg) remarkablely attenuated arthritic symptoms based on clinical arthritis scores and histopathology in collagen-induced arthritis mice. Furthermore, the TLR4 expression and NF-κB p65 activation were inhibited by paeonol in vitro and in vivo. Our findings illustrated that paeonol had significantly suppressed inflammation effects in synovial tissues and RA progression. The potential mechanism might be based on the attenuation TLR4-NF-κB activation. These collective results indicated that paeonol might be a promising therapeutic agent for alleviating RA progress through inhibiting inflammations and NF-κB signalling pathway.     

Tetrandrine suppresses amyloid-β-induced inflammatory cytokines by inhibiting NF-κB pathway in murine BV2 microglial cells

Microglial cells play an important role in mediating neuroinflammation in Alzheimer's disease (AD) by production of a series of proinflammatory mediators and clearance of Aβ peptides and senile plaques. Tetrandrine, a bisbenzylisoquinoline alkaloid isolated from the Chinese herb Radix Stephania tetrandra, has been demonstrated to decrease the expression of proinflammatory mediators by inhibition of NF-κB activation. Here we investigated whether tetrandrine may affect the phagocytosis of microglia and the expression of cytokines and NF-κB in murine BV2 microglial cells. We found that fibrillar Amyloid-β (fAβ) induced phagocytosis of microglia and dramatically increased the levels of interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) as well as the expression of phospho NF-κB p65 in microglia cultures. The treatment with tetrandrine resulted in downregulation of phospho NF-κB p65 expression and strikingly reduced the production of IL-1β and TNF-α. However, tetrandrine did not affect fAβ induced phagocytosis of microglia. In conclusion, tetrandrine can decrease microglial detriment of neurotoxicity while maintaining microglial benefit of neuroprotection. Tetrandrine may be an efficacious and promising remedy in the treatment of AD.     

Monotropein exerts protective effects against IL-1β-induced apoptosis and catabolic responses on osteoarthritis chondrocytes

Osteoarthritis, characterized by a loss of articular cartilage accompanied with inflammation, is the most common age-associated degenerative disease. Monotropein, an iridoids glycoside isolated from the roots of Morinda officinalis How, has been demonstrated to exhibit anti-inflammatory activity. In the present study, monotropein was firstly to exhibit cartilage protective activity by down regulating the pro-inflammatory cytokines in the knee synovial fluid in vivo. The anti-apoptotic and anti-catabolic effects of monotropein on rat OA chondrocytes treated by IL-1β were investigated in vitro. In cultured chondrocytes, monotropein attenuated apoptosis in a dose-dependent manner in response to IL-1β stimulation. Moreover, treatment with monotropein, the expressions of MMP-3 and MMP-13 were significantly decreased, the expression of COL2A1 was increased. Taken together, these findings suggested that monotropein exerted anti-apoptosis and anti-catabolic activity in chondrocytes, which might support its possible therapeutic role in OA.     

Alpha-Mangostin suppresses interleukin-1β-induced apoptosis in rat chondrocytes by inhibiting the NF-κB signaling pathway and delays the progression of osteoarthritis in a rat model

Osteoarthritis (OA) is a chronic degenerative joint disease that is characterized by progressive joint dysfunction and pain. Apoptosis and catabolism in chondrocytes play critical roles in the development of OA. Alpha-Mangostin (α-MG), one of the main components of the mangosteen, has been reported to have anti-apoptotic, anti-inflammatory and antioxidant effects. We investigated the therapeutic effects of α-MG on OA through experiments on rat chondrocytes in vitro and in a rat model of OA induced by destabilization of the medial meniscus (DMM). In vitro, we provided experimental evidence that α-MG inhibits the expression of MMP-13 and ADAMTs-5, and promotes the expression of SOX-9 in rat chondrocytes stimulated with interleukin-1β (IL-1β). In addition, we also found that α-MG can inhibit the expression of pro-apoptotic proteins such as Bax, Cyto-c, and C-caspase3, and increase the expression of the anti-apoptotic protein Bcl-2. These changes may be related to an α-MG induced inhibition of the IL-1β-induced activation of the NF-kB signaling pathway. In vivo, we also found that α-MG can limit the development of OA in rat models. The above results show that α-MG has a potential therapeutic effect on OA, and that this effect may be achieved by inhibiting the mitochondrial apoptosis of chondrocytes induced by an activation of the NF-kB pathway.     

Effusanin C inhibits inflammatory responses via blocking NF-κB and MAPK signaling in monocytes

Effusanin C, a constituent of Isodon japonicus, has been used in oriental countries as a traditional folk medicine to treat inflammatory diseases, but its mechanism of action remains unknown. Here, we investigate the inhibitory activity of effusanin C in inflammatory monocytes. Effusanin C markedly inhibited the production of inflammatory mediators including nitric oxide, IL-1β, and TNF-α in macrophages and dendritic cells. Furthermore, molecular studies showed that effusanin C inhibited phosphorylation of p38, JNK, and ERK, degradation of IκBβ, and nuclear translocation of NF-κB p50/p65 in these cells. Taken together, these data show that effusanin C inhibits inflammatory responses by blocking NF-κB and MAPK signalings in monocytes.     

Polygalasaponin F inhibits secretion of inflammatory cytokines via NF-κB pathway regulation

To study the anti-neuroinflammatory mechanisms of polygalasaponin F (PS-F), ELISA method was used to detect the secretion of inflammatory cytokines. Western blot was used to detect the protein expression and phosphorylation levels. Immunofluorescence assay was used to observe the NF-κB nuclear translocation. PS-F could inhibit the release of inflammatory cytokines TNF-α and NO induced by lipopolysaccharides (LPS) and reduce the expression of inducible nitric oxide synthases (iNOS). As for MAPK-signaling pathway, PS-F could only inhibit the phosphorylation levels of p38 MAPK, but did not significantly affect the phosphorylation levels of JNK and ERK1/2 protein kinases. PS-F could inhibit NF-κB nuclear translocation in a dose-dependent manner. The results of Western blot assay were consistent with immunofluorescence assays. Meanwhile, p38-specific inhibitor SB203580 (20 μM) and p65-specific inhibitor PDTC (100 μM) were, respectively, administered as a positive control. In addition, PS-F could significantly inhibit the cytotoxicity of conditioned medium prepared by LPS-stimulated BV-2 microglia (LPS conditioned media) to neuronal PC12 cells and improve cell viability. PS-F inhibits the secretions of neuroinflammatory cytokines by the regulation of NF-κB-signaling pathway.     

Theobromine mitigates IL-1β-induced oxidative stress,inflammatory response,and degradation of type II collagen in human chondrocytes

Osteoarthritis is one of the major causes of disability in elderly adults. Chondrocytes are responsible for the formation and remodeling of articular cartilage in joint tissue. The dysfunction of chondrocytes is a significant factor in the development of osteoarthritis. In the current study, we found that theobromine, a constituent of the cacao plant, possesses a preventive effect against interleukin (IL)-1β-induced chondrocyte dysfunction. Theobromine ameliorates IL-1β-induced production of cellular reactive oxygen species (ROS) and inflammatory mediators including cyclooxygenase-2 (COX-2) and prostaglandin E₂ (PGE₂). The presence of theobromine suppresses IL-1β-induced inducible nitro oxide synthase (iNOS) expression and cellular nitro oxide (NO) production. Theobromine also suppresses IL-1β-induced production of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1), as well as matrix metalloproteinases (MMP)-3 and MMP-13. Additionally, theobromine mitigates IL-1β-induced type II collagen degradation. Mechanistically, we show that theobromine inhibits IL-1β-induced IκBα activation, nuclear factor-κB (NF-κB) protein p65 accumulation, and transfected NF-κB promoter activity, indicating that theobromine suppresses the NF-κB pathway in chondrocytes. Collectively, our study demonstrates that the natural molecule theobromine has a protective effect to counter cytokine-induced chondrocyte dysfunction, implying its beneficial effect in the prevention of osteoarthritis.     

Baicalin prevents LPS-induced activation of TLR4/NF-κB p65 pathway and inflammation in mice via inhibiting the expression of CD14

Previous studies have shown that baicalin,an active ingredient of the Chinese traditional medicine Huangqin,attenuates LPS-induced inflammation by inhibiting the activation of TLR4/NF-κBp65 pathway,but how it affects this pathway is unknown.It has been shown that CD14 binds directly to LPS and plays an important role in sensitizing the cells to minute quantities of LPS via chaperoning LPS molecules to the TLR4/MD-2 signaling complex.In the present study we investigated the role of CD14 in the anti-inflammatory effects of baicalin in vitro and in vivo.Exposure to LPS(1μg/mL)induced inflammatory responses in RAW264.7 cells,evidenced by marked increases in the expression of MHC II molecules and the secretion of NO and IL-6,and by activation of MyD88/NF-κB p65 signaling pathway,as well as the expression of CD14 and TLR4.These changes were dose-dependently attenuated by pretreatment baicalin(12.5–50μM),but not by baicalin post-treatment.In RAW264.7 cells without LPS stimulation,baicalin dose-dependently inhibit the protein and mRNA expression of CD14,but not TLR4.In RAW264.7 cells with CD14 knockdown,baicalin pretreatment did not prevent inflammatory responses and activation of MyD88/NF-κB p65 pathway induced by high concentrations(1000μg/mL)of LPS.Furthermore,baicalin pretreatment also inhibited the expression of CD14 and activation of MyD88/NF-κB p65 pathway in LPS-induced hepatocyte-derived HepG2 cells and intestinal epithelial-derived HT-29 cells.In mice with intraperitoneal injection of LPS and in DSS-induced UC mice,oral administration of baicalin exerted protective effects by inhibition of CD14 expression and inflammation.Taken together,we demonstrate that baicalin pretreatment prevents LPS-induced inflammation in RAW264.7 cells in CD14-dependent manner.This study supports the therapeutic use of baicalin in preventing the progression of LPS-induced inflammatory diseases.     

The protective effect of L-Shikonin on LPS/D-GalN-induced acute liver injury in mice via inhibiting NF-κB inflammatory signaling pathway北大核心CSCD

Aim To investigate the anti-inflammatory effect of L-Shikonin ( SK ) on lipopolysaccharide ( LPS)-induced RAW 264. 7 macrophages in vitro and its protective effect on LPS/D-GalN-induced acute liver injury. Methods The mouse model of acute liver in¬jury was established in vivo experiments by LPS/D- GalN. The survival rate of the mice and the changes of liver and spleen indices in each group were examined. The levels of AST, ALT and AKP in serum and NO, superoxide dismutase ( SOD ) and malondialdehyde (MDA) in liver tissue homogenate were measured, and the histopathological sections of the liver of each group were observed by H&E staining. M I T colorimet- ric assay was used for cell viability in vitro experi¬ments, Griess method for the detection of NO content, RT-PCR assay and Western blot assay for examining the effect of levulinic acid on the expression levels of mRNA and related pathway proteins of pro-inflammato¬ry factors in LPS-induced RAW264. 7 cells. Results The results of in vivo experiments showed that L-SK significantly improved the liver and spleen indices, de¬creased AST, ALT and AKP levels in serum, de¬creased NO and MDA in liver homogenate, and in¬creased SOD activity in mice with acute liver injury. The results of in vitro experiments showed that L-SK significantly inhibited the mRNA expression of INOS, COX2, I FN-(3 and pro-inflammatory factors 1L-6, TNF-a and IL-10 in LPS-induced RAW264. 7 cells, and significantly inhibited the protein expression of IN¬OS, COX2 and the NF-kB signaling pathway. Conclu¬sions L-SK has good anti-inflammatory effects in LPS-induced inflammation in RAW 264. 7 cells in vitro. Il inhibits the protein expression of phosphorylated P65 and IKKaαβ in the NF-kB signaling pathway, thereby suppressing the anti-inflammatory effects in vitro and L- Shikonin has protective effects against acute liver injury in mice. © 2023 Publication Centre of Anhui Medical University. All rights reserved.     

Formula PSORI-CM01 inhibits the inflammatory cytokine and chemokine release in keratinocytes via NF-κB expression

Psoriasis is a common chronic inflammatory disease in which T-helper 1(Th1) and T-helper 17(Th17) cells play an important role in its pathology. Formula PSORI-CM01 was a novel formulated Chinese medicine used for psoriasis therapy. It had been demonstrated previously that PSORI-CM01 and serum contained Formula PSORI-CM01 (PCM01CS) could improve psoriasis by inhibiting the epithelial hyperplasia, how PSORI-CM01 affects inflammatory cytokine and chemokine in dermis is still unknown. In this study we found PSORI-CM01 pre-treated 3 days before IMQ painting could ameliorated IMQ-induced mice skin lesion as PASI score was apparently reduced. Th1 related cytokine IFN-γ and Th17 related cytokine IL-17/IL-22 was used to induce inflammatory models on human keratinocyte cell line HaCaT in vitro, respectively. PCM01CS significantly reduced IFN-γ induced mRNA expression of IL-6, IL-12 and CXCL-10, reduced IL-6 and CXCL-10 release into HaCaT supernatant. 20 ng/ml IL-17/IL-22 co-stimulation significantly upregulated expression of IL-6, IL-8 and CCL20 mRNA expression in HaCaT cells, PCM01CS significantly inhibit these cytokines expression both in mRNA and in protein levels. Finally, PCM01CS could obviously inhibit nuclear NF-κB p65 expression which activated by IFN-γ and IL-17/IL-22 stimulation. Thus, our new findings reveal that Formula PSORI-CM01 may possess therapeutic action on psoriasis by inhibiting inflammatory within skin environments.     

Anti-arthritic effects of chlorogenic acid in interleukin-1β-induced rabbit chondrocytes and a rabbit osteoarthritis model

Cartilage degradation is one of the pathological changes of osteoarthritis (OA), and accumulating evidence suggests an excess of matrix metalloproteinases (MMPs) plays a role in this cartilage breakdown. Here, we investigated the effects of chlorogenic acid (CGA) on the mRNA and protein expression of MMPs in interleukin (IL)-1β-induced rabbit chondrocytes and evaluated the in vivo effects of CGA in experimental OA induced by anterior cruciate ligament transection (ACLT) in rabbits. Using quantitative real-time PCR and ELISA to investigate the expression levels of MMP-1, MMP-3, MMP-13, and tissue inhibitors of metalloproteinase-1(TIMP-1) in IL-1β-induced rabbit chondrocytes, we showed that CGA inhibits the expression of these MMPs while increasing TIMP-1 expression, at both the mRNA and protein levels. In addition, IL-1β-induced activation of nuclear factor kappa B (NF-κB) and the degradation of inhibitor of κB (IκB)-α were suppressed by CGA. In rabbits, CGA decreased cartilage degradation as assessed by morphological and histological analyses. The down-regulation of MMP-1, MMP-3, and MMP-13 expression and up-regulation of TIMP-1 expression were also detected in CGA-treated cartilage compared with vehicle-treated cartilage, confirming these findings in an in vivo model. Taken together, these findings indicate that CGA may be considered as a possible candidate agent in the treatment of OA.     

Alpha-Mangostin protects rat articular chondrocytes against IL-1β-induced inflammation and slows the progression of osteoarthritis in a rat model

Osteoarthritis (OA) is a joint disease characterized by inflammation and cartilage degradation. α-Mangostin (α-MG), which can be isolated from the fruit of the tropical evergreen tree Garcinia mangostana-L, is known to have anti-inflammatory properties. The aim of the study was to investigate the use of α-MG in the treatment of OA, using both rat chondrocytes and an OA rat model induced by destabilization of the medial meniscus (DMM). Rat chondrocytes were pretreated with α-MG (0, 1.25, 2.5, and 5.0 μg/ml for 24 h) prior to stimulation with interleukin-1β (IL-1β) (10 ng/ml for 24 h). Nitric oxide (NO) production was determined using the Griess method and prostaglandin E₂ (PGE₂) was assessed using an enzyme-linked immunosorbent assay (ELISA). The expression of inducible nitric oxide synthase (INOS), cyclooxygenase-2 (COX-2), matrix metalloproteinase-3, -9, and -13 (MMP-3, MMP-9, and MMP-13), Collagen II, and Aggrecan were detected by both quantitative real-time PCR (qRT-PCR) and a western blot analysis. Nuclear factor-κB (NF-κB) signaling molecules were detected by western blot analysis. Detection of p65 nuclear translocation of NF-κB was examined using immunofluorescence staining. The OA rats received intraperitoneal injections of α-MG (10 mg/kg) or saline every other day. Hematoxylin and eosin and Safranin-O-Fast green staining were used to evaluate the severity of cartilage lesions up to 8 weeks following surgery. α-MG inhibited the production of NO and PGE₂. The elevated expression of INOS, COX-2, MMP-3, MMP-9, and MMP-13, and the degradation of Collagen II and Aggrecan, were reversed by α-MG in IL-1β-stimulated chondrocytes. In addition, IL-1β induced considerable phosphorylation of the NF-kB signaling pathway, which was inhibited by α-MG. Furthermore, the immunofluorescence staining demonstrated that α-MG could suppress IL-1β-induced p65 nuclear translocation. In vivo, cartilage treated with α-MG showed attenuated degeneration and had low Osteoarthritis Research Society International (OARSI) scores compared with the control group. Taken together, these results show that α-MG has potential therapeutic value in the treatment of OA.