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 5.0μg/ml for 24h) prior to stimulation with interleukin-1β (IL-1β) (10ng/ml for 24h). 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 (10mg/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 8weeks 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.

Pan T ，Wu D ，Cai N ，Chen R ，Shi X ，Li B ，Pan J ... -  《-》

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, 100μM) for 2h, then incubated with IL-1β (10ng/mL) for 24h. 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 (25mg/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 8weeks 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.

Lou Y ，Wang C ，Zheng W ，Tang Q ，Chen Y ，Zhang X ，Guo X ，Wang J ... -  《-》

Luteolin inhibits IL-1β-induced inflammation in rat chondrocytes and attenuates osteoarthritis progression in a rat model.

Osteoarthritis (OA) is a joint disease characterized by inflammation and cartilage degradation. Accumulating evidence has demonstrated that luteolin, a natural flavonoid, has anti-inflammatory and anticatabolic effects. The present study aimed to assess the protective effect of luteolin on interleukin (IL)-1β-stimulated rat chondrocytes and a monosodium iodoacetate (MIA)-induced model of OA. Rat chondrocytes were pretreated with luteolin (0, 25, 50, and 100 μM for 12 h) prior to stimulation with IL-1β (10 ng/ml for 24 h). Nitric oxide (NO) production was determined using the Griess method. Production of prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and matrix metalloproteinase-2, -8, and -9 (MMP-2, MMP-8 and MMP-9) was measured by an enzyme-linked immunosorbent assay (ELISA). Protein levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), MMP-1, MMP-3, MMP-13, p65, p-p65, IκB, and p-IκB were determined by Western blotting. The OA rats received luteolin (10 mg/kg/day) by gavage in vivo. Morphological and ultrastructural scanning electron microscopy (SEM) observations were performed to assess the severity of OA at 45 days following MIA injection. Collagen II protein expression was determined by immunohistochemistry. In this study, luteolin considerably reduced the IL-1β-induced production of NO, PGE2, TNF-α, MMP-2, MMP-8 and MMP-9 and the expression of COX-2, iNOS, MMP-1, MMP-3 and MMP-13. Luteolin reversed the degradation of collagen II induced by IL-1β. Luteolin also significantly inhibited IL-1β-induced phosphorylation of NF-κB in vitro. Luteolin treatment prevented cartilage destruction and enhanced collagen II expression in OA rats in vivo. Overall, our findings suggest that luteolin may be a useful therapeutic agent for patients with OA.

Fei J ，Liang B ，Jiang C ，Ni H ，Wang L ... -  《-》

Aucubin prevents interleukin-1 beta induced inflammation and cartilage matrix degradation via inhibition of NF-κB signaling pathway in rat articular chondrocytes.

Proinflammatory cytokine interleukin-1β (IL-1β) plays a crucial role in the pathogenesis of Osteoarthritis (OA) by stimulating several mediators contributed to cartilage degradation. Aucubin, a natural compound derived from plants which has been shown to possess diverse biological activities including anti-inflammatory property, may benefit the IL-1β stimulated chondrocytes. The present study was aimed to investigate the effects of Aucubin on IL-1β stimulated rat chondrocytes. Rat chondrocytes were cultured and pretreated with Aucubin (1, 10, 20, 50μM), and then stimulated with or without IL-1β (10ng/ml). Gene and protein expression of MMP-3, MMP-9, MMP-13, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) was determined by real-time PCR and Western blotting respectively. Nitric oxide (NO) production was quantified by Griess reagent. Phosphorylation and nuclear translocation of p65 were detected by western blotting and immunofluorescence, respectively. We found that Aucubin significantly reversed the elevated gene and protein expression of MMP-3, MMP-9, MMP-13, iNOS, COX-2 and the production of NO induced by IL-1β challenge in rat chondrocytes. Furthermore, Aucubin was able to suppress the IL-1β-mediated phosphorylation and nuclear translocation of p65, indicating Aucubin may possibly act via the NF-κB signaling pathway. The present study proposes that Aucubin may be a potential therapeutic choice in the treatment of OA due to its anti-inflammatory and chondroprotective features.

Wang SN ，Xie GP ，Qin CH ，Chen YR ，Zhang KR ，Li X ，Wu Q ，Dong WQ ，Yang J ，Yu B ... -  《-》

Chondroprotective effects of aqueous extract of Anthriscus sylvestris leaves on osteoarthritis in vitro and in vivo through MAPKs and NF-κB signaling inhibition.

Osteoarthritis (OA) is a common degenerative joint disease, characterized by cartilage degradation and inflammation, in the elderly population. Anthriscus sylvestris has been used in Korean traditional medicine and contains many polyphenolic compounds such as cynaroside and chlorogenic acid, which are major active components responsible for its antioxidant effect. In this study, we aimed to evaluate the chondroprotective effect of an aqueous extract of A. sylvestris leaves (AE-ASL) on OA, both in vitro and in vivo. Rat primary chondrocytes were pretreated with AE-ASL for 1 h before interleukin-1β (20 ng/mL) stimulation. The production of nitrite, PGE2, aggrecan, and collagen type II were detected by Griess reagent and ELISAs. The mRNA levels of iNOS, COX-2, MMP-3, and MMP-13 were measured by RT-PCR. In addition, protein levels of iNOS, COX-2, MMP-3, MMP-13, ADAMTS-4, MAPKs, and NF-κB p65 subunit were measured by western blot analysis. Sulfated glycosaminoglycan (sGAGs) were detected by dimethylmethylene blue (DMMB) assay. During in vivo study, the effects of AE-ASL were evaluated for 8 weeks in a rat model of destabilization of the medial meniscus (DMM) surgery-induced OA. AE-ASL significantly inhibited expression of nitrite, iNOS, PGE2, COX-2, MMP-3, MMP-13, and ADAMTS-4 in IL-1β-stimulated chondrocytes. Moreover, it decreased the IL-1β-induced degradation of aggrecan, collagen type II, and proteoglycan. In addition, AE-ASL suppressed IL-1β-induced phosphorylation of MAPKs and NF-κB p65 subunit translocation to nucleus. In vivo, AE-ASL inhibited DMM surgery-induced cartilage destruction and proteoglycan loss. Taken together, these results suggest that AE-ASL may be a potential therapeutic agent for the alleviation of OA progression.

Lee SA ，Moon SM ，Han SH ，Hwang EJ ，Park BR ，Kim JS ，Kim DK ，Kim CS ... -  《-》