Anti-inflammatory effects of traditional mixed extract of medicinal herbs (MEMH) on monosodium urate crystal-induced gouty arthritis

The potential role of herbal extract Wedelolactone for treating particle-induced osteolysis: an in vivo study

Background

Osteolysis is one of the most prevalent clinical complications affecting people who undergo total joint replacement (TJR). Wedelolactone (WDL) is a coumestan compound derived from the Wedelia chinensis plant and has been demonstrated to exhibit anti-inflammatory properties. This study aimed to investigate the oral administration of WDL as a potential treatment for particle-induced osteolysis using a well-established mice calvarial disease model.

Methods

Thirty-two C57BL/6 J mice were randomized into four groups: Sham, vehicle, osteolysis group with oral WDL treatment for 4 weeks (WDL 4w), and osteolysis group treated for 8 weeks (WDL 8w). Micro-CT was used to quantitatively analyze the bone mineral density (BMD), bone volume/tissue volume (BV/TV) and trabecular bone thickness (Tb.Th). Osteoclast numbers were also measured from histological slides by two investigators who were blind to the treatment used.

Results

The results from micro-CT observation showed that BMD in the WDL 8w group improved significantly over the vehicle group (p < 0.05), but there was no significant difference between WDL 4w and 8w for BV/TV and Tb.Th. Osteoclast numbers in the WDL 4w group were also lower than the vehicle group (p < 0.05), but the difference between WDL 8w and 4w groups was not significant.

Conclusions

Particle-induced osteolysis is an inevitable long-term complication after TJR. The results of this animal study indicate that an oral administration of WDL can help reduce the severity of osteolysis without adverse effects.

Medicinal Plants for Glioblastoma Treatment

Glioblastoma, an aggressive brain cancer, demonstrates the least life expectancy among all brain cancers. Because of the regulation of diverse signaling pathways in cancers, the chemotherapeutic approaches used to suppress their multiplication and spreading are restricted. Sensitivity towards chemotherapeutic agents has developed because of the pathological and drug-evading abilities of these diverse mechanisms. As a result, the identification and exploration of strategies or treatments, which can overcome such refractory obstacles to improve glioblastoma response to treatment as well as recovery, is essential. Medicinal herbs contain a wide variety of bioactive compounds, which could trigger aggressive brain cancers, regulate their anti-cancer mechanisms and immune responses to assist in cancer elimination, and cause cell death. Numerous tumor-causing proteins, which facilitate invasion as well as metastasis of cancer, tolerance of chemotherapies, and angiogenesis, are also inhibited by these phytochemicals. Such herbs remain valuable for glioblastoma prevention and its incidence by effectively being used as anti-glioma therapies. This review thus presents the latest findings on medicinal plants using which the extracts or bioactive components are being used against glioblastoma, their mechanism of functioning, pharmacological description as well as recent clinical studies conducted on them.

Anti-Inflammatory Activity of Cnidoscolus aconitifolius (Mill.) Ethyl Acetate Extract on Croton Oil-Induced Mouse Ear Edema

Nowadays, there is a growing interest in the development of medicinal plant-based therapies to diminish the ravages of the inflammatory process related to diseases and tissue damage. Most therapeutic effects of these traditional medicinal plants are owed to their phenolic and antioxidant properties. C. aconitifolius is a traditional medicinal plant in Mexico. Previous characterization reports have stated its high nutritional and antioxidant components. The present study aimed to better understand the biological activity of C. aconitifolius in inflammation response. We developed an ethyl acetate extract of this plant to evaluate its anti-inflammatory capacity and its flavonoid content. The topical anti-inflammatory effect of the ethyl acetate extract of C. aconitifolius was determined by the croton oil-induced mouse ear edema test, while flavonoid detection and concentration were determined by thin layer chromatography and the aluminum chloride colorimetric assay, respectively. Topical application of the extract showed significant inhibition of the induced-ear edema (23.52 and 49.41% for 25 and 50 mg/kg dose, respectively). The extract also exhibited the presence of flavonoids. The finding of the anti-inflammatory activity exerted by the C. aconitifolius and the identification of its active principles may suggest and support its use for inflammation treatment.

Ameliorative Effects of Cardamonin on Monosodium Urate-Induced Gouty Arthritis through Inhibiting NLRP3 Inflammasome Mediation

Background and Objectives: Gouty arthritis is an acute inflammatory response caused by the precipitation of monosodium urate (MSU) crystals in joints. The triggering of MSU leads to increased production of inflammatory cytokines, such as interleukin-1β, which in turn lead to the formation of macromolecular complexes, referred to as inflammasomes. Thorough characterization of the NLRP3 inflammasome can be used as an indicator of an immune response against harmful stimuli. Cardamonin is a chalcone, mainly found in the seeds of Alpinia katsumadai, and exhibits anti-inflammatory activity by inhibiting the release of pro-inflammatory cytokines in vitro. However, the mechanism by which cardamonin treatment alleviates gouty arthritis has yet to be fully elucidated. Materials and Methods: In vitro or in vivo models were used to study whether cardamonimn inhibited NLRP3 inflammasome activation or suppressed gouty inflammation. Results: In the current study, we determined that most NLRP3 was released passively after MSU stimulation, and this release of NLRP3 promoted caspase-1 activation and IL-1β secretion. Cardamonin was shown to decrease both the activity of caspase-1 and secretion of IL-1β in J774A.1 macrophage cells subjected to MSU stimulation. Cardamonin was also shown to attenuate the production of COX-2 in MSU-stimulated J774A.1 macrophage cells. Finally, cardamonin reduced the thickness of the synovial lining and the infiltration of gouty arthritis in a rat model. Conclusions: Overall, cardamonin significantly attenuated IL-1β secretion, caspase-1 activity, and COX-2 production stimulated by MSU. These findings provide new insights into the molecular mechanisms underlying the effects of cardamonin treatment for gouty arthritis.

Sclerostin-Mediated Impaired Osteogenesis by Fibroblast-Like Synoviocytes in the Particle-Induced Osteolysis Model

Engineered biomaterials are envisioned to replace, augment, or interact with living tissues for improving the functional deformities associated with end-stage joint pathologies. Unfortunately, wear debris from implant interfaces is the major factor leading to periprosthetic osteolysis. Fibroblast-like synoviocytes (FLSs) populate the intimal lining of the synovium and are in direct contact with wear debris. This study aimed to elucidate the effect of Ti particles as wear debris on human FLSs and the mechanism by which they might participate in the bone remodeling process during periprosthetic osteolysis. FLSs were isolated from synovial tissue from patients, and the condition medium (CM) was collected after treating FLSs with sterilized Ti particles. The effect of CM was analyzed for the induction of osteoclastogenesis or any effect on osteogenesis and signaling pathways. The results demonstrated that Ti particles could induce activation of the NFκB signaling pathway and induction of COX-2 and inflammatory cytokines in FLSs. The amount of Rankl in the conditioned medium collected from Ti particle–stimulated FLSs (Ti CM) showed the ability to stimulate osteoclast formation. The Ti CM also suppressed the osteogenic initial and terminal differentiation markers for osteoprogenitors, such as alkaline phosphate activity, matrix mineralization, collagen synthesis, and expression levels of Osterix, Runx2, collagen 1α, and bone sialoprotein. Inhibition of the WNT and BMP signaling pathways was observed in osteoprogenitors after the treatment with the Ti CM. In the presence of the Ti CM, exogenous stimulation by WNT and BMP signaling pathways failed to stimulate osteogenic activity in osteoprogenitors. Induced expression of sclerostin (SOST: an antagonist of WNT and BMP signaling) in Ti particle–treated FLSs and secretion of SOST in the Ti CM were detected. Neutralization of SOST in the Ti CM partially restored the suppressed WNT and BMP signaling activity as well as the osteogenic activity in osteoprogenitors. Our results reveal that wear debris–stimulated FLSs might affect bone loss by not only stimulating osteoclastogenesis but also suppressing the bone-forming ability of osteoprogenitors. In the clinical setting, targeting FLSs for the secretion of antagonists like SOST might be a novel therapeutic approach for preventing bone loss during inflammatory osteolysis.

Zisheng Shenqi Decoction Ameliorates Monosodium Urate-Mediated Gouty Arthritis in Rats via Promotion of Autophagy through the AMPK/mTOR Signaling Pathway

Gouty arthritis (GA) is an inflammatory disease owing to the accumulation of monosodium urate (MSU) in joints, leading to redness and burning pain. In this study, the effect of Zisheng Shenqi Decoction (ZSD) on a rat model of MSU-induced GA was investigated. ZSD obviously diminished the right paw thickness, the degree of the swelling of the paw, and the infiltration of the inflammatory cell, as well as cartilage erosion, and widened the joint space in MSU-treated rats. Besides, MSU remarkably elevated the release of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and IL-18; however, ZSD treatment dose dependently lowered these levels and resulted in a significant decrease in articular elastase activity. Also, ZSD administration increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) but declined malondialdehyde (MDA) and nitrogen monoxide (NO) contents. Importantly, western blotting analysis revealed that NOD-like receptor protein 3 (NLRP3), cleaved caspase-1, IL-1β, nuclear factor-E2-related factor 2 (Nrf2) in the cytoplasm, phosphorylated mammalian target of rapamyclin (p-mTOR), and p62 expressions were downregulated, whereas the levels of nuclear Nrf2, phosphorylated AMP-activated protein kinase (p-AMPK), Beclin-1, and LC3II/I were upregulated by ZSD. Immunofluorescence assay indicated that ZSD evidently promoted nuclear translocation of LC3. Taken together, ZSD inhibited inflammation and oxidative stress and facilitated autophagy through the activation of the AMPK pathway and suppression of the mTOR signaling pathway, demonstrating its potential for preventing and curing GA.

Sinomenine Inhibited Interleukin-1β-Induced Matrix Metalloproteinases Levels via SOCS3 Up-Regulation in SW1353 Cells

Matrix metalloproteinases (MMPs) are required for collagen degradation which play a key pathological role in arthritis progression. Herein, the effect of sinomenine (SN) on Interleukin 1 beta (IL-1β)-induced MMPs production and its underlying mechanism were explored in SW1353 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that 200 and 400 µM SN significantly inhibited SW1353 cell proliferation, thus the lower dose of SN (25-100 µM) were used in the subsequent experiments. Notably, the increased mRNA and protein levels of suppressor of cytokine signaling (SOCS) 3 were dose-dependently induced by SN. SN significantly suppressed mRNA and protein levels of MMPs in IL-1β-induced SW1353 cells. Through Western blot analysis, SN showed inhibitory effect on IL-1β-induced TAK1 and p65 phosphorylation. Moreover, SN blocked the interaction of TRAF6 and TAK1 resulting in inactivation of IL-1β pathway. Mechanistically, the inhibitory effect of SN on MMPs levels alongside TRAF6 and TAK1 interactions was abrogated by silencing SOCS3. Moreover, SN did not inhibit TAK1 kinase activity. In TAK1 silencing cells, the levels of MMPs and p65 phosphorylation of SN-treatedcells were lower than dimethyl sulfoxide (DMSO)-treated cells, indicating that blocking interaction was not a unique way for SN to inhibit MMPs levels. Finally, SN significantly inhibited IL-6-induced Janus tyrosine kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) phosphorylation in SW1353 cells. The levels of JAK2 phosphorylation and MMPs did not show a significant difference between IL-6 + SOCS3-small interfering RNA (siRNA) + SN group and IL-6 + SOCS3-siRNA + DMSO group. These findings demonstrated that SOCS3 expression was increased by SN blocked IL-1β-induced interaction between TRAF6 and TAK1 as well as IL-6 pathway activation, thereby culminating in the inhibition of MMPs levels.

Fibroblast-Like-Synoviocytes Mediate Secretion of Pro-Inflammatory Cytokines via ERK and JNK MAPKs in Ti-Particle-Induced Osteolysis

Biomaterials are designed to replace and augment living tissues in order to provide functional support to skeletal deformities. However, wear debris produced from the interfaces of metal implants initiates inflammatory bone loss, causing periprosthetic osteolysis. Lately, fibroblast-like synoviocytes (FLS) have been shown to play a role in wear-debris-induced osteolysis. Thus, here we have tried to understand the underlying mechanism of FLS involvement in wear-debris-induced osteolysis. Our results demonstrate that the effects of Ti particle (1:100 cell-to-Ti particle ratio) on FLS can induce Cox-2 expression and activate NFkB signaling. Moreover, the mRNA expression of pro-inflammatory cytokines such as IL-6, IL-8, IL-11, IL-1β, and TNFα was found to be elevated. However, among these pro-inflammatory cytokines, the mRNA and protein levels of only IL-6, IL-1β, and TNFα were found to be significantly higher. Ti particles activated extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs) as an early response in FLS. Co-inhibition of ERK and JNK signaling pathways by their specific inhibitors (PD9805 and SP600125, respectively) resulted in the suppression of mRNA and protein levels of IL-6, IL-1β, and TNFα in FLS. Taken together, targeting ERK and JNK MAPKs in FLS might provide a therapeutic option for reducing the secretion of bone-resorbing pro-inflammatory cytokines, thus preventing periprosthetic osteolysis.

Preventive effect of dioscin against monosodium urate-mediated gouty arthritis through inhibiting inflammasome NLRP3 and TLR4/NF-κB signaling pathway activation: an in vivo and in vitro study

Monosodium urate (MSU)-mediated inflammation is closely related to gouty arthritis (GA). Dioscin, an active ingredient, has been reported to possess anti-inflammatory property. Nevertheless, the role of dioscin in GA and the underlying mechanism have not been fully understood. In the present study, we investigated the anti-inflammatory effect of dioscin on MSU-induced GA through in vivo and in vitro experiments. Histopathological analysis showed that dioscin alleviated the severity of GA concomitant with the lowered uric acid and creatinine levels. Moreover, the increasing IL-1β, IL-6, and TNF-α levels induced by MSU were decreased via administration of dioscin in mice and human synoviocytes. Western blotting results suggested that dioscin inhibited the activation of NLRP3 through down-regulating the protein expressions of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cleaved-caspase-1, as well as IL-1β. In addition, TLR4, myeloid differentiation primary response gene 88 (MyD88), p-IKKβ, p-p65, and NF-κB p65 in nuclei levels were significantly reduced by dioscin. Importantly, dioscin remarkably lowered the NF-κB p65-DNA activity in MSU-treated mice utilizing electrophoretic mobility shift assay (EMSA) analysis. Taken together, dioscin had a protective effect against MSU-initiated inflammatory response via repressing the production of inflammatory cytokines and the activation of inflammasome NLRP3 and TLR4/NF-κB signaling pathway. The above findings revealed that dioscin could be a potential drug for the treatment of GA.

Etoricoxib prevents progression of osteolysis in repeated intra-articular monosodium urate-induced gouty arthritis in rats

Deposition of monosodium urate (MSU) crystals in the joint or synovium is the major factor in Gouty arthritis (GA). The clinical features of chronic and recurrent GA include pain and the subsequent development of chronic tophaceous GA with multiple tophi deposits accompanied by osteolysis. The majority of previous animal studies have focused on MSU-induced acute GA without making observations regarding osteolysis. In the study, intra-articular injections of MSU into the knee (2 times/week for 10 weeks) was used to induce chronic and recurrent attacks of GA that in turn induced progressive osteolysis. Moreover, we also evaluated whether the clinical, nonsteroidal anti-inflammatory drug (NSAID) etoricoxib attenuated the osteoclastogenesis of progressive osteolysis. The knee morphometry and the expression of osteoclastogenesis-related proteins (cathepsin K and matrix metalloproteinase-9 and -13) in the knee were examined by micro-CT and immunohistochemistry, respectively. Results showed that oral etoricoxib not only significantly attenuated the nociceptive behaviors of the rats but that it also inhibited the expression of osteoclastogenesis-related proteins in their knee joints in chronic and recurrent attacks of GA. Our findings thus suggest that NSAIDs not only inhibit nociception but also prevent the progression of osteolysis in chronic and repeated attacks of GA.

Differential Expression Patterns of Rspondin Family and Leucine-Rich Repeat-Containing G-Protein Coupled Receptors in Chondrocytes and Osteoblasts

Objective

Rspondins (RSPOs) are regarded as the significant modulators of WNT signaling pathway and they are expressed dynamically during developmental stages. Since in osteoarthritis (OA) both cartilage and subchondral bone suffer damages and WNT signaling pathway has a crucial role in their maintenance, the objective of the study was to analyze expression profile of RSPO family and its receptors [leucine-rich repeat-containing G-protein coupled receptors (LGRs)] in OA tissue samples as well as in differentiating chondrocytes and osteoblasts.

Materials and Methods

In this experimental study, human early and advanced stage of OA tissue samples were analyzed for the morphological changes of articular cartilage by hematoxylin and eosin (H and E) staining, safranin-O staining and lubricin immunostaining. RSPOs and LGRs expression were confirmed by immunohistochemistry. Human primary chondrocytes and human osteoblast cell line, SaOS-2, were cultured in differentiation medium till day 14 and they were analyzed in terms of expression of RSPOs, LGRs and specific marker for chondrogenesis and osteogenesis by western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Results

Advanced stage OA tissue samples showed increased expression of RSPO1 and LGR6 in a region close to subchondral bone. While RSPO2 and LGR5 expression were seen overlapping in the deep region of articular cartilage. Differentiating chondrocytes demonstrated elevated expression of RSPO2 and LGR5 from day 7 to day 14, whereas, osteoblasts undergoing differentiation showed enhanced expression of RSPO1 and LGR6 from day 2 to day 14. Under tumor necrosis factor alpha (TNFα) stimulatory conditions, RSPO2 and RSPO1 recovered the suppressed expression of inflammatory, chondrogenic and osteogenic markers, respectively. A recovery in the stability of β-catenin was also noticed in both cases.

Conclusion

Spatial expression of RSPOs during progression of OA might be dynamically controlled by cartilage and subchondral bone. Interplay amid chondrocytes and osteoblasts, via RSPOs, might provide probable mechanisms for treating inflammatory pathogenic conditions like OA.