The protective effect of tetramethylpyrazine on cartilage explants and chondrocytes

Functional meniscus reconstruction with biological and biomechanical heterogeneities through topological self-induction of stem cells

Meniscus injury is one of the most common sports injuries within the knee joint, which is also a crucial pathogenic factor for osteoarthritis (OA). The current meniscus substitution products are far from able to restore meniscal biofunctions due to the inability to reconstruct the gradient heterogeneity of natural meniscus from biological and biomechanical perspectives. Here, inspired by the topology self-induced effect and native meniscus microstructure, we present an innovative tissue-engineered meniscus (TEM) with a unique gradient-sized diamond-pored microstructure (GSDP-TEM) through dual-stage temperature control 3D-printing system based on the mechanical/biocompatibility compatible high Mw poly(ε-caprolactone) (PCL). Biologically, the unique gradient microtopology allows the seeded mesenchymal stem cells with spatially heterogeneous differentiation, triggering gradient transition of the extracellular matrix (ECM) from the inside out. Biomechanically, GSDP-TEM presents excellent circumferential tensile modulus and load transmission ability similar to the natural meniscus. After implantation in rabbit knee, GSDP-TEM induces the regeneration of biomimetic heterogeneous neomeniscus and efficiently alleviates joint degeneration. This study provides an innovative strategy for functional meniscus reconstruction. Topological self-induced cell differentiation and biomechanical property also provides a simple and effective solution for other complex heterogeneous structure reconstructions in the human body and possesses high clinical translational potential.

Minocycline declines interleukin-1ß-induced apoptosis and matrix metalloproteinase expression in C28/I2 chondrocyte cells: an in vitro study on osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease that occurs with aging. In its late phases, it is determined by the loss of chondrocytes and the breakdown of the extracellular matrix, resulting in pain and functional impairment. Interleukin-1 beta (IL-1β) is increased in the injured joints and contributes to the OA pathobiology by inducing chondrocyte apoptosis and up-regulation of matrix metalloproteinases (MMPs). Here, we aimed to understand whether minocycline could protect chondrocytes against the IL-1β-induced effects. The human C28/I2 chondrocyte cell line was treated with IL-1β or IL-1β plus minocycline. Cell viability/toxicity, cell cycle progression, and apoptosis were assessed with MMT assay and flow cytometry. Expression of apoptotic genes and MMPs were evaluated with qRT-PCR and western blotting. IL-1β showed a significant cytotoxic effect on the C28/I2 chondrocyte cells. The minocycline effective concentration (EC50) significantly protected the C28/I2 cells against the IL-1β-induced cytotoxic effect. Besides, minocycline effectively lowered IL-1β-induced sub-G1 cell population increase, indicating the minocycline anti-apoptotic effect. When assessed by real-time PCR and western blotting, the minocycline treatment group showed an elevated level of Bcl-2 and a significant decrease in the mRNA and protein expression of the apoptotic markers Bax and Caspase-3 and Matrix metalloproteinases (MMPs) such as MMP-3 and MMP-13. In conclusion, IL-1β promotes OA by inducing chondrocyte death and MMPs overexpression. Treatment with minocycline reduces these effects and decreases the production of apoptotic factors as well as the MMP-3 and MMP-13. Minocycline might be considered as an anti-IL-1β therapeutic supplement in the treatment of osteoarthritis. See also the graphical abstract(Fig. 1).

Dissolving microneedle patches-mediated percutaneous delivery of tetramethylpyrazine for rheumatoid arthritis treatment

Recently, transdermal treatment of rheumatoid arthritis (RA) has received increasing attention due to the advantages of improving patient compliance and avoiding gastrointestinal side effects. However, the stratum corneum (SC) barrier limits the transdermal delivery of most substances. Therefore, we constructed tetramethylpyrazine-loaded dissolving microneedle patches (TMP-DMNPs) and investigated its anti-rheumatoid arthritis effect. The cone-shaped dissolving microneedle patch had complete, neatly arranged needles and great mechanical strength. It could effectively penetrate the stratum corneum when applied to the skin. In vitro transdermal experiment showed that DMNPs could significantly promote the transdermal penetration of TMP compared with TMP-cream. The needles were completely dissolved within 18 min and the applied skin recovered completely within 3 h. The excipients and blank DMNP had good safety and biocompatibility to human rheumatoid arthritis fibroblast synovial cells. To compare the therapeutic effects, the animal model was established. The experiments of paw swelling, histopathology and X-ray examination showed that dissolving microneedles significantly alleviated paw condition, reduced the serum concentrations of proinflammatory cytokines, and inhibited synovial tissue damage in AIA rats. These results indicate that the DMNPs we prepared can deliver TMP safely, effectively and conveniently, providing a basis for the percutaneous treatment of RA.

An Overview of Tetramethylpyrazine (Ligustrazine) and its Derivatives as Potent Anti-Alzheimer’s Disease Agents

Abstract:

Tetramethylpyrazine (TMP), or ligustrazine, is an alkaloid isolated from the Chinese herb Ligusticum wallichii. It is known for its broad-spectrum medicinal properties against several diseases, and various studies have shown that it can modulate diverse biological targets and signaling pathways to produce neuroprotective effects, especially against Alzheimer’s disease (AD). This has attracted significant research attention evaluating TMP as a potent multitarget anti-AD agent. This review compiles the results of studies assessing the neuroprotective mechanisms exerted by TMP as well as its derivatives prepared using a multi-target-directed ligand strategy to explore its multitarget modulating properties. The present review also highlights the work done on the design, synthesis, structure-activity relationships, and mechanisms of some potent TMP derivatives that have shown promising anti-AD activities. These derivatives were designed, synthesized, and evaluated to develop anti-AD molecules with enhanced biological and pharmacokinetic activities compared to TMP. This review article paves the way for the exploration and development of TMP and TMP derivatives as an effective treatment for AD.

Inflammatory-associated apoptotic markers: are they the culprit to rheumatoid arthritis pain?

BACKGROUND

Rheumatoid arthritis (RA) is a prolonged inflammatory disease resulting from autoimmune reactions that leads to local and systemic bone erosion, joint defects and functional impairment. Although the inflammation is subsided through the prescription of anti-inflammatory therapeutics, the patients persistently complained of sleepless nights due to flare pain. This indicates the possible contribution of other pathways besides inflammation in leading to RA pain. This review aims to uncover the roles and involvement of several inflammatory-associated apoptotic markers in facilitating pain transmission and processing during the pathogenesis of RA.

MATERIALS AND METHODS

This narrative review focused on the reports from the previous literature based on the search string of "apoptotic marker AND inflammation AND 'chronic pain' OR 'neuropathic pain' and apoptosis AND 'rheumatoid arthritis' OR arthritis from the databases including Science Direct and Scopus, considering the exclusion criteria of the published abstracts, proceedings or articles on other neuropathic pain types such as painful bowel syndrom, insterstitial cystitis, fibrosis and so on.

RESULTS

Several studies in the literature demonstrate a close association between imbalanced apoptotic regulations and an increased number of synovial fibroblasts and inflammatory cells in RA. Cell death or specific cell survival has been linked with increased central hypersensitivity in various types of chronic and neuropathic pain.

CONCLUSION

The RA-related flare pain is possibly contributed by the abnormal regulation of apoptosis through several inflammatory-related pathways, and further studies need to modulate these pathways for the putative anti-nociceptive benefits.

Upregulation of P2Y12 inhibits chondrocyte apoptosis in lumbar osteoarthritis through the PI3K/AKT signaling pathway

Lumbar facet osteoarthritis (FJOA) is a major cause of severe lower back pain and disability worldwide. However, the mechanism underlying cartilage degeneration in FJOA remains unclear. The purpose of this study was to investigate the regulation and mechanism of P2Y12 on chondrocyte apoptosis in FJOA. The experimental rats were randomly divided into non-operation (n = 20) and operation groups (n = 20). In the operation group, Sodium iodoacetate (MIA, Sigma, 200 mg/mL) was injected into the right L4/5 facet process using a blunt nanoneedle 26 (WPI, Sarasota, FL, USA) under the control of an injection pump. The final injection volume was 5µL and the injection rate was 2µL/min. The facet joint was removed four weeks after surgery. After the operation, samples were stored at -80 °C until further use, whereby the right facet joints in each group were tested. Hematoxylin and eosin (HE) and iron-red solid green staining were used to observe the degeneration of articular chondrocytes in rats. Immunohistochemistry and western blotting were used to observe the expressions of P2Y12, Matrix metalloproteinase 13 (MMP13), Collagen II (COL2), and other cartilage degeneration and apoptosis-related genes. Co-localization of P2Y12-cleaved caspase-3 in the apoptosis model was detected by dual-standard immunofluorescence staining. Apoptosis was also detected by flow cytometry and TUNEL assay.P2Y12 is highly expressed in OA cartilage tissue, and inhibits IL-1β -induced chondrocyte apoptosis through PI3K/AKT signaling pathway, thus playing a certain protective role on cartilage.

Network Pharmacology and Molecular Docking to Elucidate the Potential Mechanism of Ligusticum Chuanxiong Against Osteoarthritis

Background: Osteoarthritis (OA) is a degenerative disease which serious affects patients. Ligusticum chuanxiong (CX) has been shown to have a certain curative effect on osteoarthritis in traditional Chinese medicine therapy. This study is based on network pharmacology and molecular docking technology to explore the potential mechanism of CX.

Methods: Components of CX to treat osteoarthritis were screened in the TCMSP database and targets were predicted by the PharmMapper database, the osteoarthritis targets were collected from the GeneCards database, and intersection genes were found to be the possible targets of CX anti-OA. The STRING database and Cytoscape software were utilized for protein-protein interaction analysis and further screening of core targets. The Metascape database was used for KEGG and GO enrichment analyses. Then, the top 10 pathways were selected to construct “drug-compound-target-pathway-disease” network analysis. Finally, molecular docking was used to analyze the binding affinity of seven compounds with core targets and TNF-α.

Results: Seven compounds with 253 non-repetitive targets of CX were screened from the TCMSP database and 60 potential intersection targets of CX anti-OA were found. PPI network analysis showed that the core targets were ALB, AKT1, IGF1, CASP3, MAPK1, ANXA5, and MAPK14, while GO and KEGG pathway enrichment analyses showed that the relevant biological processes involved in the treatment of osteoarthritis by CX might include the MAPK cascade and reactive oxygen species metabolic process. The KEGG pathway analysis result was mainly associated with the MAPK signaling pathway and PI3K-AKT signaling pathway. We further docked seven ingredients with MAPK1 and MAPK14 enriched in the MAPK pathway, and TNF-α as the typical inflammatory cytokine. The results also showed good binding affinity, especially FA, which may be the most important component of CX anti-OA.

Conclusion: Our research revealed the potential mechanism of CX in the treatment of OA, and our findings can also pave the way for subsequent basic experimental verification and a new research direction.

Botanical Drug Extracts Combined With Biomaterial Carriers for Osteoarthritis Cartilage Degeneration Treatment: A Review of 10 Years of Research

Osteoarthritis (OA) is a long-term chronic arthrosis disease which is usually characterized by pain, swelling, joint stiffness, reduced range of motion, and other clinical manifestations and even results in disability in severe cases. The main pathological manifestation of OA is the degeneration of cartilage. However, due to the special physiological structure of the cartilage, once damaged, it is unable to repair itself, which is one of the challenges of treating OA clinically. Abundant studies have reported the application of cartilage tissue engineering in OA cartilage repair. Among them, cell combined with biological carrier implantation has unique advantages. However, cell senescence, death and dedifferentiation are some problems when cultured in vitro. Botanical drug remedies for OA have a long history in many countries in Asia. In fact, botanical drug extracts (BDEs) have great potential in anti-inflammatory, antioxidant, antiaging, and other properties, and many studies have confirmed their effects. BDEs combined with cartilage tissue engineering has attracted increasing attention in recent years. In this review, we will explain in detail how cartilage tissue engineering materials and BDEs play a role in cartilage repair, as well as the current research status.

Intra-Articular Drug Delivery for Osteoarthritis Treatment

Osteoarthritis (OA) is the most prevalent degenerative joint disease affecting millions of people worldwide. Currently, clinical nonsurgical treatments of OA are only limited to pain relief, anti-inflammation, and viscosupplementation. Developing disease-modifying OA drugs (DMOADs) is highly demanded for the efficient treatment of OA. As OA is a local disease, intra-articular (IA) injection directly delivers drugs to synovial joints, resulting in high-concentration drugs in the joint and reduced side effects, accompanied with traditional oral or topical administrations. However, the injected drugs are rapidly cleaved. By properly designing the drug delivery systems, prolonged retention time and targeting could be obtained. In this review, we summarize the drugs investigated for OA treatment and recent advances in the IA drug delivery systems, including micro- and nano-particles, liposomes, and hydrogels, hoping to provide some information for designing the IA injected formulations.

Intra-Articular Injection of a Nanosuspension of Tetramethylpyrazine Dihydroxynaphthalenate for Stronger and Longer-Lasting Effects Against Osteoarthritis

Tetramethylpyrazine (TMP), isolated from the rhizome of the traditional Chinese medicinal plant Chuanxiong (Ligusticum wallichii Franchat) shows therapeutic efficacy against osteoarthritis. After intra-articular injection, the retention time of TMP in the joint cavity is short, which limits its treatment effect. To avoid this problem, the present study explored the preparation of a TMP nanosuspension (TMP-NS) based on hydrophobic ion pairing. TMP-NS showed a particle size of approximately 588 nm and, after intra-articular injection in rats, it had longer retention in the articular cavity, higher TMP concentrations in joints, and greater anti-osteoarthritic efficacy than TMP solution. TMP-NS didn't cause significant inflammation at the joint. These results suggest that TMP-NS may strengthen and prolong the therapeutic efficacy of TMP against osteoarthritis without systemic toxicity.

Recent advance in treatment of osteoarthritis by bioactive components from herbal medicine

Osteoarthritis (OA) is a common chronic articular degenerative disease, and characterized by articular cartilage degradation, synovial inflammation/immunity, and subchondral bone lesion, etc. The disease affects 2-6% of the population around the world, and its prevalence rises with age and exceeds 40% in people over 70. Recently, increasing interest has been devoted to the treatment or prevention of OA by herbal medicines. In this paper, the herbal compounds with anti-OA activities were reviewed, and the cheminformatics tools were used to predict their drug-likeness properties and pharmacokinetic parameters. A total of 43 herbal compounds were analyzed, which mainly target the damaged joints (e.g. cartilage, subchondral bone, and synovium, etc.) and circulatory system to improve the pathogenesis of OA. Through cheminformatics analysis, over half of these compounds have good drug-likeness properties, and the pharmacokinetic behavior of these components still needs to be further optimized, which is conducive to the enhancement in their drug-likeness properties. Most of the compounds can be an alternative and valuable source for anti-OA drug discovery, which may be worthy of further investigation and development.

Ligustrazine Prevents Intervertebral Disc Degeneration via Suppression of Aberrant TGFβ Activation in Nucleus Pulposus Cells

Objectives

Aberrant transforming growth factor β (TGFβ) activation is detrimental to both nucleus pulposus (NP) cells and cartilage endplates (CEPs), which can lead to intervertebral disc degeneration (IDD). Ligustrazine (LIG) reduces the expression of inflammatory factors and TGFβ1 in hypertrophic CEP to prevent IDD. In this study, we investigate the effects of LIG on NP cells and the TGFβ signaling.

Design

LIG was injected to the lumbar spinal instability (LSI) mouse model. The effect of LIG was evaluated by intervertebral disc (IVD) score in the LSI mouse model. The expression of activated TGFβ was examined using immunostaining with pSmad2/3 antibody. The upright posture (UP) rat model was also treated and evaluated in the same manner to assess the effect of LIG. In ex vivo study, IVDs from four-week old mice were isolated and treated with 10⁻⁵, 10⁻⁶, and 10⁻⁷ M of LIG. We used western blot to detect activated TGFβ expression. TGFβ-treated human nucleus pulposus cells (HNPCs) were cotreated with optimized dose of LIG in vitro. Immunofluorescence staining was performed to determine pSmad2/3, connective tissue growth factor (CCN2), and aggrecan (ACAN) expression levels.

Results

IVD score and the percentage of pSmad2/3+ NP cells were low in LIG-treated LSI mice in comparison with LSI mice, but close to the levels in the Sham group. Similarly, LIG reduced the overexpression of TGFβ1 in NP cells. The inhibitory effect of LIG was dose dependent. A dose of 10⁻⁵ M LIG not only strongly attenuated Smad2/3 phosphorylation in TGFβ-treated IVD ex vivo but also suppressed pSmad2/3, CCN2, and ACAN expression in TGFβ-treated NP cells in vitro.

Conclusions

LIG prevents IDD via suppression of TGFβ overactivation in NP cells.

RETRACTED: Tetramethylpyrazine alleviates lipopolysaccharide-induced damage in ATDC5 cells via down-regulating MyD88

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief and the authors. Following the concerns raised about the background pattern of the Western Blots from Figures 7A and 7C, the authors have contacted the journal to request the retraction of the article as they were reportedly not confident of the accuracy of the data and the conclusions of the article. Given the comments of Dr Elisabeth Bik regarding this article “This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Natural Products as Sources of Novel Drug Candidates for the Pharmacological Management of Osteoarthritis: A Narrative Review

Osteoarthritis is a chronic degenerative articular disorder. Formation of bone spurs, synovial inflammation, loss of cartilage, and underlying bone restructuring have been reported to be the main pathologic characteristics of osteoarthritis symptoms. The onset and progression of osteoarthritis are attributed to various inflammatory cytokines in joint tissues and fluids that are produced by chondrocytes and/or interact with chondrocytes, as well as to low-grade inflammation in intra-articular tissues. Disruption of the equilibrium between the synthesis and degradation of the cartilage of the joint is the major cause of osteoarthritis. Hence, developing a promising pharmacological tool to restore the equilibrium between the synthesis and degradation of osteoarthritic joint cartilage can be a useful strategy for effectively managing osteoarthritis. In this review, we provide an overview of the research results pertaining to the search for a novel candidate agent for osteoarthritis management via restoration of the equilibrium between cartilage synthesis and degradation. We especially focused on investigations of medicinal plants and natural products derived from them to shed light on the potential pharmacotherapy of osteoarthritis.

Evaluation of five additives to mitigate toxicity of cryoprotective agents on porcine chondrocytes

Cryoprotective agents (CPAs) are used in cryopreservation protocols to achieve vitrification. However, the high CPA concentrations required to vitrify a tissue such as articular cartilage are a major drawback due to their cellular toxicity. Oxidation is one factor related to CPA toxicity to cells and tissues. Addition of antioxidants has proven to be beneficial to cell survival and cellular functions after cryopreservation. Investigation of additives for mitigating cellular CPA toxicity will aid in developing successful cryopreservation protocols. The current work shows that antioxidant additives can reduce the toxic effect of CPAs on porcine chondrocytes. Our findings showed that chondroitin sulphate, glucosamine, 2,3,5,6-tetramethylpyrazine and ascorbic acid improved chondrocyte cell survival after exposure to high concentrations of CPAs according to a live-dead cell viability assay. In addition, similar results were seen when additives were added during CPA removal and articular cartilage sample incubation post CPA exposure. Furthermore, we found that incubation of articular cartilage in the presence of additives for 2 days improved chondrocyte recovery compared with those incubated for 4 days. The current results indicated that the inclusion of antioxidant additives during exposure to high concentrations of CPAs is beneficial to chondrocyte survival and recovery in porcine articular cartilage and provided knowledge to improve vitrification protocols for tissue banking of articular cartilage.

Up-regulation of TRAF2 inhibits chondrocytes apoptosis in lumbar facet joint osteoarthritis

Tumor necrosis factor receptor-associated factor 2 (TRAF2) has been demonstrated that it plays a significant role in cell death receptor signal transduction. The purpose of this study was to investigate the expression of TRAF2 and its possible role in FJOA. We observed an up-regulation of TRAF2 in FJOA by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) compared to normal tissues. In vitro, we used TNF-α to stimulate Human SW1353 chondrosarcoma cells to establish the chondrocytes injury model. Western blot analysis revealed significant expression of TRAF2 and cleaved caspase-3/8 in SW1353 cells. Co-localization of TRAF2/cleaved caspase-3/8 was detected in the cells injury model by double-labeling immunofluorescent staining. We demonstrated a possible anti-apoptotic effect of TRAF2 in chondrocyte apoptosis in FJOA by knockdown of its expression with siRNA. Moreover, TRAF2 knockdown was demonstrated to enhance TNF-α-induced apoptosis by flow cytometry assay. In conclusion, our results show that the up-regulation of TRAF2 may play an important role in the inhibition of chondrocyte apoptosis of FJOA.

Metabolomic Analysis of Biochemical Changes in the Serum and Urine of Freund's Adjuvant-Induced Arthritis in Rats after Treatment with Silkworm Excrement

Silkworm excrement (SE), is used as a traditional antirheumatic medicine in China. The present study was designed to investigate the therapeutic efficacy of water fraction of SE (ST) and ethanol fraction of SE (CT) at two different doses on adjuvant induced arthritis (AA) rats. Arthritis severity was evaluated by body weight, paw thickness, histological changes and index of paws oedema and spleen. Serum samples were collected for estimation of biochemical indicators and cytokines. In addition, a metabonomic method based on the ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) had been established to investigate the holistic efficacy of SE by serum and urine. Multivariate statistical approaches, such as partial least-squares discriminant analysis (PLS-DA) and orthogonal projection to latent structures squares-discriminant analysis (OPLS-DA) were built to evaluate the therapeutic effects of SE and find potential biomarkers and metabolic pathways. Administration with SE significantly ameliorated the AA severity, including body weight loss, paw swelling, histological changes and the levels of biochemical index. 33 endogenous metabolites had been identified (10 in serum and 23 in urine) in the AA rats. Urinary and serum metabolic profiling revealed that the metabolites underpin the metabolic pathway including nicotinate and nicotinamide metabolism; pentose and glucuronate interconversions; TCA cycle; beta-Alanine metabolism; purine metabolism and glycolysis or gluconeogenesis. The altered metabolites could be regulated closer to normal level after SE intervention. The results suggested SE possesses substantial anti-arthritic activity and demonstrated that metabonomics is a powerful tool to gain insight in the mechanism of SE formula in therapy.

A systematic review on the rhizome of Ligusticum chuanxiong Hort. (Chuanxiong)

Chuanxiong Rhizome (called Chuanxiong, CX in Chinese), the dried rhizome of Ligusticum chuanxiong Hort, is an extremely common traditional edible-medicinal herb. As a widely used ethnomedicine in Asia including China, Japan and Korea, CX possesses ideal therapeutic effect on cardiovascular and cerebrovascular diseases, and is also used as a major ingredient in soups for regular consumption to benefit health. Based on the traditional perception, amounts of investigations on different aspects have been done for CX in the past decades. However, no literature systematic review about these achievements have been compiled. Herein, the aim of this review is to present the up-to-date information on the ethnobotany, ethnopharmacological uses, phytochemicals, pharmacological activities, toxicology of this plant to identify their therapeutic potential and directs future research opportunities. So far, about 174 compounds has been isolated and identified from CX, in which phthalides and alkaloids would be the main bioactive ingredients for its pharmacological properties, such as anti-cerebral ischemia, anti-myocardial ischemia, blood vessel protection, anti-thrombotic, anti-hypertensive, anti-atherosclerosis, anti-spasmodic, anti-inflammatory, anti-cancer, anti-oxidant, and anti-asthma effects. Even so, due to the incomplete standardized planting, unstable herbal quality, and outdated preparation techniques, the industrial progress of CX is still less developed.

Intra-articular delivery of tetramethylpyrazine microspheres with enhanced articular cavity retention for treating osteoarthritis

Tetramethylpyrazine (TMP) is a traditional Chinese herbal medicine with strong anti-inflammatory and cartilage protection activities, and thus a promising candidate for treating osteoarthritis. However, TMP is rapidly cleared from the joint cavity after intra-articular injection and requires multiple injections to maintain efficacy. The aim of this study was to encapsulate TMP into poly (lactic-co-glycolic acid) (PLGA) microspheres to enhance the TMP retention in the joint, reducing injection frequencies and decreasing dosage. TMP microspheres were prepared by emulsion/solvent evaporation method. The intra-articular retention of the drug was assessed by detecting the drug concentration distributed in the joint tissue at different time points. The therapeutic effect of TMP microspheres was evaluated by the swelling of knee joints and histologic analysis in papain-induced OA rat model. The prepared freeze-dried microspheres with a particle size of about 10 µm can effectively prolong the retention time of the drug in the articular cavity to 30 d, which is 4.7 times that of the TMP solution. Intra-articular injection of TMP microspheres efficiently relieved inflammatory symptoms, improved joint lesions and decreased the depletion of proteoglycan. In conclusion, intra-articular injection of TMP loaded microspheres was a promising therapeutic method in the treatment of OA.

Modulation of cartilage's response to injury: Can chondrocyte apoptosis be reversed?

Osteoarthritis is characterized by a chronic, progressive and irreversible degradation of the articular cartilage associated with joint inflammation and a reparative bone response. More than 100 million people are affected by this condition worldwide with significant health and welfare costs. Our available treatment options in osteoarthritis are extremely limited. Chondral or osteochondral grafts have shown some promising results but joint replacement surgery is by far the most common therapeutic approach. The difficulty lies on the limited regeneration capacity of the articular cartilage, poor blood supply and the paucity of resident progenitor stem cells. In addition, our poor understanding of the molecular signalling pathways involved in the senescence and apoptosis of chondrocytes is a major factor restricting further progress in the area. This review focuses on molecules and approaches that can be implemented to delay or even rescue chondrocyte apoptosis. Ways of modulating the physiologic response to trauma preventing chondrocyte death are proposed. The use of several cytokines, growth factors and advances made in altering several of the degenerative genetic pathways involved in chondrocyte apoptosis and degradation are also presented. The suggested approaches can help clinicians to improve cartilage tissue regeneration.

Anti-inflammatory effect of combined tetramethylpyrazine, resveratrol and curcumin in vivo

BACKGROUND

Resveratrol and curcumin, as natural flavones products, have good therapeutic effect in acute and chronic inflammation; on the other hand, tetramethylpyrazine (TMP) has angiogenesis and vessel protection effect as well as anti-inflammatory function. In this paper, the anti-inflammatory effect of the tetramethylpyrazine, resveratrol and curcumin (TRC) combination in acute and chronic inflammation was reported in vivo.

METHODS

The dose of the combined three natural products was optimized based on the acute paw swelling mouse model with a Uniform Design methodology. The therapeutic effect of TRC combination on chronic inflammation was investigated by using the collagen-induced arthritis (CIA) rat model based upon the following indexes: the volume of paw swelling, arthritis score, serum mediators and histological examination as well as immunohistochemical staining. The levels of alanine aminotransferase (ALT) and aspartate transaminase (AST) in serum were measured and the pathological sections of liver and kidney were analysed. LD₅₀ was measured based on the acute oral toxicity (AOT) standard method.

RESULTS

The best formulation was the three components combined at the same mass proportion revealed by the Uniform Design methodology. This combination could significantly reduce the paw swelling in acute paw swelling mouse model, could reduce paw swelling and alleviate the damage in joint structural of ankle, cartilages and fibrous tissue in CIA rat model. The dose relationship was clear in both cases. Immunohistochemical staining of ankle tissue revealed that TRC combination was able to inhibit the expression of NF-κB p65 and TNF-α which were closely related to the inflammatory process. Analysis of serum mediators revealed TRC combination could inhibit the production of TNF-α, IL-1β, and IL-6 in the serum. Toxic study revealed this formulation was low toxic, LD₅₀ was larger than 5 g/kg, both the level of ALT and AST and histopathology in the liver and kidney exhibited no distinctions between the TRC combination and the blank group, no mortality occurred at the administered doses of 5 g/kg.

CONCLUSIONS

The results showed this formulation could provide a novel potent treatment for acute and chronic inflammation (RA) without side effect like gastric injury occurring in NSAIDs.

The effect of additive compounds on glycerol-induced damage to human chondrocytes

High concentrations of cryoprotective agents are required for cryopreservation techniques such as vitrification. Glycerol is a common cryoprotective agent used in cryopreservation protocols but this agent is toxic at high concentrations. This work is an attempt to mitigate the toxic effects of high concentrations of glycerol on intact chondrocytes in human knee articular cartilage from total knee arthroplasty patients by simultaneous exposure to glycerol and a variety of additive compounds. The resulting cell viability in the cartilage samples as measured by membrane integrity staining showed that, in at least one concentration or in combination, all of the tested additive compounds (tetramethylpyrazine, ascorbic acid, chondroitin sulphate, glucosamine sulphate) were able to reduce the deleterious effects of glycerol exposure when examination of membrane integrity took place on a delayed time frame. The use of additive compounds to reduce cryoprotectant toxicity in articular cartilage may help improve cell recovery after cryopreservation.

Insights into the Action Mechanisms of Traditional Chinese Medicine in Osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by articular cartilage destruction, synovial inflammation, and osteophyte formation. No effective treatments are available. The current pharmacological medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics, accompanied by possible adverse effects, might ameliorate OA symptoms. But they do not arrest the progression of OA. Traditional Chinese medicine (TCM) provides medical value by modification of disease and symptoms in OA. Valuable work on exploring TCM merits for OA patients has been investigated using modern technologies, although the complicated interacting network among the numerous components indicates the uncertainty of target specification. This review will provide an overview of the action mechanism of TCM in the last 5 years, discussing the TCM activities of anti-inflammation, antiapoptosis, antioxidation, anticatabolism, and proliferation in OA. TCM is a proposed medical option for OA treatment.

SGTB Promotes the Caspase-Dependent Apoptosis in Chondrocytes of Osteoarthritis

The purpose of this study is to investigate the expression of small glutamine-rich tetratricopeptide repeat (TPR)-containing β (SGTB) in articular cartilage of osteoarthritis (OA) and analyze the relationship between SGTB and chondrocyte apoptosis. We established an OA rat model by the meniscal/ligamentous injury (MLI) modeling method and observed the expression of SGTB in articular cartilage by immunohistochemistry and RT-PCR. Human SW1353 chondrosarcoma cells were treated with interleukin-1β (IL-1β) to mimic the OA-like chondrocyte injury in vitro, and Western blot was employed to examine the IL-1β-induced expression of SGTB and active caspase-3. The co-localization of SGTB and active caspase-3 was confirmed by immunofluorescence. We knocked down SGTB expression by RNA interference (RNAi) and overexpressed SGTB by plasmid transfection. Western blot was carried out to detect the knockdown/overexpressing efficiency of SGTB and evaluate its effects on IL-1β-stimulated expression of active caspase-3 in SW1353 cells. Annexin V/propidium iodide staining was used to detect chondrocyte apoptosis. Then, Western blot was carried out to examine the IL-1β-induced expression of Hsp70 and evaluate SGTB effects on IL-1β-stimulated expression of Hsp70 in SW1353 cells. SGTB expression was significantly up-regulated in articular cartilage of OA rat model. IL-1β stimulation increased the expression of SGTB and active caspase-3 in SW1353 cells. SGTB co-localized with active caspase-3 in IL-1β-treated SW1353 cells. SGTB inhibition significantly reduced IL-1β-stimulated expression of active caspase-3 in SW1353 cells. In line with this, overexpressing SGTB via Myc-SGTB transfection increased the active caspase-3 level in IL-1β-stimulated SW1353 cells. Moreover, flow cytometry assay demonstrated that SGTB knockdown alleviated IL-1β-induced apoptosis, but it was increased in SW1353 cells that overexpressed SGTB. Overexpressing SGTB via Myc-SGTB transfection decreased the Hsp70 level in IL-1β-stimulated SW1353 cells. Our results suggested that SGTB positively regulate the activation of caspase-3 by negatively regulating the activity of Hsp70 and might promote chondrocyte apoptosis in OA. This study may provide a novel insight into the pathophysiology of OA and a potential therapeutic target for its treatment.

Efficacy of Ligustrazine Injection as Adjunctive Therapy for Angina Pectoris: A Systematic Review and Meta-Analysis

Background

In the past decades, a large number of randomized controlled trials (RCTs) on the efficacy of ligustrazine injection combined with conventional antianginal drugs for angina pectoris have been reported. However, these RCTs have not been evaluated in accordance with PRISMA systematic review standards. The aim of this study was to evaluate the efficacy of ligustrazine injection as adjunctive therapy for angina pectoris.

Material/Methods

The databases PubMed, Medline, Cochrane Library, Embase, Sino-Med, Wanfang Databases, Chinese Scientific Journal Database, Google Scholar, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and the Chinese Science Citation Database were searched for published RCTs. Meta-analysis was performed on the primary outcome measures, including the improvements of electrocardiography (ECG) and the reductions in angina symptoms. Sensitivity and subgroup analysis based on the M score (the refined Jadad scores) were also used to evaluate the effect of quality, sample size, and publication year of the included RCTs on the overall effect of ligustrazine injection.

Results

Eleven RCTs involving 870 patients with angina pectoris were selected in this study. Compared with conventional antianginal drugs alone, ligustrazine injection combined with antianginal drugs significantly increased the efficacy in symptom improvement (odds ratio [OR], 3.59; 95% confidence interval [CI]: 2.39 to 5.40) and in ECG improvement (OR, 3.42; 95% CI: 2.33 to 5.01). Sensitivity and subgroup analysis also confirmed that ligustrazine injection had better effect in the treatment of angina pectoris as adjunctive therapy.

Conclusions

The 11 eligible RCTs indicated that ligustrazine injection as adjunctive therapy was more effective than antianginal drugs alone. However, due to the low quality of included RCTs, more rigorously designed RCTs were still needed to verify the effects of ligustrazine injection as adjunctive therapy for angina pectoris.

Protective effect of ligustrazine on lumbar intervertebral disc degeneration of rats induced by prolonged upright posture

Most chronic low back pain is the result of degeneration of the lumbar intervertebral disc. Ligustrazine, an alkaloid from Chuanxiong, reportedly is able to relieve pain, suppress inflammation, and treat osteoarthritis and it has the protective effect on cartilage and chondrocytes. Therefore, we asked whether ligustrazine could reduce intervertebral disc degeneration. To determine the effect of ligustrazine on disc degeneration, we applied a rat model. The intervertebral disc degeneration of the rats was induced by prolonged upright posture. We found that pretreatment with ligustrazine for 1 month recovered the structural distortion of the degenerative disc; inhibited the expression of type X collagen, matrix metalloproteinase (MMP)-13, and MMP3; upregulated type II collagen; and decreased IL-1β, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) expression. In conclusion, ligustrazine is a promising agent for treating lumbar intervertebral disc degeneration disease.

Protection of ginsenoside Rg1 on chondrocyte from IL-1β-induced mitochondria-activated apoptosis through PI3K/Akt signaling

Chondrocyte apoptosis is closely related to the development and progression of osteoarthritis. Ginsenoside Rg1 protects cells by antagonizing apoptosis. This study aimed to investigate the protective effect of Rg1 on interleukin 1β (IL-1β)-induced chondrocyte apoptosis and the underlying molecular mechanisms. Chondrocytes were harvested from the joints of 1-week-old Sprague-Dawley rats. After treated with 10 μg/mL Rg1 for 2 h, the chondrocytes were cultured with 10 ng/mL IL-1β to induce cytotoxicity. Cell viability was assessed with MTT assays. Annexin V/propidium iodide staining and terminal deoxynucleotidyl transferase dUTP nick-end labeling were used to detect chondrocyte apoptosis. The contents of total Akt, phosphorylated Akt (p-Akt), Bcl-2, Bax, and cytochrome C (Cyt c) were determined by Western blotting assay. A quantitative colorimetric assay was used to determine caspase-3 activity. Our present findings have shown that pre-treatment of chondrocytes with Rg1 reduces IL-1β induced cytotoxicity/apoptosis. Rg1 pretreatment also decreases the activity of IL-1β that reduces expression of Bcl-2 and level of p-Akt, and increases Bax activity, Cyt c release, and caspase-3 activation. It also reverses the activity of IL-1β that reduces the expression of tissue inhibitor of metalloproteinase-1 expression and increased the synthesis of matrix metalloproteinase-13, with the net effect of inhibiting extracellular matrix degradation. These results indicate that Rg1 may protect chondrocytes from IL-1β-induced apoptosis via the phosphatidylinositol 3-kinase/protein kinase B signaling pathway, through preventing caspase-3 release.

Ligusticum chuanxiong Hort: a review of chemistry and pharmacology

CONTEXT

Ligusticum chuanxiong Hort (LC; Umbelliferae) is an effective medical plant, which has been extensively applied for many years to treat various diseases with other Chinese herbal medicines. Although a considerable amount of scientific research was reported on LC in the last decade, it is currently scattered across various publications. The present review comprises the chemical and pharmacological research on LC in the last decade.

OBJECTIVE

The objective of this review is to bring together most of the scientific research available on LC and evaluate its effects and mechanisms.

METHODS

The information for 82 cases included in this review was compiled using major databases such as Medline, Elsevier, Springer, Pubmed, and Scholar.

RESULTS

The compounds contained in LC can be divided into five kinds, essential oil (EO), alkaloids, phenolic acids, phthalide lactones, and other constituents. A great deal of pharmacological research has been done, which mainly focuses on cardiovascular and cerebrovascular effects, antioxidation, neuroprotection, antifibrosis, antinociception, antiinflammation, and antineoplastic activity.

CONCLUSION

A large number of pharmacological and chemical studies during the last 10 years have demonstrated the vast medicinal potential of LC. It is still very clear that LC is a plant with widespread use now and also with extraordinary potential for the future. The documents strongly support the view that LC has beneficial therapeutic properties and indicates its potential as an effective adaptogenic herbal remedy.