Confirmation of pain-related neuromodulation mechanism of Bushen Zhuangjin Decoction on knee osteoarthritis.

ETHNOPHARMACOLOGICAL RELEVANCE: Bushen Zhuangjin Decoction (BZD) are an herbal compound commonly used to treat osteoarthritis (OA) in China. AIM OF THE STUDY: This study aimed to verify the mechanism of Bushen Zhuangjin Decoction in relieving the pain of knee osteoarthritis. MATERIALS AND METHODS: Network pharmacology evaluation was used to discover the potential targets of BZD to relieve pain in KOA. The therapeutic effects of BZD treatment on KOA pain using histomorphology, behavioral assessments, suspension chip analysis, and ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS) assays. The functional magnetic resonance imaging was used to explore the effects of BZD treatment on brain function associated to KOA. RESULTS: Network pharmacological analysis revealed the association between the analgesic effect of BZD on KOA and the pain signaling neurotransmitter 5-HT. Subsequently, we conducted experiments to verify the therapeutic effect of BZD on pain in KOA animal models. Behavioral tests demonstrated that the pain threshold of knee osteoarthritis rats decreased in PWT and PWL, but BZD was able to increase the pain threshold. Histopathological staining indicated thinning of the cartilage layer and sparse trabeculae in the subchondral bone. Suspension chip analysis revealed a significant increase in pro-inflammatory factors of IL-1α, IL-5, IL-12, IL-17A, RANTES, TNF-α and M-CSF in KOA, along with a significant decrease in anti-inflammatory factor of IL-13. However, BZD treatment decreased the expression of pro-inflammatory factors and increased the content of anti-inflammatory factor. UHPLC-MS/MS analysis showed a significant decrease in the serum levels of GABA, E, GSH, Kyn, Met, and VMA in KOA, which were significantly increased by BZD. Conversely, the serum levels of TrpA, TyrA, Spd, and BALa were significantly increased in KOA and significantly decreased by BZD. ELISA and Western blot analysis showed increased expression of subchondral bone pain-related neuropeptides SP, CGRP, TH, NPY, VEGFA, 5-HT3 in KOA, which were decreased in BZD. Functional magnetic resonance imaging demonstrated that BZD exerts its therapeutic effect on KOA by modulating the activity and functional connections of the cortex, hypothalamus, and hippocampus. CONCLUSIONS: This study confirmed the significant role of pain-related neuromodulation mechanisms in the analgesic therapy of BZD and provides a theoretical foundation for using BZD as a traditional Chinese medical treatment for KOA pain.

Tougu Xiaotong capsules may inhibit p38 MAPK pathway-mediated inflammation: In vivo and in vitro verification.

ETHNOPHARMACOLOGICAL RELEVANCE: Tougu Xiaotong capsules (TXC) are an herbal compound commonly used to treat osteoarthritis (OA) in China. AIM OF THE STUDY: We attempted to verify TXC's therapeutic effects and mechanisms related to the p38 mitogen-activated protein kinase (MAPK) pathway in vivo and in vitro. MATERIALS AND METHODS: TXC's therapeutic effects were assessed by observing cartilage degeneration and inflammatory factors in a modified Hulth's model (in vivo) and a lipopolysaccharides (LPS)-exposed cellular model (in vitro). The expression of biomarkers related to p38 MAPK pathway-mediated inflammation was also investigated. RESULTS: TXC treatment reversed cartilage degeneration related biomarkers (ADAMTS 4, ADAMTS 5, Col I, Col V, MMP 3, MMP 9, and MMP 13) and inflammation factors (IL-1ß, TNF-α, and IL-6) in both the animal and cellular OA models. Expression of p-p38 MAPK was downregulated following TXC administration, and changes to microRNAs in the cellular models were recovered. These results indicated that the p38 MAPK pathway-related mechanism may involve therapeutic effects of TXC. CONCLUSIONS: This study verified TXC's efficacy to treat OA in vivo and in vitro and suggests that p38 MAPK pathway-related mechanisms may be involved in TXC's therapeutic effects.

[Effect of electroacupuncture at Wnt/ß-catenin signaling pathway on inhibiting cartilage degeneration in rats with knee osteoarthritis].

OBJECTIVE: To explore the action mechanism of electroacupuncture (EA) for knee osteoarthritis (KOA) based on Wnt/beta-catenin (Wnt/ß-catenin) signaling pathway. METHODS: Ten rats were randomly selected into a sham-operation group among 50 male 2-month-old SD rats, and the KOA model was established in the remaining 40 rats by modified Hulth method. Four weeks after the model establishment, the rats were randomly divided into a model group, an experimental A group, an experimental B group and an experimental C group, 10 rats in each group. The rats in the sham-operation group and model group did not receive any intervention. The rats in the experimental A group were treated with EA at "Neixiyan" (EX-LE 4) and "Dubi"(ST 35) for 15 min. The rats in the experimental B group were treated with EA at "Neixiyan" (EX-LE 4) and "Dubi"(ST 35) for 30 min. The rats in the experimental C group were treated with EA at non-acupoint for 15 min. EA intervention was given once a day, five times a week, and totally 12-week treatment was given. After 12 weeks, the knee cartilage tissues were stained and the morphological changes were observed under light microscopy; the severity of cartilage degeneration was evaluated by modified Mankin's score; the content of interleukin-1ß (IL-1ß) in synovium tissues was detected by ELISA method; the content of Wnt-4, ß-catenin and matrix metalloprotein-13 (MMP-13) in cartilage tissues was detected by Western blot method. RESULTS: Compared with the sham-operation group, in the model group the morphology and structure of cartilage were disordered, the number of cells was significantly reduced, the matrix was decontaminated and tidal line was incomplete; the Mankin's score was significantly increased (P<0.01), the content of IL-1ß in synovium tissues were significantly increased (P<0.01), and the expressions of Wnt-4, ß-catenin and MMP-13 at protein level were significantly increased (P<0.01). Compared with the model group, in the experimental A group and experimental B group the morphology and structure of cartilage were more orderly, the number of cells was increased, the matrix staining was deepened and the tidal line was more complete; Mankin's scores were decreased significantly (P<0.01); the contents of IL-1ß in synovium tissues were decreased significantly (P<0.01), and the expressions of Wnt-4, ß-catenin and MMP-13 at protein level were decreased significantly (P<0.01). Compared with the model group, no improvement was observed in the experimental C group. Compared with the experimental A group, in the experimental C group the morphology and structure of cartilage were disordered, the number of cells was significantly reduced, the matrix was decontaminated and the tidal line was incomplete; Mankin's score was significantly increased (P<0.01), the content of IL-1ß in synovium tissues was significantly increased (P<0.01), and the expressions of Wnt-4, ß-catenin and MMP-13 at protein level were significantly increased (P<0.01). The morphological structure of cartilage in the experimental B group was similar to that in the experimental A group, and there was no significant difference in Mankin's score, IL-1ß content in synovium tissues and the expressions of Wnt-4, ß- catenin and MMP-13 at protein level between the two groups (P>0.05). CONCLUSION: EA at "Neixiyan" (EX-LE 4) and "Dubi"(ST 35) may reduce the expression of MMP-13 and the production of inflammatory factor IL-1ß through Wnt/ß-catenin signaling pathway, thus inhibit the degradation of cartilage matrix and the apoptosis of chondrocyte, and improve the morphology and structure of cartilage.

An in vitro validation of the therapeutic effects of Tougu Xiaotong capsule on tunicamycin-treated chondrocytes.

ETHNOPHARMACOLOGICAL RELEVANCE: Tougu Xiaotong capsule (TXC) is a Chinese herbal compound that belongs to a range of Chinese herbs functioning as 'kidney invigorators and liver softeners' commonly used to treat osteoarthritis (OA) in China. AIMS OF THE STUDY: The aims of the present study are to confirm the therapeutic effects of TXC in an OA cell model and to determine the mechanisms involved in such effects. MATERIALS AND METHODS: A tunicamycin (Tm)-exposed OA cell model was employed, and the effects of TXC were confirmed by observing cell viability and apoptosis. The reduced cell viability and increased apoptosis caused by Tm were improved by TXC, confirming the cellular protection of TXC. We then investigated the expression of biomarkers related to the endoplasmic reticulum (ER) stress pathway, including microRNA-211 (miR-211), a regulator in the ER stress pathway. RESULTS: Downregulation of X-box binding protein 1 (Xbp-1) and miR-211 expression following Tm administration was reversed by TXC. Moreover, the upregulation by Tm of the expression levels of binding immunoglobulin protein, Xbp-1, activating transcription factor 4, C/EBP-homologous protein, Caspase-9 and Caspase-3 was downregulated by TXC. These results indicated that the ER stress pathway-related mechanism may play a potential role in the therapeutic effects of TXC. CONCLUSIONS: The present study provides evidence of the therapeutic effects of TXC at the cell level and describes a cellular model for establishing the mechanisms of the effects of TXC used in the treatment of OA.

Tougu Xiaotong capsule exerts a therapeutic effect on knee osteoarthritis by regulating subchondral bone remodeling.

Previous studies have shown that Tougu Xiaotong capsule (TGXTC) has therapeutic effects on knee osteoarthritis (OA) through multiple targets. However, the mechanisms of action underlying its regulation of subchondral bone reconstruction remain unclear. In this study, we investigated the effects of TGXTC on subchondral bone remodeling. Eighteen six-month-old New Zealand white rabbits of average sex were randomly divided into the normal, model and TGXTC groups. The rabbit knee OA model was induced by a modified Hulth's method in the model and TGXTC groups, but not the normal group. Five weeks postoperatively, intragastric administration of TGXTC was performed for four weeks. After drug administration, the medial femoral condyle and tibia were prepared for observation of cartilage histology via optical microscopy and micro-computed tomography, the serum was collected for biochemical parameters assay and the subchondral bone isolated from the lateral femoral condyle was collected for detection of IL-1ß and TNF-α mRNA and protein by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. The results showed that treatment with TGXTC significantly mitigated cartilage injury and subchondral bone damage, improved the parameter of subchondral trabecular bone, decreased alkaline phosphatase and tartrate-resistant acid phosphatase activity, and significantly reducing the osteoprotegerin/receptor activator of nuclear factor-κB ligand ratio, reduced the expression of IL-1ß and TNF-α mRNA and protein. These results suggest that TGXTC could delay the pathological development of OA by regulating subchondral bone remodeling through regulation of bone formation and bone resorption and its relating inflammatory factors, and this may partly explain its clinical efficacy in the treatment of knee OA.

Sirt1/Foxo Axis Plays a Crucial Role in the Mechanisms of Therapeutic Effects of Erzhi Pill in Ovariectomized Rats.

Background. Erzhi pill (EZP), a traditional Chinese herbal formula, has been widely used to treat postmenopausal osteoporosis (PMOP) in China. However, its molecular mechanisms remain unclear. The aim of the present study is to investigate the antiosteoporotic effect of EZP on an ovariectomized rat model of PMOP. We performed the biomarkers of bone metabolism disorder, bone morphology, bone mineral density (BMD), and bone biomechanics to confirm the successful establishment of the PMOP model. We then investigated the expression of biomarkers related to the Sirt1/Foxo axis. We also examined microRNA-132 (miR-132), a regulator in the Sirtuin1 (Sirt1) expression. The bone metabolism disorder, bone morphology, BMD, and bone biomechanics in ovariectomized rats were improved by EZP administration. The antiosteoporotic effect of EZP was confirmed. We also found that the expressions of Sirt1, Runx2, Foxo1, and Foxo3a were downregulated in ovariectomized rats, while being then upregulated by EZP administration. And the expression of PPAR-γ and miR-132 was upregulated in ovariectomized rats and then downregulated by EZP administration. These results provided evidence that Sirt1/Foxo axis related mechanism may play a crucial role in the therapeutic effects of EZP, indicating that Sirt1/Foxo axis can be considered as a potential therapeutic target for PMOP in the future.

Psoralen promotes the expression of cyclin D1 in chondrocytes via the Wnt/ß-catenin signaling pathway.

Psoralen (PSO), the active ingredient of Fructus Psoraleae (FP) the dried ripe fruit of Psoralea corylifolia L., has been commonly used in traditional Chinese medicine (TCM) for the treatment of osteoarthritis (OA). We found that PSO activates cartilaginous cellular functions of rat chondrocytes in vitro. However, the effect of PSO on chondrocyte proliferation and the precise mechanisms involved remain to be elucidated. We investigated the effects of PSO on chondrocytes isolated from Sprague­Dawley (SD) rats and evaluated involvement of the Wnt/ß-catenin signaling pathway. The viability of chondrocytes treated with PSO was increased in a dose- and time-dependent manner, as assessed by MTT assay. We found that the gene expression and protein levels of Wnt-4, Frizzled-2, ß-catenin and cyclin D1 in the PSO-treated chondrocytes were significantly upregulated, while the gene expression and protein level of glycogen synthase kinase-3ß (GSK-3ß) were downregulated, compared with the untreated chondrocytes. By immunofluorescence, we also found that PSO induced ß-catenin nuclear translocation. Importantly, the expression of ß-catenin and cyclin D1 was partly inhibited by Dickkopf-1 (DKK-1), an inhibitor of the Wnt/ß-catenin signaling pathway. Additionally, Col-II expression in chondrocytes was increased after treatment with PSO. Taken together, these results indicate that PSO promotes chondrocyte proliferation by activating the Wnt/ß-catenin signaling pathway, and it may play an important role in the treatment of OA.

Electroacupuncture serum inhibits TNF­α­mediated chondrocyte inflammation via the Ras­Raf­MEK1/2­ERK1/2 signaling pathway.

The Ras­Raf­mitogen­activated protein kinase kinase (MEK)1/2­extracellular signal­regulated kinase (ERK)1/2 signaling pathway contributes to the release of chondral matrix­degrading enzymes and accelerates the degradation of articular cartilage. Electroacupuncture (EA) treatment has been widely used for the treatment of osteoarthritis (OA); however, the mechanism underlying the effects of EA on OA remains unclear. Therefore, the present study evaluated the anti­inflammatory effects and potential underlying mechanisms of EA serum (EAS) on tumor necrosis factor (TNF)­α­mediated chondrocyte inflammation. A total of 30 Sprague Dawley rats were randomly divided into three groups: The blank group; experimental group I, which received 15 min of EA treatment; and experimental group II, which received 30 min of EA treatment. Subsequently, serum samples were obtained. Chondrocytes were isolated from the knee cartilage of Sprague Dawley rats, and were identified using collagen type II immunohistochemistry. TNF­α­treated chondrocytes were used as a cell model, and subsequently the cells were treated with EAS from each group for various durations. The results demonstrated that EAS treatment significantly promoted the viability and inhibited the apoptosis of TNF­α­treated chondrocytes. In addition, interleukin (IL)­1ß concentration was significantly increased in the model group compared with in the control group, whereas EAS significantly reduced IL­1ß concentration in TNF­α­treated chondrocytes. Furthermore, the protein expression levels of Ras, Raf and MEK1/2 were reduced in the EAS groups compared with in the model group. EAS also significantly inhibited the phosphorylation of ERK1/2, and the expression of downstream regulators matrix metalloproteinase (MMP)­3 and MMP­13. In conclusion, these results indicated that EAS may inhibit TNF­α­mediated chondrocyte inflammation via the Ras­Raf­MEK1/2­ERK1/2 signaling pathway in vitro, thus suggesting that EAS may be considered a potential therapeutic strategy for the treatment of OA.

Cibotium barometz polysaccharides stimulate chondrocyte proliferation in vitro by promoting G1/S cell cycle transition.

Cibotium barometz polysaccharides (CBPS) are one of the most important bioactive components extracted from the Cibotium barometz plant, which belongs to the Dicksoniaceae family. It has been widely used for the treatment of orthopedic diseases in traditional Chinese medicine. However, the molecular mechanisms behind the therapeutic effects of CBPS remain to be clarified. In the present study, the concentration of CBPS was detected by phenol-vitriol colorimetry. Furthermore, the effects stimulated by CBPS on the viability and G1/S cell cycle transition in primary chondrocytes from Sprague-Dawley rats were investigated. A cell viability assay demonstrated that chondrocyte proliferation may be enhanced by CBPS in a dose­ and time­dependent manner. The mechanism underlying the promotion of chondrocyte cell cycle was suggested to involve the stimulation of G1 to S phase transition. To further confirm the results, reverse transcription­quantitative polymerase chain reaction and western blot analyses were used to detect the expression of mRNA and protein levels of cyclin D1, cyclin­dependent kinase 4 and retinoblastoma protein. The results suggested that CBPS may stimulate chondrocyte proliferation via promoting G1/S cell cycle transition. Since osteoarthritis is characterized by deficient proliferation in chondrocytes, the present study indicates that CBPS may potentially serve as a novel method for the treatment of osteoarthritis.

Protective effects of the Tougu Xiaotong capsule on morphology and osteoprotegerin/nuclear factor-κB ligand expression in rabbits with knee osteoarthritis.

The imbalance of subchondral bone remodeling is a common pathological feature in the progression of osteoarthritis. In the current study, using a rabbit model of knee osteoarthritis, the effects of the Tougu Xiaotong capsule (TGXTC) on the cartilage and subchondral bone were investigated. In addition, osteoprotegerin (OPG), an inducer of bone formation, and receptor activator of nuclear factor­κB ligand (RANKL), a regulator of bone resorption in the subchondral bone, were assessed, in order to further explore the protective role of TGXTC in subchondral bone remodeling. The rabbit model of knee osteoarthritis, which was induced by a modified version of Hulth's method, was treated with TGXTC or glucosamine hydrochloride for 4 or 8 weeks. Subsequently, the tibia and femur were harvested for observation of cartilage histology, and the subchondral bone was observed by scanning electron microscopy. The expression levels of OPG and RANKL at the gene and protein levels were determined by reverse transcription­quantitative polymerase chain reaction and western blotting. TGXTC and glucosamine hydrochloride were identified to mitigate cartilage injury, reduce trabecular number and thickness and accelerate trabecular separation. It was additionally observed that the level of OPG mRNA and protein expression was reduced, and the RANKL mRNA and protein expression level was increased, in addition to the observation of a lower OPG/RANKL ratio in the TGXTC and hydrochloride groups. Taken together, these results suggest that TGXTC may mitigate cartilage injury and subchondral sclerosis, thus delaying the pathological development of osteoarthritis. This is suggested to be mediated partly through the reduction of OPG expression and increase of RANKL expression, which reduces the OPG/RANKL ratio, suppressing excessive bone formation.

Protective effects of Tougu Xiaotong capsule on tumor necrosis factor-α-injured UMR-106 cells.

Tumor necrosis factor-α (TNF-α) plays an important role in the abnormal metabolism of osteoblasts (OBs), which leads to subchondral bone (SB) alterations in osteoarthritis. In the present study, Tougu Xiaotong capsule (TXC), a traditional Chinese medicine, was used to treat TNF-α-injured OB-like cells. The cellular viability, mortality and ultramicroscopic morphology were evaluated. Thereafter, the activity of alkaline phosphatase (ALP), secretion of osteocalcin (OCN) and mineralization of nodules were analyzed. The results showed that TXC treatment significantly promoted cell proliferation, reduced cellular mortality and improved cellular ultrastructure, particularly that of the endoplasmic reticulum and nucleus. These data indicate that TXC is able to promote cell growth, as well as prevent inflammation in OB-like cells. Furthermore, the activity of ALP, secretion of OCN and mineralization of nodules were accelerated, and the calcium content of the TNF-α-injured OB-like cells was promoted by TXC treatment. These results indicate that TXC protected the OB-like cells from TNF-α-induced injuries. This may be a potential mechanism through which TXC regulates SB remodeling in the clinical treatment of osteoarthritis.

Effect of serum from postmenopausal women with osteoporosis exhibiting the Kidney-Yang deficiency pattern on bone formation in an hFOB 1.19 human osteoblastic cell line.

The aim of the present study was to investigate the underlying mechanism of the Kidney-Yang deficiency (KYD) pattern of osteoporosis in postmenopausal women of a certain age range by comparing the effect of serum from postmenopausal women with osteoporosis exhibiting the KYD pattern with that of serum from postmenopausal women without osteoporosis on bone formation in an hFOB 1.19 human osteoblastic cell line. A random selection of 30 female, postmenopausal volunteers aged 60-70 years, including 15 cases without osteoporosis and 15 cases with the KYD pattern of osteoporosis, were enrolled at the Physical Examination Center of the Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine. Venous blood was extracted and the serum was separated. The hFOB 1.19 cells were treated with 10% KYD pattern-serum or control serum from postmenopausal women of the same age range without osteoporosis. It was found that the KYD pattern-serum significantly decreased the cell viability, activity of alkaline phosphatase and number of calcified nodules, as well as downregulated the expression of osteocalcin and osteoprotegerin (OPG) and upregulated that of receptor activator of nuclear factor κB ligand (RANKL) in the hFOB 1.19 cells. In addition, the present results showed that the concentrations of estradiol (E2), OPG and insulin-like factor-1 (IGF-1) in the KYD pattern-serum were lower than those in the control serum. In combination, these findings suggest that the downregulation of E2, OPG and IGF-1 in the KYD pattern-serum inhibits the OPG/RANKL system, leading to a decrease in bone formation in the hFOB 1.19 cells. This indicates that the alterations in E2, OPG and IGF-1 may account for the susceptibility of certain postmenopausal women to the KYD pattern of osteoporosis.

Bushen Zhuangjin decoction inhibits TM-induced chondrocyte apoptosis mediated by endoplasmic reticulum stress.

Chondrocyte apoptosis triggered by endoplasmic reticulum (ER) stress plays a vital role in the pathogenesis of osteoarthritis (OA). Bushen Zhuangjin decoction (BZD) has been widely used in the treatment of OA. However, the cellular and molecular mechanisms responsible for the inhibitory effects of BZD on chondrocyte apoptosis remain to be elucidated. In the present study, we investigated the effects of BZD on ER stress-induced chondrocyte apoptosis using a chondrocyte in vitro model of OA. Chondrocytes obtained from the articular cartilage of the knee joints of Sprague Dawley (SD) rats were detected by immunohistochemical staining for type Ⅱ collagen. The ER stress-mediated apoptosis of tunicamycin (TM)­stimulated chondrocytes was detected using 4-phenylbutyric acid (4­PBA). We found that 4­PBA inhibited TM-induced chondrocyte apoptosis, which confirmed the successful induction of chondrocyte apoptosis. BZD enhanced the viability of the TM-stimulated chondrocytes in a dose- and time-dependent manner, as shown by MTT assay. The apoptotic rate and the loss of mitochondrial membrane potential (ΔΨm) of the TM-stimulated chondrocytes treated with BZD was markedly decreased compared with those of chondrocytes not treated with BZD, as shown by 4',6-diamidino-2-phenylindole (DAPI) staining, Annexin V-FITC binding assay and JC-1 assay. To further elucidate the mechanisms responsible for the inhibitory effects of BZD on TM­induced chondrocyte apoptosis mediated by ER stress, the mRNA and protein expression levels of binding immunoglobulin protein (Bip), X­box binding protein 1 (Xbp1), activating transcription factor 4 (Atf4), C/EBP­homologous protein (Chop), caspase­9, caspase-3, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were measured by reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis. In the TM-stimulated chondrocytes treated with BZD, the mRNA and protein expression levels of Bip, Atf4, Chop, caspase-9, caspase-3 and Bax were significantly decreased, whereas the mRNA and protein expression levels of Xbp1 and Bcl-2 were significantly increased compared with the TM­stimulated chondrocytes not treated with BZD. Additionally, all our findings demonstrated that there was no significant difference between the TM­stimulated chondrocytes treated with BZD and those treated with 4­PBA. Taken together, our results indicate that BZD inhibits TM­induced chondrocyte apoptosis mediated by ER stress. Thus, BZD may be a potential therapeutic agent for use in the treatment of OA.

Duhuo Jisheng decoction inhibits endoplasmic reticulum stress in chondrocytes induced by tunicamycin through the downregulation of miR-34a.

Our previous study showed that Duhuo Jisheng decoction (DHJSD) inhibited chondrocyte apoptosis by the mitochondria-dependent signaling pathway. Endoplasmic reticulum (ER) stress is upstream of the mitochondria-dependent signaling pathway and has been shown to promote chondrocyte apoptosis that occurs in osteoarthritis (OA). The present study aimed to evaluate whether DHJSD inhibits the chondrocyte apoptosis by regulating ER stress. DHJSD enhanced the viability of tunicamycin (TM)­exposed chondrocytes, a model of ER stress-induced apoptosis, in a dose­ and time­dependent manner, as shown by MTT assay. The present results showed that DHJSD and sodium 4-phenylbutyrate (PBA), an ER stress inhibitor, reduced TM­induced chondrocyte apoptosis by 4',6-diamidino­2-phenylindole staining. To gain insight into the mechanisms of DHJSD that are responsible for enhancing the viability and inhibiting TM­induced chondrocyte apoptosis, the associated mRNA expressions and protein levels were detected by reverse transcription­polymerase chain reaction (RT­PCR) and western blot analysis, respectively. The results showed that the expression levels of Xbp1, Xbp1s and Bcl­2 were increased, and the expression levels of Bip, Atf4, Chop, Bax, caspase­9 and ­3 were decreased in the TM­exposed chondrocytes treated with DHJSD or PBA compared with that in the TM­exposed chondrocytes. To identify the possible mechanisms, the expression of miR­34a was examined by the TaqMan microRNA assay, and was downregulated in the TM­exposed chondrocytes treated with DHJSD or PBA compared with that in the TM-exposed chondrocytes. DHJSD inhibits ER stress in chondrocytes induced by exposure to TM by downregulating miR­34a, suggesting that DHJSD may be a potential therapeutic agent for OA.

Deciphering the underlying mechanisms of Diesun Miaofang in traumatic injury from a systems pharmacology perspective.

Diesun Miaofang (DSMF) is a traditional herbal formula, which has been reported to activate blood, remove stasis, promote qi circulation and relieve pain. DSMF holds a great promise for the treatment of traumatic injury in an integrative and holistic manner. However, its underlying mechanisms remain to be elucidated. In the present study, a systems pharmacology model, which integrated cluster ligands, human intestinal absorption and aqueous solution prediction, chemical space mapping, molecular docking and network pharmacology techniques were used. The compounds from DSMF were diverse in the clusters and chemical space. The majority of the compounds exhibited drug-like properties. A total of 59 compounds were identified to interact with 16 potential targets. In the herb-compound-target network, the majority of compounds acted on only one target; however, a small number of compounds acted on a large number of targets, up to a maximum of 12. The comparison of key topological properties in compound-target networks associated with the above efficacy intuitively demonstrated that potential active compounds possessed diverse functions. These results successfully explained the polypharmacological mechanism underlying the efficiency of DSMF for the treatment of traumatic injury as well as provided insight into potential novel therapeutic strategies for traumatic injury from herbal medicine.

Millimeter Wave Treatment Inhibits Apoptosis of Chondrocytes via Regulation Dynamic Equilibrium of Intracellular Free Ca (2+).

The molecular mechanisms of TNF-α-induced apoptosis of chondrocyte and the role of Ca(2+) mediating the effects of MW on TNF-α-induced apoptosis of chondrocytes remained unclear. In this study, we investigated the molecular mechanism underlying inhibiting TNF-α-induced chondrocytes apoptosis of MW. MTT assay, DAPI, and flow cytometry demonstrated that MW significantly increased cell activity and inhibited chromatin condensation accompanying the loss of plasma membrane asymmetry and the collapse of mitochondrial membrane potential. Our results also indicated that MW reduced the elevation of [Ca(2+)] i in chondrocytes by LSCM. Moreover, MW suppressed the protein levels of calpain, Bax, cytochrome c, and caspase-3, while the expressions of Bcl-2, collagen II, and aggrecan were increased. Our evidences indicated that MW treatment inhibited the apoptosis of chondrocytes through depression of [Ca(2+)] i . It also inhibited calpain activation, which mediated Bax cleavage and cytochrome c release and initiated the apoptotic execution phase. In addition, MW treatment increased the expression of collagen II and aggrecan of chondrocytes.

Bushen Zhuangjin Decoction promotes chondrocyte proliferation by stimulating cell cycle progression.

Bushen Zhuangjin Decoction (BZD), a well-known formulation in Traditional Chinese Medicine, has been widely used for the treatment of osteoarthritis (OA). Due to the poor intrinsic repair capacity of chondrocytes, promoting the proliferation of chondrocytes is an efficient treatment to delay the progression of cartilage degradation. The present study, therefore, focused on the effect of BZD on chondrocyte proliferation, exploring the mechanism of BZD on the inhibition of cartilage degradation. Chondrocytes isolated from the knee articular cartilage of Sprague Dawley rats were cultured and identified by type II collagen immunohistochemistry. It was found that BZD promoted chondrocyte viability in a dose- and time-dependent manner. To investigate if BZD promoted the chondrocyte viability by stimulating the cell cycle progression a flow cytometer was used, and the results showed that the percentage proportion of G0/G1 cells was significantly lower, and the percentage proportion of S cells was significantly higher, in treated cells compared with that in untreated cells. To gain insight into the mechanism underlying the effect of BZD on the cell cycle progression, the mRNA and protein expression of cyclin D1, cyclin-dependent kinase 4 (CDK4), CDK6 and p21 was measured by reverse transcription-polymerase chain reaction and western blotting, respectively. The mRNA and protein expression of cyclin D1, CDK4 and CDK6 in the BZD-treated chondrocytes was significantly upregulated, while the mRNA and protein expression of p21 was significantly downregulated, compared with that in the untreated chondrocytes. These results suggested that BZD promoted chondrocyte proliferation by accelerating G1/S transition, indicating that BZD is a potential therapeutic agent for the treatment of OA.

Tougu Xiaotong formula induces chondrogenic differentiation in association with transforming growth factor-ß1 and promotes proliferation in bone marrow stromal cells.

Indian hedgehog (Ihh), one of the hedgehog gene families, is indicated in the regulation of chondrocyte differentiation. Tougu Xiaotong formula (TXF), a traditional Chinese medicinal compound, has been used for the treatment of bone and joint disease. However, the underlying molecular mechanisms of TXF on the function of bone marrow stromal cells (BMSCs) remain unclear. In the present study, the affect of TXF on proliferation and chondrogenic differentiation was investigated in primary BMSCs from four­week­old Sprague Dawley rats. The cell viability in BMSCs treated with TXF was higher compared to the untreated cells. Additionally, the percentage of G(0)/G(1) phase cells was significantly decreased, whereas that of the S phase cells was significantly increased. Furthermore, following TXF treatment, cyclin D1, cyclin­dependent kinase 4 (CDK4) and CDK6 expression in BMSCs was significantly enhanced. The results showed that TXF had no cytotoxicity to BMSCs. To explore the effect of TXF on the differentiation in BMSCs, whether TXF induced chondrogenic differentiation of BMSCs by the regulation of Ihh signaling pathway was investigated. The protein expression of Ihh, Patched and Smoothened in the induction group were significantly increased when compared to those in the control group, and the highest protein level of Ihh was in the induction group that was treated with the combination of TXF and transforming growth factor­ß1 (TGF­ß1). In addition, TXF combined with TGF­ß1 significantly induced the protein expression of cartilage oligomeric matrix protein and collagen II compared to the TGF­ß1 group. Taken together, these results indicate that TXF promotes the proliferation via accelerating the G(1)/S transition, and induces chondrogenic differentiation in BMSCs by activation of the Ihh signaling pathway in association with TGF­ß1.

Duhuo Jisheng decoction treatment inhibits the sodium nitroprussiate­induced apoptosis of chondrocytes through the mitochondrial­dependent signaling pathway.

Chondrocyte apoptosis activated by the mitochondrial-dependent signaling pathway plays a crucial role in the cartilage degeneration of osteoarthritis. Duhuo Jisheng decoction (DHJSD), a herbal formula from traditional Chinese medicine, has been widely used for treating osteoarthritis (OA). However, the molecular mechanisms behind the therapeutic effect of DHJSD remain to be elucidated. In the present study, the effects of DHJSD on the mitochondrial-dependent signaling pathway in sodium nitroprussiate (SNP)-induced chondrocyte apoptosis were investigated. Chondrocytes, from the knee articular cartilage of Sprague Dawley rats, were identified by type II collagen immunohistochemistry. The chondrocytes, stimulated with or without SNP to induce apoptosis, were treated by DHJSD for various concentrations and times. The viability of SNP-induced chondrocytes treated with DHJSD was enhanced compared to SNP-induced chondrocytes in a dose- and time-dependent manner, as assessed by the MTT assay. The apoptosis of SNP-induced chondrocytes treated by DHJSD was significantly decreased compared to SNP-induced chondrocyte, as shown by 4',6-diamidino-2-phenylindole and Annexin V/propidium iodide staining. The mitochondrial membrane potential (∆Ψm) of SNP-induced chondrocytes treated by DHJSD was significantly decreased compared to SNP-induced chondrocyte, as shown by JC-1 staining. To understand the mechanism, the mRNA and protein levels of Bax, B-cell lymphoma 2 (Bcl-2), caspase-9 and caspase-3 were detected by reverse transcription­polymerase chain reaction and western blot analysis, respectively. In SNP-induced chondrocyte treated by DHJSD, the Bcl-2 expression was increased, whereas the expression of Bax, caspase-9 and caspase-3 was decreased compared to SNP-induced chondrocyte. Taken together, these results indicated that DHJSD inhibits the apoptosis of SNP-induced chondrocyte by the mitochondrial-dependent apoptotic pathway, and this may partly explain its therapeutic efficacy for OA.

Achyranthes bidentata polysaccharides activate the Wnt/ß-catenin signaling pathway to promote chondrocyte proliferation.

Achyranthes bidentata polysaccharides (ABPS) are the active components of Radix Achyranthis Bidentatae (AB), which has been extensively used in Traditional Chinese medicine (TCM) in the treatment of osteoarthritis (OA). Our previous study provided evidence that ABPS regulated the G1/S transition to promote chondrocyte proliferation. However, the precise mechanisms involved remain to be elucidated. In the present study, we aimed to investigate the effects of ABPS on the Wnt/ß­catenin signaling pathway in chondrocytes. Chondrocytes, obtained from the knee cartilage of Sprague-Dawley rats, were identified by type II collagen immunohistochemistry. ABPS upregulated the expression of Wnt-4, Frizzled-2, ß-catenin and cyclin D1, and downregulated the expression of glycogen synthase kinase 3ß (GSK-3ß), as shown by reverse transcription PCR (RT-PCR) and western blot analysis. Using immunofluorescence, we also found that ABPS induced ß-catenin nuclear translocation. Importantly, the expression of ß-catenin and cyclin D1 was partly inhibited by Dickkopf-1 (DKK-1), an inhibitor of the Wnt/ß-catenin signaling pathway. In addition, we found that ABPS increased the expression of type II collagen in chondrocytes. These results suggest that ABPS promote chondrocyte proliferation by activating the Wnt/ß-catenin signaling pathway.