Gallic acid ameliorates synovial inflammation and fibrosis by regulating the intestinal flora and its metabolites.

Gallic acid (GA) has been found by a large number of studies to have pharmacological effects such as antioxidant and anti-inflammatory properties. However, the underlying therapeutic mechanisms are not fully understood.. Studies have shown that altering the intestinal flora affects host metabolism and effectively mediates the development of synovitis. The aim of this study was to explore the pharmacological effects of GA in the treatment of synovial inflammation and anti-synovial fibrosis in knee osteoarthritis (KOA) and the underlying mechanisms by macrogenomics combined with off-target metabolomics. We established a synovitis model via in vivo and in vitro experiments to observe the effect of GA intervention on synovitis. Moreover, we collected serum and feces from rats and analyzed the changes in intestinal flora by macro-genome sequencing and the changes in metabolites in the serum by untargeted metabolomics. We found that GA reduced the levels of IL-1ß, IL-6, and TNF-α, and decreased the protein expression levels of α-SMA, TGF-ß, and Collagen I in synovial tissues and cells, and the composition and function of the intestinal flora were similarly altered. Combined with macrogenomic pathway enrichment analysis and metabolic pathway enrichment analysis, these findings revealed that GA impacts Bacteroidia and Muribaculaceae abundance, and via the following metabolic pathways: sphingolipid metabolism, glycerophospholipid metabolism, and arginine biology.to ameliorate synovial inflammation and fibrosis in KOA. The therapeutic effect of GA on KOA synovitis and fibrosis is partly attributed to the alleviation of metabolic disorder and the rebalancing of the intestinal flora. These results provides a rationale for the therapeutic application of GA in the treatment of synovitis.

Total glucosides of white paeony capsule alleviate articular cartilage degeneration and aberrant subchondral bone remodeling in knee osteoarthritis.

Knee osteoarthritis (KOA) is a prevalent degenerative joint disease that is primarily managed by improving the destroyed cartilage and reversing subchondral bone remodeling. Total glucosides of white paeony (TGP) capsule primarily contains extracts from the white peony root and has been shown to have various pharmacological effects, but its role in KOA still requires comprehensive evaluation. In this study, we aimed to investigate the protective effect of TGP on knee cartilage and subchondral bone, as well as elucidate the underlying molecular mechanisms. The effect of TGP on KOA progression was evaluated in the destabilization of the medial meniscus (DMM)-induced KOA model of mouse and interleukin (IL)-1ß-induced KOA model of primary mouse chondrocytes. In vivo and in vitro experiments demonstrated that TGP had a protective effect on the cartilage. Treatment with TGP could induce the synthesis of critical elements in the cartilage extracellular matrix and downregulate the synthesis of degrading enzymes in the extracellular matrix. Regarding the underlying mechanisms, TGP inhibited the phosphorylation and nuclear translocation of p65 by regulating the nuclear factor-kappa B (NF-κB) signaling pathway. In addition, TGP could reduce the secretion of IL-1ß, IL-6, and tumor necrosis factor-α (TNF-α). Moreover, it has a sustained effect on coupled subchondral bone remodeling through regulation of the OPG/RANKL/RANK pathway. In conclusion, TGP may protect articular cartilage by downregulating the NF-κB signaling pathway and may support coupled subchondral bone remodeling by regulating OPG/RANKL/RANK signaling pathway in the DMM-induced KOA model of mouse, suggesting a new therapeutic potential for KOA treatment.

The potential causal relationship between various lifestyles and depression: a univariable and multivariable Mendelian randomization study.

Background: Previous studies have shown that lifestyle was associated with depression. Thus, the aim of this study was to examine the causality between multiple lifestyles and depression by Mendelian randomization (MR) analysis. Methods: The single-nucleotide polymorphisms (SNPs) of depression, alcoholic drinks per week, sleeplessness or insomnia, body mass index (BMI), mood swings, weekly usage of mobile phone in the last 3 months, beef intake, cooked vegetable intake, and "smoking status: never" were acquired from the Integrative Epidemiology Unit Open genome-wide association study database. Causal effects of eight exposure factors and depression were investigated using MR-Egger, weighted median, inverse variance weighted (IVW), simple mode, and weighted mode, and results were primarily referred to IVW. Subsequently, univariable MR (UVMR) analysis was performed on eight exposure factors and depression, separately. In addition, sensitivity analysis, including heterogeneity test, horizontal pleiotropy, and leave-one-out (LOO) methods, was conducted to evaluate the stability of MR results. Furthermore, multivariable MR (MVMR) analysis was carried out. Results: UVMR analysis revealed that all eight exposure factors were causally associated with depression; alcoholic drinks per week, sleeplessness or insomnia, BMI, mood swings, weekly usage of mobile phone in the last 3 months, and cooked vegetable intake were risk factors, and beef intake and "smoking status: never" were protection factors. Heterogeneity tests revealed no heterogeneity for alcoholic drinks per week, sleeplessness or insomnia, mood swings, weekly usage of mobile phone in the last 3 months, and cooked vegetable intake. Meanwhile, there was no horizontal pleiotropy in UVMR, and LOO analysis verified that univariable analysis results were reliable. Moreover, MVMR analysis indicated that mood swings and weekly usage of mobile phone in the last 3 months were risk factors, and beef intake was a protection factor for depression when multiple factors occurred at the same time. Conclusion: Alcoholic drinks per week, sleeplessness or insomnia, BMI, mood swings, weekly usage of mobile phone in the last 3 months, and cooked vegetable intake were risk factors, and beef intake and "smoking status: never" were protection factors. In addition, mood swings, weekly usage of mobile phone in the last 3 months, and beef intake had a direct effect on depression when multiple factors occurred simultaneously.

NGF Signaling Exacerbates KOA Peripheral Hyperalgesia via the Increased TRPV1-Labeled Synovial Sensory Innervation in KOA Rats.

Objectives: Knee osteoarthritis (KOA) pain is caused by nociceptors, which are actually sensory nerve fiber endings that can detect stimuli to produce and transmit pain signals, and high levels of NGF in synovial tissue led to peripheral hyperalgesia in KOA. The purpose of this study is to investigate how sensory nerve fibers respond to the NGF/TrKA signal pathway and mediate the peripheral hyperalgesia in KOA rats. Methods: Forty SD male rats were randomly divided into 4 groups: normal, KOA, KOA + NGF, and KOA + siRNA TrKA. KOA model rats were induced by anterior cruciate ligament transection (ACLT). Mechanical and cold withdrawal thresholds (MWT and CWT) were measured 4 times in each group. The synovial tissues were harvested on day 28, and the expressions of NGF, TrKA, TRPV1, IL-1ß, and PGP9.5 were determined using western blot, qPCR, and immunofluorescence staining. The primary rat fibroblast-like synoviocytes (FLSs) and DRG cells were divided into 4 groups as in vivo. The expressions of NGF, TrKA, TRPV1, and CGRP in vitro were determined using western blot and qPCR. Results: KOA and intra-articular injection with NGF protein increased both mRNA and protein levels, not only TRPV1, PGP 9.5, and IL-1ß in the synovial tissue, but also TRPV1, PGP 9.5, and S100 in the DRG tissue, while above changes were partly reversed after siRNA TrKA intervention. Besides, siRNA TrKA could improve peripheral hyperalgesia and decreased the TRPV1 positive nerve fiber innervation in synovial tissue. The results in vitro were consistent with those in vivo. Conclusion: This study showed the activation of the NGF/TrKA signaling pathway in KOA promoted the release of pain mediators, increased the innervation of sensory nerve fibers in the synovium, and worsened peripheral hyperalgesia. It also showed increased TRPV1 positive sensory innervation in KOA was mediated by NGF/TrKA signaling and exacerbated peripheral hyperalgesia.

Protocatechuic aldehyde attenuates chondrocyte senescence via the regulation of PTEN-induced kinase 1/Parkin-mediated mitochondrial autophagy.

This study aimed to investigate whether the beneficial effects of PCA on chondrocyte senescence are mediated through the regulation of mitophagy. Chondrocyte senescence plays a significant role in the development and progression of knee osteoarthritis (OA). The compound protocatechuic aldehyde (PCA), which is abundant in the roots of Salvia miltiorrhiza, has been reported to have antioxidant properties and the ability to protect against cellular senescence. To achieve this goal, a destabilization of the medial meniscus (DMM)-induced mouse OA model and a lipopolysaccharide (LPS)-induced chondrocyte senescence model were used, in combination with PINK1 gene knockdown or overexpression. After treatment with PCA, cellular senescence was assessed using Senescence-Associated ß-Galactosidase (SA-ß-Gal) staining, DNA damage was evaluated using Hosphorylation of the Ser-139 (γH2AX) staining, reactive oxygen species (ROS) levels were measured using Dichlorodihydrofluorescein diacetate (DCFH-DA) staining, mitochondrial membrane potential was determined using a 5,5',6,6'-TETRACHLORO-1,1',3,3'-*. TETRAETHYBENZIMIDA (JC-1) kit, and mitochondrial autophagy was examined using Mitophagy staining. Western blot analysis was also performed to detect changes in senescence-related proteins, PINK1/Parkin pathway proteins, and mitophagy-related proteins. Our results demonstrated that PCA effectively reduced chondrocyte senescence, increased the mitochondrial membrane potential, facilitated mitochondrial autophagy, and upregulated the PINK1/Parkin pathway. Furthermore, silencing PINK1 weakened the protective effects of PCA, whereas PINK1 overexpression enhanced the effects of PCA on LPS-induced chondrocytes. PCA attenuates chondrocyte senescence by regulating PINK1/Parkin-mediated mitochondrial autophagy, ultimately reducing cartilage degeneration.

Casticin ameliorates osteoarthritic cartilage damage in rats through PI3K/AKT/HIF-1α signaling.

Knee osteoarthritis (KOA) is a chronic, disabling knee joint lesion in which degeneration and defects in articular cartilage are the most important features. Casticin (CAS) is a flavonoid extracted from the Chinese herb Vitex species that has anti-inflammatory and antitumor effects. The aim of this study was to investigate the therapeutic and mechanistic effects of CAS on cartilage damage in KOA. A KOA rat model was established by anterior cruciate ligament transection (ACLT), and cartilage morphological changes were assessed by histological analysis and micro-CT scans. Subsequently, chondrocytes were treated with 10 ng/mL IL-1ß to establish an OA model. CCK-8 assays and EdU assays were performed to assess the viability of CAS-treated chondrocytes. Western blotting, flow cytometry and Hoechst 33342/PI Double Stain were used to detect chondrocyte apoptosis. Western blotting, qRT‒PCR and ELISA were used to detect changes in inflammatory mediators. In addition, cartilage matrix-related indices were detected by Western blotting, qRT‒PCR and immunofluorescence (IF) analysis. Immunohistochemistry (IHC) and Western blotting were performed to detect the expression of p-PI3K, p-AKT and HIF-1α in vivo and in vitro. Micro-CT, pathological sections and related scores showed that CAS improved the alterations in bony structures and reduced cartilage damage and osteophyte formation in the ACLT model. In vivo, CAS attenuated IL-1ß-induced cartilage matrix degradation, apoptosis and the inflammatory response. In addition, CAS inhibited the expression of the PI3K/AKT/HIF-1α signaling pathway in the ACLT animal model and IL-1ß cell model. CAS may ameliorate cartilage damage in OA by inhibiting the PI3K/AKT/HIF-1α signaling pathway, suggesting that CAS is a potential strategy for the treatment of OA.

Clinical and Animal Studies of Waist and Knee Scraping Therapy for Knee Osteoarthritis.

BACKGROUND: Knee osteoarthritis (KOA) is a degenerative condition with knee pain as the main clinical manifestation. Scraping is one of the commonly used traditional Chinese medicine treatment methods, which activates blood circulation, removes blood stasis, reduces inflammation, and so on. Although scholars have proposed that the synergistic treatment of the waist and knee for KOA is superior to simple knee treatment, there is no relevant reference literature on the application of scraping therapy. Therefore, this study aims to explore the effectiveness and potential mechanisms of waist and knee scraping therapy for treating KOA through clinical and animal studies in order to promote its clinical application. OBJECTIVE: To explore the clinical efficacy of waist and knee scraping therapy in the treatment of KOA from clinical study and increase animal study on this basis to preliminarily explore its mechanism, providing an objective basis for better treatment of KOA. METHODS: The clinical study recruited 90 KOA patients and divided them into a control group, a knee scraping group, and a waist and knee scraping group using a random number table method. All patients were evaluated for clinical efficacy, the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), and Traditional Chinese Medicine Syndrome Score. The KOA rat model was established using the Hulth method. The rats were randomly divided into a control group, KOA group, waist scraping group, knee scraping group, and waist and knee scraping group. During the intervention process of rats, the pain sensitivity threshold was measured, and HE staining was performed on the synovium and cartilage. The protein and mRNA expression levels of TNF-α, IL- 1ß, IL-6, PGP9.5, SP and TRPA1, TRPV4, SP, and NGF were measured by Western blot and real-time PCR. RESULTS: In the clinical study, the clinical efficacy of the 2 scraping groups was significantly higher than that of the control group. The clinical efficacy of the waist and knee scraping group on the 60th day of treatment was significantly higher than that of the knee scraping group. In terms of improving WOMAC scores, all 3 groups had significance; The function and total score of the waist and knee scraping group on the 28th day of treatment, as well as the pain, function, and total score on the 60th day, were lower than those of the knee scraping group. In terms of improving pain while standing, pain when walking on flat ground, and total score, the scraping group had significant differences. The score of heavy limbs in the waist and knee scraping group was lower than that in the knee scraping group. In an animal study, during the 4th week after modeling, there were differences in the pain sensitivity threshold between the KOA group and the waist scraping group compared to the control group, while there were differences in the pain sensitivity threshold between the knee scraping group and the waist and knee scraping group compared to the KOA group. The expression levels of various proteins and genes in the KOA group and waist scraping group increased compared to the control group; The knee scraping group and the waist and knee scraping group were lower than those in the KOA group. CONCLUSION: Scraping therapy can significantly alleviate knee joint pain and stiffness, improve joint function, and improve clinical efficacy, and the short-term and long-term effects of waist and knee scraping therapy are more significant. The scraping therapy has a definite therapeutic effect on KOA rats, which can improve the threshold of cold hyperalgesia and mechanical hyperalgesia, and the waist and knee scraping therapy is more obvious. This may be related to reducing inflammatory reactions in synovial and ganglion tissues.