Inhibition of PI3K/Akt/NF-κB signaling by Aloin for ameliorating the progression of osteoarthritis: In vitro and in vivo studies

Metabolites of traditional Chinese medicine targeting PI3K/AKT signaling pathway for hypoglycemic effect in type 2 diabetes

Type 2 diabetes mellitus is a chronic metabolic disease characterized by insulin resistance, with high morbidity and mortality worldwide. Due to the tightly intertwined connection between the insulin resistance pathway and the PI3K/AKT signaling pathway, regulating the PI3K/AKT pathway and its associated targets is essential for hypoglycemia and the prevention of type 2 diabetes mellitus. In recent years, metabolites isolated from traditional Chinese medicine has received more attention and acceptance for its superior bioactivity, high safety, and fewer side effects. Meanwhile, numerous in vivo and in vitro studies have revealed that the metabolites present in traditional Chinese medicine possess better bioactivities in regulating the balance of glucose metabolism, ameliorating insulin resistance, and preventing type 2 diabetes mellitus via the PI3K/AKT signaling pathway. In this article, we reviewed the literature related to the metabolites of traditional Chinese medicine improving IR and possessing therapeutic potential for type 2 diabetes mellitus by targeting the PI3K/AKT signaling pathway, focusing on the hypoglycemic mechanism of the metabolites of traditional Chinese medicine in type 2 diabetes mellitus and elaborating on the significant role of the PI3K/AKT signaling pathway in type 2 diabetes mellitus. In order to provide reference for clinical prevention and treatment of type 2 diabetes mellitus.

Sipeimine ameliorates osteoarthritis progression by suppression of NLRP3 inflammasome-mediated pyroptosis through inhibition of PI3K/AKT/NF-κB pathway: An in vitro and in vivo study

Background

Osteoarthritis (OA) is a chronic and degenerative condition that persists and progresses over time. Sipeimine (Sip), a steroidal alkaloid derived from Fritillariae Cirrhosae Bulbus, has attracted considerable attention due to its exceptional anti-inflammatory, analgesic, antioxidant, and anti-cancer characteristics. However, Sip's effects on OA and its mechanism still need further research.

Methods

This study utilized network pharmacology to identify initial targets for Sip. Functional associations of Sip in OA were clarified through Gene Ontology (GO) enrichment analysis, bioinformatically analyzing a list of targets. Subsequently, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis assessed pathways linked to Sip's therapeutic efficacy in OA. Molecular docking techniques explored Sip's binding affinity with key targets. In vitro experiments assessed Sip's impact on lipopolysaccharide (LPS)-induced pro-inflammatory factors and its protective effects on collagen-II and aggrecan degradation within the extracellular matrix (ECM). Western blotting and fluorescence analyses were conducted to determine Sip-mediated signaling pathways. Moreover, in vivo experiments using a mouse OA model validated Sip's therapeutic efficacy.

Results

The results from network pharmacology revealed a total of 57 candidate targets for Sip in OA treatment. GO enrichment analysis demonstrated a robust correlation between Sip and inflammatory response, response to LPS and NF-κB-inducing kinase activity in OA. KEGG enrichment analysis highlighted the significance of NF-κB and PI3K-AKT pathways in Sip's therapeutic potential for OA. Furthermore, molecular docking results demonstrated Sip's robust binding affinity with p65 and PI3K. In vitro experiments demonstrated Sip's effectively suppressed the expression of pro-inflammatory factors induced by LPS, such as COX-2, iNOS, IL-1β, and IL-18. Besides, Sip counteracted the degradation of collagen-II and aggrecan within the ECM and the expression of MMP-13 and ADAMTS-5 mediated by LPS. The safeguarding effects of Sip were ascribed to its inhibition of PI3K/AKT/NF-κB pathway and NLRP3 inflammasome mediated pyroptosis. Additionally, in vivo experiments revealed that Sip could alleviate the subchondral remodeling, cartilage degeneration, synovitis as well as ECM degradation a mouse model of OA.

Conclusion

Sip exhibited potential in attenuating OA progression by suppressing the PI3K/AKT/NF-κB pathway, consequently inhibiting the activation of NLRP3 inflammasome and pyroptosis.

The translational potential statement

The translational potential of this articleThis study provides a biological rationale for the use of Sip as a potential candidate for OA treatment, provide a new concept for the cartilage targeted application of natural compounds.

From medical strategy to foodborne prophylactic strategy: Stabilizing dental collagen with aloin

Infectious oral diseases are longstanding global public health concerns. However, traditional medical approaches to address these diseases are costly, traumatic, and prone to relapse. Here, we propose a foodborne prophylactic strategy using aloin to safeguard dental collagen. The effect of aloin on the stability of dental collagen was evaluated by treating dentin with a solution containing aloin (0.1 mg/mL) for 2 min. This concentration is comparable to the natural aloin content of edible aloe. Furthermore, we investigated the mechanisms underlying the interactions between aloin and dentin collagen. Our findings, obtained through fluorescence spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy, Gaussian peak fitting, circular dichroism spectroscopy, and X-ray diffraction, revealed that aloin interacts with dental collagen through noncovalent bonding, specifically hydrogen bonding in situ. This interaction leads to a reduction in the distance between molecules and an increase in the proportion of stable α-helical chains in the dental collagen. The ultimate tensile strength and thermogravimetric analysis demonstrated that dental collagen treated with aloin exhibited improved mechanical strength and thermostability. Additionally, the release of hydroxyproline, cross-linked carboxy-terminal telopeptide of type I collagen, and C-terminal cross-linked telopeptide of type I collagen, along with weight loss, indicated an enhancement in the enzymatic stability of dental collagen. These findings suggest that aloin administration could be a daily, nondestructive, and cost-effective strategy for managing infectious oral diseases.

Rutaecarpine ameliorates osteoarthritis by inhibiting PI3K/AKT/NF‑κB and MAPK signalling transduction through integrin αVβ3

Osteoarthritis (OA) is a chronic progressive articular illness which commonly affects older‑aged adults, presenting with cartilage inflammation and degradation. Rutaecarpine (RUT) has been shown to exert promising anti‑inflammatory effects; however, the efficacy of RUT in the treatment of OA is debatable. The present study investigated the potential of RUT in alleviating OA in a mouse model. Treatment with RUT inhibited the inflammatory response and extracellular matrix degradation by suppressing process regulators in interleukin (IL)‑1β‑stimulated chondrocytes. Moreover, treatment with RUT in vitro upregulated the gene expression of anabolic agents, such as collagen type II, aggrecan and SRY‑box transcription factor 9, indicating that RUT contributed to cartilage repair. Additionally, flow cytometric assays, and the measurement of β‑galactosidase levels, autophagic flux and related protein expression revealed that RUT effectively attenuated IL‑1β‑induced chondrocyte apoptosis, senescence and autophagy impairment. In addition, bioinformatics analysis and in vitro experiments demonstrated that RUT protected cartilage by mediating the phosphoinositide‑3‑kinase (PI3K)/Akt/nuclear factor‑κB (NF‑κB) and mitogen‑activated protein kinase (MAPK) pathways. The ameliorative effects of RUT on IL‑1β‑stimulated chondrocytes were abrogated when siRNA was used to knock down integrin αVβ3. Furthermore, the results of immunohistochemical analysis and microcomputed tomography confirmed the in vivo therapeutic effects of RUT in mice with OA. On the whole, the present study demonstrates that RUT attenuates the inflammatory response and cartilage degradation in mice with OA by suppressing the activation of the PI3K/AKT/NF‑κB and MAPK pathways. Integrin αVβ3 may play a pivotal role in these effects.

Extracellular matrix in synovium development, homeostasis and arthritis disease

Extracellular matrix (ECM) is a three-dimensional network entity composed of extracellular macromolecules. ECM in synovium not only supports the structural integrity of synovium, but also plays a crucial role in regulating homeostasis and damage repair response in synovium. Obvious disorders in the composition, behavior and function of synovial ECM will lead to the occurrence and development of arthritis diseases such as rheumatoid arthritis (RA), osteoarthritis (OA) and psoriatic arthritis (PsA). Based on the importance of synovial ECM, targeted regulation of the composition and structure of ECM is considered to be an effective measure for the treatment of arthritis disease. This paper reviews the current research status of synovial ECM biology, discusses the role and mechanism of synovial ECM in physiological status and arthritis disease, and summarizes the current strategies for targeting synovial ECM to provide information for the pathogenesis, diagnosis and treatment of arthritis disease.

Stevioside protects primary articular chondrocytes against IL-1β-induced inflammation and catabolism by targeting integrin

Osteoarthritis (OA) is a common, progressive, and chronic disorder of the joints that is characterized by the inflammation and degradation of articular cartilage and is known to significantly impair quality of daily life. Stevioside (SVS) is a natural diterpenoid glycoside that has anti-inflammatory benefits. Hence, in the current research, it was hypothesized that SVS might exert anti-inflammatory effects on articular chondrocytes and alleviate cartilage degradation in mice with OA. The expression of inflammatory cytokines, like inducible nitric oxide synthase (iNOS), NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3), and cyclooxygenase-2 (COX-2) in chondrocytes after interleukin-1β (IL-1β) exposure, was inhibited by the pretreatment of SVS. As well, SVS inhibited the reduction of collagen II and sry-box transcription factor 9 (SOX9) in chondrocytes stimulated by IL-1β and suppressed the expression of MMP3 and MMP13. Further, after treatment with SVS, cell cytometry, autophagy flux, and related protein expression showed diminished cell apoptosis and reduced autophagy impairment. Moreover, SVS blocked the activation of phosphoinositide-3-kinase/Akt/nuclear factor-kappa beta (PI3K/Akt/NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways stimulated by IL-1β. This resulted in decreased cellular inflammation. In vivo experiments with intra-articular injections of SVS in mice with the DMM mouse model demonstrated a decrease in cartilage degradation and an improvement in subchondral bone remodeling. After the integrin αVβ3-related knockdown using siRNA, a reversed effect was observed on the anti-inflammatory, anabolic promoting, catabolic blocking, and NF-κB and MAPK signaling pathway inhibition of SVS on chondrocytes treated with IL-1β. The above findings highlighted that SVS blocked IL-1β, triggered an inflammatory response in mice chondrocytes, and prevented cartilage degradation in vivo through integrin αVβ3. This suggested that SVS might serve as a novel therapeutic option for OA.

Potential role of nutraceuticals via targeting a Wnt/β-catenin and NF-κB pathway in treatment of osteoarthritis

Osteoarthritis (OA) is a disease due to the aging of the articular cartilage, a post-mitotic tissue that stays functioning until primary homeostatic processes fail. Because of pain and disability, OA significantly influences national healthcare expenses and patient quality of life. It is a whole-joint illness characterized by inflammatory and oxidative signaling pathways and significant epigenetic alterations that cause cartilage extracellular matrix degradation. The canonical Wnt pathway (Wnt/β-catenin pathway) and nuclear factor kappa B (NF-κB) signaling pathways may function in joint tissues by modulating the activity of synovial cells, osteoblasts, and chondrocytes. However, finding innovative ways to treat osteoarthritis and get the joint back to average balance is still a struggle. Nutraceuticals are dietary supplements that promote joint health by balancing anabolic and catabolic signals. New therapeutic methods for OA treatment have been developed based on many research findings that show nutraceuticals have strong anti-inflammation, antioxidant, anti-bone resorption, and anabolic properties. For the treatment of osteoarthritis, we explore the possible involvement of nutraceuticals that target the Wnt/β-catenin and NF-κB pathways. PRACTICAL APPLICATIONS: In keeping with the aging population, osteoarthritis is becoming more widespread. In this extensive research, we studied the role of the Wnt/β-catenin and NF-κB pathway in OA formation and progression. Nutraceuticals that target these OA-related signaling pathways are a viable therapy option. Wnt/β-catenin and NF-κB signaling pathway are inhibited by polyphenols, flavonoids, alkaloids, and vitamins from the nutraceutical category, making them possible therapeutic drugs for OA therapy.

Intra-articular injection of placental mesenchymal stromal cells ameliorates pain and cartilage anabolism/catabolism in knee osteoarthritis

Background: Knee Osteoarthritis (kOA), the most common joint degenerative disorder, lacks effective therapeutics. Placenta-derived mesenchymal stromal cells (PMSCs) are effective in tissue repairing and generation, which have potential in treating kOA. This study aimed to determine the anti-kOA efficacy of PMSCs and to explore its action mode. Methods: Flow cytometry and three-line differentiation were performed for identification of PMSCs. In vivo, a rat kOA model established by anterior cruciate ligament transection (ACLT) surgery was used to evaluate the efficacy of PMSCs. Histopathological HE and SO staining with Osteoarthritis Research Society International scoring were conducted, and cartilage expressions of MMP13 and Col2 were measured by immunohistochemistry. Pain behavior parameters by mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL), were measured. In vitro, wound healing and cell immunofluorescence assays were conducted to detect the proliferation and migration ability of chondrocytes treated with PMSCs conditioned medium (PMSCs-CM). Quantitative real-time PCR (qRT-PCR) and Western blot (WB) assays were applied to explore the molecular action of PMSCs on chondrocytes. Results: The results of flow cytometry indicated that the surface markers of PMSCs (CD73 > 95%, CD90 > 95%, and CD34 < 2%) were consistent with the typical mesenchymal stromal cells. The in vivo data showed that PMSCs significantly reversed the kOA progression by protection of cartilage, regulation of anabolic (Col2) and catabolic (MMP13) expressions, and relief of pain symptoms. The in vitro data showed that PMSCs promoted chondrocyte proliferation and migration and significantly restored the IL-1β-induced abnormal gene expressions of Col2, Mmp13, Adamts4, Adamts5 and Sox9 and also restored the abnormal protein expressions of Col2, Mmp13 and Sox9 of chondrocytes. The molecular actions of PMSCs on chondrocytes in nested co-culture way or in conditioned medium way were similar, confirming a paracrine-based mode of action. Conclusion: This study demonstrated PMSCs' anti-kOA efficacy and its paracrine-based action mode, providing novel knowledge of PMSCs and suggesting it as a promising cell therapy for treatment of kOA.

Dihydroartemisinin Attenuated Intervertebral Disc Degeneration via Inhibiting PI3K/AKT and NF-κB Signaling Pathways

Intervertebral disc degeneration (IDD) is the leading cause of low back pain (LBP). However, effective therapeutic drugs for IDD remain to be further explored. Inflammatory cytokines play a pivotal role in the onset and progression of IDD. Dihydroartemisinin (DHA) has been well reported to have powerful anti-inflammatory effects, but whether DHA could ameliorate the development of IDD remained unclear. In this study, the effects of DHA on extracellular matrix (ECM) metabolism and cellular senescence were firstly investigated in nucleus pulposus cells (NPCs) under tumor necrosis factor alpha (TNFα)-induced inflammation. Meanwhile, AKT agonist sc-79 was used to determine whether DHA exerted its actions through regulating PI3K/AKT and NF-κB signaling pathways. Next, the therapeutic effects of DHA were tested in a puncture-induced rat IDD model. Finally, we detected the activation of PI3K/AKT and NF-κB signaling pathways in clinical degenerative nucleus pulposus specimens. We demonstrated that DHA ameliorated the imbalance between anabolism and catabolism of extracellular matrix and alleviated NPCs senescence induced by TNFα in vitro. Further, we illustrated that DHA mitigated the IDD progression in a puncture-induced rat model. Mechanistically, DHA inhibited the activation of PI3K/AKT and NF-κB signaling pathways induced by TNFα, which was undermined by AKT agonist sc-79. Molecular docking predicted that DHA bound to the PI3K directly. Intriguingly, we also verified the activation of PI3K/AKT and NF-κB signaling pathways in clinical degenerative nucleus pulposus specimens, suggesting that DHA may qualify itself as a promising drug for mitigating IDD.

Calycosin prevents IL-1β-induced articular chondrocyte damage in osteoarthritis through regulating the PI3K/AKT/FoxO1 pathway

Osteoarthritis (OA) is a joint disorder that is associated with chondrocyte damage under inflammatory environment. Calycosin is an astragalus extract with potential anti-inflammatory and anti-tumor activities. The purpose of this research is to explore the activity and mechanism of calycosin in interleukin-1beta (IL-1β)-induced chondrocyte injury. In the present study, the targets of calycosin and OA were analyzed according to HERB, DisGeNet, String, GO terms, and KEGG pathway enrichment assays. Human primary chondrocytes were treated with calycosin, and stimulated with IL-1β. Cell viability was detected by CCK-8 assay. Cell apoptosis was investigated by flow cytometry, and caspase-3 activity analyses. Inflammation was analyzed according to inflammatory cytokines levels by enzyme-linked immunosorbent assay (ELISA). The proteins associated with extracellular matrix (ECM) degradation and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/forkhead box O1 (FoxO1) signaling pathways were measured using Western blotting. The results showed that total of 25 overlapping targets of calycosin against OA were predicted. These targets might drive the FoxO pathway. Calycosin alone induced little cytotoxicity to chondrocytes, and it alleviated IL-1β-induced viability inhibition, cell apoptosis, inflammatory cytokine secretion, and ECM degradation in chondrocytes. Calycosin repressed IL-1β-induced activation of the PI3K/AKT/FoxO1 signaling. Activation of the PI3K/AKT/FoxO1 signaling mitigated the suppressive effect of calycosin on chondrocyte apoptosis, inflammation, and ECM degradation induced by IL-1β. As a conclusion, calycosin prevents IL-1β-induced chondrocyte apoptosis, inflammation, and ECM degradation through inactivating the PI3K/AKT/FoxO1 pathway.

Combination of UHPLC-Q Exactive-Orbitrap MS and network pharmacology to reveal the mechanism of Eucommia ulmoides leaves in the treatment of osteoarthritis

Osteoarthritis (OA) is a disabling disease and seriously affects the quality of life of patients. is A potential medicine for the treatment of OA is Eucommia ulmoides leaves (EULs). However, its active compounds and therapeutic mechanisms are unclear. Therefore, it is necessary to develop a method using LC-MS and network pharmacology for the detection and identification of compounds and the mechanisms of action of EULs. The compounds were detected and identified based on ultra-high-performance liquid chromatography coupled with Quadrupole Exactive-Orbitrap MS (UHPLC-Q Exactive-Orbitrap MS) and followed by the network pharmacology analysis. Seventy-three compounds, including 15 flavonoids, 8 iridoids, 10 lignans, 24 phenolic acids, and 16 additional compounds, were identified by UHPLC-Q Exactive-Orbitrap MS. The network of the pharmacological analysis revealed that 29 active compounds regulated 17 main pathways through 38 target genes, including NF-kappa B signaling pathway, PI3K-Akt signaling pathway, AMPK signaling pathway, etc. In conclusion, EULs were effective in the treatment of OA by regulating the abovementioned key pathways. This study showed that LC-MS/MS followed by network pharmacology analysis is useful to elucidate the complex mechanisms of action of Chinese herb. PRACTICAL APPLICATIONS: This study describes a rapid method of detecting and identifying the constituents and systematic mechanism of Eucommia ulmoides based on LC-MS and network pharmacology. Our results show that 73 compounds of E. ulmoides leaves were identified and predicted that E. ulmoides leaves were effective in the treatment of OA by regulating key pathways, including NF-kappa B signaling pathway, PI3K-Akt signaling pathway, and AMPK signaling pathway by network pharmacology, which lays the foundation for subsequent research.

Aloin Regulates Matrix Metabolism and Apoptosis in Human Nucleus Pulposus Cells via the TAK1/NF-κB/NLRP3 Signaling Pathway

Intervertebral disc degeneration (IDD) is a degenerative disease that is characterized by decreased matrix synthesis and extra degradation, nucleus pulposus cells (NPCs) apoptosis, and infiltration of inflammatory factors. Aloin, a colored compound from aloe plants, has been shown to be effective against skeletal degenerative diseases, but it is unclear whether it is protective against IDD. Herein, we investigated the role of aloin in NPCs. In our study, the upregulation of proinflammatory factors, apoptosis, and unbalanced matrix metabolism were observed in degenerative NP tissues. We found that aloin had a curative effect on extracellular matrix metabolism and apoptosis in TNF-alpha- (TNF-α-) treated NPCs by inhibiting oxidative stress and the proinflammatory factor expression. Further investigation revealed that aloin treatment suppressed the TAK1/NF-κB pathway. Moreover, the expression level of the NLPR3 inflammasome was downregulated after aloin treatment in TNF-α-treated NPCs. In summary, our results demonstrated that aloin treatment can reverse TNF-α-induced unbalanced matrix metabolism and apoptosis of NPCs via the TAK1/NF-κB/NLRP3 axis. This study supports that aloin can be a promising therapeutic agent for IDD.

The potential health benefits of aloin from genus Aloe

The Aloe species is known for its medicinal and cosmetic properties. Aloin is an active ingredient found in the leaves of medicinal plants of the genus Aloe. Aloin has attracted considerable interest for its antiinflammatory, anticancer, antibacterial, and antioxidant activities. However, since its clinical application is restricted by its unclear mechanism of action, a deeper understanding of its pharmacological activity is required. This review provides an overview of current pharmacological and toxicological studies published in English from February 2000 to August 2021. Herein, we summarized the sources and potential health benefits of aloin from a clinical application perspective to guide for further studies on the sources of aloin, aimed at efficiently increasing aloin production. Importantly, the function and mechanism of action of aloin remain unclarified. In future research, it is necessary to develop new approaches for studying the pharmacological molecular mechanisms underlying the activity of this compound against various diseases.

The Health Benefits of Emodin, a Natural Anthraquinone Derived from Rhubarb-A Summary Update

Emodin (6-methyl-1,3,8-trihydroxyanthraquinone) is a naturally occurring anthraquinone derivative found in roots and leaves of various plants, fungi and lichens. For a long time it has been used in traditional Chinese medicine as an active ingredient in herbs. Among other sources, it is isolated from the rhubarb Rheum palmatum or tuber fleece-flower Polygonam multiflorum. Emodin has a wide range of biological activities, including diuretic, antibacterial, antiulcer, anti-inflammatory, anticancer and antinociceptive. According to the most recent studies, emodin acts as an antimalarial and antiallergic agent, and can also reverse resistance to chemotherapy. In the present work the potential therapeutic role of emodin in treatment of inflammatory diseases, cancers and microbial infections is analysed.

Isovitexin Depresses Osteoarthritis Progression via the Nrf2/NF-κB Pathway: An in vitro Study

Purpose

Osteoarthritis (OA) is a multifactorial joint disease and inflammatory processes contribute to joint destruction. Isovitexin (IVX) is a flavone component found in passion flower, Cannabis and, and the palm that is known for its anti-inflammatory properties.

Materials and Methods

This study investigated in vitro the role and underlying mechanism used by IVX in its regulation of OA development. Effects of IVX on the viability of chondrocytes were measured by CCK-8 assays. The phenotypes of extracellular matrix (ECM) degeneration and inflammation were measured by qPCR, Western blot, and ELISA; and NF-κB pathway was detected by immunofluorescence and Western blot. Molecular docking was applied to predict the interacting protein of IVX, while Nrf2 was knocked down by siRNAs to confirm its role.

Results

We demonstrated that IVX suppressed ECM degeneration and suppressed pro-inflammatory factors in IL-1β-treated chondrocytes. Additionally, IVX impact on NF-κB signaling in IL-1β-exposed chondrocytic cells; Mechanistically, it was also demonstrated in molecular docking and knock down studies that IVX might bind to Nrf2 to suppress NF-κB pathway.

Conclusion

Our data suggest that IVX halts OA disease advancement through the Nrf2/NF-κB axis, suggesting a possibility of IVX as a target for OA therapy.