Chondroprotective Activity Research Articles

Evidence base of pharmaconutraceuticals with chondroprotective action

Evidence base of pharmaconutraceuticals with chondroprotective action

Analgesic, Anti-Inflammatory, and Chondroprotective Activities of Siraitia grosvenorii Residual Extract.

Inflammation is crucial to osteoarthritis (OA) pathogenesis. The aim of this study was to evaluate Siraitia grosvenorii residue extract (NHGRE) obtained by extracting S. grosvenorii fruits with water as a potential food supplement for treating arthritis based on its analgesic, anti-inflammatory, and chondroprotective effects and the remaining residue with 70% ethanol. We observed the analgesic activity of NHGRE based on the acetic acid-induced writhing response in mice, examined its anti-inflammatory efficacy against carrageenan-induced paw oedema in mice, and investigated its effect on inflammatory cytokine expression in interleukin (IL)-1β-induced SW1353 cells. Furthermore, we determined its effects on cartilage protection in interleukin-1β (IL-1β)-treated SW1353 cells. NHGRE at 200 mg/kg significantly reduced the acetic acid-induced writhing response and prevented oedema formation in the carrageenan-induced paw oedema model. In IL-1β-induced SW1353 cells, NHGRE at 400 µg/mL reduced the expression of inflammation mediators such as tumour necrosis factor (TNF)-α (55.3%), IL-6 (35.4%), and prostaglandin E2 (PGE2) (36.9%) and down-regulated the expression of matrix metalloproteinase (MMP)-1 (38.6%), MMP-3 (29.3%), and MMP-13 (44.8%). Additionally, it restored degraded collagen II levels in chondrocytes. NHGRE plays a protective role in chondrocytes by regulating Nuclear factor kappa B (NF-κB) activation. Overall, NHGRE may be a useful therapeutic agent for OA by controlling pain, oedema formation, and inflammation-related mechanisms.

MYOKINE FUNDC5 COMPROMISES MITOCHONDRIAL DYSFUNCTION IN OSTEOARTHRITIS

Chondrocytic activity is downregulated by compromised autophagy and mitochondrial dysfunction to accelerate the development of osteoarthritis (OA). Irisin is a cleaved form of fibronectin type III domain containing 5 (FNDC5) and known to regulate bone turnover and muscle homeostasis. However, little is known about the role of irisin in chondrocytes and the development of OA. This talk will shed light on FNDC5 expression by human articular chondrocytes and compare normal and osteoarthritic cells with respect to autophagosome marker LC3-II and oxidative DNA damage marker 8-hydroxydeoxyguanosine (8-OHdG). In chondrocytes in vitro, irisin improves IL-1β-mediated growth inhibition, loss of specific cartilage markers and glycosaminoglycan production. Irisin further suppressed Sirt3 and UCP- 1 to improve mitochondrial membrane potential, ATP production, and catalase. This attenuated IL-1β-mediated production of reactive oxygen species, mitochondrial fusion, mitophagy, and autophagosome formation. In a surgical murine model of destabilization of the medial meniscus (DMM) intra-articular administration of irisin alleviates symptoms like cartilage erosion and synovitis. Furthermore, gait profiles of the treated limbs improved. In chondrocytes, irisin treatment upregulates autophagy, 8-OHdG and apoptosis in cartilage of DMM limbs. Loss of FNDC5 in chondrocytes correlates with human knee OA and irisin repressed inflammation-mediated oxidative stress and deficient extracellular matrix synthesis through retaining mitochondrial biogenesis and autophagy. The talk sheds new light on the chondroprotective actions of this myokine and highlights the remedial effects of irisin during progression of OA.

Positive Regulation of S-Adenosylmethionine on Chondrocytic Differentiation via Stimulation of Polyamine Production and the Gene Expression of Chondrogenic Differentiation Factors.

S-adenosylmethionine (SAM) is considered to be a useful therapeutic agent for degenerative cartilage diseases, although its mechanism is not clear. We previously found that polyamines stimulate the expression of differentiated phenotype of chondrocytes. We also found that the cellular communication network factor 2 (CCN2) played a huge role in the proliferation and differentiation of chondrocytes. Therefore, we hypothesized that polyamines and CCN2 could be involved in the chondroprotective action of SAM. In this study, we initially found that exogenous SAM enhanced proteoglycan production but not cell proliferation in human chondrocyte-like cell line-2/8 (HCS-2/8) cells. Moreover, SAM enhanced gene expression of cartilage-specific matrix (aggrecan and type II collagen), Sry-Box transcription factor 9 (SOX9), CCN2, and chondroitin sulfate biosynthetic enzymes. The blockade of the methionine adenosyltransferase 2A (MAT2A) enzyme catalyzing intracellular SAM biosynthesis restrained the effect of SAM on chondrocytes. The polyamine level in chondrocytes was higher in SAM-treated culture than control culture. Additionally, Alcian blue staining and RT-qPCR indicated that the effects of SAM on the production and gene expression of aggrecan were reduced by the inhibition of polyamine synthesis. These results suggest that the stimulation of polyamine synthesis and gene expression of chondrogenic differentiation factors, such as CCN2, account for the mechanism underlying the action of SAM on chondrocytes.

Polyherbal formulation PL02 alleviates pain, inflammation, and subchondral bone deterioration in an osteoarthritis rodent model.

Osteoarthritis (OA) is a debilitating disease with significant personal and socioeconomic burdens worldwide. To address this, we developed a multitargeted formulation called PL02, which includes standardized extracts of Rosa canina L, Hippophae rhamnoides, and collagen peptide. We tested the pharmacological efficacy of PL02 in a rodent model of OA induced by Monosodium iodoacetate (MIA). Our results demonstrate that oral administration of PL02 has antioxidant effects by down-regulating NOS, reduces pain-related behavior, and mitigates inflammation by inhibiting IL-1b and TNF-α production, as well as downregulating CGRP1 and COX-II. PL02 also exhibits anti-catabolic and chondroprotective activity by significantly downregulating MMP13 and upregulating BCL2. Additionally, PL02 demonstrates chondrogenic activity by significantly upregulating SOX-9 (a master regulator of chondrogenesis), Coll-I, and aggrecan, which are major components of articular cartilage. Furthermore, PL02 prevents microarchitectural deterioration of subchondral bone. Overall, PL02 is an orally active, multi-targeted therapy that not only alleviates pain and inflammation but also effectively halts cartilage and subchondral bone deterioration. It represents a safe and promising candidate for the treatment and management of OA.

Pharmacological and Medicinal Important of Plant Phyllanthus Emblica Linn. (Syn.Emblica Officinalis), Indian Gooseberry

Abstract: The plant names phyllanthus emblica linn (Amla) are very precious gift of nature which have a vital role in health care. Nowadays, use of herbal product become most important for humans over the world. This drug is very useful for the treatment of disease. The most important part of this plant (phyllanthus emblica) is fruit. Phyllanthus emblica Linn. (syn. Emblica officinalis), commonly known as Indian gooseberry or amla, belongs to the family Euphorbiaceae. Though all parts of the plant are used for medicinal purposes, the fruits especially are found tremendous pharmacological applications. They are highly nutritious and form an important dietary source of vitamin C, amino acids, and minerals. Emblica Officinalis Plant is reported to have diverse Pharmacological actions like Adaptogenic Activity, Hepatoprotective Activity, Anti-Bacterial Activity, Anti-Hyperlipidemia Activity, Hypolipidemic Activity, Anti-Atherogenic Activity, Immunostimulatory Activity, Anti-oxidant Activity, Anti-Tumor Activity,Anti-Microbial Activity,Chondroprotective Activity, Analgesic Activity, Anti-Inflammatory Activity & AntiDiarreheal Activity. Emblica Officinalis plant is used in the treatments of various ailments. The diverse ailments like cancer, Atherosclerosis, Inflammation, Osteoporosis, Nuerological disorders, Hypertention and other infectious disorders.

Natural compounds protect against the pathogenesis of osteoarthritis by mediating the NRF2/ARE signaling.

Osteoarthritis (OA), a chronic joint cartilage disease, is characterized by the imbalanced homeostasis between anabolism and catabolism. Oxidative stress contributes to inflammatory responses, extracellular matrix (ECM) degradation, and chondrocyte apoptosis and promotes the pathogenesis of OA. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central regulator of intracellular redox homeostasis. Activation of the NRF2/ARE signaling may effectively suppress oxidative stress, attenuate ECM degradation, and inhibit chondrocyte apoptosis. Increasing evidence suggests that the NRF2/ARE signaling has become a potential target for the therapeutic management of OA. Natural compounds, such as polyphenols and terpenoids, have been explored to protect against OA cartilage degeneration by activating the NRF2/ARE pathway. Specifically, flavonoids may function as NRF2 activators and exhibit chondroprotective activity. In conclusion, natural compounds provide rich resources to explore the therapeutic management of OA by activating NRF2/ARE signaling.

The recombinant Link module of human TSG-6 suppresses cartilage damage in models of osteoarthritis: A potential disease-modifying OA drug

To investigate the role of endogenous TSG-6 in human osteoarthritis (OA) and assess the disease-modifying potential of a TSG-6-based biological treatment in cell, explant and animal models of OA. Knee articular cartilages from OA patients were analyzed for TSG-6 protein and mRNA expression using immunohistochemistry and RNAscope, respectively. The inhibitory activities of TSG-6 and its isolated Link module (Link_TSG6) on cytokine-induced degradation of OA cartilage explants were compared. Human mesenchymal stem/stromal cell-derived chondrocyte pellet cultures were used to determine the effects of Link_TSG6 and full-length TSG-6 on IL-1α-, IL-1β-, or TNF-stimulated ADAMTS4, ADAMTS5, and MMP13 mRNA expression. Link_TSG6 was administered i.a. to the rat ACLTpMMx model; cartilage damage and tactile allodynia were assessed. TSG-6 is predominantly associated with chondrocytes in regions of cartilage damage where high TSG-6 expression aligns with low MMP13, the major collagenase implicated in OA progression. Link_TSG6 is more potent than full-length TSG-6 at inhibiting cytokine-mediated matrix breakdown in human OA cartilage explants;>50% of donor cartilages, from 59 tested, were responsive to Link_TSG6 treatment. Link_TSG6 also displayed more potent effects in 3D pellet cultures, suppressing ADAMTS4, ADAMTS5, and MMP13 gene expression, which was consistent with reduced aggrecanase and collagenase activities in explant cultures. Link_TSG6 treatment reduced touch-evoked pain behavior and dose-dependently inhibited cartilage damage in a rodent model of surgically-induced OA. Link_TSG6 has enhanced chondroprotective activity compared to the full-length TSG-6 protein and shows potential as a disease modifying OA drug via its inhibition of aggrecanase and collagenase activity.

The Formulation of the N-Acetylglucosamine as Nanoparticles Increases Its Anti-Inflammatory Activities: An In Vitro Study

Nanomedicine can represent a new strategy to treat several types of diseases such as those with inflammatory aetiology. Through this strategy, it is possible to obtain nanoparticles with controlled shape, size, and eventually surface charge. Moreover, the use of molecules in nanoform may allow more effective delivery into the diseased cells and tissues, reducing toxicity and side effects of the used compounds. The aim of the present manuscript was the evaluation of the effects of N-acetylglucosamine in nanoform (GlcNAc NP) in an in vitro model of osteoarthritis (OA). Human primary chondrocytes were treated with Tumor Necrosis Factor (TNF)-α to simulate a low-grade inflammation and then treated with both GlcNAc and GlcNAc NP, in order to find the lowest concentrations able to counteract the inflammatory state of the cells and ensure a chondroprotective action. The findings showed that GlcNAc NP was able to decrease the pro-inflammatory mediators, IL-6 and IL-8, which are among the main effectors of inflammation; moreover, the nanoparticles downregulated the production of metalloprotease enzymes. GlcNAc NP was effective at a very low concentration compared to GlcNAc in its native form. Furthermore, GlcNAc NP stimulated an increase in collagen type II synthesis. In conclusion, the GlcNAc in nanoform showed better performance than GlcNAc, at concentrations lower than those reached in the joints after oral administration to patients of 1.5 g/die of glucosamine.

Chondroprotective Mechanism of Eucommia ulmoides Oliv.-Glycyrrhiza uralensis Fisch. Couplet Medicines in Knee Osteoarthritis via Experimental Study and Network Pharmacology Analysis.

Knee osteoarthritis (KOA) is the primary prevalent disabling joint disorder among osteoarthritis (OA), and there is no particularly effective treatment at the clinic. Traditional Chinese medicine (TCM) herbs, such as Eucommia ulmoides Oliv. and Glycyrrhiza uralensis Fisch. (E.G.) couplet medicines, have been reported to exhibit beneficial health effects on KOA, exact mechanism of E.G. nevertheless is not fully elucidated. We assess the therapeutic effects of E.G. on KOA and explore its underlying molecular mechanism. UPLC-Q-TOF/MS technique was used to analyze the active chemical constituents of E.G. The destabilization of the medial meniscus model (DMM) was employed to evaluate the chondroprotective action of E.G. in KOA mice using histomorphometry, μCT, behavioral testing and immunohistochemical staining. Additionally, network pharmacology and molecular docking were used to predict potential targets for anti-KOA activities of E.G., which was further verified through in vitro experiments. In vivo studies have shown that E.G. could significantly ameliorate DMM-induced KOA phenotypes including subchondral bone sclerosis, cartilage degradation, gait abnormality and thermal pain reaction sensibility. E.G. treatment could also promote extracellular matrix synthesis to protect articular chondrocytes, which was indicated by Col2 and Aggrecan expressions, as well as reducing matrix degradation by inhibiting MMP13 expression. Interestingly, network pharmacologic analysis showed that PPARG might be a therapeutic center. Further study proved that E.G.-containing serum (EGS) could up-regulate PPARG mRNA level in IL-1β-induced chondrocytes. Notably, significant effects of EGS on the increment of anabolic gene expressions (Col2, Aggrecan) and the decrement of catabolic gene expressions (MMP13, Adamts5) in KOA chondrocytes were abolished due to the silence of PPARG. E.G. played a chondroprotective role in anti-KOA by inhibiting extracellular matrix degradation, which might be related to PPARG.

Comparative analyses of the effects of Glucosamine and Chondroitin Sulphate Iontophoresis on Cartilage Thickening, Interleukine-6 and Uric Acid in patients with Knee Osteoarthritis

This study compared the chondroprotective actions of glucosamine and chondroitin sulphate iontophoresis forcartilage remodeling using Interleukine-6 and Uric Acid as biomarkers. 78 participants with grade II knee OA wererandomly assigned to 3 groups. Group one participants received 1g of glucosamine sulphate (GS) while group tworeceived 1g of chondroitin sulphate (CS) through iontophoresis (40mA- min as dosage). Group three participantsserved as control. The serum concentrations of IL–6 and uric acid were determined while the cartilage thicknesswas measured using a 7- to 12-MHz linear probe. Descriptive statistics and ANOVA were used to analyze thedata. There were significant reductions in the concentrations of interleukin-6 and uric acid at 12th week comparedto baseline for the 3 groups (p = 0.01). The IL–6 in the CS group was significantly lower compared to that ofthe GS group (p = 0.01). After 12 weeks, across the 3 groups, no significant changes were observed in uric acidconcentrations and sonographic features (JSW and ICT). The administration of both drugs significantly reducedinflammatory reactions. However, CS significantly lowered IL–6 compared to GS but there was no significanteffect on uric acid concentration. Also, there was no significant change in cartilage thickening after 12 weeks.

Characteristics of sulfated glycosaminoglycans in the cartilage tissue of skate and sturgeon

Sulfated glycosaminoglycans (GAGs) or chondroitin sulfates were obtained from the cartilage tissue of skate (indefinite species) and sturgeon (kaluga) under the processes of hydrothermal treatment of raw materials at 50 о C, then hydrolysis with proteolytic enzyme in 4 hours under temperature 45 о C (hydromodulus 1 : 1), then sequential precipitation of GAGs in 2–3 volumes of 96 о ethyl alcohol and salting out with 2 % sodium chloride solution. The content of hexosamines and sulfated GAGs was determined in the extracted samples. GAGs of both skate and sturgeon have a high content of sulfated forms, comparable to commercial preparations, that opens up prospects for development of technology for production of monocomponent biologically active additives of chondroprotective action from the wastes of skates and sturgeons processing.

Intra-Articular Adeno-Associated Virus-Mediated Proteoglycan 4 Gene Therapy for Preventing Posttraumatic Osteoarthritis.

Lubricin, a glycoprotein encoded by the proteoglycan 4 (PRG4) gene, is an essential boundary lubricant that reduces friction between articular cartilage surfaces. The loss of lubricin subsequent to joint injury plays a role in the pathogenesis of posttraumatic osteoarthritis. In this study, we describe the development and evaluation of an adeno-associated virus (AAV)-based PRG4 gene therapy intended to restore lubricin in injured joints. The green fluorescent protein (GFP) gene was inserted the PRG4 gene to facilitate tracing the distribution of the transgene product (AAV-PRG4-GFP) in vivo. Transduction efficiency of AAV-PRG4-GFP was evaluated in joint cells, and the conditioned medium containing secreted PRG4-GFP was used for shear loading/friction and viability tests. In vivo transduction of joint tissues following intra-articular injection of AAV-PRG4-GFP was confirmed in the mouse stifle joint in a surgical model of destabilization of the medial meniscus (DMM), and chondroprotective activity was tested in a rabbit anterior cruciate ligament transection (ACLT) model. In vitro studies showed that PRG4-GFP has lubricin-like cartilage-binding and antifriction properties. Significant cytoprotective effects were seen when cartilage was soaked in PRG4-GFP before cyclic shear loading (n = 3). Polymerase chain reaction and confocal microscopy confirmed the presence of PRG4-GFP DNA and protein, respectively, in a mouse DMM (n = 3 per group). In the rabbit ACLT model, AAV-PRG4-GFP gene therapy enhanced lubricin expression (p = 0.001 vs. AAV-GFP: n = 7-14) and protected the cartilage from degeneration (p = 0.014 vs. AAV-GFP: n = 9-10) when treatments were administered immediately postoperation, but efficacy was lost when treatment was delayed for 2 weeks. AAV-PRG4-GFP gene therapy protected cartilage from degeneration in a rabbit ACLT model; however, data from the ACLT model suggest that early intervention is essential for efficacy.

In-vivo evaluation of chondroprotective activity of Ariflex tablet in comparison with aceclofenac tablet and chondroitin sulfate/glucosamine (CG) in monosodium iodoacetate-induced osteoarthritis in rats

Background: Degenerative changes in a joint subsequent to alterations in cartilage formation equilibrium lead to development of osteoarthritis (OA). Aims: Chondroprotective activity of Ariflex tablet (a polyherbal formulation) was evaluated in comparison with chondroitin/glucosamine and aceclofenac in monosodium iodoacetate-induced OA in Wistar rat models. Materials and Methods: A total of 42 animals were divided into seven groups, viz., four control groups [negative, positive, standard and vehicle controls] and three test groups [low, medium, and high dosages]. Animals in seven groups were treated with various study drugs for the period of 28 days. In this study period, measurement of body weight and knee joint swelling was done periodically. Gait score was recorded on the last day, and histopathological examination of joints was done after sacrificing the animals. Results: Chondroprotective activity of medium and high dose of Ariflex tablet was comparable to that of aceclofenac and superior to chondroitin + glucosamine combination. In few rats of medium and high dose of Ariflex tablet groups, chondrocyte regeneration and formation of new blood vessels were seen, which indicated possibility of chondrocyte regeneration activity of Ariflex tablet. Conclusion: Ariflex tablet possesses significant chondroprotective activity comparable to aceclofenac and superior to chondroitin and glucosamine combination. There was a possibility of chondrocyte regeneration activity of Ariflex tablet, which can be confirmed by conducting another study with long-term treatment.

Digoxin targets low density lipoprotein receptor-related protein 4 and protects against osteoarthritis

ObjectivesDysregulated chondrocyte metabolism is closely associated with the pathogenesis of osteoarthritis (OA). Suppressing chondrocyte catabolism to restore cartilage homeostasis has been extensively explored, whereas far less effort has been invested...

Evaluation of the effect of an ayurvedic formulation Myostaal Forte tablets on chondroprotective biomarkers in an experimental model of osteoarthritis in rats

BackgroundOsteoarthritis is a chronic progressive disease commonly affecting the hip and knee joints. Although many drugs are available and afford symptomatic relief, their side effects pose limitations to their continuous use. IntroductionMyostaal Forte (MF) is a poly-herbal Ayurvedic formulation that has shown protection against damage to the chondrocyte layer on histopathological examination in previous studies. But biomarkers which are indicative of chondroprotection have not been assessed. So, the present study was planned to reconfirm the protective effect of MF in osteoarthritic rats by histopathology and create a more substantial evidence by assessing the levels of Cartilage oligomeric matrix protein (COMP) and matrix metalloproteinase-13 (MMP-13). Methods32 rats were divided into four groups (n = 8 each group); sham control (SC), disease control (DC), positive control (PC) and a MF group. Behavioural tests were compared from baseline to 7th day, 14th day, 21st day and on 28th day. Histopathology and bone markers were compared on the 28th day. p < 0.05 was considered as statistically significant. Analysis of Variance (ANOVA) with post hoc Tukey's test was used for parametric data. Non-parametric data was analysed using Kruskal Wallis test with post hoc Dunn's test. ResultsOn measurement of locomotor activity, number of squares crossed was significantly higher in MF group when compared to DC group & there was a significant decrease in the immobility time in MF group when compared DC group. Number of falls on Rota rod test was significantly lower in MF group when compared to DC on day 28. Hot Plate Analgesiometer showed no significant difference in the MF group compared to DC group but over the period of time till day 28, the latency time to lick hind paw was higher in the MF group compared to DC group. In histopathology grading, the scores in MF group were significantly reduced compared to DC group. MMP-13 levels and COMP levels in MF group were significantly decreased as compared to the DC and were statistically significant (p < 0.05). ConclusionMyostaal Forte has shown antiarthritic effect by virtue of its chondroprotective action.

Anti-arthritic and cartilage damage prevention via regulation of Nrf2/HO-1 signaling by glabridin on osteoarthritis

Osteoarthritis is a common degenerative disease linked with inflammatory disorders and oxidative stress. Glabridin is an isoflavonoid and major active constituent of licorice. This study aims to investigate the anti-arthritic effects of glabridin on nuclear factor erythroid 2 – related factor 2 (Nrf2) signaling pathway, inflammatory responses, and cartilage degeneration in in-vitro and in-vivo models. Studies on IL-1β-induced chondrocyte model was performed to evaluate matrix metalloproteinase (MMP), Nrf2 signaling pathway. Glabridin was orally administered in monosodium-iodoacetate (MIA)-induced osteoarthritic (OA) rats for in-vivo evaluation. Pain and swelling of limbs were observed, oxidative stress markers and inflammatory cytokines were measured. Histomorphological changes in the joint cartilage were analyzed. Glabridin significantly reduced the arthritic score and paw swelling along with improved body weight, and organ index of rats. Histopathological score showed significant prevention of joint cartilage degeneration by glabridin. Expressions of TNF-α, IL-6, IL-10, and IL-1β were attenuated by glabridin (p < 0.05) in MIA-induced rats. Protein expressions of iNOS, COX-2, ADAMTS5, MMP-3, and MMP-13 were suppressed (p < 0.05) whereas the Nrf2/HO-1 signaling was activated by glabridin (p < 0.05) in osteoarthritic chondrocytes. Therefore, anti-arthritic and chondroprotective activity of glabridin is suggested by the inhibition of MMP expression and regulation of Nrf2/HO-1 signaling.

Exercise myokine counteracts chondrocyte senescence and osteoarthritis development through mitochondrial metabolism reprogramming

Purpose: Chondrocyte senescence accelerates apoptosis and extracellular matrix loss, accelerating articular cartilage deterioration in the development of osteoarthritis (OA). Fibronectin type III domain containing 5 (FNDC5), is an important exercise myokine to slow age-related diseases, like sarcopenia, osteoporosis, obesity, and neural degeneration, etc. Little is known about whether the molecule affect chondrocyte fate or cartilage metabolism in OA joints. This study aimed to investigate what role FNDC5 may play in chondrocyte aging and OA development in human and in mice. Methods: Osteoarthritic cartilage and non-OA cartilage in the leftover articular specimens were biopsied from patients with knee OA who required total knee replacement. FNDC5 transgenic mice were received destabilized medial meniscus (DMM) to induce OA. Articular cartilage damage, osteophyte formation, kinematics, and pain behavior of injured legs were probed using OARSI score, μCT imaging, catwalk, and von Frey filaments test. Senescence-associated β-galactosidase (SA-β-gal) activity, aging makers, and inflammatory cytokines were quantified using biochemical staining and RTPCR. Mitochondrial metabolites and biology were quantified using liquid chromatography-tandem mass spectrometry, seahorse extracellular influx, and laser confocal microscopy. Results: A plenty of SA-β-gal-stained senescent chondrocytes together with weak FNDC5 immunostaining were present in human osteoarthritic cartilage, as compared with the non-OA cartilage. FNDC5 transgenic (FNDC5Tg) mice showed thickened articular cartilage, increased chondrocytes, high subchondral bone mass, and well woven trabecular microstructure. DMM-injured knee joints displayed less OA signs, including articular cartilage erosion, synovitis, and osteophyte formation. FNDC5 overexpression compromised DMM-mediated pain score and irregular walking patterns and repressed gait profiles of injured legs. Likewise, intra-articular injection with Irisin, a soluble form of FNDC5, slowed OA development in DMM-injured legs. In vitro, FNDC5 overexpression reversed IL-1β-inhibited mitochondrial respiration, ATP production, mitochondrial fusion, and mitophagy. FNDC5 improved mitochondrial α-ketoglutarate production, a key TCA cycle metabolite, repressing senescence program (SA-β-gal activity, p16, p21 expression, and IL-6 production) and retaining ECM production in inflamed chondrocytes. Conclusions: FDNC5 loss is correlate with chondrocyte aging in the development of OA in human and in mice. The myokine sustains chondrocytic activity through sustaining mitochondrial TCA cycle metabolism and biology to protect against inflammation-induced senescence. This study shines light onto the mitochondrial mechanism underlying the chondroprotective actions of FNDC5 to articular integrity. Collective investigations also highlight the remedial effects of FNDC5 and Irisin for OA development.

In Vitro Effects of Low Doses of β-Caryophyllene, Ascorbic Acid and d-Glucosamine on Human Chondrocyte Viability and Inflammation

β-caryophyllene (BCP), a plant-derived sesquiterpene, has been reported to have anti-inflammatory and antioxidant effects. The purpose of this study is to evaluate the effects of BCP in combination with ascorbic acid (AA) and d-glucosamine (GlcN) against macrophage-mediated inflammation on in vitro primary human chondrocytes. Changes in cell viability, intracellular ROS generation, gene expression of pro-inflammatory mediators, metalloproteinases (MMPs), collagen type II and aggrecan were analyzed in primary human chondrocytes exposed to the conditioned medium (CM) of activated U937 monocytes and subsequently treated with BCP alone or in combination with AA and GlcN. The CM-induced chondrocyte cytotoxicity was reduced by the presence of low doses of BCP alone or in combination with AA and GlcN. The exposure of cells to CM significantly increased IL-1β, NF-κB1 and MMP-13 expression, but when BCP was added to the inflamed cells, alone or in combination with AA and GlcN, gene transcription for all these molecules was restored to near baseline values. Moreover, chondrocytes increased the expression of collagen type II and aggrecan when stimulated with AA and GlcN alone or in combination with BCP. This study showed the synergistic anti-inflammatory and antioxidative effects of BCP, AA and GlcN at low doses on human chondrocyte cultures treated with the CM of activated U937 cells. Moreover, the combination of the three molecules was able to promote the expression of collagen type II and aggrecan. All together, these data could suggest that BCP, AA and GlcN exert a chondro-protective action.

Novel rhein integrate transphytosomes as non-invasive local therapy for osteoarthritis to ameliorate cartilage deterioration in MIA-arthritic rats

Rhein (RH), a natural chondroprotective agent, suffers from poor systemic availability (20–25%) after oral administration concomitant to side effects on the gastrointestinal tract and liver. We present a new approach for non-invasive local targeted delivery of rhein to ameliorate cartilage deterioration employing cartilage-homing phospholipids nanocarriers. This is the first work to elaborate RH loaded transphytosome (RH-T-PHY) as novel nanovesicular systems for transdermal drug delivery based on an advantageous hybrid between phytosomes and transfersomes or bilosomes. Here, we developed transphytosomes through incorporating various edge activators (EAs) such as Tween 80, Span 80 and sodium deoxycholate into the lipid bilayer of RH phytosomes to affix the flexibility. RH-T-PHY with high flexibility and entrapment efficacy showed the highest significant skin permeation compared to conventional phytosomes. Additionally, RH-T-PHY have a magnificent potential in maintaining high chondroprotective activity as demonstrated by enhanced repair, regeneration of chondrocytes and GAG formation in MIA-induced osteoarthritis (OA) rat model. Besides, histological examination of vital organs revealed the formulation safety. Confocal laser microscopy images revealed the highest drug availability in the articular cartilage of RH-T-PHY treated group. Conclusively, novel RH-T-PHY can serve as a promising alternative means for delivery of chondroprotective drugs for effective non-invasive local therapy of OA.