Chondroprotective activity of acti-joint®, a combination of chondroitin sulfate, glucosamine and a natural ingredient rich in hyaluronic acid

Abstract

and, in addition to its powerful antioxidant activity, it may exert modulatory effects on different signalling pathways. Methods: The immortalized human cell line C-28/I2 and primary cultures of human chondrocytes (prepared from fragments of articular cartilage obtained from adult OA patients undergoing knee arthroplasty) were treated with HT, 30 minutes before exposition to hydrogen peroxide to induce oxidative stress and samples were collected at different times. We tested cell viability through reading on MUSE Ò Cell Analyzer. The expression of genes and proteins known or potentially implicated in OA was evaluated by Real-Time RT-PCR assay and by Western blot method, respectively. By 6 different algorithms (TargetScan, miRanda, PICTAR4, miRDB, miRWalk, RNA22) bioinformatic analysis selected possible candidate microRNAs that could interact with targets of interest. Subsequently we verified by Real Time RT-PCR assay possible variations in the expression of these microRNAs after treatments. Results: We evaluated the gene expression of runt-related transcription factor-2 and matrix metalloproteinase-13, two molecular markers of OA, in human primary chondrocytes cultured in monolayer. HT prevents the increase induced by oxidative stress in the mRNA amount of both markers. Moreover this compound is able to reduce significantly C-28/I2 cells death. In order to investigate a possible involvement of autophagic process in this context, we evaluated the protein expression of LC3 II (active form associated to autophagosomes), after oxidative stress in presence or in absence of HT. We found that HT induces an increase of protein levels of this autophagic marker, suggesting a possible mechanism of cytoprotection. This effect of HT on autophagy may be promoted by modulating several effectors such as AMP-activated protein kinase (AMPK) and the NAD-dependent deacetylase Sirtuin-1 (SIRT-1). Indeed HT causes the increase of phospho-AMPK and SIRT-1 protein levels. At the same time, this compound is able to decrease the amount of microRNA-9, which can target SIRT-1 mRNA thus modulating its expression. Conclusions:This study suggests new molecular mechanisms by which HT may prevent some aspects of OA pathogenesis and progression. Indeed the beneficial action of HT in this context seems to be related to the stimulation of autophagy. These data indicate that HT can be considered an attractive tool for the prevention of OA.This work was supported by FIRB (Ministero dell'istruzione, dell'Universit a e della Ricerca, Italy) grant RBAP10KCNS.

Chondroprotective efficiencies of intra-articular treatment of glucosamine sulfate and hyaluronic acid

“…Research is still underway for the ideal procedure. Recently, disease-modifying agents have been emphasized [4,7,8]. Several studies have been conducted on HA and have been reported in many studies that have modified OA.…”

“…In the literature, HA is routinely used in the treatment of joint OA. There are very few studies in the literature comparing the effects of intra-articular administration of GS and HA [4,8,18].…”

“…Studies in the literature have generally achieved better results in groups using HA and GS molecules than in control groups although there are few reports showing opposite results [4,8]. GS has been used in different medical studies and the results have been reported to be most effective in these studies.…”

“…GS has been used in different medical studies and the results have been reported to be most effective in these studies. Although, there are many studies in the literature on oral GS application, there are limited studies on the intra-articular application [4,8].…”

“…HA and glucosamine sulfate (GS) are drugs that are used for a long time for the treatment of OA. There are many clinical publications about the efficacy of these drugs [2][3][4][5][6][7][8][9][10][11]. Intra-articular HA application is preferred by most physicians because it shows more promising results in patients [2,3,12].…”