Can curcumin improve the methotrexate based treatment for rheumatoid arthritis?

Rheumatoid arthritis (RA) is an autoimmune disorder characterised by its varied and unpredictable origin, eventual destruction of cartilage and bone and the perpetual length of treatment involved. Even though significant developments have taken place over the past couple of decades in the treatment, the efficacy of drugs for RA is a major concern due to the side effects involved. Methotrexate (MTX) is currently used as first line treatment due to its ability to modify the rheumatic conditions so that disease progression can be prevented. However, at the same time prolonged exposure to MTX can lead to severe side effects such as lung fibrosis and hepatotoxicity. Recent research has focused on developing an alternative to MTX with similar efficacy but with reduced adverse effects. One such promising option is curcumin, an active compound extracted from Indian spice Turmeric. Various studies have indicated the synergistic properties exhibited by curcumin and its ability to modulate the underlying inflammatory pathways involved in RA. However, no previous studies have been reported with regards to using a combination of MTX and curcumin for the treatment of RA. A novel RP-HPLC stability indicating method was developed in order to establish the compatibility of the two compounds. The method was developed using Waters Reverse Phase (XBridgeTM Shield RP18 4.6x250 mm, 5 µM) column. A gradient system, consisting of two mobile phases with acetonitrile concentrations of 35% and 60% respectively, was designed to optimise the separation of the two compounds while taking into consideration the difference in hydrophobicity. The wavelengths for detection were 305 nm and 430 nm for MTX and curcumin, respectively. The retention time for MTX and curcumin was 4.8 ± 0.10 min and 12.3 ± 0.10 min, respectively. The Page 4 of 192 total run time of analysis was 25 minutes. The developed method was validated for parameters such as accuracy, precision, linearity, limit of detection and lower limit of quantification. The system was tested through intraday and interday repeatability and reproducibility. The method was used to analyse the MTX and curcumin under different stress conditions such as pH, UV radiation, temperature and humidity to establish their compatibility. The degradation products are successfully separated and therefore, the method can be effectively used as stability indicating method. Gene expression profiling was performed using HFLS-RA cells treated with MTX and curcumin separately and concurrently. The DNA microarray data identified 53 genes that were downregulated and 21 genes that were upregulated in all the treated samples using both stringent and non-stringent filtering. The total of 13 genes were selected based on the fold change obtained in the microarray data and their potential as therapeutic biomarkers based on previous research. The gene validation using qRTPCR confirmed the higher efficacy of curcumin in the inhibition of the proinflammatory genes such as ANGPTL7, CD248, CH25H, COL14A1, CXCL12, CYTL1, IFITM1 and IL7. Curcumin was found to also increase the expression levels of genes associated with anti-inflammatory roles, namely BCAR4, CD274, HSPA6, OTP and RELT. The increased gene expression in samples treated with both MTX and curcumin confirmed the possible synergistic activity which is encouraging, taking in to account the fact that these compounds are compatible according to the stability studies carried out and thus could be used in combination for the treatment of RA. This could improve the current treatment by reducing the severity of side-effects attributed to MTX while maintaining the efficacy of the treatment due to the ability of curcumin to modulate specific therapeutic biomarkers involved in the RA pathogenesis

Identifying Reliable Diagnostic/Predictive Biomarkers for Rheumatoid Arthritis

Introduction and objective: Elevated C-reactive protein is usually a good indicator of rheumatoid arthritis (RA); however, there are limitations that compromise its specificity and therefore there is an urgent need to identify more reliable diagnostic biomarkers to detect early stages of RA. In addition, identifying the correct therapeutic biomarker for the treatment of RA using methotrexate (MTX) would greatly increase the benefits experienced by the patients. Materials and methods: Primary normal synoviocytes human fibroblast-like synoviocytes (HFLS) and its phenotype rheumatic HFLS-RA cells were chosen for this study. The HFLS-RA–untreated and MTX-treated cells were subjected to microarray analysis. Results: Microarray data identified 74 differentially expressed genes. These genes were mapped against an RA inflammatory pathway, shortlisting 10 candidate genes. Gene expression profiling of the 10 genes were studied. Fold change (FC) was calculated to determine the differential expression of the samples. Discussion: The transcription profiles of the 10 candidate genes were highly induced in HFLS-RA cells compared with HFLS cells. However, on treating the HFLS-RA cells with MTX, the transcription profiles of these genes were highly downregulated. The most significant expression FC difference between HFLS and HFLS-RA (treated and untreated) was observed with HSPA6, MMP1, MMP13, and TNFSF10 genes. Conclusions: The data from this study suggest the use of HSPA6, MMP1, MMP13, and TNFSF10 gene expression profiles as potential diagnostic biomarkers. In addition, these gene profiles can help in predicting the therapeutic efficacy of MTX