Anti-inflammatory and anti-arthritic potential of methotrexate in combination with BA-25, an amino analogue of ß-boswellic acid in the treatment of rheumatoid arthritis.

ß- boswellic acid, a pentacyclic triterpene derived from Boswellia serrata is extensively known for its anti-inflammatory potential. BA-25 (3-α-o-acetoxy-4ß-amino-11-oxo-24-norurs-12-ene) is an amino analogue of ß-boswellic acid that has shown anti-inflammatory potential in LPS-induced macrophages and animal models. The present study aims at investigation of the combination of BA-25 with the conventional gold standard DMARD methotrexate (MTX) for its anti-inflammatory and anti-arthritic potential using in vitro and in vivo experimental models. The anti-inflammatory potential of MTX versus the combination (BA-25 + MTX) was investigated for inhibition of NO, ROS and pro-inflammatory cytokines including TNF-α and IL-6 using ELISA in LPS-stimulated RAW-264.7 cells. The results demonstrated significant reduction in NO, ROS, TNF- α and IL-6 production with the combination treatment in comparison to MTX alone. The cytokine inhibition potential of the combination was further validated in-vivo using balb/c wherein the combination restored LPS-induced increase in pro-inflammatory cytokines. The toxicological aspect of the in vivo doses of the combination was also investigated in mice after dosing for 28 days wherein the results suggested no significant change in the hematological parameters and serum biochemical parameters in the combination versus the vehicle group. The effect of BA-25 was also investigated on MTX-induced increase in liver function tests and the expression of Bax and blc2. The results demonstrated decrease in the production of liver enzymes with BA-25 administration along with downregulating the expression of apoptotic protein Bax while increasing the expression of anti-apoptotic protein Bcl2. Furthermore, pharmacokinetic studies of BA-25 were conducted in Balb/c mice wherein the compound showed rapid absorption, high volume of distribution and a t1/2 of 13.08. Finally the anti-arthritic effect of the combination of MTX + BA-25 vs MTX alone was investigated using CIA model in DBA/1 mice wherein the treatment with the combination resulted in significant reduction in paw inflammation, IL-6 and IL-1ß levels. Furthermore, the western blot analysis demonstrated considerable decrease in the expression of p-NF-κB p65 and p-IκB in the ankle-joint tissue of the CIA mice treated with the combination therapy. The results insinuated increased anti-inflammatory and anti-arthritic potential of the combination of MTX with BA-25 as evident from in to vitro and in-vivo studies.

Phytochemicals targeting JAK/STAT pathway in the treatment of rheumatoid arthritis: Is there a future?

Rheumatoid arthritis (RA) is a chronic autoimmune disorder and the treatment involves the use of traditional and biological disease modifying anti-rheumatic drugs (DMARDs). Recent studies have shown JAK/STAT signaling pathway as potential target for the treatment of RA. Novel JAK/STAT inhibitors viz tofacitinib and baricitinib have been recently approved by FDA for RA treatment and have attained substantial importance. However, the discernible risks of thromboembolism, gastrointestinal (GIT) perforations, hepatotoxicity and serious infections including tuberculosis, herpes zoster associated with their administration cannot be overlooked. Furthermore, these are highly expensive which limits their application for a broader use. These limitations provide the basis of exploring novel JAK/STAT inhibitors of natural origin with increased tolerability, safety and cost-effectiveness. In this review we confer an account of various natural compounds/phytochemicals that have proved to be beneficial in attenuating inflammation in RA via modulation of JAK/STAT signaling pathway. Some of these natural compounds including resveratrol have clearly indicated biochemical and clinically significant therapeutic effects in ameliorating RA both in vivo and in clinical settings. We further discuss the physicochemical challenges of poor solubility and absorption coupled with the use of natural JAK/STAT inhibitors. We thereafter discuss and summarize various drug delivery systems (DDS) to confront the physicochemical limitations of natural JAK/STAT inhibitors with the aim to enhance the therapeutic efficacy. Overall the review unveils the potential of natural JAK/STAT inhibitors as a cost-effective approach in ameliorating RA without incorporating the risks of adverse repercussions, thus setting the stage for clinical exploration of these compounds that may possibly complement the present RA therapy.