Nerolidol: a potential approach in rheumatoid arthritis through reduction of TNF-α, IL-1ß, IL-6, NF-kB, COX-2 and antioxidant effect in CFA-induced arthritic model.

Rheumatoid arthritis is primarily associated with inflammation and increased level of proinflammatory cytokines which are released by immune cells, macrophages or activation of arachidonic acid metabolism. The expression of these cytokines, oxidative free radicals and the activation of COX-2 enzymes are crucial targets for chronic inflammation. On the basis of established anti-inflammatory efficacy of nerolidol, the primary study was further appraised to determine its approach against Freund's complete adjuvant (CFA) rheumatoid model. Arthritis was induced by inoculation of 0.1 mL CFA injection into the left hind footpad of rats. Anti-arthritic potential of nerolidol (at 200, 400 and 800 mg/kg doses) was assessed by measuring the paw volume, body weight, serum analysis, histopathological and radiographs of ankle joints. Expressions of cytokine's panels such as IL-10, IL-4, COX-2, NF-kB, TNF-α, IL-6, PGE-2 and IL-1ß were determined by real-time qPCR. Antioxidant enzyme analyses were conducted by measuring the SOD, POD and catalase activity from serum and equated with arthritic control group. Nerolidol prevented body weight loss, stabilized biochemical and haematological homeostasis and significantly reduced the paw volume. Furthermore, X-ray and histopathological assessment of ankle joints showed an improvement in the joint structure of rats treated with nerolidol. Besides that, overexpression of gene pointers like TNF-α, IL-1ß, IL-6, NF-kB, PGE-2 and COX-2 in CFA-treated control rats were also reversed with nerolidol. This anti-arthritic mechanism was further supported by the increased level of IL-10, IL-4 and serum antioxidant activity. The present findings demonstrate that nerolidol reduced adjuvant arthritis by downregulating the proinflammatory cytokines and upregulating the aforementioned anti-inflammatory cytokines and may be used as a therapeutic substance for the management of human rheumatoid arthritis.

Noscapine hydrochloride (benzyl-isoquinoline alkaloid) effectively prevents protein denaturation through reduction of IL-6, NF-kB, COX-2, Prostaglandin-E2 in rheumatic rats.

Noscapine hydrochloride (benzyl-isoquinoline antitussive alkaloid) is an opium derivative and generally used as a cough suppressant. Numerous studies on noscapine hydrochloride have reported that it has potent anti-inflammatory activity. However, the mechanisms by which it exerts an anti-inflammatory function is not well understood. Protein denaturation is the primary step that leads to the organ destruction and permanent arthritic disability. The above-mentioned facts provided the ground to plan this study using different in-vitro and in-vivo approaches. RT-qPCR and ELISA assays were used to assess the inflammatory markers related to protein denaturation in complete adjuvant persuaded rheumatism in Sprague - Dawley rats. The results were collected as paw volume and body weight changes, arthritic scoring and serum antioxidant enzymes assays. These findings demonstrated that all doses of noscapine hydrochloride (10, 20 and 40 mg/kg) studied in this study, significantly (p < 0.001) decreased the protein denaturation by preventing the increase in levels of interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), nuclear factor-kB (NF-kB), cyclooxygenase-2 (COX-2) and prostaglandin E2. Noscapine hydrochloride significantly reduced the paw volume (p < 0.001), arthritic scoring and reversed the body mass as compared to arthritic control diseased rats.

Toxicity studies and anti-arthritic effect of mandelic acid (2-hydroxy -2-phenyl acetic acid) using in vitro and in vivo techniques.

The major concern to search for new anti-arthritic drugs is primarily to prevent systemic complications and to maintain quality of life. As these drugs are prescribed for long duration so the objective is to ensure their safety in terms of toxicity. By keeping in view this concept, the present study was investigated to determine new anti-arthritic potential using in-vitro and in-vivo methods. The in-vitro tests comprised of protein denaturation (BSA and egg albumin) and Human Red Blood cell (HRBC) membrane stabilization assays at 50-6400µg/mL, for in-vivo testing, formaldehyde-induced arthritic rats were treated with 40, 80 and 160mg/kg mandelic acid. Mandelic acid (MA) inhibited the protein denaturation and stabilized the membrane of HRBC in a concentration dependent manner. Likewise, mandelic acid exhibited dose dependent reduction in paw volume induced by formaldehyde. For acute and sub-acute treatment, MA did not show any sign of toxicity and mortality in each rat and LD50 might be greater than 2000mg/kg. In addition, histopathological assessment presented slight increased interstitial spaces in the kidney, disorganization of glomerulus, dilated sinusoids at highest dose 800mg/kg which were not observed in sub-chronic therapy. Hence, these results conclude that mandelic acid has the potential to treat rheumatoid arthritis with observed no significant signs of toxicity and should be tested further to determine anti-arthritic mechanism of drug action at cellular level.