Rheumatoid arthritis (RA) is a debilitating autoimmune disease whose etiology remains unknown, but studies have consistently implicated a plethora of inflammatory mechanisms culminating in chronic symmetric and erosive synovitis. Importantly, reactive oxygen species (ROS) have been attributed to directly contribute towards the destructive, proliferative synovitis evident in RA. Accordingly, this study aimed to establish whether the degree of oxidative stress and disease activity score (DAS28) correlated with the downstream effects of oxidative damage. The redox status of neutrophils sourced from synovial fluid (SF) was measured by flow cytometry in terms of total ROS and hydroxyl radicals. Among the molecular damage markers, protein carbonylation and lipid peroxidation were detected by spectrophotometry and S-nitrosothiols by fluorimetry. Neutrophils constituted the major cellular component of the SF of patients with RA and their levels of ROS and hydroxyl radicals correlated strongly with protein carbonylation and lipid peroxidation. However, all the oxidative damage markers correlated positively with DAS28. Taken together, in patients with RA, the strong correlation between levels of ROS and DAS28 with markers of oxidative damage suggests that measurement of oxidative stress could serve as a biomarker for monitoring disease severity in RA.

Guinea pig airway smooth muscle (ASM) cells were maintained in a primary tissue culture (passages 1-3). Cells were exposed to human recombinant interleukin-1 beta (IL-1 beta; 20-100 pg/ml) or interleukin-6 (IL-6; 1-4 ng/ml) in the presence of indomethacin (1 microgram/ml) for up to 5 days. Proliferation of ASM cells was assessed with two techniques, direct counting of cells with a hemacytometer and [3H]thymidine incorporation corrected for total protein content. Hypertrophy of ASM cells was assessed by [3H]leucine incorporation (evaluation of protein synthesis), determination of total DNA content, DNA content per cell, and protein content per cell. We observed that the exposure of ASM cells to human recombinant IL-1 beta or IL-6, in all studied concentrations, significantly increased the number of cells as well as [3H]thymidine incorporation into ASM cells. We also found that exposure of ASM to these two cytokines increased [3H]leucine incorporation into the ASM cells and increased protein content and DNA content per single cell. These changes were also concentration dependent. We conclude that the two proinflammatory cytokines, IL-1 beta and IL-6, which are present in asthmatic lungs, increased the proliferation of ASM cells (hyperplasia) as well as their overall size and size of their nuclei, as measured by biochemical markers. These findings are compatible with the presence of ASM hypertrophy.

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Methotrexate (MTX), a folate antagonist, is currently used as first line therapy for autoimmune diseases like rheumatoid arthritis and psoriasis, but its use is limited by the associated hepatotoxicity. As leaves of Piper betle, belonging to family Piperaceae, have antioxidant and anti-inflammatory properties, the present study was undertaken to investigate the potential of Piper betle leaf extract (PB) in attenuating MTX-induced hepatotoxicity. Rats pre-treated with PB (50 or 100 mg kg(-1) b.w., p.o.) were administered with a single dose of MTX (20 mg kg(-1), b.w., i.p.) and its hepatoprotective efficacy was compared with folic acid (1 mg kg(-1) b.w., i.p.), conventionally used to minimize MTX-induced toxicity. MTX-induced hepatotoxicity was confirmed by increased activities of marker enzymes, alanine transaminase, aspartate transaminase, and alkaline phosphatase which were remitted by pre-treatment with PB and corroborated with histopathology. Additionally, MTX-induced hepatic oxidative stress which included increased generation of reactive oxygen species, enhanced lipid peroxidation, depleted levels of glutathione and decreased activities of antioxidant enzymes was effectively mitigated by PB, indicative that its promising antioxidant-mediated hepatoprotective activity was worthy of future pharmacological consideration.