Can levels of antioxidants in synovial fluid predict the severity of primary knee osteoarthritis: a preliminary study

Abstract

BackgroundLittle is known about differences in amounts of antioxidants or oxidative stress at different stages of knee osteoarthritis. This study investigated the relationship between concentrations of antioxidants, iron and lipid peroxidation in synovial fluid and levels of severity of primary knee osteoarthritis.Materials and methodsFrom 2011 to 2013, 23 patients (mean age, 66.7 ± 7.6 years) with primary knee osteoarthritis were recruited. Patients were divided into 2 groups based on pre-treatment knee society scores (KSS): n = 9, severe KSS ≤46; and n = 14, mild-moderate KSS >46. Synovial fluid was analyzed to determine levels of antioxidants, iron concentrations and lipid peroxidation (thiobarbituric acid reactive substances [TBARs]). Baseline data, including Kellgren- Lawrence radiographic grade, were collected for all patients.ResultsMean KSS was 49.1 ± 10.8. Total mean concentrations of antioxidants were 2.29 ± 1.71 ng/mL vitamin E and 0.47 ± 0.51 nmol/mL glutathione (GSH). Total mean levels of TBARs and iron were 1.20 ± 0.37 nmol/mL and 2.13 ± 0.82 μg/mL, respectively. The mean concentration of vitamin E was inversely related to severity of knee osteoarthritis (mild-moderate > severe, p = 0.006). There were no significant differences between the two groups in terms of GSH (p = 0.90), TBARs (p = 0.84) or iron levels (p = 0.27). There was a significant positive correlation between KSS and vitamin E concentration (r = 0.43, p = 0.04). No significant correlations were shown between KSS and GSH (r = -0.01, p = 0.97), TBARs (r = -0.06, p = 0.81) or iron level (r = 0.28, p = 0.20).ConclusionUsing synovial fluid profiles, vitamin E concentration is an essential prognostic factor in primary knee osteoarthritis and may act as a basis for treatment directions. The concentration of vitamin E decreased as the clinical severity of primary knee osteoarthritis increased.

The Role Played by Ferroptosis in Osteoarthritis: Evidence Based on Iron Dyshomeostasis and Lipid Peroxidation

“…Specifically, Sutipornpalangkul et al [ 53 ] found that the vitamin E concentration in synovial fluid was inversely related to primary knee OA severity in 32 patients, indicating that oxidative stress increased as the clinical severity of OA increased. A similar study later confirmed this result [ 54 ]. Regarding the therapeutic effect of vitamin E supplementation, Bhattacharya et al [ 55 ] conducted a cohort study in which the levels of antioxidant enzymes, such as GPX and MDA in plasma, were estimated in 40 healthy individuals (control group) and in 40 OA patients 50–70 years old before and after 3 months of vitamin E supplementation; the patients were divided into group I (no supplementation) and group II (200 mg/day vitamin E supplementation.…”

Danshen prevents articular cartilage degeneration via antioxidation in rabbits with osteoarthritis

“…Glutathione (GSH) is a naturally occurring tripeptide with nucleophilic and reducing properties that play a central role in the antioxidant system of most aerobic cells. Since GSH is a naturally occurring antioxidant with several functions including detoxification of xenobiotics and removal of hydroperoxides and free radicals, GSH concentration has been determined in many studies on oxidative stress 15,16 .…”

Danshen Attenuates Intervertebral Disc Degeneration via Antioxidation in SD Rats

“…GSH is an important antioxidant, which is essential in the regulation of protein disulfide bonds and the treatment of electrophiles and oxidants. The determination of the GSH concentration is indispensable in many studies on oxidative stress [ 12 , 13 ].…”