In vitro studies
In in vitro studies, four authors investigated effects of corticosteroids in normal cartilage/tissues (without inflammatory stimulus) (Doyle et al., 2005; Byron et al., 2008; Palma et al., 2019a; Palma et al., 2019b) and seven studies included normal tissues exposed to corticosteroids as one of the control groups and reported their results (Murphy et al., 2000; Fubini et al., 2001; Frean, Cambridge & Lees, 2002; Tung, Venta & Caron, 2002; Tung et al., 2002; Richardson & Dodge, 2003; Busschers, Holt & Richardson, 2010). The corticosteroids were MPA/MPS (four studies), TA (four studies), DEX (four studies), and BTM (one study). Concentrations ranged from 0.001 to 10 mg/mL or 102 to 1010 for MPA, 0.06 mg/mL or 10-10 M to 10-4 M for TA, 10-10 M to 10-4 M for DEX, and 0.1 to 100 𝜇g/mL for BTM. Nine studies were performed with equine chondrocytes (Fubini et al., 2001; Tung et al., 2002; Tung, Venta & Caron, 2002; Richardson & Dodge, 2003; Doyle et al., 2005; Byron et al., 2008; Busschers, Holt & Richardson, 2010; Palma et al., 2019a; Palma et al., 2019b), one with equine cartilage explants (Murphy et al., 2000) and one with experiments in both (Frean, Cambridge & Lees, 2002). Follow-ups ranged from 6 hours to 13 days. Outcome measurements included PG and collagen synthesis, PG degradation, total PG and GAG, GAG content in cartilage, total GAG content in media, total cartilage DNA content, oxidative profile, gene expression proteolytic enzymes, extracellular matrix (ECM) components, and inflammatory proteins.