Using Freund’s adjuvant-induced arthritis rat model, Wu et al. found that honeysuckle extract inhibited the production of pro-inflammatory factors (TNF-α, IL-1β, IL-6, NO/iNOS, and cyclooxygenase-2 [COX-2]) and increased the activity of antioxidant enzymes (SOD, GSH-Px, and heme oxygenase-1 [HO-1]), attenuating arthritis symptoms (18). This evidence concerns the gene HMOX1 and Arthritis.