MMP9 and Arthritis: Hemshekhar et al., 2012 showed that crocin can reduce the serum concentration of inflammatory factors including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), NF-κB, ROS, cyclooxygenase (COX)-2, and prostaglandin E2 (PGE) as well as matrix metalloproteinases (MMPs)-3, MMP-9, MMP-13 in arthritis model.38