Andrographolide protected the loss of collagen and uronic acid from cartilage explant tissues induced by IL-1β. The equine cartilage explants were cultured in the conditioned media containing IL-1β (25 ng/mL), with or without andrographolide (10 to 50 µM), or left untreated as the control. After 21 days of treatment period, the cartilage tissues were digested with papain and levels of collagen and UA were measured by colorimetric assays. The results were expressed as a percentage relative to the control. Data are expressed as mean ± SD of three independent experiments. The significant differences were tested by one-way ANOVA at (, #). Significant difference from the control () and IL-1β treated group (#), respectively.