Effects of Catalpa Alcohol From Rehmannia glutinosa on Calcium-Binding Protein, Interleukin-1β, and Galectin-3 in Synovial Tissues of Rats With Knee Osteoarthritis

Abstract

Objectives We aimed to evaluate the effects of catalpa alcohol from Rehmannia glutinosa on the expressions of calcium-binding protein (S100A12), interleukin-1β (IL-1β), and galectin-3 in the synovium of rats with early knee osteoarthritis (KOA). Methods Fifty-two adult male Wistar rats aged 3 to 8 weeks were divided into normal control (n = 16), model (n = 12), low-dose (n = 12), and high-dose groups (n = 12). On the 10th day after modeling, 6 rats in normal control group and 6 in the other 3 groups were randomly selected. X-ray and 3-dimensional computed tomography (3D CT) images of the left knee joint were taken under live anesthesia. The joint cavity of sacrificed rats was opened to observe cartilage surface. After 28 consecutive days of administration, the synovial tissue of left knee joint was collected. Results The S100A12, IL-1β, and galectin-3 levels in synovial tissue were detected by immunohistochemistry and ELISA. There were articular cartilage defects in left knees. Radiologic examination showed significant joint space narrowing and hyperplasia, and 3D CT joint space value decreased (P < 0.05). The Mankins and OARSI scores of synovial histopathology were significantly different (P < 0.05). The S100A12, IL-1β, and galectin-3 levels in synovial tissue of the model group significantly exceeded those of the normal control group (P < 0.01). Compared with the model group, such levels of low-dose (P < 0.05) and high-dose groups (P < 0.01) were significantly lower. Conclusions The S100A12, IL-1β and galectin-3 levels in synovium tissue decreased with rising concentration of catalpa alcohol from R. glutinosa. Therefore, this drug is potentially suitable for inhibiting an inflammatory response to delay the progression of KOA.