(P04-011-24) Chondroprotective Action of Tart Cherry in the Monosodium iodoacetate (MIA) Rat Model of Osteoarthritis

Objectives: This study investigated the dose-dependent effects of whole tart cherry in a monosodium iodoacetate (MIA) induced rat osteoarthritis (OA) model. OA is a common degenerative disease with no currently known cure.

Methods: Forty, 45-day-old female caesarean-derived (CD) rats were utilized. Thirty animals were injected with MIA to induce joint destruction. The MIA-induced rats were randomized into three groups of 10 animals each. The remaining 10 rats served as a control (non-MIA). All groups were fed a casein-based diet. Animals in the two MIA groups were fed whole tart cherry powder added to their diet at 5% and 10%, respectively. All groups were fed their respective diets for 48 days. Blinded to the treatment protocol, researchers evaluated mechanical allodynia at three time points during treatment. Upon euthanasia, right knee joints were excised and fixed. An independent researcher, blinded to the treatment protocol, examined and scored the stained joint specimens for inflammatory infiltration, synovial hyperplasia, and erosion of cartilage and bone. Real-time polymerase chain reaction (PCR) was conducted on cDNA to evaluate gene expression for various cartilage markers including metalloproteinases (MMP2 and MMP3).

Results: The mechanical allodynia force observed on Day 0 was significantly lower in all MIA groups compared to non-MIA. No significant impact of tart cherry feeding was observed. The total histology score for the MIA group was significantly higher than that of the control group, with significantly increased inflammatory infiltration, synovial hyperplasia, and erosion of cartilage and bone observed. We observed a reversal in the tart cherry-fed groups for scores related to these parameters. However, these lower scores did not reach significance. MMP3 expression was significantly upregulated in the MIA group compared to the control. This MMP3 expression was significantly downregulated in both tart cherry groups. MMP2 expression was also downregulated, but not significantly.

Conclusions: Incorporating tart cherry into the diets of rats with MIA-induced OA demonstrated a potential reduction in damage and inflammation in OA-affected joints. These results suggest that tart cherries and its bioactive constituents may impart cellular and molecular actions that could benefit cartilage metabolism.

Funding Sources: Cherry Marketing Institute