Dietary Supplements of Shiikuwasha Extract Attenuates Osteoarthritis Progression in Meniscal/ligamentous Injury and Obese Rats

Osteoarthritis (OA), also called degenerative joint disease, is characterized by joint cartilage loss and is strongly linked to obesity. Medicine to alleviate pain is currently the only treatment. Shiikuwasha extract (SE) has been reported to possess valuable bioactive substances exhibiting anti-inflammatory, antiobesity, and anticancer effects. Research is limited to the use of SE in the treatment of OA and obesity. We performed both anterior cruciate ligament transections and medial meniscectomies to induce OA on Sprague-Dawley rats after 11 weeks of a high fat diet followed by 9 weeks of oral SE administration (300, 600, and 1500 mg/kg). This study showed that SE treatment could reduce weight gain and joint pain. Additionally, SE significantly decreased triglycerides and total cholesterol in plasma of the S1500 group but increased high-density lipoprotein cholesterol in the plasma of the S600 group. Meanwhile, plasma levels of tumor necrosis factor alpha (TNF-α) was significantly reduced in the S1500 groups. Histopathological findings confirmed administration of SE attenuated cartilage degeneration. Immunohistochemistry examination demonstrated that caspase 3 and phospho-Janus kinase 2 (p-JAK2) expression levels on chondrocytes were downregulated by SE treatment. Our findings demonstrate that SE can alleviate OA progression by improving obesity.