Shea Nut Oil Triterpene Concentrate Attenuates Knee Osteoarthritis Development in Rats: Evidence from Knee Joint Histology

BACKGROUND: Shea nut oil triterpene concentrate is considered to have anti-inflammatory and antioxidant properties. Traditionally, it has been used to treat arthritic conditions in humans. This study aimed to investigate the effect of attenuating osteoarthritis (OA)-induced pain and joint destruction in rats by administering shea nut oil triterpene concentrate (SheaFlex75, which is more than 50% triterpenes). METHODS: An anterior cruciate ligament transaction (ACLT) with medial meniscectomy (MMx) was used to induce OA in male Wistar rats. Different doses of SheaFlex75 (111.6 mg/kg, 223.2 mg/kg, and 446.4 mg/kg) were then intragastrically administered daily for 12 weeks after surgery. Body weight and the width of the knee joint were measured weekly. Additionally, incapacitance tests were performed at weeks 2, 4, 6, 8, 10 and 12 to measure the weight bearing of the hind limbs, and the morphology and histopathology of the medial femoral condyles were examined and were evaluated using the Osteoarthritis Research Society International (OARSI) scoring system. RESULTS: This study showed that SheaFlex75 reduced the swelling of the knee joint with OA and rectified its weight bearing after ACLT plus MMx surgery in rats. Treatment with SheaFlex75 also decreased ACLT plus MMx surgery-induced knee joint matrix loss and cartilage degeneration. CONCLUSION: SheaFlex75 relieves the symptoms of OA and protects cartilage from degeneration. SheaFlex75 thus has the potential to be an ideal nutraceutical supplement for joint protection, particularly for injured knee joints.