Osteoarthritis (OA) is a joint disorder caused by wear and tear on the joint over time; as a result, the protective cartilage of the bone in the joint gradually wears down. The lifetime risk of developing OA in the knee, with symptoms such as pain, aching, and stiffness, is 40% in men and 47% in women. It is estimated that approximately 19% of Americans aged 45 and older are affected by knee OA. Knee OA accounts for 83% of the global burden caused by all OA types. Pain and stiffness in knees, a large weight-bearing joint, often leads to disability, which interferes with daily life activities and demands expensive medical treatments or care. Losina et al. reported that in the United States, the average lifetime costs for symptomatic knee OA management is $12,400 USD, but the cost can be higher with knee surgeries for advanced OA. The economic burden is expected to continue increasing in the near future due to the aging population and increasing prevalence of obesity in many developed countries.

Although the exact etiology of OA is unknown, many risk factors are associated with the development of knee OA, such as obesity, repetitive use of joints, age, and previous knee injury or surgery. Multiple studies have shown a positive association between pro-inflammatory cytokines (e.g. tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) and OA development. Cytokine-induced nuclear factor-κB (NF-κB) activation can stimulate articular chondrocyte catabolism and extracellular matrix degradation, leading to the breakdown of articular cartilage. The severity of cartilage disintegration and osteophyte (a bony outgrowth) formation can be identified radiographically and used for the Kellgren-Lawrence (KL) grading scheme. A KL score of one (doubtful narrowing of the joint space with possible osteophyte formation) is considered possible OA, while a score of two (possible narrowing of joint space with definite osteophyte formation) or three (definite narrowing of joint space and moderate osteophyte formation) is considered as a definite/mild OA.

It is crucial to treat OA early, before it develops into more severe cases and causes mobility disability. The first step of OA treatment is exercise and/or physiotherapy, which has demonstrated long-term benefits but often difficult to maintain compliance. Once the pain is difficult to manage, over-the-counter medicines such as Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are introduced to provide relief. NSAIDs are effective in reducing pain, however, long-term usage requires medical supervision. Chronic NSAID use is associated with high incidence of adverse events such as upper gastrointestinal tract problems, kidney and liver injury, hypertension, and congestive heart failure. When the abovementioned treatments are ineffective, intra-articular injections of hyaluronic acid, cortisol, or platelet rich plasma are applied and proven effective, but they can be costly and may cause reactive flares or infections at the injection site. Surgery serves as last resort; it is a successful treatment for advanced OA, but it is invasive and may increase risks of infection, bleeding, and deep vein thrombosis. Given the limitations of current OA treatment methods, there is an increasing demand for effective and safer alternatives, such as natural health products with pain-relieving potential.

The investigational product, JointAlive™, is a supplement designed to alleviate knee OA symptoms and to improve knee functionality. JointAlive™ contains extract from flowering plants that are endemic to China.The main bioactive component is icariin; a flavonoid glycoside demonstrating various antioxidant and anti-inflammatory benefits. Numerous in vitro cell culture studies showed that icariin has the potential to suppress inflammatory pathways involved in OA. In rodent OA models, joint injection of icariin for 32 and 84 days was found to protect the articular cartilage from degeneration.

The present study will investigate the safety and efficacy of JointAlive™ in reducing knee OA symptoms and improving joint functionality in an otherwise healthy adult population with mild to moderate knee OA. Based on the previous studies conducted on the ingredients of this investigational product and their previous application in OA, participants identifying mild or moderate OA in a target knee will be investigated in this study. As OA is a secondary complication in sports injuries as well as a primary development during aging, an age range between 40-75 years will be considered for enrolment. The Kellgren-Lawrence grading scale will be used to confirm OA. As well, BMI cut offs between 18.5 and 29.9 kg/m2 will be considered to excluded those with complications due to obesity and the associated increase in concomitant medication use. To allow for pain relief, as this study involves a placebo group, a rescue medication will be provided. However, in order to ensure that the capture of pain in the target knee is unbiased, participants will be required to abstain from the rescue medication use for 48 hours prior to their clinic visits. Confounders due to medical history and concomitant medications will be ensured by several targeted exclusion criteria with the intent of decreasing potential confounders of the study results.