The pharmacological effects of glucosamine chondroitin, chitosan, and phytoestrogen on knee osteoarthritis

Osteoarthritis (OA) of the knee significantly disrupts daily activities and reduces quality of life due to pain. The primary treatment involves anti-inflammatories, which can cause stomach issues. Alternative therapies, including glucosamine, chondroitin, chitosan, and phytoestrogens, are being explored, but their effects need further study. While some benefits may be due to the placebo effect, researchers conducted a literature review to determine their actual benefits. A review of seven meta-analyses found that glucosamine and chondroitin can alleviate pain, reduce stiffness, improve function, and reduce joint space narrowing (JSN) in OA patients. Chitosan's use in intra-articular injections for OA has been studied in four observational studies and clinical trials on animals, but the effects of oral chitosan supplements remain unknown. A literature review on phytoestrogens in OA, particularly in post-menopausal women, identified four relevant studies. The review suggests that glucosamine, chondroitin, chitosan, and phytoestrogens have significant therapeutic benefits for OA, such as reducing pain (measured by VAS score), relieving stiffness, and improving functionality due to their anti-inflammatory and chondroprotective effects. Therefore, additional randomized controlled trials are needed to confirm their effectiveness in managing knee OA.