Are herbal remedies effective in osteoarthritis and rheumatoid arthritis?
Yes. Herbal products have been referred to as the most commonly used and abused form of alternative therapies. Herbs are claimed to treat arthritis and other diseases, but are there truths to the claim? Yes. Data does point toward a potential for phytoantiinflammation, likely through effects on eicosanoid metabolism.
OA: randomized controlled trials (RCTs) have shown that devil’s claw ( Harpagophytum procumbens ), bromelain (a pineapple extract), and willow bark extract are effective in reducing pain in patients with OA. Phytodolor (golden rod, aspen leaf/bark, and ash bark) has been shown in RCTs to be as effective as NSAIDs in treating OA pain. Nettle ( Urtica dioica ) inhibits cyclooxygenase and lipoxygenase pathways as well as suppresses cytokine release. Ginger ( Zingibar officinale ) contains gingerol and shogaol that inhibits PG and LT production. Uncontrolled studies have shown benefit. Note that ginger can interact with antiplatelet and anticoagulant medications, which may cause excess bleeding during surgery. Avocado soybean unsaponifiables (ASU) are reported to slow progression of hip and knee OA. ASU contain plant sterols that are chondroprotective by their antiinflammatory and proanabolic effects on articular chondrocytes. Green-lipped mussels ( Perna canaliculus ) contain omega-3 FAs, which are converted into less inflammatory mediators (PGE3, LTB5).
RA: a herb used in China is extract of thunder god vine ( Tripterygium wilfordii Hook F). Its active compounds are celastrol and triptolide, which inhibit nuclear factor κβ and T-cell proliferation as well as production of proinflammatory cytokines to include interleukin (IL)-2 and gamma-interferon. An RCT showed that it was superior to sulfasalazine in the treatment of RA. Side effects, however, were significant. Cat’s claw ( Uncaria tomentosa ) and turmeric ( Curcuma longa ) contain immunomodulatory and antiinflammatory ingredients and have been shown in small RCTs to be moderately effective in RA. Turmeric is also used to treat OA pain by depleting substance P from nerve root endings similar to capsaicin. Tibetan five-nectar formula medicated bath therapy is derived from five types of plants that are considered antiinflammatory. Studies in RA demonstrating benefit are of poor quality and cannot be critically evaluated.