HMOX1 and arthritic joint disease: Moreover, thanks to the action on antioxidant defense systems, such as Nrf2/HO-1, these two mushrooms seem to be able to act indirectly also on LXA4, a metabolic product of arachidonic acid, which is considered an endogenous “stop signal” for inflammation and which has been shown to have significant anti-inflammatory abilities in a variety of diseases such as nephritis, periodontitis, arthritis and inflammatory bowel disease [64].