Bioactive compounds Many bioactive compounds showed anti-inflammatory activities on albino rat. In April 2014, plumericin from the Amazonian plant Himatanthus sucuuba has been described as a potent anti-inflammatory agent in vitro and in vivo. Essential oils and extracts from some condiment plants have also been reported with anti-inflammatory activities—due to the presence of bioactive compounds such as eugenol, eucalyptol, menthone, and menthol. Long-term effects Anti-inflammatory treatment trials for existing Alzheimer's disease have typically shown little to no effect on halting or reversing the disease. Research and clinical trials continue. Two studies from 2012 and 2013 found that regular use of aspirin for over ten years is associated with an increase in the risk of macular degeneration. Ice treatment Applying ice, or even cool water, to a tissue injury has an anti-inflammatory effect, and is often suggested as an injury treatment and pain management technique for athletes. One common approach is rest, ice, compression and elevation. Cool temperatures inhibit local blood circulation, which reduces swelling in the injured tissue and relieves pain. Health supplements In addition to medical drugs, some herbs and health supplements may have anti-inflammatory qualities: bromelain from pineapples (Ananas comosus). Cannabichromene, a cannabinoid, also has anti-inflammatory effect. Honokiol from Magnolia inhibits platelet aggregation, and works as an inverse agonist at the CB2 receptor. Black seed (Nigella sativa) has shown anti-inflammatory effect due to its high thymoquinone content. St. John's wort's chief constituent, hyperforin, has been found to be a potent COX-1 and 5-LO inhibitor, with anti-inflammatory effect several fold that of aspirin. Coal tar has been used for centuries for its anti-inflammatory and analgesic effects. Oral administration for central effects is now rare as coal tar also contains a range of dangerous and carcinogenic compounds, and does not allow for the administration of standardized doses, although some doctors readily utilize coal tar preparations for topical administration (e.g., Denorex, Psoriasin) in the treatment of skin conditions such as eczema and atopic dermatitis. Many modern analgesics and anti-inflammatory agents (such as paracetamol and its predecessor phenacetin) are derived from compounds which were originally discovered during studies to elucidate the chemicals responsible for the tars reputed health benefits. Dietary patterns Nutrition is linked to oxidative stress and inflammation. Foods that promote oxidative stress can also promote inflammation, while antioxidative foods may help bringing inflammation levels down. Other pathways may include the link between nutrition and hormones that effect inflammation. Observational studies