COX 2

Natural COX-2 inhibitors

Natural alternatives such as herbal extracts of turmeric, ginger, rosemary, green tea and their active phytochemical constituents are reported to be effective COX-2 inhibitors. Others such as Boswellia serrata extract (boswellic acids) inhibit the formation of inflammatory leukotrienes. Some of these herbal extracts such as curcuminoids from turmeric are known to also inhibit other inflammatory molecules such as cytokines.

Boswellic acids are specific nonredox inhibitors of 5- lipoxygenase the enzyme which catalyzes conversion of arachidonic acid to inflammatory leukotrienes. Boswellic acids also inhibit the enzyme human leukocyte elastase (HLE), matrix metalloprotease enzyme (MMP) which catalyzes connective tissue breakdown. Boswellic acids show anti-complementary activity. Complement proteins are known to trigger inflammatory mediators. 2
Curcuminoids from turmeric roots exhibit an inhibitory effect on COX-2 and on the production of other inflammatory mediators such as interleukins and TNF-alpha (that generates inflammatory cytokines). Such effects are believed to be responsible for the beneficial role of curcuminoids in colorectal cancer. 3
Green tea polyphenols are also reported to inhibit COX-2 and TNF-alpha. Similarly, ginger extract (6-gingerol and gingerdiones) is a dual inhibitor of inflammation, acting by inhibiting the formation of both prostaglandins and leukotrienes. 4
Ursolic acid (a natural constituent of Rosemary extract and Tulsi extract), its isomer, oleanolic acid (found in olive leaf extract) and rosmarinic acid (found in sage, rosemary , Tulsi, lemon balm and other medicinal plants) also inhibit COX-2 Ursolic and oleanolic acids also inhibit HLE activity. A study that compared the COX-2/COX-1 selectivity ratios of ursolic acid and oleanolic acid to those of the traditional NSAIDS, ibuprofen, naproxen, and indomethacin, and NS-398 (a synthetic selective COX-2 inhibitor), reported the following rank order : NS-398 > ursolic acid > oleanolic acid > ibuprofen > naproxen > indomethacin.