How Nettle extract (Urtica dioica) works to stop allergies

Using a Stinging Nettle Extract (Urtica dioica) on immune cells it was found that it inhibits key haywire immune system reactions that trigger the inflammation and symptoms in allergic reactions in people with pollen allergies. Nettle blocks the receptor site for histamine and the enzyme known as mast cell tryptase that allows the white blood cells to release its granules that are bundled with histamine and bradykinin and a host of other inflammation causing immune system mediators that cause the symptoms of hay fever. The nettle extract also inhibits prostaglandin formation through inhibition of Cyclooxygenase-1 (COX-1), Cyclooxygenase-2 (COX-2), and Hematopoietic Prostaglandin D(2) synthase (HPGDS), central enzymes in pro-inflammatory pathways. These results provide for the first time, a mechanistic understanding of thefa role of nettle extracts in reducing allergic and other inflammatory responses in vitro. The study is published in the July 2009 issue of the journal Phytotherapy Research.