Nettles Inhibitory Effect on Allergies

NAPLES, Fla.Scientists with HerbalScience identified specific bioactives in nettle leaf extracts that inhibit in vitro receptors and enzymes known to be key in generating symptoms of allergic rhinitis, or hay fever. An article detailing the research, "Nettle Extract (Urtica dioica) Affects Key Receptors and Enzymes Associated with Allergic Rhinitis," was published in the July 2009 issue of Phythotherapy Research, a peer-reviewed scientific journal. The authors are affiliated with HerbalScience Group LLC, a company dedicated to applying advanced science and technology to the production of botanical drugs and nutraceuticals, and the University of Miami Leonard M. Miller School of Medicine.

The study utilized a proprietary nettle extract prepared using HerbalScience's patented extraction technologies, which standardize the chemical profile of any selected botanical in order to deliver a compositionally and functionally consistent product, batch to batch. Separate assays were conducted to determine the extent of anti-inflammatory activities of the nettle extract in targeting key cellular-level processes that generate the symptoms of allergic rhinitis. The results showed the nettle extract has multiple anti-inflammatory activities that include:  H1 receptor inactivation and inhibition, which blocks histamine production and release; tryptase inhibition, which blocks mast cell degranulation and the subsequent release of cytokines and chemokines that cause allergy symptoms such as sneezing, nasal congestion and itchy and watery eyes; COX-1 and COX-2 (pro-inflammatory enzymes) inhibition, which blocks the formation of prostaglandin, known inflammatory mediators that trigger many responses associated with allergies and arthritis; and hematopoietic prostaglandin D2 synthase (HPGDS) inhibition, which specifically blocks prostaglandin D2 production, a primary pro-inflammatory mediator in allergic rhinitis.

In addition to documenting the anti-inflammatory activities of the nettle extract, the study used advanced DART (direct analysis in real time) time-of-flight mass spectrometry technology to identify a number of specific bioactive compounds in the nettle extract that provided inhibition activities. The results suggest that the synergistic interactions of the many functional bioactives present address multiple steps in the pro-inflammatory cascade associated with seasonal allergies and other inflammatory disorders.