title: Sulforaphane-rich broccoli sprout extract attenuates nasal allergic response to diesel exhaust particles.
abstract: The generation of oxidative stress by ambient air pollution particles contributes to the development of allergic sensitization and asthma, as demonstrated by intranasal challenge with well-characterized diesel exhaust particle (DEP) suspensions in humans. This effect is due to the presence of redox active organic chemicals in DEP, and can be suppressed by antioxidants and inducers of phase II enzymes in animals. In this communication, we determined whether the administration of a standardized broccoli sprout extract (BSE), which contains a reproducible amount of the sulforaphane (SFN) precursor, glucoraphanin, could be used to suppress the nasal inflammatory response in human subjects challenged with 300 μg of an aqueous DEP suspension (equivalent to daily PM exposure levels on a Los Angeles freeway). SFN is capable of inducing an antioxidant and phase II response via activation of the nuclear transcription factor (erythroid-derived 2)-like 2 (Nrf2). Previous studies have shown that 70-90% SFN delivered by BSE is absorbed, metabolized, and excreted in humans. An initial intranasal challenge with DEP in 29 human subjects was used to characterize the magnitude of the inflammatory response. Following a 4 week washout, a BSE that delivers a reproducible and standardized dose of 100 μmol SFN in mango juice was administered daily for four days. The nasal DEP challenge was repeated and lavage fluid collected to perform white blood cell (WBC) counts. The average nasal WBC increased by 66% over the initial screening levels and by 85% over the control levels 24 hours after DEP exposure. However, total cell counts decreased by 54% when DEP challenge was preceded by daily BSE administration for 4 days (p < 0.001). Since the SFN dose in these studies is equivalent to the consumption of 100-200 g broccoli, our study demonstrates the potential preventive and therapeutic potential of broccoli or broccoli sprouts rich in glucoraphanin for reducing the impact of particulate pollution on allergic disease and asthma.
authors.affiliation: UCLA Center for Human Nutrition and the Division of NanoMedicine, David Geffen School of Medicine at UCLA, 900 Veteran Avenue, Room 12-217, 12-217 Warren Hall, Box 951742, Los Angeles, California 90095, USA. dheber@mednet.ucla.edu.
authors.forename: David
authors.initials: D
authors.lastname: Heber
authors.forename: Zhaoping
authors.initials: Z
authors.lastname: Li
authors.forename: Maria
authors.initials: M
authors.lastname: Garcia-Lloret
authors.forename: Angela M
authors.initials: AM
authors.lastname: Wong
authors.forename: Tsz Ying Amy
authors.initials: TY
authors.lastname: Lee
authors.forename: Gail
authors.initials: G
authors.lastname: Thames
authors.forename: Michael
authors.initials: M
authors.lastname: Krak
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Andre
authors.initials: A
authors.lastname: Nel
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000276:immunology*; D001937:Brassica / Q000737:chemistry*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology; D017879:Isothiocyanates / Q000008:administration & dosage*; D008297:Male; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000276:immunology; D009666:Nose / Q000187:drug effects / Q000276:immunology*; D010936:Plant Extracts / Q000008:administration & dosage*; D013454:Sulfoxides; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D017879:Isothiocyanates; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D010936:Plant Extracts; D013454:Sulfoxides; D001335:Vehicle Emissions; C016766:sulforaphane