Kazani, SArm, Jonathan PBoyce, JoshuaChhay, HengDutile, StefanieWechsler, Michael EGovindarajulu, UshaIvester, PriscillaAinsworth, Hannah CSergeant, SusanChilton, Floyd HIsrael, Elliot2015-01-052014Kazani, S., J. P. Arm, J. Boyce, H. Chhay, S. Dutile, M. E. Wechsler, U. Govindarajulu, et al. 2014. “LTC4 synthase polymorphism modifies efficacy of botanical seed oil combination in asthma.” SpringerPlus 3 (1): 661. doi:10.1186/2193-1801-3-661. http://dx.doi.org/10.1186/2193-1801-3-661.2193-1801http://nrs.harvard.edu/urn-3:HUL.InstRepos:13581258Botanical seed oils reduce the generation of leukotrienes in patients with asthma. Our objective was to determine the efficacy of a botanical seed oil combination against airflow obstruction in asthma, and to determine the pharmacogenomic effect of the leukotriene C4 synthase (LTC4S) polymorphism A-444C. We conducted a randomized, double-blind, placebo-controlled, cross-over clinical trial in mild to moderate asthmatics to determine the change in FEV1 after 6 weeks of therapy with borage and echium seed oils versus corn oil placebo. We also examined the effect of the variant LTC4S -444C allele on the change in lung function. We did not identify a difference in FEV1 in the study cohort as a whole (n = 28), nor in the group of A homozygotes. In the C allele carriers (n = 9), FEV1 improved by 3% after treatment with borage and echium seed oils and declined by 4% after placebo corn oil (p = 0.02). All 9 C allele carriers demonstrated an improvement in their FEV1 on active treatment compared to placebo as compared to only 7 out of 19 A allele homozygotes (p = 0.007). We observed transient differences in ex vivo leukotriene generation from circulating basophils and granulocytes. We did not observe significant differences in urinary LTE4 levels. We conclude that compared to corn oil, a combination of borage and echium seed oils improves airflow obstruction in mild to moderate asthmatics who carry the variant allele in the LTC4S gene (A-444C). Botanical oil supplementation may have therapeutic potential in asthma if used in a personalized manner. Trial registration: This trial was registered at http://www.clinicaltrials.gov as NCT00806442.en-USAsthmaBorage oilEchium oilLeukotrienesLTCJournal Article2015-01-0510.1186/2193-1801-3-661