Evaluation of anise essential oil effects on LPS-induced inflammation in human normal tracheal and bronchial cells (HBEpC/HTEpC)

Pimpinella anisum L., well known as aniseed, is an annual herb belonging to the Apiaceae family and native to the Mediterranean area. The plant is used for its fruits that are small schizocarps yielding 1-4% of a yellow essential oil containing 75-90% of (E)-anethole. Owing to its aromatic properties, aniseed is widely used in foodstuffs, as ingredient of alcoholic (brandy and liquers) and non alcoholic beverages, confectionery and bakery products. Aniseed enjoys a good reputation also in the Mediterranean traditional medicine as digestive, carminative, diuretic, tranquillizer, galactugoge, and mild expectorant [1]. Given its traditional use as expectorant agent, in this work we investigated the aniseed essential oil(AEO) effects on two primary human airway (bronchial and tracheal) epithelial cell lines (HBEpC/HTEpC), in a in vitro model of lung acute inflammation. Both cell lines were treated with Lipopolysaccharides (LPS) from E. coli, to mimic an inflammation response. To determine the effect of AEO in reducing inflammatory markers and in regulating mucolytic activity, both LPS-treated cell lines were co-treated with AEO. We evaluated the gene and protein expression levels of IL-1, IL-8 and Muc5ac, in LPS- and LPS+AEO-treated cells by RT/PCR and Western Blot analysis, respectively. Since inflammation is thigtly correlated with lung cancer, the effects of AEO on human lung cancer cell line (H460) were investigated as well. Summarizing, the results showed that AEO reduced the release of pro-inflammatory cytokines (IL-1 beta and IL-8) in HBEpC - and HTEpC LPS-treated cells and, on the other hand, stimulated the release of Muc5ac protein in both cells. FInally, we preliminarily evaluated the role of AEO in inducing cytotoxic effects on H460 lung cancer cells. Our results, although preliminary, may support the traditional use of aniseeds in the treatment of respiratory diseases and, at the same time, may open new applications as nutraceutical.