Alveolar macrophage is the predominant cell type in the lung and is thought to be the major target for anti-inflammatory
therapy in
chronic obstructive pulmonary disease (
COPD).
Aromatherapy using natural
essential oils with anti-inflammatory effects for inhalable administration is a potential complementary and alternative
therapy for
COPD treatment. The Gardenia jasminoides flower is famous for its fragrance in East Asia and is used for treating colds and lung problems in
folk medicine. Therefore, in the present study, flower
essential oils from two main medicinal gardenia varieties (G. jasminoides J. Ellis and G. jasminoides f. longicarpa Z.W. Xie & M. Okada) were extracted by hydro-distillation, and their chemical components were analyzed by GC-MS. The anti-inflammatory effects of the two
essential oils and their main ingredients were further studied on
lipopolysaccharide (LPS)-induced models in murine alveolar macrophages (MH-S). The results indicated that the chemical constituents of the two gardenia varieties were quite different. Alcohol accounted for 53.8% of the G. jasminoides
essential oil, followed by
terpenes (16.01%).
Terpenes accounted for 34.32% of the G. jasminoides f. longicarpa
essential oil, followed by
alcohols (19.6%) and
esters (13.85%). Both the two gardenia
essential oils inhibited the LPS-induced
nitric oxide (NO) release and reduced the production of
tumor necrosis factor-α (TNF-α) and
prostaglandin E2 (
PGE2) in the MH-S cells.
Linalool and α-
farnesene dose-dependently reduced the NO release in the MH-S cells.
Linalool and α-
farnesene did not affect the
PGE2 production but regulated the expression of TNF- α. In addition to
linalool and α-
farnesene, other components in the gardenia flower
essential oils appeared to be able to act as
anti-inflammatory agents and influence the
PGE2 pathway.