Chemical constituents of the rhizomes of Hedychium coronarium and their inhibitory effect on the pro-inflammatory cytokines production LPS-stimulated in bone marrow-derived dendritic cells

The rhizomes of Hedychium coronarium have been used for the treatment of inflammation, skin diseases, headache, and sharp pain due to rheumatism in traditional medicine. From this plant, three new labdane-type diterpenes 1–3, named coronarins G–I as well as seven known 4–10, coronarin D, coronarin D methyl ether, hedyforrestin C, (E)-nerolidol, β-sitosterol, daucosterol, and stigmasterol were isolated. Their chemical structures were elucidated by mass, 1D- and 2D-nuclear magnetic resonance spectroscopy. They were evaluated for inhibitory effects on lipopolysaccharide-stimulated production of pro-inflammatory cytokines in bone marrow-derived dendritic cells. Among of them, compounds 1, 2, and 6 were significant inhibitors of LPS-stimulated TNF-α, IL-6, and IL-12 p40 productions with IC₅₀ ranging from 0.19 ± 0.11 to 10.38 ± 2.34 μM. The remains of compounds showed inactivity or due to cytotoxicity. These results warrant further studies concerning the potential anti-inflammatory benefits of labdane-type diterpenes from H. coronarium.