Anti-Inflammatory Activities of Constituents from Hayata Leaves and Their Mechanisms.

is an endemic species of Taiwan. Although most Cinnamomum plants have significant biological activity, the bioactivity investment of is rare. Since inflammation plays an important role in many diseases, anti-inflammatory compounds can be developed into healthcare products. Therefore, we first conducted a study on the anti-inflammatory activity of leaves. First, we examined the antiinflammation activity of essential oil from leaves, and it revealed potent anti-inflammatory activity. A total of 23 volatile compounds were identified in leaves' essential oil by using GC/MS analysis. Among them were 1,8-cineole (35.94%), α-eudesmol (6.17%), pinene (7.55%), sabinene (5.06%), and isobornyl acetate (4.81%). According to previous studies, 1,8-cineole might be an anti-inflammation principal compound of leaves. Next, the ethanolic extracts of leaves also exhibited good anti-inflammatory activity. Two bioactive compounds, isoburmanol () and burmanol (), were isolated from the ethyl acetate soluble fraction by using the bioactivity-guided separation protocol and spectroscopic analysis. was obtained from for the first time, and was isolated for the first time from natural resources. Both and could inhibit the production of nitric oxide (NO), and the IC values were 14.0 μM and 43.8 μM, RAW 264.7 cells after induction of lipopolysaccharide. Furthermore, and also revealed significant inhabitation effects on iNOS and COX-2 protein expression. The anti-inflammation activity of and was different from the common pathway of inhibiting NF-κB. Both of them could inhibit the production of NO and PGE by directly inhibiting the AP-1 (c-Jun) protein and then inhibiting the downstream iNOS and COX-2. Although both and possessed significant anti-inflammatory activity, the activity of was better than . Through molecular docking simulation analysis, the results show that and interact with AP-1, inhibit the binding of AP-1 to DNA, and cause AP-1 to fail to transcribe the related factors of inflammation. The binding ability of AP-1 and was stronger than , and that is the reason why exhibited better activities in both downstream proteins and inflammatory cytokines. Based on the results obtained in this study, the essential oil and and isolated from leaves have good anti-inflammatory activities, and it is expected to be used as a reference for the development of medical care products in the future.