Scrodentoids H and I, a Pair of Natural Epimerides from Scrophularia dentata, Inhibit Inflammation through JNK‐STAT3 Axis in THP‐1 Cells

Abstract

Background. Scrophularia dentata is an important medicinal plant and used for the treatment of exanthema and fever in Traditional Tibetan Medicine. Scrodentoids H and I (SHI), a pair of epimerides of C19-norditerpenoids isolated from Scrophularia dentata, could transfer to each other in room temperature and were firstly reported in our previous work. Here, we first reported the anti-inflammatory effects of SHI on LPS-induced inflammation. Purpose. To evaluate the anti-inflammatory property of SHI, we investigated the effects of SHI on LPS-activated THP-1 cells. Methods. THP-1 human macrophages were pretreated with SHI and stimulated with LPS. Proinflammatory cytokines IL-1β and IL-6 were measured by RT-PCR and enzyme-linked immunosorbent assays (ELISA). The mechanism of action involving phosphorylation of ERK, JNK, P38, and STAT3 was measured by western Blot. The NF-κB promoter activity was evaluated by Dual-Luciferase Reporter Assay System in TNF-α stimulated 293T cells. Results. SHI dose-dependently reduced the production of proinflammatory cytokines IL-1β and IL-6. The ability of SHI to reduce production of cytokines is associated with phosphorylation depress of JNK and STAT3 rather than p38, ERK, and NF-κB promoter. Conclusions. Our experimental results indicated that anti-inflammatory effects of SHI exhibit attenuation of LPS-induced inflammation and inhibit activation through JNK/STAT3 pathway in macrophages. These results suggest that SHI might have a potential in treating inflammatory disease.

A Comprehensive Review of the Classification, Sources, Phytochemistry, and Pharmacology of Norditerpenes

“…In response to inflammatory stimuli, STAT3 acts as a transcription factor that directly governs the expression of pro-inflammatory cytokines. Scrodentoids H and I might be beneficial in the treatment of inflammatory diseases, like ulcerative colitis and atherosclerotic diseases [ 105 ].…”