Solidagenone from Solidago chilensis Meyen inhibits skin inflammation in experimental models

Solidagenone (SOL) is a labdane‐type diterpenoid found in Solidago chilensis, a plant traditionally used to treat skin diseases, kidney pain and ovarian inflammation. In this study, the topical anti‐inflammatory activity of SOL was evaluated using in vivo and in silico assays. Croton oil‐, arachidonic acid (AA)‐ and phenol‐induced ear oedema mouse models were applied in the in vivo studies. Myeloperoxidase (MPO) and N‐acetyl‐β‐D‐glucosaminidase (NAG) activities and tumour necrosis factor alpha (TNF‐α), interleukin‐6 (IL‐6) and nitric oxide (NO) levels were determined, as well as histopathological analyses were conducted. Interaction profiles between SOL and cyclooxygenase‐1 (COX‐1), cyclooxygenase‐2 (COX‐2), glucocorticoid receptor, estradiol‐17‐β‐dehydrogenase and prostaglandin‐E(2)‐9‐reductase were established using molecular docking. SOL significantly inhibited croton oil‐, AA‐ and phenol‐induced ear oedema (P < .001) at doses of 0.1, 0.5 and 1.0 mg/ear. The MPO and NAG activities and TNF‐α, IL‐6 and NO levels were decreased (P < .001). The histopathological data revealed that inflammatory parameters (oedema thickness, leucocyte infiltration and vasodilatation) were reduced by treatment with SOL at doses of 0.1, 0.5 and 1.0 mg/ear. The docking study showed that SOL interacts with COX‐1 and prostaglandin‐E(2)‐9‐reductase through hydrogen bonding, inhibiting these enzymes. These results indicate that SOL may be a promising compound for the treatment of cutaneous inflammatory disorders and has potential as a topical anti‐inflammatory agent.