title: Topical anti-inflammatory and analgesic activity of kirenol isolated from Siegesbeckia orientalis.
abstract: BACKGROUND
  Siegesbeckia orientalis has been traditionally used as a topical anti-inflammatory and analgesic agent.
  
  
  OBJECTIVE
  Current study was designed to explore the topical anti-inflammatory and analgesic effects of a constituent isolated from Siegesbeckia orientalis (Compositae), in order to validate its folk use.
  
  
  METHODS
  Kirenol was isolated from ethanolic extract of Siegesbeckia orientalis. Several topical formulations containing kirenol were investigated for anti-inflammatory and analgesic activities in rat. The effects were studied using carrageenan-induced rat acute inflammation model, complete Freund's adjuvant (CFA)-induced chronic inflammation and formalin test in rats. Piroxicam gel and methyl salicylate ointment were studied as positive control for anti-inflammatory and analgesic activity, respectively.
  
  
  RESULTS
  The anti-inflammatory effect of kirenol 0.4-0.5% (w/w) was similar to the effect of piroxicam gel 4h after carrageenan injection. The analgesic activity of topical preparation with more than 0.4% (w/w) was observed in the late phase. These effects may be due, at least in part, to the pro-inflammatory cytokine production of IL-1β and TNF-α. The administration of kirenol cream at the dose of 0.3, 0.4 and 0.5% (w/w) significantly inhibited the development of joint swelling induced by CFA, which was auxiliary supported by histopathological studies.
  
  
  CONCLUSIONS
  Kirenol has demonstrated its significant potential to be further investigated for its discovery as a new lead compound for management of topical pain and inflammation, although further pharmacological research is necessary to fully understand its mechanism of action. It also supports the potential beneficial effect of topically administered Siegesbeckia orientalis in inflammatory diseases.
authors.affiliation: Key Laboratory of Natural Medicinal Chemistry and Resources Evaluation of Hubei Province, College of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, PR Chinaany. jpwang1001@163.com
authors.forename: Jian-ping
authors.initials: JP
authors.lastname: Wang
authors.forename: Ya-ming
authors.initials: YM
authors.lastname: Zhou
authors.forename: Yu-jie
authors.initials: YJ
authors.lastname: Ye
authors.forename: Xian-mei
authors.initials: XM
authors.lastname: Shang
authors.forename: Ya-ling
authors.initials: YL
authors.lastname: Cai
authors.forename: Chao-mei
authors.initials: CM
authors.lastname: Xiong
authors.forename: Yun-Xia
authors.initials: YX
authors.lastname: Wu
authors.forename: Hai-Xing
authors.initials: HX
authors.lastname: Xu
mesh_terms: D000287:Administration, Topical; D000700:Analgesics / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000276:immunology / Q000517:prevention & control*; D019659:Asteraceae / Q000737:chemistry; D002351:Carrageenan; D004224:Diterpenes / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D000431:Ethanol / Q000737:chemistry; D005557:Formaldehyde; D005620:Freund's Adjuvant; D007249:Inflammation / Q000139:chemically induced / Q000276:immunology / Q000517:prevention & control*; D018836:Inflammation Mediators / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D010146:Pain / Q000139:chemically induced / Q000276:immunology / Q000517:prevention & control*; D010894:Piroxicam / Q000494:pharmacology; D035261:Plant Components, Aerial; D010946:Plants, Medicinal; D051381:Rats; D012459:Salicylates / Q000494:pharmacology; D012997:Solvents / Q000737:chemistry; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000700:Analgesics; D000893:Anti-Inflammatory Agents; D004224:Diterpenes; D004365:Drugs, Chinese Herbal; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D012459:Salicylates; D012997:Solvents; D014409:Tumor Necrosis Factor-alpha; C560087:kirenol; D010894:Piroxicam; D005557:Formaldehyde; D000431:Ethanol; D002351:Carrageenan; D005620:Freund's Adjuvant; C033069:methyl salicylate