title: Therapeutic effect of emodin on collagen-induced arthritis in mice.
abstract: Emodin, an anthraquinone isolated from the Chinese herb Radix et Rhizoma Rhei, has been reported to have anti-inflammatory, antibacterial, and antitumor activities. However, the effect of emodin on collagen-induced arthritis (CIA) has not yet been investigated. The purpose of this study was to investigate whether emodin has a protective effect against collagen-induced arthritis in mice and its possible mechanisms. CIA was induced in mice by immunization with bovine type II collagen. The mice were treated with emodin (5, 10, and 20 mg/kg/day, i.g.) from days 21 to 42 after immunization. The clinical scores and hind paw swelling were evaluated. The expression of prostaglandin E2 (PGE2) and cyclooxygenase-2 (COX-2) in synovial tissues was determined. The levels of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in the plasma were measured by enzyme-linked immunosorbent assay. The results showed that emodin treatment significantly alleviated the severity of the disease, based on the reduced hind paw swelling and clinical scores, compared with untreated CIA mice. Comparing with untreated CIA mice, emodin treatment inhibited the levels of TNF-α and IL-6 in the plasma, PGE2 production, and COX-2 protein expression in synovial tissues in a dose manner. In conclusion, our results suggest that anti-inflammatory effects of emodin against collagen-induced arthritis in mice may be due to its ability to inhibit pro-inflammatory mediators. Emodin may be a promising potential therapeutic reagent for arthritis treatment.
authors.affiliation: Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Zhu
authors.forename: Kai
authors.initials: K
authors.lastname: Zeng
authors.forename: Yu
authors.initials: Y
authors.lastname: Qiu
authors.forename: Fuhua
authors.initials: F
authors.lastname: Yan
authors.forename: Caizhu
authors.initials: C
authors.lastname: Lin
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000188:drug therapy*; D003094:Collagen; D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D015232:Dinoprostone / Q000096:biosynthesis; D004642:Emodin / Q000627:therapeutic use*; D015850:Interleukin-6 / Q000097:blood; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D013583:Synovial Membrane / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D000893:Anti-Inflammatory Agents; D015850:Interleukin-6; D047428:Protein Kinase Inhibitors; D014409:Tumor Necrosis Factor-alpha; C577686:interleukin-6, mouse; D003094:Collagen; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D015232:Dinoprostone; D004642:Emodin