Premium
Eucalyptol alleviates inflammation and pain responses in a mouse model of gout arthritis
Author(s) -
Yin Chengyu,
Liu Boyu,
Wang Ping,
Li Xiaojie,
Li Yuanyuan,
Zheng Xiaoli,
Tai Yan,
Wang Chuan,
Liu Boyi
Publication year - 2020
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/bph.14967
Subject(s) - arthritis , eucalyptol , inflammation , medicine , proinflammatory cytokine , inflammasome , oxidative stress , pharmacology , inflammatory arthritis , ankle , immunology , chemistry , pathology , chromatography , essential oil
Background and Purpose Gout arthritis, which is provoked by monosodium urate (MSU) crystal accumulation in the joint and periarticular tissues, induces severe pain and affects quality of life of the patients. Eucalyptol (1,8‐cineol), the principal component in the essential oils of eucalyptus leaves, is known to possess anti‐inflammatory and analgesic properties. We aimed to examine the therapeutic effects of eucalyptol on gout arthritis and related mechanisms. Experimental Approach A mouse model of gout arthritis was established via MSU injection into the ankle joint. Ankle oedema, mechanical allodynia, neutrophil infiltration, oxidative stress, NLRP3 inflammasome, and TRPV1 expression were examined. Key Results Eucalyptol attenuated MSU‐induced mechanical allodynia and ankle oedema in dose‐dependently, with effectiveness similar to indomethacin. Eucalyptol reduced inflammatory cell infiltrations in ankle tissues. Eucalyptol inhibited NLRP3 inflammasome activation and pro‐inflammatory cytokine production induced by MSU in ankle tissues in vivo. Eucalyptol reduced oxidative stress induced by MSU in RAW264.7 cells in vitro as well as in ankle tissues in vivo, indicated by an increase in activities of antioxidant enzymes and reduction of ROS. Eucalyptol attenuated MSU‐induced up‐regulation of TRPV1 expression in ankle tissues and dorsal root ganglion neurons innervating the ankle. The in vivo effects of eucalyptol on ankle oedema, mechanical allodynia, NLRP3 inflammasome, IL‐1β, and TRPV1 expression were mimicked by treating MSU‐injected mice with antioxidants. Conclusion and Implications Eucalyptol alleviates MSU‐induced pain and inflammation via mechanisms possibly involving anti‐oxidative effect. Eucalyptol and other antioxidants may represent promising therapeutic options for gout arthritis.