Therapeutic effect of sesame oil on monosodium urate monohydrate crystal-induced acute inflammation in rat air pouches
Te-Jung Hsu, Pey-Yi Chu & Ming-Yie Liu
Hyperuricemia, results from the disorder of purine metabolism or endocrine system, leads to an inflammatory arthritis and gout. Sesame oil has been reported to have a potent anti-inflammatory effect in various animal models. The aim of the present study is to examine the therapeutic effect of sesame oil on monosodium urate monohydrate (MSU) crystal-induced acute inflammation in air pouch in unanaesthetised SpragueDawley rats. Air pouch, a commonly used model for gouty arthritis, was established in rats by injecting 10 and 3 ml of sterilized air into subcutaneous tissue of the back at day -6 and day -3, respectively. At day 0, inflammation in air pouch was induced by injecting MSU crystal (5 mg/rat, suspended in sterilized phosphate buffered saline, pH 7.4), while sesame oil (0, 1, 2, or 4 ml/kg, orally) was given 6 h after MSU injection. Total cell counts, nitrite, and inflammatory cytokines levels in lavage and tissue from pouch were determined 6 h after sesame oil administration. MSU crystal increased the total cell counts, nitrite, interleukin (IL)-1β, and IL-6 levels in lavage compared with normal group. Sesame oil significantly decreased all the parameters in a dose-dependent manner compared with MSU alone group. In addition, sesame oil significantly decreased tumour necrosis factor-α, IL-1β, IL-6 levels in pouch tissue compared with MSU alone group. In conclusion, sesame oil showed a potent therapeutic effect against MSU-induced inflammation in rats. Further, sesame oil may have the potential in treating patients with gouty arthritis in the future.