Inhibitory Effect of Amygdalin on Lipopolysaccharide Inducible TNF-a and IL-lp mRNA Expression and Carrageenan-induced Rat Arthritis

摘要

Amygdalin is a cyanogenic glycoside plant compound found in the seeds of rosaceous stone fruits. We evaluated the anti-inflammatory and analgesic activities of amygdalin, using an in vitro Iipopolysaccharide (LPS)-induced cell line and a rat model with carrageenan-induced ankle arthritis. One mM amygdalin significantly inhibited the expression of TNF-a and IL-ip mRNAs in LPS-treated RAW 264.7 ceDs. Amygdalin (0.005, 0.05, and 0.1 mg/kg) was intramuscularly injected immediately after the induction of carrageenan-induced arthritic pain in rats, and the anti-arthritic effect of amygdalin was assessed by measuring the weight distribution ratio of the bearing forces of both feet and the ankle circumference, and by analyzing the expression levels of three molecular markers of pain and inflammation (c-Fos, TNF-a, and IL-lp) in the spinal cord. The hyperalgesia of the arthritic ankle was alleviated most significantly by the injection of 0.005 mg/kg amygdalin. At this dosage, the expressions of c-Fos, TNF-a, and IL-ip in the spinal cord were significantly inhibited. However, at dosage greater than 0.005 mg/kg, the pain-relieving effect of amygdalin was not observed. Thus, amygdalin treatment effectively alleviated responses to LPS-treatment in RAW 264.7 cells and carrageenan-induced arthritis in rats, and may serve as an analgesic for relieving inflammatory pain.