Fiebich B L, Chrubasik S
Department of Psychiatry and Psychotherapy, University of Freiburg Medical School, Freiburg, Germany.
Phytomedicine. 2004 Feb;11(2-3):135-8. doi: 10.1078/0944-7113-00338.
Salix extracts are in current use for the treatment of pain and inflammation. In order to obtain an insight into the mechanism(s) of action of the ethanolic Salix extract 1520L--which is essentially similar to an extract for which clinical studies have demonstrated analgesic effectiveness--its effects were evaluated in an established in vitro assay test system using primary human monocytes. The IC50-values obtained for the inhibition of lipopolysaccharide (LPS)-induced release of prostaglandin E2 (PGE2) reflecting cyclooxygenase (COX)-2-mediated PGE2 release were 47 microg/ml and 0.6 microg/ml, for the Salix extract 1520L and rofecoxib-like research compound L745337, respectively. There was no effect on COX-1 and COX-2 activity. The Salix extract inhibited the LPS-induced release of tumor necrosis factor-alpha, interleukin-1beta and interleukin-6 with IC50-values of 180.0, 33.0 and 86.0 microg/ml, respectively. Both, salicin and salicylate, had no effect in any of the parameters. Our results indicate that Salix extract 1520L inhibits COX-2-mediated PGE2 release through compounds other than salicin or salicylate. Our data further suggest that the proprietary Salix extract is a weak inhibitor of proinflammatory cytokines.