Degranulation of rat mesentery mast cells by antihistamines: influence of ionization

Marrubiin Inhibits Peritoneal Inflammatory Response Induced by Carrageenan Application in C57 Mice

Marrubiin is a diterpene with a long history of a wide range of biological activities. In this study, the anti-inflammatory effects of marrubiin were investigated using several in vitro and in vivo assays. Marrubiin inhibited carrageenan-induced peritoneal inflammation by preventing inflammatory cell infiltration and peritoneal mast cell degranulation. The anti-inflammatory activity was further demonstrated by monitoring a set of biochemical parameters, showing that the peritoneal fluid of animals treated with marrubiin had lower levels of proteins and lower myeloperoxidase activity compared with the fluid of animals that were not treated. Marrubiin exerted the most pronounced cytotoxic activity towards peripheral mononuclear cells, being the main contributors to peritoneal inflammation. Additionally, a moderate lipoxygenase inhibition activity of marrubiin was observed.

Comparative effects of oxatomide on the release of histamine from rat peritoneal mast cells

Oxatomide inhibits the release of histamine from rat peritoneal mast cells in vitro induced by C 48/80, antigen, anti-IgE and ionophore A 23 187, without effect on non-specific release by n-decylamine. Its effect is concentration- and pH-dependent and decreases with increasing extracellular Ca2+-concentrations. Prolonged incubation does not enhance the inhibition, which is lost after one single wash-out. Aminophylline and isoproterenol are not potentiated by oxatomide. The present study points to an effect of oxatomide on a Ca2+-dependent process at the level of cell membrane common to antigen, C 48/80 and ionophore A 23 187.