Biol. Pharm. Bull. 30(1) 63—67 (2007)

is a bis-Mannich base. Mannich bases have various biological activities such as antimicrobial, cytotoxic, anticancer, analgesic, and anticonvulsant activities. It has been reported that Mannich bases such as 1-diphenylaminomethyl-3-(1-naphthylimino)-1,3-dihydroindol-3-one, 1diphenylaminomethyl-3-(4-methylphenylimino)-1,3-dihydroindol-3-one and 1,3-dicyclohexyl-5-alkyl-5-aminomethylbarbituric acids have very high levels of anti-inflammatory activity. In addition, 8 compounds out of the 18 Mannich bases with structure of 2-substituted-2-dimethylaminomethyl-5-(E)-arylidene cyclopentanone have demonstrated remarkable anti-inflammatory activity. Mannich bases with structure of 2-(E)-(un)substituted benzylidene-5dimethylaminomethyl cyclopentanone have been synthesized as dual inhibitors of cyclooxygenase and lipooxygenase. These compounds have inhibited carrageenan-induced paw edema. Anti-inflammatory activity of 3-benzoyl-1-methyl4-phenyl-4-piperidinol hydrochloride (C1, Fig. 1), which is a semi-cyclic Mannich base and structural and nonclassic isomer of compound B1 (Fig. 2), has been shown in rats in our previous study. Acute anti-inflammatory activities of compounds or drugs are generally investigated using acute aseptic arthritis model (paw edema) that has been induced by histamine, formalin, dextran, or carrageenan. Cotton pellet granuloma test is widely used to investigate their effects on the chronic phase of inflammation. The observation, that Mannich bases with various chemical structures including compound C1 have anti-inflammatory effects led us to investigate the anti-inflammatory effect of compound B1, which is a bis-Mannich base and also structural and nonclassic isomer of compound C1. The aim of this study was to investigate the anti-inflammatory effects of compound B1, on acute and chronic phases of inflammation by carrageenan-induced paw edema and cotton pellet granuloma tests, respectively. In addition, its effect on hyaluronidase-induced capillary vascular permeability was tested to give an insight into its mechanism of action.