Preventive and/or therapeutic drugs for inflammatory intestinal diseases

A method for preventing and/or treating inflammatory bowel disease which comprises a step of administering to mammals such as a human, a pyrazolone derivative represented by the following formula (I) or a physiologically acceptable salt thereof, or a hydrate thereof or a solvate thereof, at an amount that is effective for prevention and/or treatment of the disease.

• wherein R1 represents a hydrogen atom, an aryl group, a C1-5 alkyl group, or a C3-6 (total carbon number) alkoxycarbonylalkyl group;
• R2 represents a hydrogen atom, an aryloxy group, an arylmercapto group, a C1-5 alkyl group or a C1-3 hydroxyalkyl group;
• or R1 and R2 are combined with each other to represent C3-5 alkylene group;
• and R3 represents a hydrogen atom, a C1-5 alkyl group, a C5-7 cycloalkyl group, a C1-3 hydroxyalkyl group, a benzyl group, a naphthyl group, a phenyl group, or a phenyl group substituted with the same or different 1 to 3 substituents selected from the group consisting of a C1-5 alkyl group, a C1-5 alkoxy group, a C1-3 hydroxyalkyl group, a C2-5 (total carbon number) alkoxycarbonyl group, a C1-3 alkylmercapto group, a C1-4 alkylamino group, a C2-8 (total carbon number) dialkylamino group, a halogen atom, a trifluoromethyl group, a carboxyl group, a cyano group, a hydroxyl group, a nitro group, an amino group and an acetamide group.

A method for protecting the intestinal mucosa which comprises a step of administering to mammals such as a human, a pyrazolone derivative represented by the following formula (I) or a physiologically acceptable salt thereof, or a hydrate thereof or a solvate thereof, at an effective amount.

• wherein R1 represents a hydrogen atom, an aryl group, a C1-5 alkyl group, or a C3-6 (total carbon number) alkoxycarbonylalkyl group;
• R2 represents a hydrogen atom, an aryloxy group, an arylmercapto group, a C1-5 alkyl group or a C1-3 hydroxyalkyl group;
• or R1 and R2 are combined with each other to represent C3-5 alkylene group;
• and R3 represents a hydrogen atom, a C1-5 alkyl group, a C5-7 cycloalkyl group, a C1-3 hydroxyalkyl group, a benzyl group, a naphthyl group, a phenyl group, or a phenyl group substituted with the same or different 1 to 3 substituents selected from the group consisting of a C1-5 alkyl group, a C1-5 alkoxy group, a C1-3 hydroxyalkyl group, a C2-5 (total carbon number) alkoxycarbonyl group, a C1-3 alkylmercapto group, a C1-4 alkylamino group, a C2-8 (total carbon number) dialkylamino group, a halogen atom, a trifluoromethyl group, a carboxyl group, a cyano group, a hydroxyl group, a nitro group, an amino group and an acetamide group.

A method for inhibiting the activation of neutrophilic leucocytes which comprises a step of administering to mammals such as a human, a pyrazolone derivative represented by the following formula (I) or a physiologically acceptable salt thereof, or a hydrate thereof or a solvate thereof, at an effective amount.

• wherein R1 represents a hydrogen atom, an aryl group, a C1-5 alkyl group, or a C3-6 (total carbon number) alkoxycarbonylalkyl group;
• R2 represents a hydrogen atom, an aryloxy group, an arylmercapto group, a C1-5 alkyl group or a C1-3 hydroxyalkyl group;
• or R1 and R2 are combined with each other to represent C3-5 alkylene group;
• and R3 represents a hydrogen atom, a C1-5 alkyl group, a C5-7 cycloalkyl group, a C1-3 hydroxyalkyl group, a benzyl group, a naphthyl group, a phenyl group, or a phenyl group substituted with the same or different 1 to 3 substituents selected from the group consisting of a C1-5 alkyl group, a C1-5 alkoxy group, a C1-3 hydroxyalkyl group, a C2-5 (total carbon number) alkoxycarbonyl group, a C1-3 alkylmercapto group, a C1-4 alkylamino group, a C2-8 (total carbon number) dialkylamino group, a halogen atom, a trifluoromethyl group, a carboxyl group, a cyano group, a hydroxyl group, a nitro group, an amino group and an acetamide group.

A method for inhibiting myeloperoxidase activity which comprises a step of administering to mammals such as a human, a pyrazolone derivative represented by the following formula (I) or a physiologically acceptable salt thereof, or a hydrate thereof or a solvate thereof, at an effective amount.

• wherein R1 represents a hydrogen atom, an aryl group, a C1-5 alkyl group, or a C3-6 (total carbon number) alkoxycarbonylalkyl group;
• R2 represents a hydrogen atom, an aryloxy group, an arylmercapto group, a C1-5 alkyl group or a C1-3 hydroxyalkyl group;
• or R1 and R2 are combined with each other to represent C3-5 alkylene group;
• and R3 represents a hydrogen atom, a C1-5 alkyl group, a C5-7 cycloalkyl group, a C1-3 hydroxyalkyl group, a benzyl group, a naphthyl group, a phenyl group, or a phenyl group substituted with the same or different 1 to 3 substituents selected from the group consisting of a C1-5 alkyl group, a C1-5 alkoxy group, a C1-3 hydroxyalkyl group, a C2-5 (total carbon number) alkoxycarbonyl group, a C1-3 alkylmercapto group, a C1-4 alkylamino group, a C2-8 (total carbon number) dialkylamino group, a halogen atom, a trifluoromethyl group, a carboxyl group, a cyano group, a hydroxyl group, a nitro group, an amino group and an acetamide group.