The present invention provides a novel bicyclic or tricyclic heterocyclic compound represented by the formula (I) wherein ring A is an optionally substituted aromatic group, one of X1 and X2 is a carbon atom, and the other is a nitrogen atom, X3 is a nitrogen atom, or CR2, X4 is a nitrogen atom, or CR3, X5 is a sulfur atom, or —CH═CH—, Z1 is an oxygen atom, —C(R6)(R7)—, —NH—, —C(R6)(R7)—NH—, —NH—C(R6)(R7)—, —C(R6)(R7)—O—, —O—C(R6)(R7)—, or a single bond, one of Z2 and Z3 is CH and the other is a nitrogen atom, or both are nitrogen atoms, and other symbols are as defined in the DESCRIPTION, or a pharmacologically acceptable salt thereof.