A tricyclic compound represented by the general formula [wherein Y is a hydrogen atom, lower alkyl optionally having substituent(s), lower alkoxy optionally having substituent(s), cycloalkyl optionally having substituent(s) or halogen, R A is a hydrogen atom, halogen, hydroxy, lower alkoxy, or lower alkyl, X is the formula - (wherein R B-2 is lower alkyl optionally having substituent(s) or cycloalkyl optionally having substituent(s), R B is a hydrogen atom, lower alkyl optionally having substituent(s) or cycloalkyl optionally having substituent(s), and the broken line shows absent or a single bond), A is the formula (al) - (wherein R 1, R 2 and R 3 are the same or different and each is a hydrogen atom, cyano, lower alkyl optionally having substituent(s), cycloalkyl optionally having substituent(s), halogen, lower alkoxy optionally having substituent(s), -NR F R G (wherein R F and R G are the same or different and each is a hydrogen atom, lower alkyl optionally having substituent(s), lower alkanoyl optionally having substituent(s), lower alkoxycarbonyl optionally having substituent(s) or aralkyl optionally having substituent(s), or R F and R G form, together with the adjacent nitrogen atom, a nitrogen-containing heterocyclic group optionally having substituent(s)), lower alkylsulfanyl optionally having substituent(s), lower alkenyl optionally having substituent(s), lower alkanoyl optionally having substituent(s), lower alkoxycarbonyl optionally having substituent(s), carbamoyl, lower alkylcarbamoyl, optionally having substituent(s), di-lower alkylcarbamoyl optionally having substituent(s), aliphatic heterocyclylcarbonyl optionally having substituent(s), aryloxy optionally having substituent(s), aryl optionally having substituent(s), aromatic heterocyclic group optionally having substituent(s), aliphatic heterocyclic group optionally having substituent(s), aralkyl optionally having substituent(s) or aralkyloxy optionally having substituent(s), R C, R D and R E are the same or different and each is a hydrogen atom, halogen, nitro, cyano, formyl, oxo, hydroxy, lower alkoxy optionally having substituent(s), -NR Fa R Ga (wherein R Fa and R Ga are as defined for the aforementioned R F and R G, respectively), lower alkanoyloxy optionally having substituent(s), lower alkyl optionally having substituent(s), lower alkenyl optionally having substituent(s), lower alkynyl optionally having substituent(s), lower alkanoyl optionally having substituent(s), lower alkoxycarbonyl optionally having substituent(s), lower alkylsulfonyl optionally having substituent(s), lower alkylsulfanyl optionally having substituent(s), cycloalkyl optionally having substituent(s) or -CONR H R 1 (wherein R H and R 1 are the same or different and each is a hydrogen atom, lower alkyl optionally having substituent(s), lower alkanoyl optionally having substituent(s), lower alkoxycarbonyl optionally having substituent(s) or aralkyl optionally having substituent(s), or R H and R 1 form, together with the adjacent nitrogen atom, a nitrogen-containing heterocyclic group optionally having substituent(s)), R J is a hydrogen atom, lower alkyl optionally having substituent(s), lower alkanoyl optionally having substituent(s), lower alkoxycarbonyl optionally having substituent(s), aryl optionally having substituent(s), lower alkylsulfonyl optionally having substituent(s), aralkyl optionally having substituent(s) or cycloalkyl optionally having substituent(s), and R K is a hydrogen atom, halogen, hydroxy, lower alkoxy, lower alkyl or-NR Fb R Gb (wherein R Fb and R Gb are as defined for the aforementioned R F and R G, respectively)], or a pharmaceutically acceptable salt thereof; wherein lower alkyl, and the lower alkyl moiety of lower alkoxy, lower alkylsulfanyl, lower alkylsulfonyl, lower alkanoyloxy, lower alkanoyl, lower alkoxycarbonyl, lower alkylcarbamoyl and di-lower alkylcarbamoyl means straight chain or branched alkyl having 1 - 10 carbon atoms, and the two lower alkyl moieties of di-lower alkylcarbamoyl may be the same or different, wherein lower alkenyl means straight chain or branched alkenyl having 2 - 10 carbon atoms, and wherein lower alkynyl means straight chain or branched alkynyl having 2 - 10 carbon atoms.