Human chymase inhibitor and drug for preventing and treating disease associated with human chymase activity

Provided is a novel human chymase inhibitor. The human chymase inhibitor, which comprises a compound represented by general formula (A) as an active ingredient, exhibits a selective and excellent enzyme activity inhibitory effect on human chymase. Among such compounds, one or more compounds selected from the group consisting of quercitrin, isoquercitrin, hyperoside, kaempferol and luteolin are preferred. A drug comprising the aforesaid human chymase inhibitor inhibits human chymase activity and thus is useful as a medicine for preventing and treating various diseases associated with human chymase activity. In general formula (A): R 1 to R 5 independently represent a hydroxyl group or a methoxy group; and X 1 represents a hydroxyl group or an -OG group [wherein G represents a sugar chain].