Method for lowering blood glucose level by the administration of bioflavonoid

A method for lowering the blood glucose level in a mammal which comprises administering an effective amount of a bioflavonoid selected from the group consisting of hesperetin, naringenin and a mixture thereof or a plant extract containing same ##STR3## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 are each independently hydrogen;

• a hydroxy group;
• a C.sub.1-9 alkoxy group optionally substituted with one or more substituents selected from the group consisting of a hydroxy, C.sub.1-5 alkoxy, aryloxy, and phenyl group substituted with 1 to 3 substituents selected from the group consisting of a hydroxy, alkoxy, aryloxy, halogen, nitro and amido group;
• a C.sub.5-9 cycloalkyloxy group substituted with 1 to 3 substituents selected from the group consisting of a hydroxy, alkoxy, aryloxy, halogen, nitro and amido group;
• a C.sub.5-9 cycloalkylcarbonyloxy group substituted with 1 to 3 substituents selected from the group consisting or a hydroxy, alkoxy, aryloxy, halogen, nitro and amido group;
• a C.sub.2-10 or C.sub.16-18 acyloxy group optionally substituted with one or more substituents selected from the group consisting of a hydroxy, C.sub.1-5 alkoxy, aryloxy, and phenyl group substituted with 1 to 3 substituents selected from the group consisting of a hydroxy, alkoxy, aryloxy, halogen, nitro group;
• a rutinosyl group;
• or a rhaminosyl group;
• and
• X is a single or double bond to the mammal.