Summary Postmenopausal diabetes is exacerbated by estrogen deficiency. Ovariectomized (OVX) animal models can be used to develop strategies for preventing or treating postmenopausal symptoms. We previously found that a diet containing kudzu (Pueraria lobata) vine ethanol extract (PVEE) suppressed weight gain in OVX mice. Therefore, this study further elucidated how PVEE affected OVX mice. Ten-week-old OVX or sham-operated mice were fed diets containing either no PVEE (control) ·d 21 puerarin (daidzein-8-C-glucoside), a major isoflavone present in PVEE, for 10 wk. The effects of puerarin on glucose tolerance were also tested in OVX mice. The experimental diets were not associated with any abnormalities in any mice tested in the present study. Weight gain and serum glucose levels were increased in OVX mice and these effects were significantly attenuated in OVX mice that consumed PVEE (5 or 20 mg·kg 21 ·d 21 ) or puerarin. Puerarin-treated OVX mice also showed reduced serum glucose levels following administration of 1,000 mg·kg 21 glucose. These results suggested that puerarin contributed to PVEE-mediated improvements in glucose metabolism in OVX mice. Although further studies are needed to clarify the molecular mechanism underlying these observations, PVEE and puerarin could provide effective approaches to the amelioration of postmenopausal diabetes. Key Words Kudzu, Pueraria lobata, postmenopausal diabetes, puerarin, glucose metabolism Postmenopausal women have an increased risk for metabolic diseases such as obesity and diabetes (1, 2), which increase their risk of developing other serious conditions including cancers, neurological disorders, hypertension, and other kinds of cardiovascular disease (3). Postmenopausal diabetes is induced by estrogen deficiency, which exacerbates insulin resistance (4, 5). The number of postmenopausal patients with diabetes has recently increased, due to the increasing age of the population. Therefore, dietary strategies to reduce the risk for diabetes are expected to be necessary in order to improve postmenopausal health.Kudzu (Pueraria lobata) is a creeping vine of the Leguminosae family. The plant has spread worldwide and is predominantly found in temperate climates. Dried kudzu roots (Puerariae radix) are traditionally used in Asian countries, including Japan, as an herbal medicine to treat the common cold, headaches, diarrhea, and hypertension. Prasain et al. demonstrated that kudzu root extract ameliorated impaired glucose and lipid metabolism in obese male mice (6). They also reported that in addition to lowering arterial blood pressure, a kudzu root extract diet significantly reduced blood cholesterol, glucose, and insulin levels in stroke-prone spontaneously hypertensive rats (7).Pharmaceutical legislation in Japan classifies the kudzu root as a medicinal resource, rather than a food, and we therefore investigated whether dietary consumption of other parts of the plant had beneficial effects on postmenopausal diabetes. Our previous study of a kudzu vine ethanol extract ...