Contrasting Effects of Puerarin and Daidzin on Glucose Homeostasis in Mice

Abstract

Puerarin and daidzin are the major isoflavone glucosides found in kudzu dietary supplements. In this study, we demonstrated that puerarin significantly improves glucose tolerance in C57BL/6J-ob/ob mice, an animal model of type 2 diabetes mellitus, blunting the rise in blood glucose levels after i.p. administration of glucose. In contrast, daidzin, the O-glucoside, had a significant but opposite effect, impairing glucose tolerance as compared to saline-treated controls. When they were administered i.p. with (14)C-glucose to C57BL/6J lean mice, puerarin inhibited glucose uptake into tissues and incorporation into glycogen, while daidzin stimulated glucose uptake, showing an opposite effect to puerarin. Puerarin also antagonized the stimulatory effect of decyl-beta-D-thiomaltoside, an artificial primer of glycogen synthesis, which increases (14)C-glucose uptake and incorporation into glycogen in mouse liver and heart. A liquid chromatography-tandem mass spectrometry procedure was used to investigate the metabolism and bioavailability of puerarin and daidzin. The blood puerarin concentration-time curve by i.p. and oral administration indicated that puerarin was four times more bioavailable via i.p. injection than via the oral route of administration. This may account for the increased hypoglycemic effect seen in the i.p. glucose tolerance test vs that seen orally. Our results suggest that puerarin is rapidly absorbed from the intestine without metabolism, while daidzin is hydrolyzed to the aglycone daidzein. The opposing effects of puerarin and daidzin on glucose homeostasis may have implications for the activity of dietary supplements that contain both of these isoflavonoids.

Anti-obese and anti-diabetic effects of a mixture of daidzin and glycitin on C57BL/6J mice fed with a high-fat diet

“…16) Health effects of daidzin have been proved on memory impairment, hepatic failure, and glucose homeostasis. [17][18][19] It was also reported that glycitin has preventive effect on bone loss and osteonecrosis. 20,21) However, to our knowledge, there are few studies that have been done on the effects of glycoside-form isoflavone supplementation on lipid metabolism associated with diabetes mellitus.…”

Puerarin Suppresses Macrophage Activation via Antioxidant Mechanisms in a CaPO₄-Induced Mouse Model of Aneurysm

“…However, 100 M or larger concentrations of puerarin required for in vitro assay were shown to be higher than the approximately 20 M concentrations of puerarin in blood when puerarin was intraperitoneally administered to mice (45). The macrophage activation assay using RAW264.7 might not reflect the in vivo response of macrophages.…”

In-Vivo Oral and Intraperitoneal Administration of Extract from Vernonia lasiopus

“…The active constituents administered orally are absorbed by the mucosal epithelial cells where they are transported to the liver by hepatic portal vein. These constituents are metabolized in the liver after which reduced amounts of un-metabolized constituents are released into the systemic circulation [20]. Table 3: Quantitative screening of the phytochemicals in the medicinal plants extract.…”

“…The phytochemicals present in aqueous leaves extract of Vernonia lasiopus (saponins, flavonoids, alkaloids, sterols, and tannins) were determined using standard procedures [19,20].…”