Antioxidant action and potential antidiabetic properties of an isoflavonoid‐containing soyabean phytochemical extract (SPE)

Abstract

The potential role of oestrogenic agents, antioxidants and intestinal glucose-uptake inhibitors in the treatment of diabetes is briefly reviewed. Reports in the literature suggest that oestrogen replacement therapy may favourably modulate glucose homeostasis. A soya phytochemical extract (SPE) containing the isoflavone phytoestrogens genistein and daidzein (mostly in their glycone forms as genistin and daidzin) was investigated as an antioxidant and modulator of intestinal glucose-transport. In the present study, SPE was found to protect against glucose-induced oxidation of human low density lipoproteins (LDL) in vitro. Equol (a gut bacterial metabolite of daidzein) was a more effective antioxidant than daidzein or genistein in this system and was of similar antioxidant potency to the dietary flavonols quercetin and kaempferol and to the endogenous antioxidant 17beta-oestradiol. SPE was found to be an inhibitor of glucose uptake into rabbit intestinal brush border membrane vesicles in vitro, though of weaker potency than the classical sodium dependent glucose transporter (SGLT) inhibitor, phlorizin. Thus SPE displays a range of properties which may be of benefit in diabetes, namely as an oestrogenic agent, an inhibitor of intestinal glucose-uptake and a preventive agent for glucose-induced lipid peroxidation.

Is there a role for soy isoflavones in the therapeutic approach to polycystic ovary syndrome? Results from a pilot study

“…Preliminary data from epidemiological surveys and nutritional intervention studies in animals and human beings have suggested that phytoestrogens may improve glycemic and insulinemic levels (3,38). Phytoestrogens, and especially genistein, are believed to exert these effects both through a direct inhibition of intestinal glucose absorption and through the inhibition of protein tyrosine kinases, which play a permissive role in the regulation of insulin secretion by pancreatic b cells (3).…”

Simultaneous determination of puerarin, daidzein, baicalin, wogonoside and liquiritin of GegenQinlian decoction in rat plasma by ultra-performance liquid chromatography–mass spectrometry

“…Isoflavonoids and flavonoids from GQD are regarded as potential contributors to those pharmacological effects. Puerarin and daidzein, two bioactive isoflavonoids in Puerariae Radix [2], have been reported to display antithrombotic, anti-allergic [3], anti-oxidative [4] and potential antidiabetic properties [5]. Baicalin and wogonoside, primary flavonoids of Radix Scutellaria [6,7], share some beneficial activities with isoflavonoids such as anti-allergic and anti-oxidative [8,9] properties.…”

Protective Effect of Potato Peel Powder in Ameliorating Oxidative Stress in Streptozotocin Diabetic Rats

“…Several dietary factors that can mitigate the symptoms of diabetes have been identified which predominantly include dietary fibers and antioxidants [6,7]. Antioxidants are currently being tested for their potential to prevent or correct diabetes-related disorders.…”