Inhibitory Effects of a Water-Soluble Extract from Culture Medium of Ganoderma lucidum (Rei-shi) Mycelia on Postprandial Blood Glucose Elevation in Type 2 Diabetic Mice and Additional Effect with .ALPHA.-Glucosidase Inhibitors
10.1625/jcam.8.1
- VernacularTitle:２ 型糖尿病マウスにおける霊芝菌糸体培養培地抽出物の糖負荷後の血糖上昇抑制効果と食後過血糖改善薬との併用効果
- Author:
Yukiko KAWAHARA
;
Shinya KAMIUCHI
;
Mari OKAZAKI
;
Naohiro IWATA
;
Tatsuhiro USUI
;
Meiyan XUAN
;
Fumiko SUZUKI
;
Hiroshi IIZUKA
;
Yasuhide HIBINO
- Publication Type:Journal Article
- Keywords:
water-soluble extract of Ganoderma lucidum mycelia (WER);
type 2 diabetes;
KK0-Ay mouse;
α
-glucosidase inhibitor;
food-drug interaction
- From:Japanese Journal of Complementary and Alternative Medicine
2011;8(1):1-9
- CountryJapan
- Language:Japanese
-
Abstract:
Objective: The water-soluble extract of Ganoderma lucidum mycelia (WER) is prepared from a solid medium composed of bagasse and rice bran overgrown with Ganoderma lucidum mycelia. Recently, we reported that WER shows a blood glucose-lowering effect in maltose-loaded non-diabetic mice. Here, we investigated the efficacy of WER in type 2 diabetic state using KK-Ay mice. Moreover, the food-drug interactions of WER with α-glucosidase inhibitors, voglibose or acarbose were examined using both in vitro and in vivo experiments.
Methods: The glucose-lowering effects of oral administration in vivo of WER alone, or concomitant administration of WER with voglibose/acarbose on the elevation of blood glucose levels by sugar-tolerance tests were examined in KK-Ay mice. The inhibitory effects on α-glucosidase in vitro were also evaluated.
Results: Oral administration of WER (1 g/kg), which did not affect fasting blood glucose, significantly suppressed the hyperglycemia after loading of maltose (18% of decrease in AUC) compared to the water-administrated control mice. In vitro study showed that WER inhibited maltase in concentration-dependent manner. The inhibitory effects of lower concentrations of voglibose or acarbose on α-glucosidase activity were additively enhanced by the presence of WER, but those of higher concentrations were not affected. The glucose-lowering effect of voglibose (0.1 mg/kg) disappeared in maltose-loaded KK-Ay mice when the drug was concomitantly administrated with WER (1 g/kg), whereas acarbose (16 mg/kg) with WER showed no significant change in its effect.
Conclusion: These results demonstrated that WER shows the glucose-lowering effect in maltose-loaded KK-Ay, which may be based on inhibition of the α-glucosidase activity. The present study suggests that concomitant intake of WER with voglibose may override the therapeutic effect of voglibose on postprandial hyperglycemia by food-drug interaction in diabetic state.
