Effects of Taiwanese Yam (Dioscorea Japonica Thunb Var. Pseudojaponica Yamamoto) on Upper Gut Function and Lipid Metabolism in Balb/c Mice

Nutrition. Jul-Aug 2003;19(7-8):646-51. doi: 10.1016/s0899-9007(03)00058-3.

Abstract

Objective: This study investigated the effects of a Taiwanese yam, Dioscorea japonica Thunb var. pseudojaponica Yamamoto, on upper gut function and lipid metabolism in adult Balb/c mice.

Methods: Mice were randomly allocated to consume the control, 25%, or 50% yam diet in which yam in an uncooked lyophilized form was incorporated into the diet for 21 d.

Results: Growth rates were similar among groups, even though the apparent protein absorption rate was decreased by the 50% yam diet. Both yam diets decreased gastric villous width but did not significantly modulate other morphologic and proliferative indices. Brush-border leucine aminopeptidase activities in the small intestine were increased approximately 30% by the 25% and 50% yam diets, respectively. In contrast, sucrase activity was decreased 40% by the 25% yam diet and 50% by the 50% yam diet. The 50% yam diet consistently improved the cholesterol profile in the plasma and liver, whereas the 25% yam diet reduced only the level of low-density lipoprotein cholesterol in plasma. Changes in blood lipid levels were associated with reduced fat absorption.

Conclusion: A 25% uncooked yam diet may benefit upper gut function and prevent hypercholesterolemia in humans, but the 50% yam diet negatively affected protein absorption.

MeSH terms

  • Aminopeptidases / metabolism
  • Animals
  • Anticholesteremic Agents / pharmacology*
  • Cell Division
  • Cholesterol / blood
  • Cholesterol / metabolism
  • Cholesterol, Dietary / pharmacokinetics*
  • Dietary Fats / pharmacokinetics
  • Dietary Proteins / pharmacokinetics*
  • Dioscorea* / chemistry
  • Dose-Response Relationship, Drug
  • Feces / chemistry
  • Gastric Mucosa / cytology
  • Intestinal Absorption
  • Intestine, Small / enzymology
  • Liver / metabolism
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Microvilli / enzymology
  • Microvilli / metabolism
  • Organ Size
  • Random Allocation
  • Sucrase / metabolism
  • Taiwan

Substances

  • Anticholesteremic Agents
  • Cholesterol, Dietary
  • Dietary Fats
  • Dietary Proteins
  • Cholesterol
  • Sucrase
  • Aminopeptidases