Effects on immune response of antidiabetic ingredients from white-skinned sweet potato ( Ipomoea batatas L.)

The present report describes the effects of antidiabetic ingredients from white-skinned sweet potato (AWSSP) on the immune response of human cells. We studied the effects of inactive Staphylococcus aureus cells coated with AWSSP on phagocytic activity, phagosome-lysosome fusion, and superoxide anion release by human leukocytes in vitro. AWSSP increased phagocytic activity and phagosome-lysosome fusion in neutrophils and monocytes in a dose-dependent manner. In contrast, AWSSP had no significant effect on superoxide anion release (O 2 −) from human neutrophils. These results show that AWSSP is useful in the prevention and improvement of diabetic symptoms by stimulating human immunity and that Ipomoea batatas L. is a beneficial food because it increases immune activity in addition to its antidiabetic effects.