Effects of cereal fiber on leptin resistance and sensitivity in C57BL/6J mice fed a high-fat/cholesterol diet
Sammanfattning
Background: Cereal fiber is reported to be associated with obesity and metabolic diseases. However, whether
cereal fiber improves leptin resistance and sensitivity remains unclear.
Design: For 24 weeks, 48 male C57BL/6J mice were randomly given a normal chow diet (Chow), high-fat/
cholesterol diet (HFD), HFD with 0.8% oat fiber (H-oat) or HFD with 0.8% wheat bran fiber (H-wheat). At
the end of feeding period, both the serum insulin and leptin levels were determined by ELISA kits. Western
blotting was used to assess the protein expressions of the leptin receptor (LepR) and the leptin-signaling
pathway in the adipose tissues.
Results: Our results suggested that mice fed oat or wheat bran fiber exhibited lower body weight, serum lipids,
as well as insulin and leptin levels. The two cereal fibers potently increased the protein expressions of LepR in
the adipose tissue. In addition, protein expressions of Janus kinase 2 (JAK2) and transcription 3 (STAT3)
(induced by LepR), which enhances leptin signaling, were significantly higher and the expression of cytokine
signaling-3 (SOCS3), which inhibits leptin signaling, was significantly lower in the two cereal fiber groups
than in the HFD group.
Conclusion: Taken together, our findings suggest that cereal fiber can improve leptin resistance and sensitivity
by the JAK2/STAT3 pathway in C57BL/6J mice fed a HFD; furthermore, oat fiber is more effective in the
improvement of leptin sensitivity than wheat bran fiber, in this murine model.