Fig. 1

Effect of IO on serum glucose levels in high-fat diet (HFD)-fed mice model. The mice receiving 45% HFD for 8 weeks exhibit ameliorated glucose tolerance; however, IOE oral administration decreased glucose tolerance. a, b Intraperitoneal glucose tolerance test (IPGTT) was performed and analyzed area under the curve (AUC) from the IPGTT in all mice groups. c Fasting and d 2 h glucose levels were in all mouse groups. Data are presented as mean ± S.D. **p < 0.01 or ***p < 0.001 vs NFD/saline group; ^#p < 0.05, ^##p < 0.01, or ***p < 0.001 vs HFD/saline group. NS, not significant