The purpose of the present study was to elucidate the pharmacological effects of
Geniposide (GEN) on high diet fed and
streptozotocin (STZ)-caused diabetic
cognitive impairment. The mice were fed with high fat diet (HFD) for 4 weeks and intraperitoneally injected with 60 mg/kg STZ for three times within 72 h. The mice with
glucose level over 15 mmol/l were regarded as diabetic and selected for further studies. The animals were intragastrically treated with
metformin or GEN once daily for 4 weeks. Afterwards, the animals were applied for Y maze, novel object recognition (NOR) test, step-through passive avoidance test, and Morris water maze (MWM) test. The
blood glucose and
body weight were examined. The SH-SY5Y cells were treated with GEN in the presence or absence of
ibrutinib and stimulated with high-
glucose culture medium. The
tumor necrosis factor-a (TNF-α) and
interleukin (IL)-6 in serum, hippocampus, and supernatant were measured using ELISA method. The
protein expressions of
Bruton's tyrosine kinase (BTK),
Toll-like receptor 4 (TLR4), myeloid differentiating factor 88 (MyD88),
nuclear factor kappa-B (NF-κB), p-NF-κB,
brain-derived neurotrophic factor (
BDNF),
cAMP-response element binding protein (CREB), p-CREB, and
glucagon-like peptide-1 receptor (GLP-1R) were detected by western blot analyses. As a result, the GEN treatment notably attenuated the
body weight,
blood glucose, and
cognitive decline. GEN also inhibited the generations of inflammatory
cytokines. Furthermore, the administrations of GEN ameliorated the alterations of BTK, TLR4, MyD88, NF-κB, and
BDNF in HFD + STZ-induced mice. With the application of
ibrutinib, the selective inhibitor of BTK, it was also found that BTK/TLR4/NF-κB pathway was associated with the GEN treatment in high
glucose-induced SH-SY5Y cells. In summary, the results suggested that GEN exerted the protective effect on STZ-induced
cognitive impairment possibly through the modulation of BTK/TLR4/NF-κB signaling.