Nao-Fu-Cong ameliorates diabetic cognitive dysfunction by inhibition of JNK/CHOP/Bcl2-mediated apoptosis in vivo and in vitro.

Chinese herbal compound Nao-Fu-Cong (NFC) has been mainly used to treat cognitive disorders in Traditional Chinese Medicine (TCM). The present study aimed to investigate whether its neuroprotective effects might be related to the inhibition of JNK/CHOP/Bcl2-mediated apoptosis pathway or not. We randomly assigned STZ (60 mg·kg-1)-induced diabetic rats into control group, diabetic model group and NFC groups (low-dose, medium-dose and high-dose). The primary culture of hippocampal neurons were transferred into different culture media on the third day. The cells were then divided into control group, high-glucose group, NFC (low-dose, medium-dose and high-dose) groups, CHOP si-RNA intervention group, JNK pathway inhibitor SP600125 group and oxidative stress inhibitor N-acetylcysteine (NAC) group. NFC significantly improved the cognitive function of diabetic rats, and had neuroprotective effect on hippocampal neurons cultured in high glucose. Further research results showed that NFC could reduce the apoptosis of hippocampal neurons in rats with diabetic cognitive dysfunction. NFC had inhibitory effects on CHOP/JNK apoptosis pathway induced by high glucose, and also decreased the levels of ROS and increased the mitochondrial membrane potential. These suggested that the neuroprotective effect of NFC might be related to the inhibition of CHOP and JNK apoptotic signaling pathways, and the cross pathway between oxidative stress and mitochondrial damage pathway.

Effect of Chinese herbal compound Naofucong () on the inflammatory process induced by high glucose in BV-2 cells.

OBJECTIVE: To determine the effect of medicated serum of Chinese herbal compound Naofucong (, NFC) on the microglia BV-2 cells viability and the transcription and expression of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) in microglia BV-2 cells to further explore the mechanisms underlying the protective effect of NFC on inflammatory process induced by high glucose. METHODS: The microglia BV-2 cells incubated in vitro were divided into different groups: the control group (25 mmol/L glucose), the model group (75 mmol/L glucose), high glucose media containing different dose medicated serum of NFC. After being cultured for 24 h, changes in IL-6 and TNF-α were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The expression of surface marker CD11b of activated microglia was measured by confocal laser scanning microscope and Western blot. Nuclear factor-κB (NF-κB) p-p65 expression was analyzed by Western blot. RESULTS: The model group obviously increased the expression of microglial surface marker CD11b and NF-κB p-p65 (all P<0.01), induced a signifificant up-regulation of release and the mRNA expression of IL-6 and TNF-α (P<0.01 or P<0.05). The medicated serum of NFC could obviously down-regulate the transcription and expression of surface marker CD11 b and NF-κB p-p65 (all P<0.01), and inhibit the mRNA and protein expression (P<0.01 or P<0.05) of inflflammatory cytokines, such as IL-6 and TNF-α, in microglia BV-2 cells cultured with high glucose for 24 h. CONCLUSIONS: The inhibition of microglial activation and IL-6 and TNF-α expression induced by high glucose may at least partly explain NFC therapeutic effects on diabetes-associated cognitive decline diseases. Its underlying mechanism could probably be related to the inhibition of NFC on NF-κB phosphorylation.

[Effect of ginsenoside Rb1 on insulin signal transduction pathway in hippocampal neurons of high-glucose-fed rats].

OBJECTIVE: To study the effect of ginsenoside Rb1 on GSKbeta/IDE signal transduction pathway and Abeta protein secretion in hippocampal neurons of high glucose-treated rats. METHOD: Hippocampal neurons of 24 h-old newly born SD rats were primarily cultured, inoculated in culture medium under different conditions, and then divided into the normal group, the high glucose group, the LiCl group and the Rb1 group. After being cultured for 72 h, the expressions of their phosphorylated GSK3beta, total GSK3beta and IDE protein were detected by Western blotting analysis. The mRNA expressions of GSK3beta and IDE were determined by RT-PCR. The ELISA assay was used to detect the secretion of Abeta protein in cell supernatant. RESULT: Compared with the normal group, the high glucose group showed increase in the p/tGSK3beta protein ratio and the secretion of Abeta protein and decrease in IDE protein and mRNA (P < 0.05). Compared with the high glucose group, both Rb1 and LiCl groups showed decrease in the p/tGSK3beta protein ratio and the expression of Abeta protein and increase in IDE protein and mRNA expression (P < 0.05). Compared with the LiCl group, the Rb1 group showed no significant difference in the expressions of p/tGSK3beta protein, IDE protein, mRNA and Abeta protein expression. In addition, the GSK3beta mRNA expression of the four groups had no significant difference. CONCLUSION: Ginsenoside Rb1 may reduce the secretion of Abeta protein in hippocampal neurons by reducing the phosphorylation of GSK3beta, down-regulating the ratio of pGSK3beta/GSK3beta and upregulating the expression of IDE.

[Study on the mechanism of naofucong granule in improving memory of cerebral ischemic mice].

OBJECTIVE: To explore the effect of Naofucong Granule (NFCG), a self-manufactured Chinese herbal preparation, on memory and cerebral cholinergic system in cerebral ischemic mice. METHODS: Mice model of learning/memory impairment was established by bilateral ligation of internal carotid arteries. The memory ability of mice was assessed by measuring latent period in the Morris Water Maze. RESULTS: Seven days after modeling, the latent period and swimming course of mice (82.3 +/- 32.0 seconds and 986.7 +/- 414.5 cm) were longer than those of control (sham-operated mice, 35.3 +/- 37.9 seconds and 410.4 +/- 507.0 cm, P < 0.01). Administration of NFCG could ameliorate these changes to 30.6 +/- 31.3 seconds and 378.1 +/- 386.3 cm (P < 0.01) and normalized. In the model animals, the choline acetylase activity in brain cortex and hippocampus was 35.64 +/- 4.96 and 45.08 +/- 4.96 respectively, which was significantly lower than that in the control (40.52 +/- 4.74 and 53.96 +/- 8.53); so was the activity of cholinergic receptor M in cerebral cortex (44.41 +/- 10.67 vs 57.56 +/- 6.98) and the activity of cholinergic receptor N in cerebral cortex and hippocampus (232.41 +/- 21.99 and 303.72 +/- 72 +/- 28.78 vs 276.66 +/- 32.46 and 385.56 +/- 46.88), P < 0.05 or P < 0.01. Administration of NFCG also could reverse them and elevate to normal level. CONCLUSION: NFCG has protective function on intellectual deficits in cerebral ischemic mice, which may be related to its action in enhancing function of cholinergic system.