ABSTRACT
Huangpu Tongqiao Capsules(HPTQC), with the functions of invigorating Qi and kidney, eliminating phlegm and removing blood stasis, have the effect of treating Alzheimer's disease(AD), but its mechanism needs further exploration. To explore the relationship between the therapeutic mechanism of HPTQC on Alzheimer's disease and EGFR-PLCγ signal pathway, 40 healthy male SD rats were selected and divided into 4 groups randomly: sham operation group(sham), model group(model), HPTQC group(HPTQC), and nimodipine group(NMP). AD rat model was established by intraperitoneal injection of D-galactose combined with an intracerebral injection of amyloid-β peptide(25-35). After 28 days of administration, Morris water maze test and HE staining showed that the learning and memory ability of AD rats were significantly decreased(P<0.01), and hippocampal neurons were obviously da-maged. However, HPTQC could improve the learning and memory ability of AD rats(P<0.05) and reduce the damage of hippocampal neurons. Immunofluorescence test results showed that the expression levels of EGFR and p-Tau in hippocampal CA1 region of AD rats were significantly increased(P<0.01), and HPTQC could reduce the expression of EGFR and p-Tau in hippocampus of AD rats(P<0.01). Western blot results showed that the protein expression levels of EGFR, PLCγ, IP3 R and p-Tau in hippocampus of AD rats were significantly increased(P<0.01), and HPTQC could reduce the protein expression of EGFR, PLCγ, IP3 R and p-Tau in AD rats(P<0.05). RT-PCR results showed that the mRNA levels of EGFR, PLCγ, IP3 R and Tau in hippocampus of AD rats were significantly increased(P<0.01), and HPTQC could reduce the mRNA levels of EGFR, PLCγ, IP3 R and Tau in AD rats(P<0.05). The results indicate that HPTQC can improve the learning and memory ability of AD rats, and its mechanism of action may be related to regulating EGFR-PLCγ signal pathway.
Subject(s)
Animals , Male , Rats , Alzheimer Disease , Amyloid beta-Peptides , Capsules , Disease Models, Animal , ErbB Receptors , Hippocampus , Rats, Sprague-Dawley , Signal TransductionABSTRACT
The loss of hippocampal neurons is one of the main pathological features of Alzheimer's disease (AD), which is related to the apoptosis of hippocampal neurons. Huangpu Tongqiao capsule is used for the treatment of AD, but the underlying mechanism is still unclear. This study is to investigate the mechanism of neuroprotective effect of Huangpu Tongqiao capsule in the treatment of AD, through observing the effect of Huangpu Tongqiao capsule containing serum on cell injury of primary cultured hippocampal neurons induced by Aβ₂₅₋₃₅ via inhibiting the cell apoptosis. Primary cultured hippocampal neurons were cultured and identified by MAP-2 immunofluorescence staining, and cell growth state was observed by inverted microscope. The Huangpu Tongqiao capsule containing serum was prepared using the method of serum pharmacology. MTT assays were used to measure the optimum concentration range of Huangpu Tongqiao capsule containing serum, and optimum Aβ concentration for establishing the AD model. After primary cultured hippocampal neurons AD cell model was induced by Aβ₂₅₋₃₅, cell survival rate was detected by MTT, cell apoptosis rate was assayed by flow cytometry, and protein expressions of Bax, Cyt C and caspase-3 were determined by Western blot analysis. The results showed that the primary cultured hippocampal neurons were cultured successfully, and cells grew mature at seventh days; Compared with normal group, the survival rate of hippocampal neurons in AD cell model group was decreased, the apoptosis rate of hippocampal neurons was increased, and the protein expressions of Bax, Cyt C and caspase-3 were increased (<0.05, <0.01); Compared with AD cell model group, the survival rate of hippocampal neurons in Huangpu Tongqiao capsule containing serum group was increased, the apoptosis rate of hippocampal neurons was decreased, and the protein expressions of Bax, Cyt C and caspase-3 were decreased (<0.05, <0.01). These findings suggest that Huangpu Tongqiao capsule containing serum has a neuroprotective effect on cell injury of the primary cultured hippocampal neurons induced by Aβ₂₅₋₃₅, and its effect on the treatment of AD is associated with the inhibition the apoptosis of hippocampal neurons.
ABSTRACT
<p><b>OBJECTIVE</b>To observe the effects of ginseng and Ligustrazine drug containing serum on the proliferation, vitality, and extracellular-signal-responsive kinase (ERK) pathway in neural stem cells undergoing in vitro oxygen-glucose deprivation/reoxygenation culture.</p><p><b>METHODS</b>The cultured neural stem cells were randomly divided into 5 groups, i.e., the normal control group (Group A), the oxygen-glucose deprivation/reoxygenation group (Group B), the oxygen-glucose deprivation/reoxygenation +ginseng serum group (Group C), the oxygen-glucose deprivation/reoxygenation + Ligustrazine serum group (Group D), and oxygen-glucose deprivation/reoxygenation +ginseng and Ligustrazine drug serum group (Group E).The protein expression levels of ERK and phosphorylated ERK (p-ERK) were observed using immunoblotting. The proliferation of neural stem cells was observed using 5-bromodeoxyuridine (BrdU) incorporation assay. The vitality of neural stem cells was detected using methyl thiazolyl tetrazolium (MTT) colorimetry.</p><p><b>RESULTS</b>The p-ERK level increased transiently at 10 min and 30 min after reoxygenation, but it decreased to the normal level at 4 h, 6 h, and 1 day, respectively. Compared with Group B, the p-ERK level at 6 h after reoxygenation could be elevated in Group C, D, and E. The proliferation and the vitality of neural stem cells at 1 day after reoxygenation could be enhanced. Furthermore, the effects of combination of ginseng and Ligusticum were better than those of using ginseng or Ligusticum alone.</p><p><b>CONCLUSIONS</b>Combination of ginseng and Ligusticum could promote the proliferation and vitality of rats' neural stem cells undergoing oxygen-glucose deprivation/reoxygenation culture through ERK signal pathway. Its effects was better than that of using ginseng or Ligusticum alone.</p>