ABSTRACT
OBJECTIVE To explore the neuroprotective effect of sodium aescinate on rats with Parkinson’s disease by regulating the silent information regulator 1 （SIRT1）/nuclear factor-κB （NF-κB） signaling pathway. METHODS The Parkinson’s disease rat model was constructed by using 6-hydroxydopamine injection method. Forty-eight rats successfully modeled were randomly divided into model group， sodium aescinate low-dose group （1.8 mg/kg）， sodium aescinate high-dose group （3.6 mg/kg）， sodium aescinate+EX527 （sodium aescinate 3.6 mg/kg+SIRT1 inhibitor EX527 5 mg/kg） group， with 12 rats in each group. Another 12 healthy rats were selected as the sham operation group. Each group was injected with the corresponding drug solution intraperitoneally， once a day， for 21 consecutive days. Twenty-four hours after the end of the last administration， the motor and cognitive functions of rats were detected， and the morphology of neurons in the substantia nigra and CA1 region of hippocampal tissue were observed. The content of dopamine （DA） in the nigrostriatal and the expression levels of tyrosine hydroxylase （TH） and α-synuclein （α-Syn） in the substantia nigra were detected. The serum levels of pro-inflammatory factor [interleukin-6 （IL-6）， IL-18]， anti-inflammatory factor （IL-10）， and the expression levels of SIRT1， phosphorylated NF-κB p65 （p-NF-κB p65） and NF- κB p65 protein in nigrostriatal were detected. RESULTS Compared with sham operation group， the neurons in the substantia nigra and CA1 region of hippocampal tissue were seriously damaged in model group； the number of rotations， escape latency， the expression levels of α-Syn in substantia nigra， the levels of serum pro-inflammatory factors， the relative expression ratio of p-NF- κB p65 and NF-κB p65 protein in nigrostriatal were increased or prolonged significantly （P＜0.05）； the target quadrant residence time， the content of DA in nigrostriatal， the expression level of TH in substantia nigra， the serum level of anti-inflammatory factor， and the expression level of SIRT1 protein in substantia nigra striatum were significantly decreased or shortened （P＜0.05）. Compared with model group， the damage degrees of neuron in sodium aescinate groups were alleviated， and the quantitative indicators were significantly improved， which were more significant in the high-dose group （P＜0.05）； EX527 could reverse the improvement effect of high-dose sodium aescinate （P＜0.05）. CONCLUSIONS Sodium aescinate can inhibit the activation of NF-κB signal by up-regulating the protein expression of SIRT1， thereby reducing the neuroinflammation of rats with Parkinson’s disease， improving the motor and cognitive dysfunctions， and finally playing a neuroprotective role.
ABSTRACT
To investigate the effects of saponins extracted from Panax japonicus(SPJ) on cardiomyocyte apoptosis in natural aging rats and explore its underlying mechanisms. SD male rats were randomly divided into four groups: young control group, natural aging group, SPJ low dose group and SPJ high dose group, with 10 rats in each group. The rats in natural aging group, SPJ low and high dose groups were respectively treated with normal saline, SPJ 10 and 60 mg•kg-1•d-1 from the beginning of 18 month-old, 6 days per week for 6 months till 24 month-old. Then the animals were sacrificed. Their myocardial morphology changes were observed by using haematoxylin-eoin(HE) staining; cardiomyocyte apoptosis was tested by using Tunel assays; and the protein expression levels of Bcl-2, Bax, IL-1β, TNF-α, AMPK, p-AMPK, Sirt1, and Ac-NF-κB p65 in myocardial tissues of rats were detected by Western blot. The results showed that SPJ could effectively improve the arrangement disorder of myocardial fibers, reduce the infiltration of inflammatory cells and inhibit cardiomyocyte apoptosis in natural aging rats. At the same time, SPJ could significantly inhibit the protein expression of Bax, IL-1β, TNF-α and Ac-NF-κB p65, and increase the expression of Bcl-2, Bcl-2/Bax, p-AMPK/AMPK and Sirt1 in the heart tissues of natural aging rats. SPJ can effectively inhibit cardiomyocyte apoptosis in natural aging rats, and its mechanisms may be related with the regulation of inflammatory reaction by AMPK/Sirt1/NF-κB signaling pathway.