ObjectiveIn order to investigate anti-ageing mechanisms of the notoginsenoside Rg1,we used Aβ_(1-42) and D-galactose to establish aging rat model. Methods Ninety rats were divided into three groups at random: sham group, model group, treatment group. Aging rat models were established by injecting peritoneally D-galactose (100 mg/kg) to the rats for 56 days and after 35 days aggregated Aβ_(1-42)(μg) was injected to the right lateral ventricle of rats. Meantime, rats were treated by intragastric administration the notoginsenoside Rg1. Then spatial memory of experimental rats was examined with the Morris water maze(MWM). The thiol antioxidants including glutathione reductase (GR) and glutathione peroxidase (GSH-Px) activities were examined by colorimetric method. The concentration of the pro-caspase-3 and Bcl-2 were examined by the immunohistochemistry and Western blotting method. Results In aging model rats escape latercies were significantly prolonged (P<0.05), while decreases were seen in the time of staying the third quadrants of platform, the number of crossing over a platform, the concentration of the GR, GSH-Px, and pro-caspase-3 as compared with the sham group(P<0.05). After treatment of the notoginsenoside Rg1, the aging model rats exhibited significant increases in the time of staying the third quadrants of platform, the number of crossing over a platform, the concentration of the GR, GSH-Px, and pro-caspase-3(P<0.05), while a decrease was observed in escape latercies as compared to control group(P<0.05). Moreover there was no significant difference in the expression of the Bcl-2(P>0.05). Conclusion The results from our study indicate that the notoginsenoside Rg1 could improve the oriented learning and memory capacity and prevent the neurodegeneration of central nervous systems in aging model rats by up-regulating the expression of the thiol antioxidants(including GR and GSH-Px) and resisting the cleavage of the pro-caspase-3.

Objective:To investigate the relationship between carotid atherosclerosis(CAS)and subclinical left ventricular(LV)dysfunction in type 2 diabetes mellitus patients with preserved LV ejection fraction(LVEF).Methods:A total of 120 patients with type 2 diabetes mellitus who had LVEF≥50% were selected in the Department of Endocrinology, the First Affiliated Hospital of Air Force Medical University from June 2021 to October 2021. The global longitudinal strain(GLS)was obtained by two-dimensional speckle tracking echocardiography(STE)to assess subclinical LV systolic function. The mitral ratio of peak early to late diastolic filling velocity(E/A), and mitral velocity to early diastolic velocity of the mitral annulus(E/E′)ratio were obtained by pulsed tissue Doppler echocardiography to assess LV diastolic function. Acrroding to bilateral carotid ultrasound examination, the subjects were divided into normal carotid arteries group( n=46) and CAS group( n=74). Demographics and biochemical parameters were compared between two groups. Binary logistic regression and Pearson correlation analysis were used to evaluate the relationship between CAS and subclinical LV dysfunction. Results:The CAS group had a higher proportion of men, older age, and a longer duration of diabetes than the normal carotid arteries group(all P<0.05). There was no difference in LVEF and GLS between the two groups [normal carotid arteries group vs CAS group, LVEF: (60.72±4.73)% vs(60.07±4.28)%; GLS: (18.24±3.72)% vs(17.81±3.47)%, respectively; both P>0.05]. However, compared with normal carotid arteries group, E/A ratio was decreased and E/E′ ratio was significantly increased in CAS group(both P<0.01). Pearson correlation analysis showed that GLS was not correlated with carotid plaque thickness and carotid intima-media thickness(CIMT; both P>0.05). By contrast, E/E′ ratio was positively correlated with carotid plaque thickness and CIMT(both P<0.05). Binary logistic regression analysis showed that GLS and E/E′ ratio were not associated with CAS( both P>0.05). However, decreased E/A ratio was significantly associated with the existence of CAS( OR=0.09, 95% CI 0.01-0.67, P=0.018). Conclusions:In type 2 diabetes mellitus patients without overt heart failure and with preserved LVEF, the occurrence of CAS is not associated with subclinical LV systolic impairment assessed by GLS, but is significantly associated with LV diastolic dysfunction, and is independent of traditional cardiovascular risk factors.