| ObjectiveWith the acceleration of the population aging process and the extension of people’s life span,cardiovascular disease has become one of the major diseases and major death factors of the elderly.Therefore,the research of aging biology has attracted more and more attention.The construction of aging animal models is the basis of aging biological research.D-galactose(D-gal),as the most recognized oxidative degener at present,has been widely used in the construction of animal and in vitro cell aging models.Studies have shown that the animal aging model constructed with D-gal is basically in line with the biological characteristics of natural aging.The model construction can cause oxidative stress damage to various organs of the body,but the mechanism is still unclear.Ginseng is a clinical ’qi replenishing medicine’ in traditional Chinese medicine,and ginsenoside is an important medicinal ingredient of ginseng.Studies have shown that ginsenoside has a variety of monomer components,so it has a variety of pharmacological functions,including anti-tumor,antioxidation,anti-inflammatory,anti-aging,promoting metabolism,regulating cell proliferation and differentiation,etc.Our previous studies have proved that ginsenoside Rg1 is an important anti-aging monomer in ginseng.It can antagonize the senescence of stem cells caused by D-gal and reduce the oxidative stress damage of multiple organs such as brain,liver,kidney and gonads.The heart is one of the most important organs of the human body.Some scholars have shown that ginsenoside Rg1 has a good preventive effect on cardiovascular and cerebrovascular diseases and cardiomyocyte damage,but its mechanism is still unclear.The latest research proves that Keap1/Nrf2/ARE signaling pathway is an important antioxidant stress pathway in organisms.After Nrf2 binds to Maf protein,it can activate antioxidant response elements(ARE)and increase the transcription of Nrf2 regulatory gene HO-1,thereby Play an anti-oxidant effect.Is the protective effect of ginsenoside Rg1 on myocardial injury directly related to the Keap1/Nrf2/ARE signaling pathway is Still not clear.Therefore,studying the mechanism of Rg1 antagonizing myocardial injury has important theoretical significance and clinical application prospects.In this study,D-gal was used to construct an aging mouse model,explore the heart injury model of aging mice,and use ginsenoside Rg1 to interfere with the aging process of D-gal to study its protective effect on aging mice’s heart damage and its anti-Nrf2 The preliminary mechanism of oxidative signaling pathway.This article aims to provide an experimental basis for elucidating the protective effect and mechanism of ginsenoside Rg1 on myocardial injury by antagonizing the aging process of D-gal.MethodRandomly divided into four groups(normal group,Rg1 group,D-gal group,Rg1+D-gal group).D-gal in vivo injection was used to construct an aging mouse model.During the modeling process,intraperitoneal injection of ginsenoside Rg1 interfered with the aging process.1.D-gal aging mouse model construction and group administration: 6-8 weeks old C57BL/6J mice,male and female,divided into 4 groups according to random drawing method,with 10 animals in each group.D-gal injury model group: intraperitoneal injection of D-gal(200mg/kg/d,qd×42d);Rg1 intervention model group: intraperitoneal injection of D-gal(the injection dose and injection time were the same as the D-gal injury model group),From the 16 th day of modeling,while D-gal was injected,Rg1(40mg mg/kg/d,qd×26d)was injected intraperitoneally;control group:intraperitoneal injection of physiological saline for 42 days(injection dose and injection time were consistent with other groups);Rg1 control group:intraperitoneal injection of normal saline(the injection dose and injection time were the same as the control group),from the 16 th day of modeling,stoped the injection of normal saline and gave intraperitoneal injection of Rg1(the injection time and injection dose were the same as the Rg1 intervention model group).Modeling and testing related indicators on the2 nd day after the completion of the administration.2.The hearts were taken to measure mouse body weight and heart wet weight,and calculate organ index.3.Observation of cardiac histopathology: preparation of paraffin sections of the heart,HE staining to observe the changes of myocardial tissue structure,Masson staining to observe the deposition of collagen fibers.4.Myocardial ultrastructure observation: Take myocardial tissue,prepare ultra-thin sections,and observe the ultrastructure changes of myocardial fibers under a transmission electron microscope.5.Determination of myocardial enzymes and myocardial oxidation and anti-oxidation indicators: the enzyme standard colorimetric method detects aspartate aminotransferase(AST),lactate dehydrogenase(LDH),total superoxide dismutase(T-SOD),and total superoxide dismutase(T-SOD)in myocardial tissue homogenate.Catalase(CAT)activity and malondialdehyde(MDA)expression.6.Keap1/Nrf2/ARE signaling pathway related protein detection:Western blot detection of the expression of Nrf2,Keap1,HO-1 protein in myocardial tissue.Result1.Heart index: The heart index of mice in the D-gal injury model group was significantly higher than that of the control group(P<0.01).Rg1 interferes with the aging process,and the mouse heart index was significantly lower than the D-gal injury model group(P<0.01).2.Cardiac histopathology and ultrastructural observation: The amount of collagen fiber deposition between myocardial fibers in the D-gal injury model group mice was increased,the arrangement of myofibril bundles was disordered,the diameter of myocardial fibers increased significantly,and the mitochondrial morphology was abnormal with swelling;After Rg1 intervenes in the aging process,the amount of collagen fiber deposition was significantly reduced,the arrangement of myofibril bundles was more orderly,the diameter of myocardial fibers was not statistically different from that of the normal control group,and the mitochondria were basically normal in shape without significant swelling.3.Myocardial enzymes and myocardial oxidation and antioxidant indicators: the AST and LDH activities of the myocardial tissue of the D-gal injury model group mice were significantly increased,the activities of TSOD and CAT were significantly reduced,and the expression of MDA was significantly increased(P<0.05);Rg1 intervention caused After the decay process,the activities of AST and LDH decreased significantly,the activities of T-SOD and CAT increased significantly,and the expression of MDA decreased significantly(P<0.05).4.The expression level of Keap1/Nrf2/ARE signaling pathway related proteins: Nrf2 and HO-1 protein expression in D-gal injury model group mice were significantly reduced(P<0.05),Keap1 protein expression did not change significantly;Rg1 intervention caused After the aging process,the expression of Nrf2 and HO-1 protein increased significantly,and the expression of Keap1 protein decreased significantly(P<0.01).Conclusion1.Ginsenoside Rg1 can effectively antagonize the damage of D-gal to mouse myocardial tissue structure and ultrastructure.2.Ginsenoside Rg1 antagonizes the myocardial damage of D-gal in mice and is related to the inhibition of oxidative stress.3.Ginsenoside Rg1 antagonizes the myocardial damage caused by Dgal in mice is related to the up-regulation of Nrf2 antioxidant signal pathway. |
PDF Full Text Request