玛咖多糖对D-半乳糖衰老模型小鼠生殖器官的保护作用

Protective Effect of Maca Polysaccharide on Reproductive Organs of Aging Model Mice Induced by D-galactose

目的:探讨玛咖多糖(MP)对D-半乳糖(D-gal)引起的衰老模型小鼠生殖器官损伤的保护作用。方法:将50只无特定病原体(SPF)级雄性癌症研究所(ICR)小鼠按体质量采用简单随机化(Simple Randomization)法分为空白组,模型组,MP低剂量组、MP中剂量组、MP高剂量组,每组10只。除空白组给予生理盐水外,其余组连续8周每天颈背部注射D-gal 500 mg/kg造模。MP低剂量组、MP中剂量组和MP高剂量组从造模起分别按75 mg/kg、150 mg/kg和300 mg/kg剂量连续8周每日灌胃MP。用透射电镜观察小鼠附睾组织形态,测定睾丸组织中谷胱甘肽过氧化物酶(GSH-Px)、丙二醛和单胺氧化酶(MAO)活力,并用实时聚合酶链式反应(PCR)检测附睾超氧化物歧化酶2(SOD 2)、过氧化氢酶表达情况,蛋白质免疫印迹法检测沉默信息调节因子1/P53信号通路中沉默信息调节因子1和P53蛋白的表达情况。结果:48 d后,MP各剂量组小鼠体质量增长高于模型组小鼠,差异有统计学意义(P<0.05);MP中剂量组睾丸指数和附睾指数较模型组升高(P<0.05)。与模型组比较,高剂量组小鼠睾丸组织中GSH-Px活力升高,丙二醛含量、MAO活力均下降(P<0.05);与模型组比较,MP高剂量组小鼠睾丸组织SOD 2、CAT在基因水平的表达增强;与模型组比较,MP各剂量组睾丸组织中沉默信息调节因子1在蛋白水平的表达均升高,P53在蛋白水平的表达均下降(P<0.05或P<0.01)。结论:MP可通过提高GSH-Px活力及SOD 2、CAT抗氧化酶在基因水平的表达,降低丙二醛、MAO活力,对沉默信息调节因子1/P53蛋白信号通路的调控作用,从而保护小鼠生殖器官。

Objective:To investigate the protective effect of maca polysaccharide(MP)on reproductive organs in aging model mice induced by D-galactose(D-gal).Methods:Fifty SPF male ICR mice were divided into a blank group,a model group,and low-,medium-,and high-dose MP groups by simple randomization according to the body weight,with 10 mice in each group.The mice,except for those in the blank group who received normal saline,underwent model induction by back neck injection of D-gal at 500 mg/kg every day for 8 consecutive weeks.The mice in the low-,medium-,and high-dose MP groups were given MP at 75,150,and 300 mg/kg daily by gavage for 8 consecutive weeks from the modeling.The morphology of mouse epididymis was observed with a transmission electron microscope,and the glutathione peroxidase(GSH-Px),malondialdehyde(MDA),and monoamine oxidase(MAO)activities in the testis tissues were measured.Real-time polymerase chain reaction(PCR)was used to detect the expression of superoxide dismutase 2(SOD 2)and catalase(CAT)in the epididymis,and Western blot was used to detect the protein expression of silent information regulator 1(SIRT1)and P53 in the SIRT1/P53 signaling pathway.Results:After 48 days,the body weight growth of mice in each MP group was higher than that of the model group(P<0.05).The testis index and epididymis index of the medium-dose MP group were higher than those in the model group(P<0.05).Compared with the model group,the high-dose MP group showed potentiated GSH-Px activity in the testis tissues,decreased MDA content,and blunted MAO activity(P<0.05).The high-dose MP group had higher expression of SOD 2 and CAT at the gene level than the model group.The expression of SIRT1 at the protein level in the testis tissues of each MP group significantly increased,and the expression of P53 at the protein level significantly decreased compared with that in the model group(P<0.05 or P<0.01).Conclusion:MP can protect the reproductive organs of mice by increasing the activity of GSH-Px and the expression of SOD 2 and CAT at the gene level,reducing the activities of MDA and MAO,and regulating the SIRT1/P53 signaling pathway.