OBJECTIVE: This study aims to comprehensively evaluate the therapeutical potential of PS in treating diabetic kidney disease (DKD) and to elucidate the underlying mechanisms through in vivo and in vitro models.
METHODS: The main composition of PS were characterized using the UPLC-QTOF-MS method. For the in vivo investigation, a mouse model mediated by streptozocin (STZ) associated with a high-fat diet (HFD) and unilateral renal excision was established. The mice were split into 6 groups (n = 8): control group (CON group), DKD group, low-dose of Plantago asiatica L. seed extract group (PASE-L group, 3 g/kg/d), medium-dose of PASE group (PASE-M, 6 g/kg/d), high-dose of PASE group (PASE-H, 9 g/kg/d), and positive drug group (valsartan, VAS group, 12 mg/kg/d). After 8 weeks of treatment, the damage induced by DKD was evaluated by using relevant parameters of urine and blood. Furthermore, indicators of inflammation and factors associated with the SphK1-S1P signaling pathway were investigated. For the in vitro study, the cell line HBZY-1 was stimulated by high glucose (HG), they were then co-cultured with different concentrations of PASE, and the corresponding associated inflammatory and sphingosine kinase 1/sphingosine-1-phosphate (SphK1-S1P) factors were examined.
RESULTS: A total of 59 major components in PS were identified, including flavonoids, iridoids, phenylethanol glycosides, guanidine derivatives, and fatty acids. In the mouse model, PS was found to significantly improve body weight, decrease fasting blood glucose (FBG) levels, increased glucose tolerance and insulin tolerance, improved kidney-related markers compared to the DKD group, pathological changes in the kidneys also improved dramatically. These effects showed a dose-dependent relationship, with higher PASE concentrations yielding significantly better outcomes than lower concentrations. However, the effects of the low PASE concentration were not evident for some indicators. In the cellular model, the high dose of PASE suppressed high glucose (HG) stimulated renal mesangial cell proliferation, suppressed inflammatory factors and NF-κB, and decreased the levels of fibrillin-1(FN-1) and collagen IV(ColIV).
CONCLUSIONS: Our results indicate that PS exerts favorable therapeutic effects on DKD, with the possible mechanisms including the inhibition of inflammatory pathways, suppression of mRNA levels and protein expressions of SphK1 and S1P, consequently leading to reduced overexpression of FN-1 and ColIV, thereby warranting further exploration.
目的:本研究旨在通过体内和体外模型全面评估PS治疗糖尿病肾病(DKD)的治疗潜力,并阐明其潜在机制。
方法:使用UPLC-QTOF-MS方法表征PS的主要组成。对于体内研究,建立了由链脲佐菌素(STZ)介导的小鼠模型,该模型与高脂饮食(HFD)和单侧肾脏切除术相关。将小鼠分为6组(n=8):对照组(CON组),DKD集团,低剂量车前草种子提取物组(PASE-L组,3g/kg/d),PASE组的中等剂量(PASE-M,6g/kg/d),高剂量PASE组(PASE-H,9g/kg/d),和阳性药物组(缬沙坦,VAS组,12mg/kg/d)。治疗8周后,使用尿液和血液的相关参数评估DKD引起的损伤。此外,研究了炎症指标和与SphK1-S1P信号通路相关的因子。对于体外研究,细胞系HBZY-1被高葡萄糖(HG)刺激,然后将它们与不同浓度的PASE共培养,并检查了相应的相关炎症和鞘氨醇激酶1/1-磷酸鞘氨醇(SphK1-S1P)因子。
结果:共鉴定了PS中的59个主要成分,包括类黄酮,环烯醚萜类,苯乙醇糖苷,胍衍生物,和脂肪酸。在老鼠模型中,PS被发现显着改善体重,降低空腹血糖(FBG)水平,葡萄糖耐量和胰岛素耐量增加,与DKD组相比,肾脏相关标志物有所改善,肾脏的病理变化也得到了显着改善。这些效应表现出剂量依赖性关系,较高的PASE浓度比低浓度产生明显更好的结果。然而,低PASE浓度对某些指标的影响不明显。在细胞模型中,高剂量的PASE抑制高糖(HG)刺激的肾系膜细胞增殖,抑制炎症因子和NF-κB,并降低了原纤维蛋白-1(FN-1)和胶原IV(ColIV)的水平。
结论:我们的结果表明PS对DKD具有良好的治疗效果,可能的机制包括抑制炎症途径,抑制SphK1和S1P的mRNA水平和蛋白表达,因此导致FN-1和ColIV过表达减少,因此需要进一步探索。