桑枝总生物碱改善糖尿病肾病小鼠肾损伤作用机制研究

Research on the Mechanism of Sangzhi Alkaloids in Improving Renal Injury in Diabetic Kidney Disease Mice

摘要: 目的：探讨桑枝总生物碱(Sangzhi alkaloids, SZ-A)对糖尿病肾病小鼠肾损伤的改善作用机制。方法：将db/m小鼠作为对照组、db/db小鼠随机分为模型组(db/db组)和桑枝总生物碱治疗组(SZ-A组)，SZ-A组小鼠接受SZ-A灌胃12周处理。对各组小鼠检测体重、空腹血糖以及血清ALP、BUN、CREA等指标，并结合HE、PAS染色观察肾组织病理改变，同时利用ELISA和Western blot检测氧化应激、炎症因子(TNF-α, IL-6, IL-1β)和纤维化标志物(TGF-β1, Collagen IV, α-SMA)以及凋亡相关蛋白(Cleaved Caspase-3, Bax, Bcl-2)的表达水平。结果：db/db小鼠较db/m组呈现显著高血糖及肾功能异常，表现为血清ALP、BUN、CREA水平升高，同时伴随氧化应激标志物SOD活性下降与MDA、LDH水平上升。该组小鼠肾脏组织出现显著炎症反应，TNF-α、IL-6、IL-1β等促炎因子表达增强，并伴有TGF-β1介导的纤维化进程加速，Collagen IV和α-SMA异常沉积。p38 MAPK通路异常激活及Cleaved Caspase-3、Bax、Bcl-2凋亡调控失衡进一步加重肾损伤(P < 0.05)。经SZ-A治疗后，上述高血糖、肾功能障碍、氧化损伤及炎症反应均获显著缓解，肾组织纤维化程度减轻，病理结构改善，同时TGF-β1/p38 MAPK信号转导及细胞凋亡相关蛋白表达趋于正常化(P < 0.05)。结论：SZ-A能显著改善糖尿病肾病小鼠的肾损伤，其作用机制可能与抑制TGF-β1/p38 MAPK纤维化信号通路以及调控细胞凋亡和炎症反应密切相关。

Abstract: Objective: To investigate the mechanism by which Sangzhi alkaloids (SZ-A) improve kidney injury in mice with diabetic kidney disease. Methods: The db/m mice were used as the control group, while the db/db mice were randomly divided into a model group (db/db group) and a treatment group administered with Sangzhi alkaloids (SZ-A group). The SZ-A group received SZ-A via gavage for 12 weeks. Body weight, fasting blood glucose, and serum levels of ALP, BUN, CREA, and other indicators were measured in each group. Additionally, HE and PAS staining were employed to observe pathological changes in the kidney tissue. The expression levels of oxidative stress markers, inflammatory factors (TNF-α, IL-6, IL-1β), fibrosis markers (TGF-β1, Collagen IV, α-SMA), and apoptosis-related proteins (Cleaved Caspase-3, Bax, Bcl-2) were assessed using ELISA and Western blot. Results: The db/db mice exhibited significantly higher blood glucose levels and renal dysfunction compared to the db/m group, characterized by elevated serum ALP, BUN, and CREA levels, along with decreased SOD activity and increased levels of MDA and LDH as markers of oxidative stress. This group displayed significant inflammatory responses, with enhanced expression of pro-inflammatory factors TNF-α, IL-6, and IL-1β, alongside accelerated fibrosis mediated by TGF-β1, resulting in abnormal deposition of Collagen IV and α-SMA. Abnormal activation of the p38 MAPK pathway and imbalances in apoptosis regulation involving Cleaved Caspase-3, Bax, and Bcl-2 further exacerbated kidney injury (P < 0.05). Following treatment with SZ-A, the aforementioned high blood glucose levels, renal dysfunction, oxidative damage, and inflammatory responses were significantly alleviated, with reduced kidney tissue fibrosis and improvements in pathological structure. Concurrently, TGF-β1/p38 MAPK signal transduction and the expression of apoptosis-related proteins tended toward normalization (P < 0.05). Conclusion: SZ-A significantly improves kidney injury in diabetic nephropathy mice, and its mechanism of action may be closely related to the inhibition of the TGF-β1/p38 MAPK fibrotic signaling pathway and the regulation of apoptosis and inflammatory responses.