作为中药,黄葵胶囊(HKC)已用于治疗肾脏疾病患者,包括糖尿病肾病(DN)。我们最近证明,HKC可以重新调节肾脏近曲小管和远曲小管中溶质载体(SLC)的活性,从而逆转DN的发展。HKC的主要活性化学成分是Abelmoschusmanihot的黄酮(L.).本研究旨在通过分析肾脏近端和远端曲小管中的SLC活性,进一步评估A.manihot总黄酮(TFA)在DN消退中的功效。在db/db小鼠中施用TFA(0.076g/kg/d)或媒介物,2型糖尿病和DN的动物模型,每天通过口服灌胃4周。测量血糖水平和尿白蛋白与肌酐之比(UACR),并用于测定T2D和DN。十个SLC,包括slc2a2,slc4A1,slc5a2,slc5A3,slc5a8,slc6a20,slc27a2,slc12a3,slc34a1和slc38a2在肾脏的近端和明显的曲小管中高表达。用实时RT-PCR和免疫组织化学分析TFA处理前后它们在mRNA和蛋白水平的表达。数据显示在TFA处理后db/db小鼠中的UACR显著降低。与非糖尿病对照组相比,DN组中的slc2a2,slc4A1,slc5a2,slc5A3,slc5a8,slc6a20,slc27a2,slc12a3,slc34a1和slc38a2在TFA处理后下调,但上调。对整个肾脏切片的进一步分析表明,在TFA处理后,db/db小鼠的肾单位数量和结构增加并得到改善。因此,目前的研究提供了进一步的证据,表明A.manihot中的黄酮通过改善肾脏SLCs的生物学功能而具有治疗DN的药理作用。
As a traditional Chinese medicine, Huangkui capsule (HKC) has been used to treat patients with kidney diseases, including diabetic nephropathy (DN). We have recently demonstrated that HKC could re-regulate the activities of solute carriers (SLC)s in proximal and distal convoluted tubules of kidneys in regression of the development of DN. The main active chemical constituents of HKC are the flavones of Abelmoschus manihot (L.). The current study aims to further evaluate the efficacy of total flavones of A. manihot (TFA) in the regression of DN by analyzing SLC activities in proximal and distal convoluted tubules of kidneys. TFA (0.076 g/kg/d) or vehicle was administered in db/db mice, the animal model of type 2 diabetes and DN, daily via oral gavage for four weeks. Blood glucose levels and urinary albumin-to-creatinine ratio (UACR) were measured and used for the determination of T2D and DN. Ten SLCs, including slc2a2, slc4A1, slc5a2, slc5A3, slc5a8, slc6a20, slc27a2, slc12a3, slc34a1 and slc38a2 were highly expressed in proximal and distinct convoluted tubules of kidneys. Their expression at mRNA and protein levels before and after TFA treatment were analyzed with real-time RT-PCR and immunohistochemistry. Data showed that UACR in the db/db mice after TFA treatment was significantly decreased. Compared with the group of non-diabetic control, slc2a2, slc4A1, slc5a2, slc5A3, slc5a8, slc6a20, slc27a2, slc12a3, slc34a1 and slc38a2 in the group of DN were down-regulated but up-regulated after TFA treatment. Further analyses of whole kidney sections indicated that the numbers and structures of the nephron in db/db mice was increased and improved after TFA treatment. Thereby, the current study provides further evidence that the flavones in A. manihot have pharmacological effects on the treatment of DN by improving the biological function of SLCs in kidneys.