Effects and mechanisms of total flavones of Abelmoschus manihot in inhibiting podocyte necroptosis and renal fibrosis in diabetic kidney disease / 中国中药杂志

Previous studies have shown that high blood glucose-induced chronic microinflammation can cause inflammatory podocyte injury in patients with diabetic kidney disease(DKD). Therein, necroptosis is a new form of podocyte death that is closely associated with renal fibrosis(RF). To explore the effects and mechanisms in vivo of total flavones of Abelmoschus manihot(TFA), an extract from traditional Chinese herbal medicine Abelmoschus manihot for treating kidney diseases, on podocyte necroptosis and RF in DKD, and to further reveal its scientific connotation with multi-pathway and multi-target, the authors randomly divided all rats into four groups: a namely normal group, a model group, a TFA group and a rapamycin(RAP) group. After the modified DKD rat models were successfully established, four group rats were given double-distilled water, TFA suspension and RAP suspension, respectively by gavage every day. At the end of the 4th week of drug treatment, all rats were sacrificed, and the samples of their urine, blood and kidneys were collected. And then, the various indicators related to podocyte necroptosis and RF in the DKD model rats were observed, detected and analyzed, respectively. The results indicated that, general condition, body weight(BW), serum creatinine(Scr), urinary albumin(UAlb), and kidney hypertrophy index(KHI) in these modified DKD model rats were both improved by TFA and RAP. Indicators of RF, including glomerular histomorphological characteristics, fibronectin(FN) and collagen type Ⅰ(collagen Ⅰ) staining extent in glomeruli, as well as the protein expression levels of FN, collagen Ⅰ, transforming growth factor-β1(TGF-β1) and Smad2/3 in the kidneys were improved respectively by TFA and RAP. Podocyte damage, including foot process form and the protein expression levels of podocin and CD2AP in the kidneys was improved by TFA and RAP. In addition, tumor necrosis factor-α(TNF-α)-mediated podocyte necroptosis in the kidneys, including the morphological characteristics of podocyte necroptosis, the extent and levels of the protein expression of TNF-α and phosphorylated mixed lineage kinase domain like pseudokinase(p-MLKL) was improved respectively by TFA and RAP. Among them, RAP had the better effect on p-MLKL. More importantly, the activation of the receptor interacting serine/threonine protein kinase 1(RIPK1)/RIPK3/MLKL signaling axis in the kidneys, including the expression levels of its key signaling molecules, such as phosphorylated receptor interacting serine/threonine protein kinase 1(p-RIPK1), p-RIPK3, p-MLKL and cysteinyl aspartate specific proteinase-8(caspase-8) was improved respectively by TFA and RAP. Among them, the effect of TFA on p-RIPK1 was superior. On the whole, in this study, the authors demonstrated that TFA alleviates podocyte necroptosis and RF in DKD through inhibiting the activation of the TNF-α-mediated RIPK1/RIPK3/MLKL signaling axis in diabetic kidneys. The authors' findings provide new pharmacological evidence to reveal the scientific connotation of TFA in treating RF in DKD in more depth.

Simultaneous determination of multiple bioactive constituents in Abelmoschi Corolla by UFLC-QTRAP-MS/MS / 中国中药杂志

A comprehensive analytical method based on ultra-fast liquid chromatography coupled with triple quadrupole/linear ion trap tandem mass spectrometry(UFLC-QTRAP-MS/MS) was established for simultaneous determination of the content of 38 active components in Abelmoschi Corolla, including flavonoids, organic acids, nucleosides and amino acids, so as to investigate the effects of different harvesting and processing methods on multi-active components in Abelmoschi Corolla. The chromatographic separation was performed on a XBridg®C_(18) column(4.6 mm×100 mm, 3.5 μm) with(0.1% formic acid water) methanol-acetonitrile(1∶1) as the mobile phase for gradient elution at 30 ℃. The flow rate was 0.5 mL·min~(-1). The components were detected in a multiple-reaction monitoring(MRM) mode. The gray relational analysis(GRA) was used to comprehensively evaluate the multiple active components of Abelmoschi Corolla at different harvesting times and drying temperatures. The results showed that 38 components had a good linearity with correlation coefficients all above 0.999 0. The method featured a good precision, repeatability and stability with the relative stan-dard deviations(RSDs) of less than 5.0%. Recoveries ranged from 98.06% to 104.4% with RSD between 0.22% and 4.9%. The results of GRA indicated that a better quality in the samples collected on September 9 th. Samples dried at 90 ℃ had a better quality. The established method is accurate and reliable, and can be used to assess the internal quality of Abelmoschi Corolla. This study can provide basic materials for determining appropriate harvesting time and processing method of Abelmoschi Corolla.