Salvianolic acid A ameliorates renal ischemia/reperfusion injury by activating Akt/mTOR/4EBP1 signaling pathway.

Salvianolic acid A (Sal A) has been shown to prevent and treat ischemic cardiovascular, as well as cerebral vascular diseases. However, little is known about Sal A in renal ischemia/reperfusion (I/R) injury. In this study, a renal I/R injury model in rats and a hypoxia/reoxygenation (H/R) model to damage proximal renal tubular cells (HK-2) were used to assess whether Sal A halts the development and progression of renal I/R injury. As compared with vehicle treatment, Sal A significantly attenuated kidney injury after renal I/R injury, accompanied by decreases in plasma creatinine, blood urea nitrogen levels, the number of apoptosis-positive tubular cells, and kidney oxidative stress. Sal A also activated phosphorylated protein kinase B (p-Akt) and phosphorylated-mammalian target of rapamycin (p-mTOR) compared with vehicle-treated I/R injury rats. In H/R-injured HK-2 cells, Sal A can reduce the levels of reactive oxygen species in a dose-related manner. Similar to the results from in vivo experiments, in vitro Sal A also increased the protein expression of phosphorylated-eukaryotic initiation factor 4E binding protein 1 (p-4EBP1) compared with vehicle. Furthermore, the cytoprotective activity of Sal A was inhibited by LY294002 and rapamycin. These findings indicate that Sal A can ameliorate renal I/R injury and promote tubular cell survival partly via the Akt/mTOR/4EBP1pathway. Sal A could be a candidate compound to prevent ischemic tissue damage.

Development of a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for simultaneous determination of epigallocatechin-3-gallate, silibinin, and curcumin in plasma and different tissues after oral dosing of Protandim in rats and its application in pharmacokinetic and tissue distribution studies.

Protandim is an over-the-counter herbal dietary supplement. The key components of Protandim, i.e., epigallocatechin-3-gallate (EGCG), silibinin (SIL), and curcumin (CUR) were simultaneously analyzed through a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method in plasma and different tissues after administration of Protandim in rats. The developed and validated method was employed to assess the pharmacokinetic profiles and the accumulation of EGCG, SIL, CUR in rat plasma and tissue homogenates. The plasma and tissue homogenates were subjected to liquid-liquid extraction and separated on a Hypurity C18 column (50 × 4.6 mm) with a gradient elution of water and acetonitrile. Mass spectrometric detection was performed in the multiple reaction monitoring mode (MRM) following the transitions: m/z 457.3/169.3, m/z 481.3/125.0, m/z 367.3/149.3 and m/z 609.4 /300.2 for EGCG, SIL, CUR, and RU (rutin), respectively. The concentrations of all the analytes in the range from 2 to 1000 ng/mL showed linear relationships with respective peak areas in different matrices. For all matrices, the values of inter-day and intra-day precisions and accuracies were less than 10.3% of the nominal concentration. The matrix effect, extraction recovery, dilution integrity, and stability values were all within acceptable levels. This method was successfully applied for determining the pharmacokinetics and tissue distribution of the components in rats after the intragastrical administration of a single-dose (364.5 mg/kg) or multiple-doses (1458 mg/kg) of Protandim. The data showed that EGCG, SIL, and CUR did not accumulate in rats after multiple doses of Protandim, and the three main components were distributed mainly in the small intestine.

A phenolic amide (LyA) isolated from the fruits of Lycium barbarum protects against cerebral ischemia-reperfusion injury via PKCε/Nrf2/HO-1 pathway.

Lyciumamide A (LyA), a dimer of phenolic amide isolated from the fruits of Lycium barbarum, has been confirmed to possess potent antioxidant activity. This study was aimed to investigate the neuroprotection and molecular mechanisms of LyA against cerebral ischemia/reperfusion (I/R) injury via improving antioxidant activity. The model of middle cerebral artery occlusion (MCAO) and SH-SY5Y cells induced by oxygen and glucose deprivation (OGD) were adopted to verify the neuroprotective effects and the potential pharmacology mechanisms of LyA in vivo and in vitro. In MCAO model, treatment with LyA significantly improved neurologic score, reduced infarct volume, and relieved oxidative stress injury at 48 h after reperfusion. Meanwhile, LyA markedly increased the transcription Nrf2 and HO-1 expressions in the ischemic cerebral cortex. In vitro results showed that LyA protected differentiated SH-SY5Y cells against OGD-induced injury. LyA significantly decreased the expression of caspase-3 and the Bax/Bcl-2 ratio. But knockdown of Nrf2 or HO-1 attenuated the protective effect of LyA. Similarly, knockdown of protein kinase Cε (PKCε) inhibited LyA-induced Nrf2/HO-1 activation, and abated its protective effects. In conclusion, this study firstly demonstrated that LyA protects against cerebral I/R injury, ameliorates oxidative damage and neuronal apoptosis, partly via activation of PKCε/Nrf2/HO-1 pathway.

Protective effect of hydroxysafflor yellow A against acute kidney injury via the TLR4/NF-κB signaling pathway.

This study aimed to evaluate the protective effect of hydroxysafflor yellow A (HSYA) on ischemia/reperfusion (I/R)-induced acute kidney injury via the TLR4/NF-κB pathway, both in vitro and in vivo. Rats were subjected to removal of the right kidney and I/R injury to the left kidney. Rats subjected to renal I/R injury were treated with HSYA at 0.5 h prior to I/R injury. Renal function, histopathological analysis, and cells apoptosis were measured in vivo. In vitro, proximal renal tubular cells (HK-2) were subjected to hypoxia/reoxygenation (H/R). Apoptotic cell death and inflammatory cytokines, Toll-like receptor 4 (TLR4), and nuclear factor (NF)-κB expression were determined. Treatment of I/R rats with HSYA markedly reduced the levels of serum creatinine and blood urea nitrogen, attenuated renal cell apoptosis, alleviated changes in renal tissue morphology, and reduced IL-1ß, TNF-α, and caspase-3 release. In vitro, HSYA effectively decreased NF-κB p65 and inflammatory cytokines, such as IL-1ß, TNF-α, and IL-6. Thus, HSYA can protect renal function from I/R injury by ameliorating acute kidney injury and partly by promoting tubular cell survival via the TLR4/NF-κB pathway. These results suggest that HSYA can be used to prevent I/R-induced acute kidney injury.