Speedy, Specific, Synchronous Sensing Platforms with Ruthenium Complexes for Multiplexed MicroRNA Detection.

Inspired by our previous study on Ru(II)-based compounds for the construction of a sensing platform toward detection of microRNA-185 (miR-185), we herein report new analytical platforms based on two additional Ru(II) compounds, Ru 2 and Ru 3, with larger aromatic ring structures and richer hydrogen bond donor/acceptor sites in comparison to the previously reported Ru 1, as simultaneous detection agents for miR-221/222, which work together to promote the occurrence and development of breast cancer. Molecular simulation docking was first used to predict the nucleic acid sequence binding affinity toward Ru(II) compounds to guide the experiment. The experimental results reveal that Ru 2 and Ru 3 can form a P-DNA@Ru sensing platform with the introduction of carboxyfluorescein (FAM)/5-carboxy-X-rhodamine (ROX) tagged single-chained probe DNA (P-DNA), to realize the discernment of the complementary P-DNA sequence of miR-221/222, giving the limit of detection (LOD) at the nanomolar level with a specific and speedy response. The detection mechanism was verified by binding capacity, luminescence decay, and fluorescence anisotropy (FA), as well as the polyacrylamide gel electrophoresis (PAGE) technique. Furthermore, the formed P-DNA@Ru 2/3 systems could be prepared for the simultaneous and synchronous detection of miR-221/222 sequences, improving the detection efficiency in a time-efficient manner and satisfying the speedy diagnosis requirements of current medical practive.

The hepatoprotective effects of Sedum sarmentosum extract and its isolated major constituent through Nrf2 activation and NF-κB inhibition.

BACKGROUND: Sedum sarmentosum, which is recorded in Chinese Pharmacopoeia, has been applied clinically to treat liver and gallbladder diseases. PURPOSE: This study aimed to explore the hepatoprotective effect of S. sarmentosum less polar extract (SSE) against ANIT-induced liver injury in rats, and the protective activity and mechanism of one major constituent isolated from this extract on D-GalN-induced human hepatic QSG7701 cell damage. METHODS: Rats were divided into groups and then administrated intragastrically with SSE at doses of 100, 200 and 400 mg/kg for 7 days. They were modeled in the experiments with ANIT (70 mg/kg) to induce liver injury after the sixth day administration. The levels of serum biochemical markers ALT, AST, ALP, GGT/γ-GT, DBiL, TBiL, ALB, TP, and bile flow rate, as well as the histopathology of the liver tissue were used as indices of liver damage and measured. The inflammatory response and oxidative stress were thought to be key contributors to ANIT-induced liver injury in rats. Therefore, the inflammatory mediators (TNF-α, IFN-γ, IL-4) and oxidative stress (ROS, SOD, GSH-PX) were measured in the serum and liver homogenates, respectively. Next, phytochemical research was performed to produce the main component, and the isolated compound was evaluated for its hepatoprotective activity against QSG7701 cell injured by D-GalN through the measurement of cell viabilities, ALT, AST, IL-1ß, TNF-α, IL-6, ROS, GSH-PX and SOD productions. Furthermore, the protein expression of the Nrf2 and NF-κB pathways were analyzed by western blotting. RESULTS: SSE had an obvious effect on the decreases of ALT, AST, ALP, GGT/γ-GT, DBiL and TBiL levels, the increases of ALB and TP levels in serum, and the ANIT-induced deceleration in bile flow for liver injury. Meanwhile, SSE pretreatment alleviated ANIT-induced liver pathological injuries exhibited by HE stain of the liver. Moreover, SSE significantly suppressed levels of pro-inflammatory cytokines TNF-α and IFN-γ, and elevated level of anti-inflammatory cytokine IL-4 in serum. SSE also attenuated oxidative stress by reducing ROS level and by enhancing antioxidative enzymes (SOD and GSH-PX) activities after ANIT administration in liver tissue. Further, the major compound shown in HPLC was isolated from SSE. Its structure was identified by the spectroscopic data analysis and comparison with literature values. The principal constituent had potent protective effect on D-GalN-induced QSG7701 cells damage in a dose dependent manner with survival rates of 58.2% and 69.5% at 10 µM and 20 µM, respectively. Its cytoprotective effect was associated with the reduction of ALT, AST, IL-1ß, TNF-α, IL-6 and ROS levels, and the elevation of GSH-PX and SOD productions in QSG7701 cells induced by D-GalN. Western blotting showed that this compound enhanced the expression of Nrf2, HO1, NQO1 and GCLC, and inhibited D-GalN-induced IκBα and NF-κB p65 phosphorylation. CONCLUSIONS: Current study showed that SSE treatment exerted a protective effect on ANIT-induced liver injury. The main compound δ-amyrone isolated from the extract was characterized as the effective component with hepatoprotective activity by promoting Nrf2 antioxidant defense and suppressing NF-κB inflammatory response.