Tanshinone IIa protects retinal endothelial cells against mitochondrial fission induced by methylglyoxal through glyoxalase 1.

Advanced glycation end products (AGEs) play an important role in the onset of diabetic retinopathy. Therefore, in the current study, we investigate whether and how Tanshinone IIa (Tan IIa) from Salvia miltiorrhiza protects bovine retinal endothelial cells (BRECs) against methylglyoxal (MGO) mediated cell dysfunction. The results showed that MGO reduced cell viability in dose dependent manner. The treatment of Tan IIa (50 µM) significantly improved cell viability induced by MGO in BRECs. MGO increased cellular reactive oxygen species formation and cellular nitric oxide (NO) level; enhanced nox1 and iNOS mRNA levels; inhibited prdx1 mRNA level. The treatment of Tan IIa effectually ameliorated cellular oxidative stress. Exposure of MGO resulted in mitochondrial fission and decrease of opa1 and mfn1. No significant difference in mRNA levels of mfn2 and drp1 was detected between MGO and medium. Tan IIa reduced mitochondrial fragmentation, enhanced the mRNA levels of mfn1 and opa1 in MGO cultured BRECs. The short time exposure of cellular antioxidatants, dimethylthiourea (10 mM) and tiron (10 mM) had no effect on mitochondrial fission although they ameliorated cellular reactive oxygen species level. Moreover, overexpression of glyoxalase 1 (GLO1) increased key proteins of mitochondrial fusion, including opa1 and mfn1 in BRECs cultured with MGO. However, inhibition of GLO1 by siRNA abolished the effect of Tan IIa on induction of mitochondrial fusion in MGO cultured BRECs. In conclusion, MGO caused the injury of retinal endothelial cells through induction of mitochondrial dysfunction and mitochondrial fission, the treatment of Tan IIa ameliorated mitochondrial dysfunction and fission induced by AGEs through enhancing GLO1.

Effect of Salvia miltiorrhiza hydrophilic extract on the endothelial biomarkers in diabetic patients with chronic artery disease.

The aim of this pilot study was to investigate whether the administration of Salvia miltiorrhiza hydrophilic extract (SMHE) reduced the level of soluble vascular cell adhesion molecule-1 (sVCAM-1) and von Willebrand factor (vWF) in diabetic patients with coronary heart disease (CHD). Sixty-two diabetic patients with CHD were recruited and randomly assigned into placebo and treatment groups. Patients were given SMHE for 60 days. Levels of sVCAM-1, vWF and oxidative low density lipoprotein (oxLDL) were determined by using enzyme linked immunosorbent assay (ELISA). The results showed that the levels of VCAM-1 and vWF positively correlated with the level of oxLDL in diabetic patients with CHD. Levels of sVCAM-1 and vWF in serum were reduced significantly in patients receiving SMHE treatment at day 60 in comparison with the baseline. Administration of SMHE also led to a clear decrease in the levels of oxLDL in diabetic patients with CHD. In summary, this study suggests that SMHE has a potential protective effect on the development of diabetic cardiovascular disease.

Effect of Salvia miltiorrhiza hydrophilic extract on antioxidant enzymes in diabetic patients with chronic heart disease: a randomized controlled trial.

To investigate whether Salvia miltiorrhiza hydrophilic extract (SMHE) has the ability to ameliorate oxidative stress in diabetic patients with chronic heart disease (CHD), 62 patients with CHD were recruited. These patients were assigned randomly into two groups: (1) placebo group receiving hypoglycemic therapy; (2) treatment group receiving hypoglycemic therapy plus SMHE. The biological markers related to oxidative stress were measured to determine the effect of treatment. Thirty patients in the placebo group and 24 patients in the treatment group were followed to completion in this study. Overall, the malondialdehyde (MDA) level at day 30 in the treatment group was significantly lower than in the placebo group. However, no significant difference in the serum antioxidant enzymes activities was observed between the groups. At day 60, the serum glutathione (GSH) level, superoxide dismutase (SOD), Paraoxonase (PONase) and glutathione reductase (GSSG-R) activities increased markedly in the treatment group compared with the placebo group. There was no significant difference in the level of lipid profile between the two groups. This study indicated that SMHE clearly reduced oxidative stress in diabetic patients with CHD.

Inhibition of glucose-induced vascular endothelial growth factor expression by Salvia miltiorrhiza hydrophilic extract in human microvascular endothelial cells: evidence for mitochondrial oxidative stress.

AIM OF STUDY: Diabetes mellitus is frequently combined with vascular diseases, which are associated with the expression of vascular endothelial growth factor (VEGF). An approach that can reverse the induction of VEGF by hyperglycemia may potentially benefit the outcome of diabetic patients. Therefore, in the present study, we investigated the effect of Salvia miltiorrhiza (S. miltiorrhiza) hydrophilic extract on the expression of VEGF induced by high concentration of glucose. MATERIALS AND METHODS: Vector of VEGF promoter luc was transiently transfected into HMEC-1 cells, and luciferase activity was measured to determine the promoter activity. In order to investigate the mechanism of Salvia miltiorrhiza hydrophilic extract, mitochondrial uncoupling protein 2(UCP2) was knockdown by using UCP2 siRNA. The expression of VEGF was obtained by using quantitative RT-PCR and dot blot. The level of reactive oxygen species (ROS) was expressed by the level of 2',7'-dichlorfluorescein. RESULTS: Exposure of HMEC-1 cells to 30 mM glucose resulted in a significant increase in the expression of VEGF mRNA (5.7 fold at 3mM glucose, P<0.005), and an increase of ROS formation (2.4 fold at 3mM glucose, P<0.005). These effects were completely antagonized by an inhibitor of electron transport chain complex II, thenoyltrifluoroacetone (TTFA) and an uncoupler of oxidative phosphorylation, carbonylcyanide-m-chlorophenylhydrazone (CCCP). Addition of Salvia miltiorrhiza hydrophilic extract (10 µg/ml) led to a significant decrease of VEGF mRNA and ROS formation in 30 mM glucose condition. Interestingly, knockdown of mitochondrial UCP-2 by UCP-2 siRNA abolished the reduction of VEGF expression and ROS formation by Salvia miltiorrhiza hydrophilic extract. CONCLUSIONS: These findings indicated that Salvia miltiorrhiza hydrophilic extract effectively reversed induction of VEGF expression by high glucose via ameliorating mitochondrial oxidative stress. Salvia miltiorrhiza hydrophilic extract can potentially be an effective antioxidant therapy for the treatment of diabetic chronic vascular complication.

Effect of annealing on the phase structure and the properties of the film formed from P(St-co-BA)/P(MMA-co-BA) composite latex.

Composite latex of P(St-co-BA)/P(MMA-co-BA) was prepared by two-step semi-continuous emulsion polymerization under starved conditions. Optical properties, water resistance and heat aging process of the film formed by the composite latex were examined. It was revealed that annealing temperature played an important role on the structure of the composite latex film. The surface of the film prepared at room temperature was very rough. Many micro-cracks were observed both on the surface and inside of the film. Increase of annealing temperature assisted film formation. There was a critical temperature at which the film properties, such as water resistance and transparency, were significantly improved. However, it was worth to note that phase rearrangement had occurred when the annealing temperature was higher than critical temperature. Micro-pinholes and micro-cracks were detected on the surface of the film. Meanwhile, the properties of the film, such as transparency and water adsorption, became remarkable deteriorated.

Temperature-pH sensitivity of bovine serum albumin protein-microgels based on cross-linked poly(N-isopropylacrylamide-co-acrylic acid).

Monodispersed poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAM/AAc) microgels with various contents of acrylic acid (AAc) and cross-linker N,N'-methylenebisacrylamide (MBAAm) were synthesized by surfactant-free emulsion polymerization. The microgels exhibited affinity of binding bovine serum albumin (BSA) with increase of AAc contents. The adsorption amount of BSA was strongly dependent on suspension pH. The maximum adsorption was observed at around pH 4.0, while both low pH and basic conditions induced the rather low adsorption. In addition, AFM images showed that the microgel particles underwent bridging aggregation by loading BSA. The resultant BSA-microgel particles became more hydrophobic after loading BSA. Importantly, the adsorption of BSA onto PNIPAM/AAc microgel was found to alter the swelling/deswelling behavior of the resultant microgel suspensions. With the increase of BSA concentration, the volume phase transition temperature of BSA-microgel particles shifted to the lower temperature.