Mixed Aqueous Extract of Salvia Miltiorrhiza Reduces Blood Pressure through Inhibition of Vascular Remodelling and Oxidative Stress in Spontaneously Hypertensive Rats.

BACKGROUND/AIMS: Salvia miltiorrhiza (SM) contains four major aqueous active ingredients, which have been isolated, purified and identified as danshensu (DSS), salvianolic acid A (Sal-A), salvianolic acid B (Sal-B) and protocatechuic aldehyde (PAL), totally abbreviated as SABP. Although SM is often used to treat various cardiovascular diseases in traditional Chinese medicine, the efficacy and function of optimal compatibility ratio of SM's active ingredients (SABP) in the prevention and treatment of cardiovascular diseases remain uncertain. This study investigated antihypertensive effect and underlying mechanisms of SABP vs. SM lyophilized powder (SMLP) in spontaneously hypertensive rats (SHR) and to establish the ratio of the optimal compatibility of DSS, Sal-A, Sal-B and PAL in improving cardiovascular functions. METHODS: The SHRs were treated with either SABP or SMLP and their systolic blood pressures (SBP) were monitored. The isolated thoracic aorta of SHRs was segregated for immunohistochemistry, Hematoxylin-Eosin stain and mRNA and protein expression of NOX4, TGF-ß1, Col-I, ET-1, α-SMA and Smad7. Moreover, the adventitial fibroblasts (AFs) were isolated and cultured from SD rats' aorta and the reactive oxygen species (ROS) production was determined after SABP or SMLP treatment. RESULTS: SABP, but not SMLP, significantly reduced SBP, which were accompanied by the inhibited morphological changes in the thoracic aorta and the reduced mRNA and protein expression of NOX4, TGF-ß1, Col-I, ET-1 and α-SMA, but the increased Smad 7 expression in SHRs. Moreover, SABP also resulted in a decreased ROS production in AFs of SD rats. CONCLUSIONS: These results indicate that SABP, but not SMLP, treatment potently inhibits hypertension through improvements of vascular remodeling and oxidative stress. The present study provides new evidence that the efficacy and function from optimal compatibility ratio of SM active ingredients is much better than its lyophilized powder, which represents a strategy to develop SM's new beneficial effect in improving cardiovascular functions.

Characterization and functions of vascular adventitial fibroblast subpopulations.

BACKGROUND: Adventitial fibroblasts have been shown to play an important role in vascular remodeling and contribute to neointimal formation in vascular diseases. However, little is known about adventitial fibroblast subpopulations. This study explored the process of isolating rat thoracic aorta adventitial fibroblast subpopulations and characterized their properties following stimulation with angiotensin II (ANG II), a critical factor involved in cardiovascular diseases such as hypertension. METHODS: Adventitial fibroblasts were isolated and cultured from rat aorta. Fibroblast subpopulations were individually expanded using cloning ring techniques. Cells were treated with ANG II (10 nM, 100 nM and 1 µM) for 0.5, 1, 1.5, 3, 6, 12, or 24 h, and ANG II-induced proliferation and migration were measured by MTT assay and Transwell. Cells were treated with ANG II (100 nM) in the presence or absence of ANG II receptor antagonists (100 µM), losartan (for AT1) and PD-123319 (for AT2). PreproET-1 mRNA and ET-1 were determined by RT-PCR and ELISA, respectively. Collagen type I was detected by western blotting. RESULTS: Two major fibroblast subpopulations were found in the adventitia, epithelioid-like cells and spindle-like cells; Although ANG II promotes the growth of both subpopulations, epithelioid-like cell proliferation shows dose-dependency on ANG II from 10 nM to 1 µM, while proliferation of spindle-like cells reaches a peak value following 100 nM ANG II stimulation; ANG II stimulation enhanced epithelioid-like but not spindle-like cell migration; ANG II dose-dependently increased the expression of preproET-1 and collagen type I, and enhanced ET-1 secretion in epithelioid-like but not spindle-like cells, effects abolished by the AT1 receptor antagonist, but not with AT2 receptor antagonist. CONCLUSION: Adventitial fibroblasts are heterogeneous and epithelioid-like subpopulations with high sensitivity to ANG II stimulation may be implicated in the pathophysiological mechanisms of vascular remodeling, reparative processes and cardiovascular diseases.

[Effects of angiotensin II and its receptor blockers on migration and endothelin-1 expression of rat vascular adventitial fibroblast subpopulations].

The study is to investigate the effect of angiotensin II (Ang II) and its receptor blockers on migration and endothelin-1 (ET-1) expression of rat vascular adventitial fibroblast subpopulations. Vascular adventitial fibroblasts were individually expanded by using cloning rings, and the effects of Ang II on the migration of adventitial fibroblast subpopulations were evaluated by Transwell. Fluorescence quantitative-PCR detected the expression of preproET-1 mRNA induced by Ang II, and its receptor antagonists losartan and PD-123319. The concentration of ET-1 was determined by ELISA. It showed that spindle shaped and epithelioid shaped cells were isolated by using cloning rings, named as spindle cells and round cells. RT-PCR showed that fibroblast subpopulations did not have leukocytes, endothelial cells and smooth muscle cells, namely pure cell lines. Compared with respective control cells, two subpopulations had transferring ability. Ang II significantly improved round cells migration in a concentration-dependent manner, and had no obvious influence on spindle cells migration. Ang II (1 x 10(-8) - 1 x 10(-6) mol x L(-1)) significantly increased the expression of preproET-1 mRNA in round cells (P < 0.01), and had no significant effect on the expression of preproET-1 mRNA in spindle cells. Losartan blocked the expression of preproET-1 mRNA induced by Ang II in round cells, and had no significant effect on the expression of preproET-1 mRNA in spindle cells. The effects of Ang II and ET-1 receptor inhibitors on the release of ET-1 were similar to the expression of preproET-1 mRNA. The results indicate that there are two cell subpopulations: round cells and spindle cells in rat vascular adventitial fibroblasts. Ang II significantly improved cells migration, and increased the expression of ET-1 in round cell subpopulation. It suggested that there may be different migratory mechanisms in two cell subpopulations, and the two subpopulations may play a different role in vascular remodeling and reparative process.

Neuroprotective effect of the active components of three Chinese herbs on brain iron load in a mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is a neurodegenerative brain disorder and the most common cause of dementia. New treatments for AD are required due to its increasing prevalence in aging populations. The present study evaluated the effects of the active components of Epimedium, Astragalus and Radix Puerariae on learning and memory impairment, ß-amyloid (Aß) reduction and brain iron load in an APPswe/PS1ΔE9 transgenic mouse model of AD. Increasing evidence indicates that a disturbance of normal iron homeostasis may contribute to the pathology of AD. However, the underlying mechanisms resulting in abnormal iron load in the AD brain remain unclear. It has been hypothesized that the brain iron load is influenced by the deregulation of certain proteins associated with brain iron metabolism, including divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1). The present study investigated the effects of the active components of Epimedium, Astragalus and Radix Puerariae on the expression levels of DMT1 and FPN1. The treatment with the active components reduced cognitive deficits, inhibited Aß plaque accumulation, reversed Aß burden and reduced the brain iron load in AD model mice. A significant increase was observed in the levels of DMT1-iron-responsive element (IRE) and DMT1-nonIRE in the hippocampus of the AD mouse brain, which was reduced by treatment with the active components. In addition, the levels of FPN1 were significantly reduced in the hippocampus of the AD mouse brain compared with those of control mice, and these levels were increased following treatment with the active components. Thus, the present study indicated that the active components of Epimedium, Astragalus and Radix Puerariae may exert a neuroprotective effect against AD by reducing iron overload in the AD brain and may provide a novel approach for the development of drugs for the treatment of AD.

Effective components of Chinese herbs reduce central nervous system function decline induced by iron overload.

Abnormally increased levels of iron in the brain trigger cascade amplification in Alzheimer's disease patients, resulting in neuronal death. This study investigated whether components extracted from the Chinese herbs epimedium herb, milkvetch root and kudzuvine root could relieve the abnormal expression of iron metabolism-related protein in Alzheimer's disease patients. An APPswe /PS1ΔE9 double transgenic mouse model of Alzheimer's disease was used. The intragastric administration of compounds from epimedium herb, milkvetch root and kudzuvine root improved pathological alterations such as neuronal edema, increased the number of neurons, downregulated divalent metal transporter 1 expression, upregulated ferroportin 1 expression, and inhibited iron overload in the cerebral cortex of mice with Alzheimer's disease. These compounds reduced iron overload-induced impairment of the central nervous system, indicating a new strategy for developing novel drugs for the treatment of Alzheimer's disease.

Salidroside attenuates beta amyloid-induced cognitive deficits via modulating oxidative stress and inflammatory mediators in rat hippocampus.

Beta amyloid (Aß)-induced oxidative stress and chronic inflammation in the brain are considered to be responsible for the pathogenesis of Alzheimer's disease (AD). Salidroside, the major active ingredient of Rhodiola crenulata, has been previously shown to have antioxidant and neuroprotective properties in vitro. The present study aimed to investigate the protective effects of salidroside on Aß-induced cognitive impairment in vivo. Rats received intrahippocampal Aß1-40 injection were treated with salidroside (25, 50 and 75 mg/kg p.o.) once daily for 21 days. Learning and memory performance were assessed in the Morris water maze (days 17-21). After behavioral testing, the rats were sacrificed and hippocampi were removed for biochemical assays (reactive oxygen species (ROS), superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), acetylcholinesterase (AChE), acetylcholine (ACh)) and molecular biological analysis (Cu/Zn-SOD, Mn-SOD, GPx, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, nuclear factor κB (NF-κB), inhibitor of κB-alpha (IκBα), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), receptor for advanced glycation end products (RAGE)). Our results confirmed that Aß1-40 peptide caused learning and memory deficits in rats. Further analysis demonstrated that the NADPH oxidase-mediated oxidative stress was increased in Aß1-40-injected rats. Furthermore, NF-κB was demonstrated to be activated in Aß1-40-injected rats, and the COX-2, iNOS and RAGE expression were also induced by Aß1-40. However, salidroside (50 and 75 mg/kg p.o.) reversed all the former alterations. Thus, the study indicates that salidroside may have a protective effect against AD via modulating oxidative stress and inflammatory mediators.