Astragalus Polysaccharides Lowers Plasma Cholesterol through Mechanisms Distinct from Statins

To determine the efficacy and underlying mechanism of Astragalus polysaccharides (APS) on plasma lipids in hypercholesterolemia hamsters. The effect of APS (0.25g/kg/d) on plasma and liver lipids, fecal bile acids and neutral sterol, cholesterol absorption and synthesis, HMG-CoA reductase activity, and gene and protein expressions in the liver and small intestine was investigated in twenty-four hypercholesterolemia hamsters. Treatment periods lasted for three months. APS significantly lowered plasma total cholesterol by 45.8%, triglycerides by 30%, and low-density lipoprotein-cholesterol by 47.4%, comparable to simvastatin. Further examinations revealed that APS reduced total cholesterol and triglycerides in the liver, increased fecal bile acid and neutral sterol excretion, inhibited cholesterol absorption, and by contrast, increased hepatic cholesterol synthesis and HMG-CoA reductase activity. Plasma total cholesterol or low-density lipoprotein-cholesterol levels were significantly correlated with cholesterol absorption rates. APS up-regulated cholesterol-7α-hydroxylase and LDL-receptor gene expressions. These new findings identify APS as a potential natural cholesterol lowering agent, working through mechanisms distinct from statins

Experimental and numerical study of natural convection in bottom-heated cylindrical cavity filled with molten salt nanofluids

This paper combines numerical and experimental to study the heat transfer by free convection for nanofluids of molten salt within a cavity with cylindrical shape which is heated at the bottom and releases heat at the top. The aim is to acquire the free convection laws for nanofluids of molten salt in a cylindrical cavity. It is found that after adding nanoparticles, the molten salts have lower viscosity, higher flow velocity and higher heat transfer rate, and therefore, the free convection heat transfer is enhanced. Meanwhile, nanofluids Nusselt number is larger than that of the molten salts at the same Rayleigh number. In addition, as the classical Garon’s equation cannot provide good predictions of free convection heat transfer for the nanofluids of molten salt, this paper establishes a free convection equation for the nanofluids of molten salt in a cylindrical cavity. This equation is able to predict with an error less than 20% the experimental results. Therefore, the findings can provide a basis for engineering applications of nanofluids and for designing optimal systems of heat stockpile with a single tank

The development of automatic emotion regulation in an implicit emotional Go/NoGo paradigm and the association with depressive symptoms and anhedonia during adolescence

Impaired automatic emotion regulation (AER) is closely related to major depressive disorder. Our research in adults has identified two AER-related components, Go N2 and NoGo P3, in an implicit emotional Go/NoGo paradigm. However, it is unclear whether Go N2 and NoGo P3 reflect the development of AER in adolescents and the relationship of these components with subclinical depressive symptoms and trait anhedonia. We collected EEG data from 55 adolescents while they completed the implicit emotional Go/NoGo task. After the experiment, the subjects completed the Chinese version of the Temporal Experience of Pleasure Scale and the Beck Depression Inventory. Consistent with results in adults, we determined that Go N2 represents automatic top-down attention to emotions in Go trials, whereas NoGo P3 represents automatic response inhibition in NoGo trials. These AER components exhibited age-dependent improvement during adolescence. Additionally, NoGo P3 amplitudes elicited by viewing positive faces were positively correlated with trait anhedonia, whereas NoGo P3 amplitudes elicited by viewing negative faces were negatively correlated with depressive symptoms. Our observations provide further understanding of the neurodevelopmental mechanism of AER and yield new insight into dissociable impairments in AER in adolescents with major depressive disorder during positive and negative implicit processing

Changes of plasma lipids in response to APS and simvastatin treatments.

<p>APS and simvastatin significantly lowered total cholesterol (TC), triglycerides (TG), high-density lipoprotein –cholesterol (HDL-C) and low-density lipoprotein-cholesterol (LDL-C) concentrations compared to the control. # P<0.05 compared with control group.</p

Effect of APS on fractional cholesterol absorption and cholesterol synthesis rates in hamsters.

<p>Values are means±SD of 8 animals per group.</p>#<p>P<0.05 compared with Control group,</p><p>*P<0.05 compared with Simvastatin group.</p

Relationships between plasma lipids and intestinal cholesterol absorption.

<p>Intestinal cholesterol absorption rates are significantly correlated with the plasma LDL-C (A) and TC (B) levels, respectively.</p

Cholesterol metabolism associated gene and protein expressions.

<p>Representative Western blot and group data depicting LDLR protein and mRNA abundance (A), cyp7α-1 protein and mRNA abundance (B) in livers, ABCG5 protein and mRNA abundance(C), ABCG8 protein and mRNA abundance(D), NPC1L1 protein and mRNA abundance(E) in intestines of hamsters. N = 8 per group. # P<0.05 compared with Control group, *P<0.05 compared with Simvastatin group.</p

Effect of APS liver lipids and plasma concentration of ALT in hamsters.

<p>Values are means±SDs of 8 animals per group.</p>#<p>P<0.05 compared with Control group.</p

Primer sequences used for real-time PCR analysis.

<p>Primer sequences used for real-time PCR analysis.</p

Effect of APS and simvastatin on fecal excrection of bile acids and neutral sterol.

<p>The daily total bile acids and neutral sterols were measured and expressed per 100 g body weight (BW). Values are means±SDs of 8 animals per group.</p>#<p>P<0.05 compared with Control group,</p><p>*P<0.05 compared with Simvastatin group.</p