Guanxinshutong Alleviates Atherosclerosis by Suppressing Oxidative Stress and Proinflammation in ApoE-/- Mice

Nitro substituent caused negative impact on occurrence and development of atherosclerotic plaque by PM2.5-bound polycyclic aromatic compounds

PM2.5 exposure is a significant risk factor for the occurrence and development of atherosclerosis. Polycyclic aromatic hydrocarbons (PAHs) play prominent roles in PM2.5-related toxicity. However, the nitrated derivatives of PAHs, nitrated polycyclic aromatic hydrocarbons (NPAHs), have strong oxidizing properties due to the nitro substituents. Thus, the in vivo and in vitro experiments exposure to benzo[a]pyrene (BaP) and 6-nitro benzo[a]pyrene (NBaP) were conducted to evaluate the effect of nitro substituent on the atherosclerosis due to (or attributable to) PAHs. The results showed that NBaP exposure induced the inhibition of human umbilical vein endothelial cells (HUVECs) viability and cell morphology damage via more severe oxidative stress than BaP exposure. Furthermore, exposure to PM2.5-bound NBaP caused dyslipidemia in the Apolipoprotein E-deficient (ApoE-/-) mice, including the increment of total cholesterol, triglycerides, low-density lipoprotein cholesterol, and malondialdehyde levels, and the decrement of high-density lipoprotein cholesterol levels, superoxide dismutase and glutathione peroxidase levels in serum and aorta. Furthermore, histology showed atherosclerotic plaque in the aorta of ApoE-/- mice. However, there were no significant differences of the physiological and pathological changes between BaP and control groups. Thus, NPAHs induced endothelial dysfunction and dyslipidemia via severe oxidative stress, and further accelerated the occurrence and development of atherosclerosis compared with the parent PAHs. Our findings provide the first evidence that nitro substituent caused much severer negative health impact of polycyclic aromatic compounds, which highlight the significance of NPAHs in health risk estimation of polycyclic aromatic compounds.

Rac2 mediate foam cell formation and associated immune responses in THP-1 to promote the process of atherosclerotic plaques

Macrophages play an important role in the pathogenesis of atherosclerosis (AS) by mediating oxidative stress, inflammation and lipid metabolism, which can lead to the formation of vascular plaque. The Rac family isoforms of small molecules GTPase are active by binding to GTPase, but are inactivated by binding to GDP, and play a role in the switch of cell information conduction. This experiment adopts shRNA interference THP-1 cells respectively each subtype expression and inhibiting Rac1, Rac2, Rac3 activity, each subtype of Rac family on lipid metabolism, inflammatory reaction and oxidative stress. THP-1 cells were stimulated with Ox-LDL to establish AS cell models including lipid loading, adhesion, migration and chemotaxis. Oil Red O staining, cell immunofluorescence, scratching test, transwell, Western blot and other experiments were performed. To observe the different effects of three subtypes of Rac family on multiple links in the foaming process of THP-1 cells. ApoE-/- mice on a high-fat diet were used as animal models to examine the effects of Rac subtypes in vivo. The results showed that the activation of immune cells induced by ox-LDL was inhibited when Rac1, Rac2 and Rac3 in THP-1 were decreased, respectively. Thus, Rac1 and Rac3 act in combination with ox-LDL and are associated with cellular oxidative stress and inflammation. This study provides new means and ideas for finding potential intervention targets that have important regulatory effects on atherosclerosis, and provides a new direction for the development of clinical drugs.

Atheroprotective Effects and Mechanisms of Postmarketing Chinese Patent Formulas in Atherosclerosis Models: A Systematic Review

BACKGROUND

Some postmarketing Chinese patent formulas have been widely used to treat atherosclerosis (AS) and play critical roles in Chinese healthcare. However, the usage of these herbs is yet controversial due to unclear effects and lack of understanding of the mechanism of action. With the modernization of traditional Chinese formulas, we are to elucidate the atheroprotective properties of these remedies from successful postmarketing experiments in vivo.

METHODS

In this systematic review, we critically searched the databases, applied stringent criteria, assessed the methodological quality, and examined the current evidence in vivo.

RESULTS

Consequently, 60 studies were included in the present qualitative synthesis. Data on models, high-fat diet, intervention time, outcome measures, efficacy, and mechanisms were collected. Finally, 23 formulas that could alleviate AS were correlated to the amelioration of plaques, improvement of plaque stability, modification of lipid level and lipid metabolism, and the effects of anti-inflammation and antioxidant stress with multiple components and targets. However, the methodological quality was low and incomplete among the included literature.

CONCLUSIONS

Thus, taken together, the studies on postmarketing Chinese patent formulas would provide a novel approach to improve the treatment of AS, and rigorously designed studies would provide high-quality evidence.