Salidroside protects against ox-LDL-induced endothelial injury by enhancing autophagy mediated by SIRT1-FoxO1 pathway.

BACKGROUND: Atherosclerosis is a condition with the vascular accumulation of lipid plaques, and its main major contributing factor is endothelial injury induced by oxidized low-density lipoprotein (ox-LDL). Salidroside (SAL) is the primary active ingredient of Rhodiola rosea, and exhibits antioxidant properties on endothelial cells and alleviates atherosclerosis. However, the effect of SAL on autophagy in ox-LDL-induced vascular endothelial injury remains unclear. Here, we investigated the effect and underlying mechanisms of SAL on autophagy in human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were incubated with ox-LDL to induce in vitro atherosclerosis model. The cell viability and injury were evaluated by cell counting kit-8 (CCK-8) assay and lactate dehydrogenase (LDH) release assay. The oxidative stress was evaluated by NADPH oxidase, malondialdehyde (MDA) and superoxide dismutase (SOD) activities. Immunofluorescence was performed to detect autophagy using LC3ß antibody. Quantitative real-time PCR (qRT-PCR) and western blot were performed to measure the mRNA expressions of SIRT1 and Forkhead box O1 (FOXO1). Nicotinamide (NAM) and AS1842856 were used to inhibit activities of SIRT1 and FOXO1, respectively. RESULTS: Exposure of HUVECs to ox-LDL (100 µg/mL) reduced cell viability, increased cellular MDA, and reduced SOD in a concentration-dependent manner. The pretreatment with SAL (20, 50 and 100 µM) significantly enhanced the cell viability and decreased LDH release in HUVECs exposed to ox-LDL (100 µg/mL). ox-LDL induced autophagy in HUVECs, which was further enhanced by pretreatment with SAL. However, SAL attenuated increase in oxidative stress in HUVECs induced by ox-LDL. ox-LDL reduced mRNA and protein expressions of SIRT1 and FOXO1, which could be reversed by SAL. The protective, anti-oxidative and pro-autophagic effects of SAL could be obviously abolished by cotreatment with SIRT1 inhibitor or FOXO1 inhibitor. CONCLUSION: Salidroside shows protective effect on endothelial cell induced by ox-LDL, and the mechanisms might be related to autophagy induction via increasing SIRT1 and FoxO1 expressions.

[Effects of moxibustion at 45 ℃ on blood lipoids and serum level of ox-LDL and NO in rats with hyperlipidemia].

OBJECTIVE: To observe the effects of moxibustion at different temperatures (38 ℃ and 45 ℃) on blood lipoids and serum level of oxidized low density lipoprotein (ox-LDL) and nitric oxide (NO) in rats with hyperlipidemia, and to explore the correlation between regulating blood fat and anti-oxidative stress and protection of vascular endothelium of moxibustion at 45 ℃. METHODS: According to random number table, 60 SD rats were randomly divided into a normal group, a model group, a moxibustion at 38 ℃ group and a moxibustion at 45 ℃ group, 15 rats in each group. The rats in the normal group received no treatment; the rats in the remaining three groups were fed with high-fat diet for 8 weeks to prepare rat models of hyperlipidemia. After successful modeling, the rats in the model group received no treatment; the rats in the moxibustion at 38 ℃ group and moxibustion at 45 ℃ group were treated with moxibustion at "Shenque" (CV 8) and "Zusanli" (ST 36), and the temperature was controlled at (38±1) ℃ and (45±1) ℃, respectively. The moxibustion was given for 10 min at each acupoint, once every two days, and totally 4-week treatment was given. After treatment, the levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured by using biochemical colorimetric method; the levels of ox-LDL and NO were measured by using ELISA method. RESULTS: ① Compared with the normal group, the levels of TC, TG and LDL-C were significantly increased in the model group (all P<0.01); compared with the model group and moxibustion at 38 ℃ group, the levels of TC, TG and LDL-C were significantly decreased in the moxibustion at 45 ℃ group (P<0.01，P<0.05); compared with the model group, the levels of TC, TG and LDL-C were insignificantly decreased in the moxibustion at 38 ℃ group (all P>0.05). ② Compared with the normal group, the level of ox-LDL was increased but that of NO was decreased in the model group (both P<0.01); compared with the model group and moxibustion at 38 ℃ group, the level of ox-LDL was decreased but that of NO was increased in the moxibustion at 45 ℃ group (P<0.01, P<0.05); compared with the model group, the level of ox-LDL was decreased but that of NO was increased in the moxibustion at 38 ℃ group (both P<0.05). CONCLUSION: Moxibustion at 45 ℃ has regulating effects on blood lipid in rats with hyperlipidemia, which can regulate blood lipid through various ways, such as anti-oxidative stress and protection of vascular endothelium.

Rutaecarpine prevented ox-LDL-induced VSMCs dysfunction through inhibiting overexpression of connexin 43.

Overexpression of connexin 43 (Cx43) was related to dysfunction of vascular smooth muscle cells (VSMCs). Our previous study reported that rutaecarpine, an active ingredient of herbal medicine Evodia, modulated connexins expression in human umbilical vein endothelial cells. This study aims to explore the effects of rutaecarpine on Cx43 expression and VSMCs dysfunction induced by oxidized low-density lipoprotein (ox-LDL). In cultured rat thoracic aortic VSMCs, ox-LDL upregulated the level of Cx43 in a time- and dose-dependent manner, which were abolished by the NF-κB inhibitor BAY11-7082 and PDTC. Furthermore, exposure to ox-LDL for 4 h induced the nuclear translocation of the NF-κB p65 in VMSCs. Ox-LDL (50 mg/l,48 h) induced dysfunction of VSMCs, demonstrated as excessive proliferation, migration, and phenotype switch of cells, which were attenuated by treatment with Cx43 gap junction blocker Gap26(100 µM)) or rutaecarpine (1, 3, and 10 µM). Rutaecarpine inhibited ox-LDL-induced upregulation of Cx43, prevented nuclear translocation of the NF-κB p65, and increased intracellular calcium level in VSMCs. These effects were abolished by pretreatment with transient receptor potential vanilloid subtype 1 (TRPV1) antagonist capsazepine, intracellular calcium chelator BAPTA-AM or CaM antagonist W-7. In conclusion, this study demonstrated that rutaecarpine inhibited Cx43 overexpression through TRPV1/[Ca2+]i/CaM/NF-κB signal pathway, thereby preventing VSMCs dysfunction induced by ox-LDL. Our study provides a novel mechanism by which rutaecarpine modulate Cx43 expression and VSMC function.

Paeoniflorin attenuates oxidized low-density lipoprotein-induced apoptosis and adhesion molecule expression by autophagy enhancement in human umbilical vein endothelial cells.

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial dysfunction is recognized as a driving force in the development of atherosclerosis (AS). Paeoniflorin (Pae), a typical traditional herbal medicine, possesses anti-inflammatory, antioxidative, antihyperglycaemic, and antiapoptotic properties. Our study aimed to investigate the effects of Pae on ox-LDL-induced injury of the human umbilical vein endothelial cells (HUVECs) and to explore its molecular mechanism. We found that ox-LDL stimulation inhibited cell viability, activated autophagy, and induced apoptosis and adhesion molecule expression in HUVECs. Pae rescued ox-LDL-induced viability reduction and enhanced the ox-LDL-induced autophagy activation in HUVECs. Pae inhibited ox-LDL-induced apoptosis and adhesion molecule expression by autophagy enhancement in HUVECs. In addition, inhibition of SIRT1 by EX-527 abolished the promoting effect of Pae on autophagy and restored the inhibitory effect of Pae on apoptosis and adhesion molecule expression in the presence of ox-LDL. In conclusion, Pae attenuated ox-LDL-induced apoptosis and adhesion molecule expression by autophagy enhancement via upregulation of SIRT1 in HUVECs, shedding light on the mechanism underlying the protective effect of Pae on ox-LDL-induced injury of HUVECs.

Effects of moxibustion at 45 ℃ on blood lipoids and serum level of ox-LDL and NO in rats with hyperlipidemia / 中国针灸

OBJECTIVE@#To observe the effects of moxibustion at different temperatures (38 ℃ and 45 ℃) on blood lipoids and serum level of oxidized low density lipoprotein (ox-LDL) and nitric oxide (NO) in rats with hyperlipidemia, and to explore the correlation between regulating blood fat and anti-oxidative stress and protection of vascular endothelium of moxibustion at 45 ℃.@*METHODS@#According to random number table, 60 SD rats were randomly divided into a normal group, a model group, a moxibustion at 38 ℃ group and a moxibustion at 45 ℃ group, 15 rats in each group. The rats in the normal group received no treatment; the rats in the remaining three groups were fed with high-fat diet for 8 weeks to prepare rat models of hyperlipidemia. After successful modeling, the rats in the model group received no treatment; the rats in the moxibustion at 38 ℃ group and moxibustion at 45 ℃ group were treated with moxibustion at "Shenque" (CV 8) and "Zusanli" (ST 36), and the temperature was controlled at (38±1) ℃ and (45±1) ℃, respectively. The moxibustion was given for 10 min at each acupoint, once every two days, and totally 4-week treatment was given. After treatment, the levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured by using biochemical colorimetric method; the levels of ox-LDL and NO were measured by using ELISA method.@*RESULTS@#① Compared with the normal group, the levels of TC, TG and LDL-C were significantly increased in the model group (all 0.05). ② Compared with the normal group, the level of ox-LDL was increased but that of NO was decreased in the model group (both <0.01); compared with the model group and moxibustion at 38 ℃ group, the level of ox-LDL was decreased but that of NO was increased in the moxibustion at 45 ℃ group (<0.01, <0.05); compared with the model group, the level of ox-LDL was decreased but that of NO was increased in the moxibustion at 38 ℃ group (both <0.05).@*CONCLUSION@#Moxibustion at 45 ℃ has regulating effects on blood lipid in rats with hyperlipidemia, which can regulate blood lipid through various ways, such as anti-oxidative stress and protection of vascular endothelium.