Research Progress on the Antioxidant Activity of Natural Diarylheptanoids: Mechanisms and Structure-activity Relationships.

Antioxidant research has recently become a popular topic. Medicinal plants are important sources of novel active compounds. Diarylheptanoids, a typical family of secondary plant metabolites, are of great interest owing to their extensive spectrum of biological activities. They possess a unique 1,7-diphenylmethane structural skeleton. Thus, this review summarizes the natural linear or macrocyclic diarylheptanoids with antioxidant activity in the last two decades. In addition, the relationships between the structural characteristics of natural diarylheptanoids and their antioxidant capacity were also discussed. All the available data highlight the potential of natural diarylheptanoids as novel antioxidants.

[Effect and mechanism of Danggui Buxue Decoction-containing serum in mitigating H9c2 cell injury caused by exposure to intermittent low oxygen].

This study aims to explore the effect and mechanism of Danggui Buxue Decoction(DBD)-containing serum in alleviating the H9c2 cell injury caused by the exposure to intermittent low oxygen. H9c2 cells were assigned into five groups: control(CON) group, intermittent low oxygen(IH) group, intermittent low oxygen plus DBD-containing serum(IH+DBD) group, intermittent low oxygen plus the autophagy enhancer rapamycin(IH+RAPA) group, and intermittent low oxygen plus DBD-containing serum and the autophagy inhibitor 3-methyladenine(IH+DBD+3-MA) group. Monodansylcadaverine(MDC) staining was employed to detect the changes of autophagosomes. Cell counting kit-8(CCK-8) assay was employed to determine the activity of myocardial cells, and lactate dehydrogenase(LDH) and creatine kinase(CK) kits were used to measure the LDH and CK levels in the cell culture, which would reflect the degree of cell damage. TdT-mediated dUTP nick-end labeling(TUNEL) staining was used to detect the apoptosis of myocardial cells, and JC-1 fluorescence probe to detect the changes in mitochondrial membrane potential. Western blot was employed to determine the expression levels of the autophagy-related proteins microtubule-associated proteins light chain 3Ⅱ(LC3Ⅱ), microtubule-associated proteins light chain 3Ⅰ(LC3Ⅰ), P62, Parkin and apoptosis related proteins pro caspase-3, caspase-3, B-cell lymphoma-2(Bcl-2), Bcl-2-associated X(Bax). The results showed that compared with the CON group, the IH group showed decreased fluorescence intensity of MDC staining, decreased LC3Ⅱ/LC3Ⅰ ratio, down-regulated Parkin expression, and up-regulated expression of P62. In addition, the IH group showed decreased cell survival rate, increased content of LDH and CK in the culture medium, increased number of TUNEL positive cells, and decreased pro caspase-3/caspase-3 and Bcl-2/Bax ratios and mitochondrial membrane potential. Compared with the IH group, the IH+DBD and IH+RAPA groups showed increased fluorescence intensity of MDC staining, increased LC3Ⅱ/LC3Ⅰ ratio, up-regulated Parkin expression, and down-regulated P62 expression. In addition, the two groups showed increased cell survival rate, reduced content of LDH and CK in the culture medium, decreased number of TUNEL positive cells, and increased pro caspase-3/caspase-3 and Bcl-2/Bax ratios and mitochondrial membrane potential. The IH+DBD+3-MA and IH groups showed no significant differences in the above indicators. Compared with the IH+DBD group, the IH+DBD+3-MA group showed decreased fluorescence intensity of MDC staining, decreased LC3Ⅱ/LC3Ⅰ ratio, down-regulated Parkin expression, and up-regulated P62 expression. In addition, the group had decreased cell survival rate, increased content of LDH and CK in the culture medium, increased number of TUNEL positive cells, decreased pro caspase-3/caspase-3 and Bcl-2/Bax ratios, and declined mitochon-drial membrane potential. To sum up, DBD could promote the mitophagy, inhibit the apoptosis, and alleviated the injury of H9c2 cells exposed to low oxygen.

Huperzine A-Liposomes Efficiently Improve Neural Injury in the Hippocampus of Mice with Chronic Intermittent Hypoxia.

Background: Chronic intermittent hypoxia (CIH) could cause neuronal damage, accelerating the progression of dementia. However, safe and effective therapeutic drugs and delivery are needed for successful CIH therapy. Purpose: To investigate the neuroprotective effect of Huperzine A (HuA) packaged with nanoliposomes (HuA-LIP) on neuronal damage induced by CIH. Methods: The stability and release of HuA-LIP in vitro were identified. Mice were randomly divided into the Control, CIH, HuA-LIP, and HuA groups. The mice in the HuA and HuA-LIP groups received HuA (0.1 mg/kg, i.p.), and HuA-LIP was administered during CIH exposure for 21 days. HuA-LIP contains the equivalent content of HuA. Results: We prepared a novel formulation of HuA-LIP that had good stability and controlled release. First, HuA-LIP significantly ameliorated cognitive dysfunction and neuronal damage in CIH mice. Second, HuA-LIP elevated T-SOD and GSH-Px abilities and decreased MDA content to resist oxidative stress damage induced by CIH. Furthermore, HuA-LIP reduced brain iron levels by downregulating TfR1, hepcidin, and FTL expression. In addition, HuA-LIP activated the PKAα/Erk/CREB/BDNF signaling pathway and elevated MAP2, PSD95, and synaptophysin to improve synaptic plasticity. Most importantly, compared with HuA, HuA-LIP showed a superior performance against neuronal damage induced by CIH. Conclusion: HuA-LIP has a good sustained-release effect and targeting ability and efficiently protects against neural injury caused by CIH.

[Effects of NLRP3/Caspase-1 pathway on Banxia Houpu decoction in the intervention of chronic intermittent hypoxia in mice with renal inflammatory injury].

Objective: To investigate the effects of Banxia Houpo decoction on the renal NLRP3/Caspase-1/IL-1ß signaling pathway in chronic intermittent hypoxia mice. Methods: C57BL/6 mice were randomly divided into 3 groups, normal control group (Control), chronic intermittent hypoxia group (CIH), and Banxia Houpo decoction treatment group (BHD), with 10 mice in each group. Mice in the CIH group and BHD group were placed in a hypoxic chamber. The oxygen volume fraction in the cabin was decreased from 21% to 9% in 90 s, and then oxygen was filled in 90 s to gradually increase the oxygen volume fraction in the cabin to 21%, while the mice in the control group were placed in the cabin and filled with normal air, processing 8 hours per day for 21 days. The mice in BHD group were treated with Banxia Houpu decoction by gavage before entering the cabin every day, and the control group and CIH group were given an equal volume of normal saline. After modeling, the changes of renal function indexes in each group were detected; HE and Masson staining were used to observe the pathological conditions of the kidney; Western blot and immunohistochemical staining were used to detect the protein expression levels of the nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3), aspartate-specific cysteine protein 1(Caspase-1) and interleukine-1beta(IL-1ß). Results: Compared with control group, the contents of serum renal functional indexes UA, BUN and SCr in CIH group were increased significantly (P<0.01), and after BHD treatment, they all were decreased significantly compared with CIH group (P<0.01). Compared with control group, the results of HE staining showed that in the CIH group, glomerular endothelial cells were degenerated and necrotic, and vacuoles of different sizes appeared in renal tubular epithelial cells, and a small amount of renal tubular epithelial cells fell off and died. The pathological condition of the BHD group was improved compared with CIH group, the glomerular morphology gradually returned to normal, and a small amount of renal tubular epithelial cells fell off and died. Compared with control group, Masson staining results showed that there was obvious fibrosis around the glomeruli in the CIH group, the fibrosis was significantly reduced in the BHD group. The expression levels of NLRP3, Caspase-1, IL-1ß and IL-18 were increased significantly compared with control group (P<0.05 or P<0.01), and immunohistochemical staining showed that NLRP3 was mainly expressed in renal tubular epithelial cells and interstitial macrophages, caspase-1 and IL-1ß were mainly found in the cytoplasm of renal tubular epithelial cells. After BHD treatment, the expression levels of each protein were decreased compared with CIH group (P<0.05). Conclusion: Banxia Houpu decoction can reduce the kidney damage by inhibiting the expression of related molecules in the NLRP3/Casapse-1/IL-1ß signaling pathway.

[Danggui Buxue Decoction improves heart function of chronic intermittent hypoxia mice by promoting mitochondrial autophagy and inhibiting cardiomyocyte apoptosis].

The study established a chronic intermittent hypoxia(CIH) model in mice to investigate the effects of Danggui Buxue Decoction(DBD) on mitochondrial autophagy and cardiomyocyte apoptosis and explore its protective effect and mechanism on cardiac function of CIH mice. Forty C57 BL/6 N male mice were randomly divided into the control(CON) group, CIH group, CIH+DBD group, and DBD group, with 10 mice in each group. CIH was induced by filling the hypoxic chamber with N_2(90 s) to reduce the O_2 concentration to 5% and then filling the hypoxic chamber with O_2(90 s) to restore O_2 concentration to 21%, 3 min per cycle, and the CIH treatment continued for 35 d, 8 h per day. Mice in the CIH+DBD and DBD groups were treated with intragastric administration of DBD every day, while those in the CON and CIH groups with the same volume of normal saline. The cardiac function of mice was measured by echocardiography. The pathological changes in myocardium were observed after HE staining, followed by the observation of cardiomyocyte apoptosis by Tunel staining. The expression of apoptosis-related proteins pro-caspase-3, caspase-3, Bcl-2, and Bax and autophagy-related proteins LC3Ⅱ, LC3Ⅰ, P62, parkin, and cytochrome C(Cytc) was detected by Western blot. The mitochondrial membrane potential was observed using JC-1 fluorescent probe. Compared with the CON group, the CIH group exhibited remar-kably lowered left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS), elevated left ventricular end-systolic volume(LVESV) and end-diastolic volume(LVEDV), disordered myocardial fiber arrangement, increased number of TUNEL-positive cells, decreased pro-caspase-3/caspase-3, Bcl-2/Bax, and LC3Ⅱ/LC3Ⅰ ratios, parkin, mitochondrial Cytc expression, and mitochondrial membrane potential, and up-regulated P62 and Cytc expression. Compared with the CIH group, DBD increased LVEF, LVFS, pro-caspase-3/caspase-3, Bcl-2/Bax, and LC3Ⅱ/LC3Ⅰ ratios, and parkin expression, as well as mitochond-rial Cytc expression, and mitochondrial membrane potential, decreased LVESV, LVEDV, and the number of Tunel-positive cells, and improved the myocardial fiber arrangement. DBD has a protective effect on the heart function of CIH mice. It improves the heart function possibly by promoting mitochondrial autophagy to ameliorate mitochondrial function and inhibiting the cardiomyocyte apoptosis.

[Effects of MCC950 on nerve injury in rats with intracerebral hemorrhage].

Objective: To investigate the effects of the pyrin domain-containing protein 3 (NLRP3) inflammasome inhibitor MCC950 on nerve injury in rats with intracerebral hemorrhage(ICH). Methods: Seventy-two SD rats were randomly divided into three groups (n=24): Sham group, ICH group and MCC950 group. ICH group and MCC950 group rats were injected with autogenous non-anticoagulant blood to establish ICH model, and then the rats in MCC950 group were intraperitoneally injected with MCC950 at the dose of 10 mg/kg(2 mg/ml) for 3 days after ICH model was established. Seventy-two hours after the establishment of the model, the forelimb placement test, the corner test and mNSS score were performed to observe the neurological function of the rats with ICH. The volume of hematoma was observed in fresh brain tissue sections. HE staining was used to observe the pathological changes of brain tissue. The dry-wet weight ratio was calculated to evaluate the changes of brain tissue edema. The degeneration of neurons was observed by FJC staining. The neuronal apoptosis was observed by TUNEL staining. The protein expression and activation levels of NLRP3, ASC, caspase-1, IL-1ß, IL-18 and GSDMD were determined by Western blot. Results: Compared with sham group, the percentage of successful placement of left forelimb and left turn was decreased significantly (P＜0.01, P＜0.05), mNSS score was increased significantly (P＜0.01) in ICH group. Hematoma volume was increased significantly, the number of microglial cells around the hematoma was increased, the number of neurons was decreased, nerve cell swelled, some cells showed pyknotic necrosis, and the staining was deepened. The water content of the right base was increased significantly (P＜0.05). The number of FJC positive and TUNEL positive cells around the hematoma was increased significantly (P＜0.05). The levels of NLRP3, ASC, caspase-1, pro-caspase-1, caspase-1/pro-caspase-1 ratio, GSDMD-N, GSDMD, GSDMD-N/GSDMD ratio, IL-1ß and IL-18 were increased significantly (P＜0.01, P＜ 0.05). Compared with ICH group, the percentage of successful placement of left forelimb and left turn was increased significantly in MCC950 group (P＜0.05), while the mNSS score and the volume of hematoma were decreased significantly (P＜0.01), the swelling degree of nerve cells around the hematoma was reduced significantly, and the number of pyrotic necrotic cells was decreased. The water content of the right base was decreased significantly (P＜0.05), and the number of FJC positive and TUNEL positive cells around the hematoma was decreased significantly (P＜0.05). The levels of NLRP3, ASC, caspase-1, pro-caspase-1, caspase-1/pro-caspase-1 ratio, GSDMD-N, GSDMD, GSDMD-N/GSDMD ratio, IL-1ß and IL-18 were decreased significantly (P＜0.05). Conclusion: MCC950 can ameliorate nerve injury after ICH by inhibiting NLRP3 inflammasome mediated inflammation and pyroptosis.

Therapeutic Potential of Astragaloside IV Against Adriamycin-Induced Renal Damage in Rats via Ferroptosis.

Adriamycin (ADR) has been utilized to treat cancer for several decades. However, ADR-induced renal injury is one of the most common side effects accompanying ADR therapy. In the present study, we revealed that astragaloside IV (ASIV) was beneficial for renal injury caused by Adriamycin. We demonstrated that ASIV significantly ameliorated kidney injury, improved renal dysfunction, reduced oxidative stress, alleviated iron accumulation, and inhibited the induction of ferroptosis by ADR. ASIV also rescued the intracellular levels of nuclear factor-erythroid-2-related factor 2 (Nrf2) and promoted nuclear translocation of Nrf2. These protective effects of ASIV on renal injury might be attained through the ASIV-induced activation of the Pi3K/Akt signaling pathway. In vitro, the treatment of the HK-2 cells with fer-1 or deferoxamine mesylate obviously improved cell viability during Adriamycin administration. On the other hand, the protective role of ASIV can be abrogated by RSL3 to some extent. Moreover, ASIV lowered the expression of transferrin receptor 1 and divalent metal transporter 1 while enhancing the expression of ferropotin 1 and glutathione peroxidase 4 in ADR administrated cells, the effects of which were akin to those of deferoxamine mesylate. Furthermore, ASIV increased the phosphorylation of Pi3K, Akt, and the expression of Nrf2 and glutathione peroxidase 4 compared to HK-2 cells stimulated by ADR. However, Pi3K inhibitor LY294002 abrogated these activations. In conclusion, ferroptosis may involve in ADR-induced nephrotoxicity, and ASIV might protect nephrocytes against ADR-induced ferroptosis, perhaps via activations of the Pi3K/Akt and Nrf2 signaling pathways.

Involvement of Hepcidin in Cognitive Damage Induced by Chronic Intermittent Hypoxia in Mice.

Obstructive sleep apnea (OSA) patients exhibit different degrees of cognitive impairment, which is related to the activation of reactive oxygen species (ROS) production by chronic intermittent hypoxia (CIH) and the deposition of iron in the brain. As a central regulator of iron homeostasis, whether hepcidin is involved in OSA-induced cognitive impairment has not been clarified. In order to simulate OSA, we established the mouse model by reducing the percentage of inspired O2 (FiO2) from 21% to 5%, 20 times/h for 8 h/day. We found hepcidin was rising during CIH, along with increasing iron levels and neuron loss. Then, we constructed a mouse with astrocyte-specific knockdown hepcidin gene (shHamp). During CIH exposure, the shHamp mice showed a lower level of total iron and neuronal iron in the hippocampus, via stabilizing ferroportin 1 (FPN1) and decreasing L-ferritin (FTL) levels, when compared with wild-type (WT) mice. Furthermore, the shHamp mice showed a decrease of ROS by downregulating the elevated NADPH oxidase (NOX2) and 4-hydroxynonenal (4-HNE) levels mediated by CIH. In addition, the shHamp mice presented improved cognitive deficit by improving synaptic plasticity and BDNF expression in the hippocampus when subjected to CIH. Therefore, our data revealed that highly expressed hepcidin might promote the degradation of FPN1, resulting in neuronal iron deposition, oxidative stress damage, reduced synaptic plasticity, and impaired cognitive performance during CIH exposure.

Deciphering the Q-markers of nourishing kidney-yin of Cortex Phellodendri amurense from ZhibaiDihuang pill based on Chinmedomics strategy.

BACKGROUND: Cortex Phellodendri amurensis (CPA) has high medicinal value in the treatment of kidney-yin deficiency diseases. However, due to the lack of research on the therapeutic material basis of CPA, the current quality control standard for CPA is defective, and the effect of the nourishing kidney-yin of CPA was limited. PURPOSE: Based on the principle of correspondence between the syndrome and prescriptions, we studied the CPA in ZhibaiDihuang pill (ZBDH) to identify quality markers (Q-markers) of CPA in ZBDH for treating kidney-yin deficiency and seek the potential Q-markers of CPA under nourishing kidney-yin effect combined with the analysis of single CPA. METHODS: Taking Chinmedomics as the core strategy, metabonomics analysis and effective component identification were performed by UPLC-MS. RESULTS: A total of 121 chemical components of ZBDH were identified, among which the contents of berberine, palmatine, jatrorrhizine and magnoflorine changed the most obviously with the addition of CPA. Forty-five components were identified in the blood in the markedly effective state, including berberine, palmatine, jatrorrhizine and magnoflorine. The therapeutic material basis of ZBDH in the treatment of kidney-yin deficiency was found, and 6 components were found to derive from CPA, including magnoflorine and jatrorrhizine. In addition, seventeen components were identified in the blood in the single CPA treatment, including berberine, palmatine, jatrorrhizine and magnoflorine. CONCLUSIONS: Magnoflorine and jatrorrhizine were the Q-markers of CPA for treating kidney-yin deficiency in the formula of ZBDH and they were also potential Q-markers of the nourishing kidney-yin of CPA.

Effect and Safety of Penetrating Moxibustion in Treatment of Migraine without Aura: A Randomized Controlled Trial.

OBJECTIVE: To observe the clinical effect of penetrating moxibustion on migraine without aura (MO) patients. METHODS: Totally 60 MO patients from the Acupuncture Clinic of the Third Affiliated Hospital of Henan University of Chinese Medicine were collected from November 2015 to February 2017. All patients were assigned to a treatment group and a control group using a random number table, 30 cases in each group. The treatment group was treated with penetrating moxibustion, and the control group was treated with mild moxibustion, thrice a week for 4 consecutive weeks. The total effective rate, Visual Analogue Scale (VAS) scores, headache intensity, and Migraine Specific Quality of Life Questionnaire (MSQ) scores of patients after treatment were compared between the two groups. The moxibustion sensation and reaction after moxibustion were observed, and the adverse reactions were evaluated. All patients were followed up at 4 and 16 weeks after treatment. RESULTS: The total effective rate of the treatment group was significantly higher than that of the control group (93.33% vs. 80.00%, P<0.05). The improvement of VAS scores, headache intensity, and the role restrictive and role preventive scores in MSQ in the treatment group was better than those in the control group (P<0.05). The person-time of moxibustion sensations of itching, numbness and cold as well as flushing and sweating after moxibustion in the treatment group was all significantly higher than that in the control group (P<0.01). There was no significant difference in safety evaluation between the two groups (P>0.05). CONCLUSIONS: Penetrating moxibustion can significantly relieve pain and improve quality of life of MO patients. After penetrating moxibustion, flushing and sweating of patients were obvious, and the curative effect was superior to the mild moxibustion.

A rapid juvenile murine model of nonalcoholic steatohepatitis (NASH): Chronic intermittent hypoxia exacerbates Western diet-induced NASH.

AIMS: Many dietary NASH models require a long duration to establish (4-6 months). Chronic intermittent hypoxia (CIH), a cardinal hallmark of obstructive sleep apnea (OSA), may accelerate the progression of pediatric nonalcoholic fatty liver disease (NAFLD). However, diet-induced obese (DIO) mice exposed to CIH have not been perceived as a fast or reliable tool in NASH research. This study was designed to establish a rapid juvenile murine NASH model, and determine whether the combination of CIH and a western-style diet (hypercaloric fatty diet plus high fructose) can fully display key pathologic features of NASH. METHODS: C57BL/6 N mice (3 weeks old) fed a control diet or western diet (WD) were exposed to CIH (9% nadir of inspired oxygen levels) or room air for 6 and 12 weeks. KEY FINDINGS: The Control/CIH group mainly exhibited hyperinsulinemia and insulin resistance (IR). In contrast, mice fed a WD developed weight gain after 3 weeks, microvesicular steatosis in 6 weeks, and indices of metabolic disorders at 12 weeks. Furthermore, CIH exposure accelerated WD- induced macromicrovesicular steatosis (liver triglycerides and de novo lipogenesis), liver injury (ballooned hepatocytes and liver enzymes), lobular/portal inflammation (inflammatory cytokines and macrophage recruitment), and fibrogenesis (hydroxyproline content and TGF-ß protein). Notably, only the WD/CIH group exhibited elevated hepatic MDA content, protein levels of NOX4, α-SMA and collagen I, as well as reduced Nrf2 and HO-1 protein expression. SIGNIFICANCE: WD/CIH treatment rapidly mimics the histological characteristics of pediatric NASH with metabolic dysfunction and fibrosis, representing an appropriate experimental model for NASH research.

[Effect of xiaotan huayu liqiao traditional Chinese medicine compound on myocardial fibrosis in rats with chronic intermittent hypoxia and its mechanism].

Objective: To explore the role of transforming growth factor-ß (TGF-ß) signaling pathway in xiaotan huayu liqiao traditional Chinese medicine compound (XC)'s anti-myocardial fibrosis in chronic intermittent hypoxia (CIH) rats. Methods: Forty SD rats were randomly divided into normoxia group, oxygen + traditional Chinese medicine compound group ( TCMC), Chronic intermittent hypoxia model group (CIH), TCMC + CIH, 10 in each group. CIH cabin was built by filling with nitrogen and oxygen. Firstly, the volume fraction of oxygen in the cabin reduced from 21% to 9% in 90 s by filling the cabin with nitrogen. And then it gradually rose to 21% by reoxygenating in 90s, as a cycle. CIH and TCMC+CIH group rats were placed in the CIH device, while normoxia and TCMC group rats were placed in the normal oxygen chamber. In addition, rats in TCMC +CIH group and TCMC group were treated with XC crude drug (24 g/kg) daily by gavage, while rats in CIH group and normoxia group were given equal volume normal saline. Using sirius red staining, the collagen in myocardial interstitium was visualized. The protein expressions of collagen I, collagen III and fibronectin were detected by Western blot, p-Smad3, p-Smad2 and TGF-ß protein in the TGF-ß/Smads signaling pathway were also analyzed by Western blot. The mRNA expressions of matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of metalloproteinase -2(TIMP-2) were measured by real-time quantitative polymerase chain reaction (PCR). Results: Compared with the rats exposed to normoxia, the CIH rats showed obvious collagen deposition, protein expressions of collagen I, collagen III and fibronectin were significantly increased in the myocardial tissue (P＜0.01). The protein expression levels of TGF-ß, p-smad2 and p-smad3 in the myocardial tissue of the CIH rats were also significantly increased (P＜0.01). The up-regulation of TIMP-2 mRNA in the myocardial tissues resulted in the decrease of MMP-2 mRNA(P＜0.01). XC reduced myocardial fibrosis of CIH rats and inhibited the expressions of collagen I and collagen III and fibronectin protein (P＜0.05,P＜0.01,P＜0.05, respectively). The further mechanism study showed that XC inhibited the expression of TGF-ß (P＜0.01), which down-regulated the expressions of p-smad2, p-smad3 and TIMP-2 (P＜0.05). Conclusion: XC could reduce the expression of TGF-ß and smad2/3 phosphorylation, down-regulate the expression of TIMP-2, which would inhibit the formation of myocardial fibrosis in CIH rats, and improve the myocardial function of CIH rats.

[The effects of Xiaotan Huayu Liqiao formula on mesenteric artery function in rats exposed to chronic intermittent hypoxia].

OBJECTIVE: To investigate the effects of Xiaotan Huayu Liqiao formula (the Chinese Medicine) on mesenteric artery function in rats exposed to chronic intermittent hypoxia (CIH), and to explore the related mechanism. METHODS: Forty-eight male SD rats were randomly divided into four groups as Normoxia, CIH, Formula+CIH and formula group. Rats were exposed to normoxia in the Normoxia and Formula group, or intermittent hypoxia in CIH or Formula+CIH group. Xiaotan Huayu Liqiao formula was given at 24g/kg by intragastric administration before intermittent hypoxia exposure. The pathological changes of mesenteric artery were determined by HE staining, and the relaxation of mesenteric artery (induced by acetylcholine(ACh) and L-arginine(L-Arg)) was recorded by microvascular ring technique. Serums of all rats were collected (0 d and 21 d) and the content of NO was detected by ELISA. The levels of endothelial nitric oxide synthase (eNOS) and p-eNOS were measured by Western blot. RESULTS: Compared with Normoxia group, the mesenteric arterial endothelial injury and media thickening were observed and the relaxation of mesenteric artery was significantly reduced in rats exposed to CIH. The level of NO in serum and the ratio of p-eNOS/eNOS were also decreased in the CIH group. Xiaotan Huayu Liqiao formula administration improved the pathologic changes and dilatation function of mesenteric artery, increased the levels of NO and p-eNOS. Compared with Normoxia group,all the results were not observed significant difference in Formula group. CONCLUSION: Xiaotan Huayu Liqiao formula increased the bioavailability of NO, and ameliorated the CIH induced mesenteric artery function injury.

Herbs-partitioned moxibustion alleviates aberrant intestinal epithelial cell apoptosis by upregulating A20 expression in a mouse model of Crohn's disease.

BACKGROUND: A20 inhibits intestinal epithelial cell apoptosis in Crohn's disease, and herbs-partitioned moxibustion (HPM) has been demonstrated to be an effective treatment for Crohn's disease. However, the mechanism by which HPM reduces intestinal epithelial cell apoptosis in Crohn's disease has not been thoroughly elucidated to date. AIM: To elucidate whether HPM exerts its effects by upregulating A20 to affect intestinal epithelial cell apoptosis in a Crohn's disease mouse model. METHODS: In this study, mice with A20 deletion in intestinal epithelial cells (A20IEC-KO) were utilized to establish a Crohn's disease mouse model with 2,4,6-trinitrobenzene sulfonic acid (TNBS) administration, as well as wild-type mice. Mice were randomly divided into normal control (NC), model control (MC), mesalazine (MESA), and HPM groups. The morphology of the colonic mucosa was observed by hematoxylin-eosin staining, and serum endotoxin and apoptosis of epithelial cells were evaluated by enzyme-linked immunosorbent assay and terminal dUTP nick-end labeling assay accordingly. The protein expression levels of A20 and tumor necrosis factor receptor 1 (TNFR1)-related signaling molecules were evaluated by Western blot, and co-expression of A20 and TNFR1-associated death domain (TRADD) and co-expression of A20 and receptor-interacting protein 1 (RIP1) were observed by double immunofluorescence staining. RESULTS: The intestinal epithelial barrier was noted to have an improvement in the HPM group of wild-type (WT) mice compared with that in A20IEC-KO mice. Compared with A20 IEC-KO HPM mice, serum endotoxin levels and apoptosis percentages were decreased (P < 0.01), A20 expression levels were increased (P < 0.01), and expression of TNFR1, TRADDD, and RIP1 was decreased in the HPM group of WT mice (P TNFR1 < 0.05, P TRADD < 0.01, P RIP1 < 0.01). Both of the co-expression of A20/TRADD and A20/RIP1 showed a predominantly yellow fluorescence in the HPM group of WT mice, while a predominantly red fluorescence was noted in the HPM group of A20IEC-KO mice. CONCLUSION: Our findings suggest that HPM in treating Crohn's disease functions possibly via upregulation of the A20 expression level, resulting in downregulation of TNFR1, TRADD, and RIP1 to alleviate increased cell apoptosis in the intestinal epithelial barrier in Crohn's disease.

[Herbal cake-partitioned moxibustion improves intestinal epithelial barrier dysfunction by suppressing TNF-α-mediated apoptosis pathway of intestinal epithelium in rats with Crohn's disease].

OBJECTIVE: To observe the effect of herbal cake-partitioned moxibustion (Moxi) on tumor necrosis factor (TNF)-α/ TNF receptor 1 (TNFR1)-associated death domain (TRADD) / Fas-associated death domain (FADD) pathway-mediated apoptosis of intestinal epithelial cells in Crohn's disease (CD) rats, so as to explore its underlying mechanisms in the treatment of CD. METHODS: Forty-eight SD male rats were randomly divided into normal, model, Moxi and medication groups (n＝12 rats in each). The CD model was established by intra-annual perfusion of 2，4，6-trinitrobenzene sulfonic acid (TNBS) solution (TNBS∶50% alcohol＝2∶1, 3 mL/kg), once every 7 days, 4 times altogether. For rats of the Moxi group, moxibustion was given to "Tianshu" (ST25) and "Qihai" (CV6), two moxa-cones every time, once daily for 10 days. For rats of the medication group, intragastric perfusion of mesalazine solution was given twice daily for 10 days. After the treatment, the colonic epithelium tissue was sampled. The epithelial cells were purified and cultured to establish an in vitro intestinal epithelial barrier, and added with TNF-α (a pro-inflammatory factor, 100 ng/mL) in the culture medium for 24 h for making an increased epithelial permeability model. The permeability of intestinal epithelial cell barrier was evaluated by detecting the fluorescence yellow transmittance of the TNF-α-incubated cell medium. Western blot was used to detect the expression levels of TNFR1, TRADD, receptor-interacting protein 1 (RIP1), FADD and zinc finger protein A20 (A20, a ubiquitination enzyme for inhibiting activation of TRADD and RIP1) of the cultured intestinal epithelium cells. The apoptosis of the TNF-α-incubated intestinal epithelial cells was detected by flow cytometry. RESULTS: After modeling and compared with the normal group, the fluorescence yellow transmittance of intestinal epithelia cells, apoptosis rate, and expression levels of TNFR1, TRADD, and RIP1 proteins were significantly increased (P<0.001, P<0.01), and the expression of A20 was significantly decreased (P<0.01) in the model group. In comparison with the model group, the fluorescence yellow transmittance of intestinal epithelial cells, the apoptosis rate and expression levels of TRADD, RIP1 and FADD were remarkably down-regulated (P<0.001, P<0.01), and the expression of A20 was significantly up-regulated (P<0.01) in both the Moxi and medication groups. CONCLUSION: Herbal cake-partitioned moxibustion may down-regulate the permeability of intestinal epithelial barrier and the apoptosis of intestinal epithelial cells by way of suppressing TNF-α-mediated cellular apoptosis pathway of intestinal epithelium in CD rats.

Hydrogen gas reduces chronic intermittent hypoxia-induced hypertension by inhibiting sympathetic nerve activity and increasing vasodilator responses via the antioxidation.

Molecular hydrogen is reported to be used medically to ameliorate various systemic pathological conditions. This study aimed to investigate the effect of hydrogen (H2 ) gas on hypertension induced by intermittent hypoxia in rats. The adult rats were exposed to chronic intermittent hypoxia (CIH) 8 hours/day for 5 weeks and/or H 2 gas 2 hours/day. We found that the systolic and diastolic blood pressure (BP) increased significantly in rats exposed to intermittent hypoxia, both of which were markedly attenuated after H treatment. Furthermore, intermittent hypoxia exposure elevated renal sympathetic nerve activity, consistent with plasma norepinephrine. Additionally, H 2 gas significantly improved CIH-induced abnormal vascular relaxation. Nevertheless, inhalation of H 2 gas alone did not cause such changes. Moreover, H 2 gas-treated rats exposed to CIH showed a significant reduction in 8-hydroxy-2 deoxyguanosine content and increases in superoxide dismutase activity, indicating improved oxidative stress. Taken together, these results indicate that H 2 gas has significant effects on the reduction of BP without any side effects. Mechanistically, inhibition of sympathetic activity and reduction of systemic vascular resistance may participate in this process via the antioxidant activity of H 2 .

[Bosentan ameliorates hypertension in rats exposed to chronic intermittent hypoxia through inhibiting renal sympathetic nerve activity].

The purpose of this study is to investigate the effect of the oral endothelin antagonist Bosentan on blood pressure and renal sympathetic nerve activity (RSNA) in rats exposed to chronic intermittent hypoxia (CIH), and to explore the sympathoexcitation mechanism of endothelin-1 (ET-1) in CIH-induced hypertension. Twenty-four male SD rats were randomly divided into normoxia, CIH and Bosentan groups. Rats in the normoxia group were exposed to normoxic environment, and rats in CIH or Bosentan group were exposed to intermittent hypoxia for 3 weeks. Bosentan was given at 50 mg/kg by intragastric administration before intermittent hypoxia exposure in Bosentan group. Systolic blood pressure (SBP) was measured by BP-2000, and the change of RSNA to sodium nitroprusside (SNP) or phenylephrine (PE) was recorded by PowerLab signal acquisition system. Serums of all rats were collected and the contents of ET-1 and norepinephrine (NE) were measured by ELISA. Results showed that blood pressure was gradually increased following CIH exposure compared with the normoxia group during the 3 weeks (P < 0.01, P < 0.01, P < 0.001). The basal RSNA was increased and baroreflex sensitivity was decreased in rats exposed to CIH. Furthermore, the blood pressure was positively correlated with the level of ET-1 in serum in rats exposed to CIH (r = 0.833, P = 0.01). Bosentan administration significantly decreased SBP and basal RSNA, increased the baroreflex sensitivity, and decreased serum NE level in rats exposed to CIH. These results suggest that ET-1 is related with blood pressure elevation in rats exposed to CIH, and Bosentan reverses CIH-induced hypertension by decreasing RSNA.

Fasudil improves endothelial dysfunction in rats exposed to chronic intermittent hypoxia through RhoA/ROCK/NFATc3 pathway.

Endothelial dysfunction is one of the main pathological changes in Obstructive sleep apnoea (OSA). The Rho kinase (ROCK) pathway is associated with endothelial dysfunction. However, the interaction between ROCK and nuclear factor of activated T cells isoform c3 (NFATc3) in the development of this pathological response under chronic intermittent hypoxia (CIH) is unclear. To simulate the OSA model, we established a moderate CIH rat model by administering the fraction of inspired O2 (FiO2) from 21% to 9%, 20 times/h, 8 h/day for 3 weeks. Fasudil (ROCK inhibitor, 8 mg/kg/d, i.p.) was administrated in the rats exposed to CIH for 3 weeks. Our results demonstrated that CIH caused significantly endothelial dysfunction, accompanying with increased ET-1 level, decreased eNOS expression and NO production, which reduced ACh-induced vascular relaxation responses. Moreover, RhoA/ROCK-2/NFATc3 expressions were up-regulated. Fasudil significantly improved CIH induced endothelial dysfunction. Data suggested that the ROCK activation is necessary for endothelial dysfunction during CIH.

Tanshinone IIA protects against chronic intermittent hypoxia-induced myocardial injury via activating the endothelin 1 pathway.

Tanshinone IIA (Tan IIA) may exert significant protective effects against heart oxidative stress damage in obstructive sleep apnoea (OSA) syndrome. Chronic intermittent hypoxia (CIH)-triggered left ventricular dysfunction is used in a rat model to mimic CIH in OSA patients. 48 rats were randomly divided into three groups: normal control (NC) group, CIH group and CIH+Tan IIA group with 16 rats in each group. At the end of experiment (day 21), the blood pressure, Plasma ET-1 and NO content, hemodynamic indexes, heart histology, myocardial apoptosis as well as the expression of eNOS, ET-1, ETA receptor and ETB receptor were compared among different groups. Tan IIA was able to inhibit the increase of blood pressure induced by CIH. Meanwhile, rat cardiac function in Tan IIA group was evaluated by hemodynamic indexes, histopathological examination. Higher ventricular eNOS activity was induced by Tan IIA with a reduction in both ET-1 and ETA receptor expression. However, Tan IIA largely inhibited the decrease of ETB receptor expression. This study demonstrated that Tan IIA has the potential to benefit rat heart against CIH via endothelin system.

Endothelin-1 and ET receptors impair left ventricular function by mediated coronary arteries dysfunction in chronic intermittent hypoxia rats.

Obstructive sleep apnea (OSA) results in cardiac dysfunction and vascular endothelium injury. Chronic intermittent hypoxia (CIH), the main characteristic of OSAS, is considered to be mainly responsible for cardiovascular system impairment. This study is aimed to evaluate the role of endothelin-1(ET-1) system in coronary injury and cardiac dysfunction in CIH rats. In our study, Sprague-Dawley rats were exposed to CIH (FiO2 9% for 1.5 min, repeated every 3 min for 8 h/d, 7 days/week for 3 weeks). After 3 weeks, the left ventricular developed pressure (LVDP) and coronary resistance (CR) were measured with the langendorff mode in isolated hearts. Meanwhile, expressions of ET-1 and ET receptors were detected by immunohistochemical and western blot, histological changes were also observed to determine effects of CIH on coronary endothelial cells. Results suggested that decreased LVDP level combined with augmented coronary resistance was exist in CIH rats. CIH could induce endothelial injury and endothelium-dependent vasodilatation dysfunction in the coronary arteries. Furthermore, ET-1 and ETA receptor expressions in coronary vessels were increased after CIH exposure, whereas ETB receptors expression was decreased. Coronary contractile response to ET-1 in both normoxia and CIH rats was inhibited by ETA receptor antagonist BQ123. However, ETB receptor antagonist BQ788 enhanced ET-1-induced contractile in normoxia group, but had no significant effects on CIH group. These results indicate that CIH-induced cardiac dysfunction may be associated with coronary injury. ET-1 plays an important role in coronary pathogenesis of CIH through ETA receptor by mediating a potent vasoconstrictor response. Moreover, decreased ETB receptor expression that leads to endothelium-dependent vasodilatation decline, might be also participated in coronary and cardiac dysfunction.