Simulated microgravity-induced oxidative stress and loss of osteogenic potential of osteoblasts can be prevented by protection of primary cilia.

Oxidative stress has been considered to be closely related to spaceflight-induced bone loss; however, mechanism is elusive and there are no effective countermeasures. Using cultured rat calvarial osteoblasts exposed to microgravity simulated by a random positioning machine, this study addressed the hypotheses that microgravity-induced shortening of primary cilia leads to oxidative stress and that primary cilium protection prevents oxidative stress and osteogenesis loss. Microgravity was found to induce oxidative stress (as represented by increased levels of reactive oxygen species (ROS) and malondialdehyde production, and decreased activities of antioxidant enzymes), which was perfectly replicated in osteoblasts growing in NG with abrogated primary cilia (created by transfection of an interfering RNA), suggesting the possibility that shortening of primary cilia leads to oxidative stress. Oxidative stress was accompanied by mitochondrial dysfunction (represented by increased mitochondrial ROS and decreased mitochondrial membrane potential) and intracellular Ca2+ overload, and the latter was found to be caused by increased activity of Ca2+ channel transient receptor potential vanilloid 4 (TRPV4), as also evidenced by TRPV4 agonist GSK1016790A-elicited Ca2+ influx. Supplementation of HC-067047, a specific antagonist of TRPV4, attenuated microgravity-induced mitochondrial dysfunction, oxidative stress, and osteogenesis loss. Although TRPV4 was found localized in primary cilia and expressed at low levels in NG, microgravity-induced shortening of primary cilia led to increased TRPV4 levels and Ca2+ influx. When primary cilia were protected by miR-129-3p overexpression or supplementation with a natural flavonoid moslosooflavone, microgravity-induced increased TRPV4 expression, mitochondrial dysfunction, oxidative stress, and osteogenesis loss were all prevented. Our data revealed a new mechanism that primary cilia function as a controller for TRPV4 expression. Microgravity-induced injury on primary cilia leads to increased expression and overactive channel of TRPV4, causing intracellular Ca2+ overload and oxidative stress, and primary cilium protection could be an effective countermeasure against microgravity-induced oxidative stress and loss of osteogenic potential of osteoblasts.

Anti-hypoxia Activity of the Novel NO Donor Acetyl Ferulic Isosorbide Mononitrate in Acute High-Altitude Hypoxia Mice.

Nitric oxide (NO) may act as either a pro-oxidant or an antioxidant in biological systems. Previous work has found inhalation of NO improved survival in a high altitude rat model. NO donor isosorbide mononitrate derivants might have a protective effect against hypoxia. We synthesized a series of isosorbide mononitrate derivant compounds to test their anti-hypoxia activities. Normobaric hypoxia and hypobaric hypoxia models were used to study the protective role of NO donor in mice. The results showed isosorbide mononitrate derivants had protective effects in hypoxia mice. Among those compounds, acetyl ferulic isosorbide mononitrate (AFIM) was the most effective. It prolonged the survival time during the normobaric hypoxia test. It decreased malondialdehyde (MDA) and H2O2 in hypobaric hypoxia mice. The antioxidase activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) remained in normal ranges in the AFIM group. As a sign of mitochondrial dysfunction, the activities of ATPase were down regulated in mice under hypobaric hypoxia conditions. AFIM also protected ATPase activities. The protective effects of AFIM might come from a sustained NO supply and the release of acetyl ferulic acid with anti-oxidant activity.

[Chemical Constituents with Anti-hypoxia Activity from Saussurea involucrata].

OBJECTIVE: To investigate the chemical constituents with anti-hypoxia activity from Saussurea involucrata. METHODS: The chemical constituents, isolated and purified by column chromatography from Saussurea involucrata, were identified by several spectroscopic methods. The anti-hypoxic activities of these compounds were examined using the normobaric hypoxic model of mice. RESULTS: Twelve compounds were isolated from petroleum ether extract of Saussurea involucrata and identified as n-octacosane (1), 1-undecanol (2), heptadecan-l-ol(3), heptacosan-1-ol(4), myristicin (5), apiol(6), ß-sitosterol(7), lupeol(8), moslosooflavone (9), mosloflavone (10), negletein(11), and 5, 6-dihydroxy-7, 8-dimethoxyflavone(12). CONCLUSION: All compounds except 7 and 8 are isolated from this plant for the first time. Compound 1, 5 and 8 - 12 can significantly prolong the survival time of hypoxic mice.

[Protective Effect of Saussurea involucrata Alcohol Extract on Liver Mitochondria in Mice Under Hypoxia Condition].

OBJECTIVE: To study the protective effect of Saussurea involucrata alcohol extract on liver mitochondria in mice under hypoxia condition. METHODS: The hypoxia mice model was established, the BALB/c mice were randomly divided into four groups:normal group ,hypoxia model group, positive control group and Saussurea involucrata alcohol extract group. Mice were put into low pressure oxygen chamber and decompressed, adapted to hypobaric hypoxia environment of simulated altitude of 8,000 m for 12 h, and then recovered to normal altitude. The mice were sacrificed and the liver mitochondria was isolated, the mitochondrial membrane potential and the activity of malate dehydrogenase, aconitase, α-ketoglutarate dehydrogenase, pyruvate dehydrogenase and mitochondrial complex I, II and V were measured. RESULTS: Compared with hypoxia model group, Saussurea involucrata alcohol extract protected mitochondrial membrane potential, sustained the activities of aconitase, α-ketoglutarate dehydrogenase, pyruvate dehydrogenase, and mitochondrial complex I, II and V under hypoxia condition. CONCLUSION: Saussurea involucrata alcohol extract can protect the liver mitochondrial function in mice under hypoxia condtion.

[Effect of ethanol extract from Saussurea involucrata on biochemical indicators of simulated high-altitude hypoxia induced mice].

OBJECTIVE: To estimate the effect of ethanol extract from Saussurea involucrata (EES) on biochemical indicators of simulated high-altitude hypoxia induced mice and its mechanism. METHODS: The oxidative stress indicator( MDA content, SOD activity) and metabolism parameters (LD content, LDH activity, ATP content, Na+ -K+ -ATPase and Ca2+ -Mg2+ -ATPase activity) in both brain and heart of the simulated high-altitude hypoxia induced mice were detected. RESULTS: Compared with the model group, the ESS group could significantly increase the activity of SOD and LDH and decrease the content of MDA and LD in both brain and heart, the content of ATP and the activity of Na+ -K -ATPase and Ca2+ -Mg2+ -ATPase were also elevated. CONCLUSION: The results demonstrate that EES can increase the antioxidant ability, decrease the injury of free radical and ease the disfunction of energy metabolism caused by hypoxia.

[Protective effect and action mechanism of petroleum ether extracts from Saussurea involucrate on brain tissues of hypoxia rats].

OBJECTIVE: To investigate the protective effect and action mechanism of petroleum ether extracts from Saussurea involucrate on brain tissues of hypoxia rats under constant pressure and closed conditions. METHOD: The PESI dosage-dependent experiment for hypoxia rats was conducted under constant pressure and closed conditions by intraperitoneally injecting 125, 250, 500 mg x kg(-1) to finalize that the optimum dosage is the high dose of PESI. Afterwards, 90 Wistar rats were randomly divided into the hypoxic model group, the acetazolamide 250 mg x kg(-1) group and the PESI high dose group. Each group was further divided into three subgroups according to different hypoxia times, with 10 rats in each subgroup. Under the same hypoxia and administration conditions, the rats were sacrificed after 0, 3, 6 h respectively. Their brain samples were collected for common pathological observation and immunohistochemical staining of HIF-1alpha. Real-time RT-PCR was used to detect HIF-1alpha, EPO, HO-1 and Caspase-3 gene expressions. And the Western blot assay was adopted to detect HIF-1alpha protein expression. RESULT: The brain tissues of the hypoxia model group were severely damaged with the increase in the hypoxia time. The acetazolamide group and the PESI high does group were damaged in a much lower degree. According to the gene expression and the Western blot assay, high dose of PESI could inhibit HIF-1alpha expression. According to the pure gene expression test, high dose of PESI could increase EPO and HO-1 mRNA expressions, but inhibit Caspase-3 mRNA expression. CONCLUSION: PESI's protective mechanism for brain tissues of hypoxia rats under constant pressure and closed conditions may be related to its effects in inhibiting HIF-1alpha expression, increasing EPO expression and resisting cell apoptosis.

Effect of the Novel Free Radical Scavenger 4'-Hydroxyl-2-Substituted Phenylnitronyl Nitroxide on Oxidative Stress, Mitochondrial Dysfunction and Apoptosis Induced by Cerebral Ischemia-Reperfusion in Rats.

Mitochondrial dysfunction, which results in the overproduction of oxygen free radicals, is a crucial mechanism underlying cerebral ischemia-reperfusion injury. 4'-Hydroxyl-2-substituted phenylnitronyl nitroxide (HPN), which is an antioxidant and free radical scavenger, can effectively scavenge oxygen free radicals, suggesting its potential as a protective agent against cerebral ischemia-reperfusion injury. In this study, we investigated the effects of HPN on mitochondrial function and apoptosis following cerebral ischemia/reperfusion injury in rats. Healthy adult SD rats were chosen as the experimental subjects, and the rat ischemia/reperfusion injury model was generated using the modified Zea Longa method. The administration of HPN significantly enhanced the activity of endogenous antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT). Additionally, HPN effectively preserved the morphology and function of mitochondria, reduced the protein and gene expression of Caspase-3 and Bax, increased the protein and gene expression of Bcl-2, mitigated neuronal apoptosis, improved neurological deficits, and decreased the volume of cerebral infarction. Of interest, the protective effect on brain tissue was more evident with increasing doses of HPN. These findings indicate that HPN can serve as an effective protective agent against cerebral ischemia-reperfusion injury.

The antioxidative effect of a novel free radical scavenger 4'-hydroxyl-2-substituted phenylnitronyl nitroxide in acute high-altitude hypoxia mice.

Acute mountain sickness is caused by sub-acute hypoxia in healthy individuals going rapidly to altitude. Both tissue hypoxia in vitro and whole-body hypoxia in vivo have been found to promote the release of reactive oxygen species. Nitronyl nitroxide can trap free radicals such as ·NO or ·OH, and may therefore be efficient protective agents. This study assessed the ability of nitronyl nitroxide to against acute mountain sickness as a free radical scavenger in acute high-altitude hypoxia mice model. Normobaric hypoxia and hypobaric hypoxia model were used to estimate the protect effects of nitronyl nitroxide against acute mountain sickness. Low pressure oxygen compartment system was used to stimulate high-altitude hypobaric hypoxia environment. Mice in nitronyl nitroxide groups survived longer than acetazolamide group in normobaric hypoxia test. Hydrogen peroxide (H2O2) and malondialdehyde (MDA) increased in both cerebrum and myocardium in vehicle group. The results indicated more radicals were generated during high-altitude hypobaric hypoxia environment. In therapeutic groups H2O2 and MDA were significantly reduced while the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) were similar to normal group. These results demonstrated that nitronyl nitroxide was an efficient tissue radical scavenger and a potential protective agent for acute mountain sickness.

5,6-Dihy-droxy-7,8-di-meth-oxy-flavone.

THE TITLE COMPOUND (SYSTEMATIC NAME: 5,6-dihy-droxy-7,8-dimeth-oxy-2-phenyl-chromen-4-one), C17H14O6, is a flavone that was isolated from the petroleum ether-soluble fraction of the rare traditional Chinese medicinal herb Saussurea involucrata. The flavone mol-ecule is almost planar, with a dihedral angle between the planes of the benzo-pyran-4-one group and the attached phenyl group of 1.89 (6)°. The 5-hy-droxy group forms a strong intra-molecular hydrogen bond with the carbonyl group, resulting in a six-membered hydrogen-bonded ring. The 6-hy-droxy group also forms an intra-molecular O-H⋯O contact. In the crystal, the molecules are linked by O-H⋯O and C-H⋯O hydrogen bonds and π-π inter-actions [3.37 (2)-3.39 (2) Å], which build up a three-dimensional network.

Effects of buyang huanwu decoction on ventricular remodeling and differential protein profile in a rat model of myocardial infarction.

Buyang Huanwu decoction (BYHWD) is a well-known and canonical Chinese medicine formula from "Correction on Errors in Medical Classics" in Qing dynasty. Here, we show that BYHWD could alleviate the ventricular remodeling induced by left anterior descending (LAD) artery ligation in rats. BYHWD treatment (18 g/kg/day) decreased heart weight/body weight (HW/BW), left ventricle (LV) dimension at end diastole (LVDd) and increased LV ejection fraction (LVEF) and LV fractional shortening (LVFS) significantly compared to model group at the end of 12 weeks. The collagen volume of BYHWD group was more significantly decreased than that of model group. Proteomic analysis showed that atrial natriuretic factor (ANF) was downregulated; heat shock protein beta-6 (HSPB6) and peroxiredoxin-6 (PRDX6) were upregulated in BYHWD-treated group among successfully identified proteins. The apoptotic index (AI) was reduced by BYHWD accompanied by decreased expression of Bax and caspase 3 activity, increased Bcl-2/Bax ratio, and phosphorylation of HSPB6 compared to that of model group. Taken together, these results suggest that BYHWD can alleviate ventricular remodeling induced by LAD artery ligation. The antiremodeling effects of BYHWD are conferred by decreasing AI through affecting multiple targets including increased Bcl-2/Bax ratio and decreased caspase 3 activity that might be via upregulated PRDX6, phosphorylation of HSPB6 and subsequently reduction of ANF.

Simultaneous determination of four shanzhiside methylester derivatives in rabbit plasma by liquid chromatography/tandem mass spectrometry.

A simple and sensitive high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for simultaneous determination of shanzhiside methylester and its three derivatives in rabbit plasma. The method showed good linearity and no endogenous material interfered with the marked compounds and internal standard (IS) capatol peaks. Samples were processed by acetonitrile precipitation. Chromatography was performed using a C18 column (150 × 3.9 mm i.d., 4 µm). The mobile phase consisted of methanol and water (60:40, v/v) during a total run time of 7 min. The main mass parent ions and daughter ions pairs (m/z) for monitoring were: shanzhiside methylester, 429.0/267.4; 8-O-acetyl shanzhiside methylester, 470.9/411.3; loganin, 413.2/251.4; phloyoside II, 479.2/281.3; and IS 385.2/203.3. Finally, the method was applied to a pharmacokinetic study of rabbits following intravenous administration of iridoid glycosides extracted from traditional herb Lamiophlomis rotata.

Methyl 2-{[2-(4,4,5,5-tetra-methyl-1,3-dioxyl-4,5-dihydro-imidazol-2-yl)phen-yl]-oxy}acetate.

In the title compound, C(16)H(21)N(2)O(5), the benzene ring is nearly perpendicular to the imidazole ring, making a torsion angle of 88.6 (8)°·The crystal structure is stabilized by non-classical C-H⋯O and C-H⋯π inter-actions, which build up a three-dimensional network.

2-[3-Hy-droxy-4-(2-hy-droxy-eth-oxy)phen-yl]-4,4,5,5-tetra-methyl-2-imidazoline-1-oxyl 3-oxide.

In the title compound, C(15)H(21)N(2)O(5), the imidazoline ring displays a twisted conformation. The mean plane of the imidazoline ring makes a dihedral angle of 22.55 (5)° with the benzene ring. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into a layer parallel to the bc plane.

Three new flavonoid glycosides from Urena lobata.

Three new flavonoid glycosides, kaempferol-3-O-ß-D-apiofuranosyl(1 → 2)-ß-D-glucopyranosyl-7-O-α-L-rhamnopyranoside (1), kaempferol-4'-O-ß-D-apiofuranosyl-3-O-ß-D-glucopyranosyl-7-O-α-l-rhamnopyranoside (2), and 5,6,7,4'-tetrahydroxy-flavone-6-O-ß-D-arabinopyranosyl-7-O-α-L-rhamnopyranoside (3), were isolated from the aerial parts of Urena lobata L., along with 10 known compounds (4-13). Their structures were determined based on spectroscopic methods including 1D and 2D NMR spectroscopy as well as HR-ESI-MS.

2-[4-(2-Hy-droxy-eth-oxy)phenyl]-4,4,5,5-tetra-methyl-2-imidazoline-1-oxyl 3-oxide.

In the title compound, C(15)H(21)N(2)O(4), the imidazoline ring displays a twisted conformation. The dihedral angle between the mean plane of the imidazoline ring and the benzene ring is 33.50 (12)°. In the crystal, mol-ecules are connected by O-H⋯O hydrogen bonds, forming a zigzag chain along the c axis. The chains are linked by C-H⋯O and C-H⋯π inter-actions.

2-[2-(2-Hy-droxy-eth-oxy)phen-yl]-4,4,5,5-tetra-methyl-2-imidazoline-1-oxyl 3-oxide.

In the title compound, C(15)H(21)N(2)O(4), the nitronyl nitroxide unit displays a twisted conformation. The crystal structure is stabilized by non-classical C-H⋯O and C-H⋯π hydrogen bonds, which build up a three-dimensional network.

(R)-2-[1-(2,6-Dichloro-3,4,5-trimeth-oxy-benzo-yl)pyrrolidin-2-yl]-4,4,5,5-tetra-methyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide.

In the title compound, C(21)H(28)Cl(2)N(3)O(6), the nitronyl nitroxide ring displays a half-chair conformation, whereas the pyrrolidine ring has an envelope conformation. These two rings are twisted to each other with N-C-C-N torsion angles around the connecting C-C bond of 48.9 (6) and -127.0 (5)°. The benzene ring is nearly perpendicular to the pyrrolidine ring, with torsion angles around the connecting C-C bond of 86.3 (6) and -97.7 (6)°. The crystal structure is stabilized by C-H⋯O and C-H⋯π hydrogen bonds, which build up a three-dimensional network.

2-[1-(4-Chloro-benzo-yl)pyrrolidin-2-yl]-4,4,5,5-tetra-methyl-4,5-dihydro-imidazole-1-oxyl-3-oxide.

In the title compound, C(18)H(23)ClN(3)O(3), the imidazole ring system has an envelope conformation, whereas the nitronyl nitroxide unit displays a half-chair or twisted conformation. In the crystal, C-H⋯O hydrogen bonds build up a three-dimensional network.

Two new compounds from Urena lobata L.

Two new compounds 1 and 2 have been isolated from the aerial parts of Urena lobata L. The structures of the two new compounds were established as ceplignan-4-O-ß-d-glucoside (1) and 2,5-dihydroxy benzoic acid-7-(2,6-dimethyl-6-hydroxy-2,7-octadienoic acid) anhydride-5-O-ß-d-apiofuranosyl(1 â†’ 2)-ß-d-glucoside (urenoside A) (2), on the basis of chemical and spectral evidence, including 1D and 2D NMR spectroscopic data as well as mass spectrometry (HR-ESI-MS).

2-(1H-Indol-3-yl)-4,4,5,5-tetra-methyl-imidazolidine-1-oxyl 3-oxide.

In the title compound, C(15)H(18)N(3)O(2), the plane of the indole ring system is twisted with respect to the plane of the nitronyl nitroxide moiety, exhibiting a dihedral angle of 21.61 (6)°. The crystal packing is stabilized by N-H⋯O hydrogen bonds and weak C-H⋯O inter-actions.