Norwogonin attenuates hypoxia-induced oxidative stress and apoptosis in PC12 cells.

BACKGROUND: Norwogonin is a natural flavone with three phenolic hydroxyl groups in skeletal structure and has excellent antioxidant activity. However, the neuroprotective effect of norwogonin remains unclear. Here, we investigated the protective capacity of norwogonin against oxidative damage elicited by hypoxia in PC12 cells. METHODS: The cell viability and apoptosis were examined by MTT assay and Annexin V-FITC/PI staining, respectively. Reactive oxygen species (ROS) content was measured using DCFH-DA assay. Lactate dehydrogenase (LDH), malondialdehyde (MDA) and antioxidant enzyme levels were determined using commercial kits. The expression of related genes and proteins was measured by real-time quantitative PCR and Western blotting, respectively. RESULTS: We found that norwogonin alleviated hypoxia-induced injury in PC12 cells by increasing the cell viability, reducing LDH release, and ameliorating the changes of cell morphology. Norwogonin also acted as an antioxidant by scavenging ROS, reducing MDA production, maintaining the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), and decreasing the expression levels of HIF-1α and VEGF. In addition, norwogonin prevented cell apoptosis via inhibiting the expression levels of caspase-3, cytochrome c and Bax, while increasing the expression levels of Bcl-2 and the ratio of Bcl-2/Bax. CONCLUSIONS: Norwogonin attenuates hypoxia-induced injury in PC12 cells by quenching ROS, maintaining the activities of antioxidant enzymes, and inhibiting mitochondrial apoptosis pathway.

Neuroligin 2 regulates absence seizures and behavioral arrests through GABAergic transmission within the thalamocortical circuitry.

Epilepsy and autism spectrum disorders (ASD) are two distinct brain disorders but have a high rate of co-occurrence, suggesting shared pathogenic mechanisms. Neuroligins are cell adhesion molecules important in synaptic function and ASD, but their role in epilepsy remains unknown. In this study, we show that Neuroligin 2 (NLG2) knockout mice exhibit abnormal spike and wave discharges (SWDs) and behavioral arrests characteristic of absence seizures. The anti-absence seizure drug ethosuximide blocks SWDs and rescues behavioral arrests and social memory impairment in the knockout mice. Restoring GABAergic transmission either by optogenetic activation of the thalamic reticular nucleus (nRT) presynaptic terminals or postsynaptic NLG2 expression in the thalamic neurons reduces the SWDs and behavioral arrests in the knockout mice. These results indicate that NLG2-mediated GABAergic transmission at the nRT-thalamic circuit represents a common mechanism underlying both epileptic seizures and ASD.

Bi-allelic GOT2 Mutations Cause a Treatable Malate-Aspartate Shuttle-Related Encephalopathy.

Early-infantile encephalopathies with epilepsy are devastating conditions mandating an accurate diagnosis to guide proper management. Whole-exome sequencing was used to investigate the disease etiology in four children from independent families with intellectual disability and epilepsy, revealing bi-allelic GOT2 mutations. In-depth metabolic studies in individual 1 showed low plasma serine, hypercitrullinemia, hyperlactatemia, and hyperammonemia. The epilepsy was serine and pyridoxine responsive. Functional consequences of observed mutations were tested by measuring enzyme activity and by cell and animal models. Zebrafish and mouse models were used to validate brain developmental and functional defects and to test therapeutic strategies. GOT2 encodes the mitochondrial glutamate oxaloacetate transaminase. GOT2 enzyme activity was deficient in fibroblasts with bi-allelic mutations. GOT2, a member of the malate-aspartate shuttle, plays an essential role in the intracellular NAD(H) redox balance. De novo serine biosynthesis was impaired in fibroblasts with GOT2 mutations and GOT2-knockout HEK293 cells. Correcting the highly oxidized cytosolic NAD-redox state by pyruvate supplementation restored serine biosynthesis in GOT2-deficient cells. Knockdown of got2a in zebrafish resulted in a brain developmental defect associated with seizure-like electroencephalography spikes, which could be rescued by supplying pyridoxine in embryo water. Both pyridoxine and serine synergistically rescued embryonic developmental defects in zebrafish got2a morphants. The two treated individuals reacted favorably to their treatment. Our data provide a mechanistic basis for the biochemical abnormalities in GOT2 deficiency that may also hold for other MAS defects.

Acute and sub-chronic toxicological studies of the iridoid glycosides extract of Lamiophlomis rotata (Benth.) Kudo in rats.

Lamiophlomis rotata(Benth.) Kudo is widely used in traditional Chinese medicine and its iridoid glycosides extract (IGLR) was the main active ingredient with hemostatic, antinociceptive and anti-inflammatory effects. This study was aimed to evaluate the safety of IGLR using acute and sub-chronic toxicity study methods on Sprague-Dawley rats. In acute toxicity test, IGLR caused slight diarrhea in three dose groups and a decreased of RBC and increased of MCH and Ret (P < .05) were observed in 16 g/kg group. In sub-chronic toxicity study, unscheduled deaths occurred in 1 and 3 rats at 0.40 and 1.00 g/kg groups, respectively. A slight diarrhea was observed in 1.00 g/kg group. Hemolytic anemia was the main toxicity effects of IGLR found in 0.40 and 1.00 g/kg groups, with a significant decrease of RBC, HGB (P < .05) and increase of Ret, MCV, MCH (P < .05) in hematological parameters, a significant decrease of ALT, Crea (P < .05) and increase of TBIL (P < .05) in biochemical parameters, and a significant increase of the percentage of rubricyte, normoblast (P < .05) in bone marrow. Overall, this study found IGLR has a potential toxicity considering with hemolytic anemia and diarrhea to rat. These results provide an important reference for further IGLR-related drug exploration.

Neu-P11, a novel MT1/MT2 agonist, reverses diabetes by suppressing the hypothalamic-pituitary-adrenal axis in rats.

Excessive glucocorticoid (GC) in type 2 diabetes mellitus (T2DM) reduces insulin sensitivity, impairs ß-cell function, increases gluconeogenesis and glycogenolysis, impairs glucose uptake and metabolism, and reduces the insulinotropic effects of glucagon-like peptide 1. Melatonin, which serves as a physiological regulator of the hypothalamic-pituitary-adrenal (HPA) axis, has been suggested to have anti-diabetic effects. The objective of the present study was to investigate the effect of the MT1/MT2 melatonin agonist Neu-P11 on glucose and lipid metabolism in T2DM rats induced by a high fat diet combined with low doses of streptozotocin. T2DM rats were intragastrically administered melatonin (20mg/kg), Neu-P11 (20, 10, 5mg/kg), or a vehicle for 4 weeks. The results showed that the increased food intake, water consumption, hyperglycemia, glucose intolerance, and insulin resistance in T2DM rats were all improved by Neu-P11 treatment. Neu-P11 increased GC receptor expression and suppressed 11ß-hydroxysteroid dehydrogenase 1 activity in the hippocampus by enhancing GC sensitivity and HPA feedback, thus decreasing the high GC levels. Transcript levels of the glucose metabolism-related genes peroxisome proliferator-activated receptor-γ, glucose transporter type-4, and adiponectin in adipose tissue were significantly increased after Neu-P11 treatment, while leptin mRNA was significantly decreased. Furthermore, MT1 and MT2 protein levels were enhanced by Neu-P11. These data suggest that normalization of the hyperactivated HPA axis by melatonin and Neu-P11 in T2DM regulates metabolic profiles and insulin sensitivity, which may attenuate insulin resistance and glucose homeostasis. Because Neu-P11 has superior pharmacokinetics and a longer half-life than melatonin, it might be beneficial in treating obesity and T2DM.

A new anti-fibrinolytic hemostatic compound 8-O-acetyl shanzhiside methylester extracted from Lamiophlomis rotata.

BACKGROUND: Fibrinolysis prevents blood clots from growing and becoming problematic. Antifibrinolytics are used as inhibitors of fibrinolysis. Aprotinin was doubted after identification of major side effects, especially on kidney. Lysine analogues has their own defects and whether they are adequate substitutes for aprotinin is still under doubt. Lamiophlomis rotata (Benth.) Kudo. was previous found to have hemostatic activity. But the active compound in L. rotata and its hemostatic mechanism were unknown. OBJECTIVES: To find the major hemostatic compound in L. rotata and identify its haemostasis mechanism. METHODS: Traumatic hemorrhage model and coagulant activity assays were monitored in mice and platelets in drug treatment group and control group. Hyperfibrinolysis model was established by intravenous administration of urokinase in mice. Capillary blood clotting time (CBCT), activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen and euglobulin clot lysis time (ECLT) were measured. RESULTS: The anti-fibrinolytic activity come from 8-O-Acetyl shanzhiside methylester (ASM) one of the highest iridoid glycosides contents in TIG extracted from L. rotata. ASM significantly (P<0.05) shorten CBCT and reduced blood loss volume in vivo, but did not influence mice APTT, PT or TT. In particular, it significantly prolonged ECLT in hyperfibrinolysis mice. It indicated that ASM could inhibit fibrinolysis. ASM was also effective in CBCT, traumatic bleeding volume and ECLT in hyperfibrinolysis mice model. CONCLUSIONS: ASM was the major hemostatic compound in L. rotata. The haemostasis mechanism of ASM was achieved by anti-fibrinolytic activity. ASM was a new fibrinolysis inhibitor as iridoid glycoside compound.

[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.

Antioxidant potential, total phenolic and total flavonoid contents of Rhododendron anthopogonoides and its protective effect on hypoxia-induced injury in PC12 cells.

BACKGROUND: Rhododendron anthopogonoides Maxim, a kind of traditional Tibetan medicine, has been used to remove body heat, body detoxification, cough, asthma, stomachic and swelling, eliminate abundant phlegm and inflammatory for a long time. In the present study, the total phenols and total flavonoid contents as well as antioxidative properties of the crude extract and solvent fractions of R. anthopogonoides were determined using seven antioxidant assays. Additionally, the protective effect of the extracts on hypoxia-induced injury in PC12 cells was also investigated. METHODS: The content of total flavonoid and total phenolic was determined by the aluminum colorimetric method and Folin-Ciocalteu assay, respectively. In vitro antioxidant study, the effect of the crude extract and solvent fractions on total antioxidant activity, reducing power, DPPH radical scavenging, ABTS radical scavenging, superoxide radical scavenging, hydroxyl radical scavenging and nitric oxide radical scavenging were examined. The correlation between the phenolic and flavonoid content of the extracts and their antioxidant properties also analyzed. Furthermore, the protective effect of extracts on hypoxia-induced damage on PC12 cells was investigated by cell viability, lactate dehydrogenase (LDH) release, malondialdehyde (MDA) production and the activities of antioxidant enzymes. RESULTS: Our results showed that ethyl acetate and n-butanol fractions had higher content of phenolics and flavonoid compounds than other fractions. Except ABTS radical assay, n-butanol fraction exhibited the strongest antioxidant activity. While the hexane fraction showed the lowest antioxidant activity. Ethyl acetate also presented excellent antioxidant activity, which was just lower than n-butanol fraction. Significant correlation between the phenolic, flavonoid content of the extract and fractions with antioxidant assay excluding ABTS, OH scavenging assay was observed. Moreover, ethyl acetate and n-butanol fractions showed protective effect in PC12 cell under hypoxia condition, while crude extract and water fraction had no protective effect. In contrast, hexane fraction exhibited strong cytoprotective effect. Further study indicated that pretreatment of PC12 cells with ethyl acetate and n-butanol fractions, prior to hypoxia exposure, significantly increased the survival of cells and the activities of SOD, CAT, GSH-Px and T-AOC, as well as reduced the level of LDH and MDA. The gathered data demonstrated that ethyl acetate and n-butanol fractions were able to protect PC12 cells against hypoxia induced injury through direct free radical scavenging and modulation of endogenous antioxidant enzymes. CONCLUSION: These findings suggested that ethyl acetate and n-butanol fractions of R. anthopogonoides had significant antioxidant activity and could prevent PC12 cells against hypoxia-induced injury. So it might be regarded as an excellent source of antioxidants and had great potential to explore as therapeutic agent for preventing hypoxia related sickness in future.

[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.

Convergent synthesis of moslosooflavone, isowogonin and norwogonin from chrysin.

A convergent synthesis route of moslooflavone, isowogonin and norwogoninis reported,starting from chrysin, an easily available flavone, by methylation, bromination, methoxylation and demethylation procedures. This synthetic route is convenient and can give the three rare flavones in good yield.

[Effects and HPA Axis Related Mechanism of Kaixin-San and Danggui-Shaoyao-San on Glucose and Lipid Metabolism in Chronic Stress Rats with High-fat Diet].

OBJECTIVE: To study the effects and potential mechanism of Kaixin-San and Danggui-Shaoyao-San on glucose and lipid metabolism in chronic stress rats fed with high-fat diet. METHODS: 50 male Wistar rats were randomly divided into normal control group (distilled water), high-fat diet with chronic stress group (distilled water), melatonin group(20 mg/kg), Kaixin-San group (445 mg/kg) and Danggui-Shaoyao-San group (3360 mg/kg). All drugs were orally administered. In addition to the normal control group, each group of rats were fed with high-fat, diet. Simultaneously, stress were carried out after drugs administration 1 h daily. The duration was lasted for six weeks. The rat body weight daily was recorded, and the 24 h period urine was collected to detect the level of urine corticosterone (CORT) after three weeks. The level of plasma intraperitoneal glucose tolerance (IVGTT) was detected after six weeks. Finally, rats were executed, and serum fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), insulin (INS), adrenocorticotropic hormone releasing hormone (CRH), adrenocorticotropic hormone (ACTH), CORT and melatonin ( MLT) were determined. The weight of adrenal gland, liver glycogen and muscle glycogen levels were detected. The adrenal gland index, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and insulin sensitivity index( ISI) were calculated. RESULTS: Compared with normal group, model rats body weight, IVGTT (120 min), plasm CORT were decreased significantly. Serum TG, TC, LDL-C and urine CORT after three weeks were increased significantly. Kaixin-San and Danggui- Shaoyao-San could regulate the above indexes. CONCLUSION: Kaixin-San and Danggui-Shaoyao-San may regulate the activity of HPA axis, and improve glucose and lipid metabolism disorder in model rats by increasing melatonin secretion.

Protective effect of apigenin on ischemia/reperfusion injury of the isolated rat heart.

Apigenin (Api), a mainly bioactive component of Apium graveolens L. var. dulce DC. (a traditional Chinese medicinal herb), possesses a wide range of biological activities, including antioxidant effects. It also has been shown to associate with lower prevalence of cardiovascular diseases, but its mechanisms of action remain unclear. The aim of the present study is to investigate the role of Api in isolated rat heart model of ischemia/reperfusion (I/R). Langendorff-perfused isolated rat hearts were used in our study. Api was added to the perfusate before ischemia and during reperfusion in the isolated pulsed rat heart exposed to 30-min ischemia followed by 50-min reperfusion. The treatment with Api conferred a cardioprotective effect, and the treated hearts demonstrated an improved ischemic cardiac functional recovery, a decreased myocardial infarct size, a reduced activities of creatine kinase isoenzyme and lactate dehydrogenase in the coronary flow, a reduced number of apoptotic cardiomyocytes, a reduced activity of caspase-3, up-regulation of the anti-apoptotic protein Bcl-2 and down-regulation of the pro-apoptotic protein Bax. In addition, Api inhibited the phosphorylation of p38 MAPKS during I/R. In conclusion, these observations provide preliminary evidence that Api can protect cardiomyocytes from I-/R-induced injury, at least partially, through the inhibition of p38 MAPKS signaling pathway.

[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.

[Isolation and identification of nine iridoid glycosides from Lamiophlomis rotata by HPLC combining PDA and MS].

OBJECTIVE: To establish a rapid chromatographic method to separate the iridoid glycosides from Lamioplomis rotata, and to identify the target compounds with PDA and MS. METHODS: Methanol-water gradient elution was used to separate and analyze the target compounds. The fluid fractions were gathered according to the chromatogram and dried with the nitrogen airflow. The mass fractions of the target compounds were determined with RP-HPLC and the structures were identified with PDA and MS. RESULTS: The purity of some compounds exceeded 90% and these 9 compounds were identified as iridoid glycosides, which were Phlorigidoside C (1), Schismoside (2), Sesamoside (3), Shanzhiside methylester (4), 6-O-Acetyl shanzhiside methylester (5), Phloyoside II (6), Penstemoside (7), Loganin (8) and 8-O-Acetyl shanzhiside methylester (9). CONCLUSION: The method is simple and practicable with high efficiency. It can be used to qualitative and quantitative analysis of the 9 iridoid glycosides in Lamiphlomis rotata and its preparations.

[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.

Ameliorating effect and potential mechanism of Rehmannia glutinosa oligosaccharides on the impaired glucose metabolism in chronic stress rats fed with high-fat diet.

The aim of this study was to determine whether the Rehmannia glutinosa oligosaccharides (ROS) ameliorate the impaired glucose metabolism and the potential mechanism in chronic stress rats fed with high-fat diet. The rats were fed by a high-fat diet and simultaneously stimulated by chronic stress over 5 weeks. Body weight, fasting plasma glucose, intraperitoneal glucose tolerance test (IPGTT), plasma lipids, gluconeogenesis test (GGT), glycogen content, and corticosterone, insulin and leptin levels were measured. The results showed that ROS administration (100, 200 mg/kg, i.g.) for 5 weeks exerted the effects of increasing the organ weights of thymus and spleen, lowering the fasting plasma glucose level, improving impaired glucose tolerance, increasing the contents of liver and muscle glycogen, decreasing the gluconeogenesis ability, plasma-free fatty acid's level, as well as plasma triglyceride and total cholesterol levels in chronic stress and high-fat fed rats, especially in the group of 200mg/kg; while the plasma corticosterone level was decreased, and plasma leptin level was increased. These results suggest that ROS exert an ameliorating effect of impaired glucose metabolism in chronic stress rats fed with high-fat diet, and the potential mechanism may be mediated through rebuilding the glucose homeostasis in the neuroendocrine immuno-modulation (NIM) network through multilinks and multitargets.

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.

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.

Anti-hypoxic activity at simulated high altitude was isolated in petroleum ether extract of Saussurea involucrata.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhodiola algida, Saussurea involucrata, and other herbs grown in Qinghai-Tibetan plateau have long been used to prevent and treat acute mountain sickness. AIM OF THE STUDY: To screen and identify the anti-hypoxic constituents in the herbs grown in Qinghai-Tibetan plateau of Northwestern China. MATERIALS AND METHODS: The anti-hypoxic activities of 20 selected plateau herbs were examined against two positive controls, Rhodiola algida and acetazolamide, using the normobaric hypoxia model of mice. The herb with the highest activity was successively extracted with 70% ethanol, petroleum ether, chloroform, ethyl acetate and n-butanol. The extract with the highest activity was identified by comparing the survival time of mice under normobaric hypoxia condition after being subjected to different extracts. The identified extract was further tested by simulating high altitudes through an acute decompression model and a chronic decompression model for mice. RESULTS: The herb found to have the highest anti-hypoxic activity was Saussurea involucrate (Kar. et Kir.) Sch.-Bip, and the most effective fraction was in the petroleum ether extract. Administration of petroleum ether extract of Saussurea involucrata (PESI) to mice at 50mg/kg significantly decreased the mortality of animals under acute decompression conditions. Changes in biochemical indicators for glycometabolism and energy metabolism, including adenosine triphosphate (ATP) content and adenosine triphosphatase (ATPase) activity in brain and cardiac muscle, lactic acid (LAC) and lactate dehydrogenase (LDH) in blood and cardiac muscles, blood sugar, and glycogen content in liver and skeletal muscle were reversed under chronic decompression conditions. CONCLUSIONS: Saussurea involucrata (Kar. et Kir.) Sch.-Bip exhibits high anti-hypoxic activity that may be effective in preventing acute mountain sickness, and the active constituents are mainly in the petroleum ether extract.

[Determination of five iridoid glycosides in Phlomis younghusbandii by HPLC].

OBJECTIVE: To develop an RP-HPLC method for the determination of five iridoid glycosides in Phlomis younghusbandii. METHOD: HPLC analysis was performed on a Symmetry C18 (4.6 mm x 150 mm, 5 microm, Waters) column eluted with acetonitrile (A) and water (B) in gradient elution. The gradient program was as follows: 0-5 min kept 7% A; 5-10 min changed to 12% A; 10-40 min kept 12% A. The flow rate was 1.0 mL x min(-1). The column temperature was 20 degrees and the detection wavelength was 235 nm. RESULT: The linear ranges of sesamoside, shanzhiside methyl ester, 7, 8-dehydropenstemoside, penstemoside and 8-O-acetylshanzhiside methyl ester were 0.050-0.650 (r = 0.999 3), 0.050-0.350 (r = 0.999 5), 0.040-0.280 (r = 0.999 4), 0.010-0.070 (r = 0.999 6), 0.040-0. 280 (r = 0.999 7) g x L(-1), respectively. The average recoveries (n = 6) of them were all between 96% and 104%, RSD < 5.0%. CONCLUSION: The method is simple, accurate, repeatable and stable, which can be used for quality control of P. younghusbandii.