OBJECTIVETo explore the effects of hyperbaric oxygen preconditioning (HBOP) on human stress responses during acute exposure to high altitude and the possible mechanism.

METHODSEight male subjects were treated with HBOP for 3, 5, and 7 days, followed by acute exposure to hypoxia simulating an altitude of 4,000 m. Subjects at rest were divided into sea-level control group, simulated high-altitude group, and 5-day HBOP intervention group, while subjects after physical load were divided into sea-level control group, simulated high-altitude group, 3-day HBOP intervention group, and 7-day HBOP intervention group. The physical load test was performed for each subject before and after HBOP, and the plasma levels of dopamine (DA), epinephrine (E), norepinephrine (NE), and adrenocorticotropic hormone (ACTH) were determined before and after exercise. The physical load test was performed by stepping up on to a 30 cm-high stepping stool at a rate of 25/min for 5 minutes, which was a type of moderate physical exercise. The stepping rate and timing were controlled by a metronome.

RESULTSThe levels of DA, E, NE, and ACTH at rest and after physical load were significantly higher in subjects acutely exposed to high altitude than in the sea-level control groups (all P<0.05). Moreover, the levels of DA, E, NE, and ACTH at rest were significantly higher after acute exposure to high altitude in the 5-day HBOP intervention group than in the simulated high-altitude group (all P<0.01). Except for the ACTH level in the 3-day HBOP intervention group, the levels of DA, E, NE, and ACTH after physical load were significantly higher after acute exposure to high altitude in the 3-day and 7-day HBOP intervention groups than in the simulated high-altitude group (all P<0.01).

CONCLUSIONHBOP can elevate the plasma expression of DA, E, NE, and ACTH, and then speed up the establishment of a new balance of homeostasis to adapt to the acute hypoxia at high altitude.

Adrenocorticotropic Hormone ; blood ; Altitude ; Dopamine ; blood ; Epinephrine ; blood ; Exercise ; Homeostasis ; Humans ; Hyperbaric Oxygenation ; Hypoxia ; blood ; Male ; Norepinephrine ; blood ; Rest ; Stress, Physiological

Objective To investigate the effects of hyperbaric oxygen preconditioning (HBOP) on the serum levels of interleukin-6 (IL-6) and matrix metalloproteinase-9 (MMP-9) during physical load at acute hypoxia,and possible mechanism involved.Methods Eight healthy male volunteers ere enrolled in the study.Serum levels of IL-6 and MMP-9 were detected by ELISA under the following conditions:at sea level and during acute exposure to 4 000 m high altitude ; as well as during acute exposure to 4 000 m high altitude both at rest and with physical load,following 3-day,5-day and 7-day HBOP respectively.Results Serum levels of IL-6 and MMP-9 at 4 000 m high altitude and after physical exercise were greatly increased [(29.56 ± 1.26) ng/L、(285.25 ± 11.67)] mg/L],as compared with the control value at the sea level (27.74 ± 1.06)] ng/L、(269.88 ± 9.90) mg/L] (P ＜ 0.01 or P ＜ 0.05).After 5-day HBOP,serum levels of IL-6 and MMP-9 at rest and during acute hypoxia were greatly decreased [(23.26 ± 1.25) ng/L、(230.28 ± 11.96) ng/L],as compared with the control value at 4 000 m[(28.96 ± 1.38)ng/L、(281.50 ± 12.32) ng/L] (P ＜ 0.01).After 3-day and 7-day HBOP,serum levels of IL-6 and MMP-9 at acute hypoxia were greatly decreased after physical load,as compared with the control value at 4 000 m(P ＜0.01).Furthermore,serum levels of IL-6 and MMP-9 after 7-day HBOP were significantly lower than those after 3-day HBOP(P ＜ 0.01).Conclusions Serum levels of IL-6 and MMP-9 could be significantly increased after acute exposure to high altitude.HBOP could not only obviously decrease serum levels of IL-6 and MMP-9 at acute hypoxia,both at rest and after physical exercise,but effectively prevent functional disorder and tissue lesion induced by acute hypoxia,thus promoting physical performance at acute hypoxia.Furthermore,7-day HBOP could produce more significant effects.

Objective To investigate the effects of hyperbaric oxygen preconditioning ( HBOP ) on human energy metabolism and antioxidant under acute hypoxia exposure , so as to provide new measures for the improvement of physical performance in those with acute hypoxia .Methods Eight healthy subjects had respectively 3-day, 5-day and 7-day HBOP, then, they underwent acute exposure to a simulated high altitude of 4 000 m.Exercise load experiments were conducted both before and after HBOP .Levels of glucose ( Glu), blood lactate ( BLA) , lactate dehydrogenase ( LDH) and superoxide dismutase ( SOD) were detected both before and after physical exercises .Results Following HBOP , no significant changes could be noticed in Glu level in the subjects , who underwent simulated 4 000 m physical exercise and its level remained relatively high during exposure(P>0.05).During exposure to hypoxia at an altitude of 4 000 m, BLA level both at rest and under physical exercise[(3.3 ±0.8)、(6.7 ±2.0) mmol/L] elevated signficantly, as compared with that at the sea level[(2.4 ±0.7)mmol/L], and statistical differences could be noted , when comparisons were made between them(P<0.05 or P<0.01).Following 7-day HBOP, the BLA levels after physical load [(4.5 ±1.3)mmol/L] were significantly decreased , as compared with those detected at 4 000 m, and at the same time, LDH activity was obviously elevated, with statistical significance(P<0.05).As compared with that of the control value at 4 000 m[(6.7 ±2.0) mmol/L], LDH levels after 3-day and 7-day HBOP were increased to some extent, which were equivalent to the control value at the sea level .After HBOP, GSH levels both at rest and under physical exercise were almost the same as that of the sea level , without statistical signficance (P<0.05). And no statistical significace could be seen in the changes of nergy metabolism , when comparisons were made between them (P <0.05).Conclusions Before acute hypoxia exposure, 3-day HBOP would enable the human body under physical load to maintain Glu at a relatively high level , increase LDH activity and help to decrease BLA level signfificantly , and at the same time , help to maintain the level of antioxidant at the sea level.For this reason, HBOP seemed to have positive effects on anti-oxidation, anti-fatigue and enhancement of physical performance under acute hypoxia .

Objective To investigate the effects of hyperbaric oxygen preconditioning (HBOP) on the serum levels of interleukin-6 (IL-6) and matrix metalloproteinase-9 (MMP-9) during physical load at acute hypoxia,and possible mechanism involved.Methods Eight healthy male volunteers ere enrolled in the study.Serum levels of IL-6 and MMP-9 were detected by ELISA under the following conditions:at sea level and during acute exposure to 4 000 m high altitude ; as well as during acute exposure to 4 000 m high altitude both at rest and with physical load,following 3-day,5-day and 7-day HBOP respectively.Results Serum levels of IL-6 and MMP-9 at 4 000 m high altitude and after physical exercise were greatly increased [(29.56 ± 1.26) ng/L、(285.25 ± 11.67)] mg/L],as compared with the control value at the sea level (27.74 ± 1.06)] ng/L、(269.88 ± 9.90) mg/L] (P ＜ 0.01 or P ＜ 0.05).After 5-day HBOP,serum levels of IL-6 and MMP-9 at rest and during acute hypoxia were greatly decreased [(23.26 ± 1.25) ng/L、(230.28 ± 11.96) ng/L],as compared with the control value at 4 000 m[(28.96 ± 1.38)ng/L、(281.50 ± 12.32) ng/L] (P ＜ 0.01).After 3-day and 7-day HBOP,serum levels of IL-6 and MMP-9 at acute hypoxia were greatly decreased after physical load,as compared with the control value at 4 000 m(P ＜0.01).Furthermore,serum levels of IL-6 and MMP-9 after 7-day HBOP were significantly lower than those after 3-day HBOP(P ＜ 0.01).Conclusions Serum levels of IL-6 and MMP-9 could be significantly increased after acute exposure to high altitude.HBOP could not only obviously decrease serum levels of IL-6 and MMP-9 at acute hypoxia,both at rest and after physical exercise,but effectively prevent functional disorder and tissue lesion induced by acute hypoxia,thus promoting physical performance at acute hypoxia.Furthermore,7-day HBOP could produce more significant effects.

Objective To investigate the effects of hyperbaric oxygen preconditioning ( HBOP ) on human energy metabolism and antioxidant under acute hypoxia exposure , so as to provide new measures for the improvement of physical performance in those with acute hypoxia .Methods Eight healthy subjects had respectively 3-day, 5-day and 7-day HBOP, then, they underwent acute exposure to a simulated high altitude of 4 000 m.Exercise load experiments were conducted both before and after HBOP .Levels of glucose ( Glu), blood lactate ( BLA) , lactate dehydrogenase ( LDH) and superoxide dismutase ( SOD) were detected both before and after physical exercises .Results Following HBOP , no significant changes could be noticed in Glu level in the subjects , who underwent simulated 4 000 m physical exercise and its level remained relatively high during exposure(P>0.05).During exposure to hypoxia at an altitude of 4 000 m, BLA level both at rest and under physical exercise[(3.3 ±0.8)、(6.7 ±2.0) mmol/L] elevated signficantly, as compared with that at the sea level[(2.4 ±0.7)mmol/L], and statistical differences could be noted , when comparisons were made between them(P<0.05 or P<0.01).Following 7-day HBOP, the BLA levels after physical load [(4.5 ±1.3)mmol/L] were significantly decreased , as compared with those detected at 4 000 m, and at the same time, LDH activity was obviously elevated, with statistical significance(P<0.05).As compared with that of the control value at 4 000 m[(6.7 ±2.0) mmol/L], LDH levels after 3-day and 7-day HBOP were increased to some extent, which were equivalent to the control value at the sea level .After HBOP, GSH levels both at rest and under physical exercise were almost the same as that of the sea level , without statistical signficance (P<0.05). And no statistical significace could be seen in the changes of nergy metabolism , when comparisons were made between them (P <0.05).Conclusions Before acute hypoxia exposure, 3-day HBOP would enable the human body under physical load to maintain Glu at a relatively high level , increase LDH activity and help to decrease BLA level signfificantly , and at the same time , help to maintain the level of antioxidant at the sea level.For this reason, HBOP seemed to have positive effects on anti-oxidation, anti-fatigue and enhancement of physical performance under acute hypoxia .

OBJECTIVETo study the chemical constituents and bioactivity of Teurium pilosum.

METHODVarious column chromatographic techniques were used to isolate the constituents. A combination of EI-MS, NMR spectroscopy and X-Ray were applied to identify the structures. The anti-microorganism was accomplished by disk diffusion method, the antioxidant activity was assayed by the DPPH microanalysis models and the inhibitory activity of alpha-glucosidase was screened In vitro.

RESULTEight compounds were isolated and identified as: glyceryl tristearate (1), 2,5-dioxolanone (2), fernenol (3), stigmasta-5,22-dien-3P-ol (4), 24-nor cholesta-5,22 (E)-dien-3beta-ol (5), ca-spinasterol (6), (3,4-dihydroxyphenyl) acrylate (7), 3,4-dihydroxy phenyl acrylic acid (8).

CONCLUSIONAll compounds have been isolated from the genus for the first time. Compound 3 [IC50 = (37.63 +/- 3.45) mg +/- L(-1)], 6 [IC50 = (178.92 +/- 4.99) mg x L(-1)] and 8 [IC50 = (44.32 +/- 7.02) mg x L(-1)] are of higher inhibitory alpha-glucosidase activity than that of acarbose [IC50 = (1081.27 +/- 12.3) mg x L(-1)]. Compound7 [IC50 = (4.81 +/- 0.96) mg x L(-1)] and 8 [IC50 = (4.16 +/- 0.11) mg L(-1)] showed higher antioxidant activity than that of BHT [IC50 = (35.64 +/- 0.36) mg x L(-1)] and BHA [IC50 = (8.74 +/- 0.39) mg x L(-1)]. Compound 5-8 exhibited inhibitory activity against Fusarium graminearum. Compound 5 and 8 showed inhibitory activity against Botrytis cinerea.

Antifungal Agents ; chemistry ; isolation & purification ; Antioxidants ; chemistry ; Enzyme Inhibitors ; chemistry ; isolation & purification ; Fusarium ; drug effects ; Glycoside Hydrolase Inhibitors ; Plant Extracts ; chemistry ; isolation & purification ; Teucrium ; chemistry ; alpha-Glucosidases ; analysis