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Objective: This study was designed to investigate the effects of low concentration hydrogen inhalation on asthma and sleep function in mice and the potential mechanism., Methods: In the asthma experiment, BALB/c mice were randomly divided into normal control group, asthma model group and hydrogen treatment group. After establishing ovalbumin (OVA)-induced asthma model, the hydrogen treatment group mice were treated by inhalation of hydrogen (24-26 mL/L per day) for 7 consecutive days, and the normal control group and asthma model group mice received similar treatment by inhalation of air. The levels of interleukin (IL)-4, IL-13, and interferon-γ (IFN-γ) in bronchoalveolar lavage fluid (BALF) were measured by commercially available ELISA kits. The levels of malondialdehyde (MDA) and glutathione (GSH), as well as the activity of superoxide dismutase (SOD) in lung tissue were detected by colorimetric assays. The pathological changes in lung tissue were assessed by HE staining. In the sleep experiment, ICR mice were randomly divided into blank control group and 1 d, 3 d, 5 d hydrogen treatment groups and diazepam group. The effects of inhalation of 24-26 mL/L per day hydrogen on the sleep duration induced by intraperitoneal injection of upper-threshold dose of sodium pentobarbital and the sleep latency in response to subthreshold dose were evaluated., Results: In the asthma experiment, the asthma model group showed higher levels of IL-4 and IL-13 ( P <0.05) and lower levels of IFN-γ ( P <0.001) in BALF, as compared to the normal control group. The content of MDA in lung tissue was also significantly increased ( P <0.01), companied by a decreased GSH concentration ( P <0.05) and a mildly reduced SOD activity ( P >0.05). Compared to the asthma model group, treatment with hydrogen significantly decreased the levels of IL-4 and IL-13 and increased the level of IFN-γ in BALF ( P <0.05). Moreover, without alteration of the MDA production ( P >0.05), hydrogen inhalation greatly increased GSH level and restored the SOD activity ( P <0.05) in lung tissue. Additionally, the HE staining data showed that the hydrogen treatment attenuated the pulmonary histopathological changes. In the sleep experiment, compared with the blank control group, the sleep latency was significantly shorter ( P <0.05) and the sleep duration was longer ( P <0.001) in all the hydrogen treatment groups after receiving an upper-threshold dose of sodium pentobarbital. Meanwhile, in all the hydrogen treatment groups, the sleep latency was significantly longer ( P <0.001) and the sleep duration was shorter ( P <0.001) when compared to the diazepam group. Compared with the blank control group, after intraperitoneal injection of a subthreshold dose of sodium pentobarbital, the sleep latency was significantly increased in both 1 d and 5 d hydrogen treatment groups, and there was no significant difference as compared to the diazepam group. In the 3 d hydrogen treatment group, the sleep latency was only slightly increased ( P >0.05), which was significantly lower than that of the diazepam group ( P <0.05)., Conclusion: Low concentration hydrogen inhalation could alleviate OVA-induced asthma in mice, and the mechanism might be related to the anti-oxidative and anti-inflammatory effects of hydrogen. Also, low concentration hydrogen inhalation could improve sleep function in mice., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Science Edition).)

Objective: To investigate the effect of ligustilide (LIG) on low potassium-induced apoptosis in primary cultured cerebellar granule neurons (CGN)., Methods: Apoptosis was induced by low potassium in cultured neonatal rat CGN in vitro. The CGN was divided into control/model/CGP54626 + LIG and LIG group. The neuronal viability of each group was measured by MTT assay. The protein expression levels of the key insulin-like growth factor 1 (IGF)-1 signaling effectors,including the phosphorylated IGF-1 receptor (IGF-1R), Akt, ERK1/2, CREB and activated caspase 3 were examined by Western blot analysis., Results: LIG ranging from 2.5 to 20 micromol/L could protect against low potassium-induced apoptosis of CGN ini a concentration-dependent manner. 20 micromol/L LIG significantly induced upregulation of the phosphorylated levels of IGF-1, Akt, ERK1/2 and CREB, and downregulation of cleaved-caspase 3 expression, which could be blocked by a selective gamma-aminobutyric acid B (GABAs) receptor antagonist CGP54626., Conclusion: LIG concentration-dependently protects against low potassium-induced apoptosis in CGN at least partly through GABAa receptor activation and its downstream IGF-1 signaling pathway.

Objective: To investigate the effects of Z-ligustilide (LIG) on Abeta25-35-induced cytotoxicity in human neuroblastoma SH-SY5Y cells., Methods: Cells were incubated with 0.1, 1.0, 2.5, 5.0 microg/mL LIG and then were exposed to 50 micromol/L Abeta25-35 to induce cytotoxicity in SH-SY5Y cell to establish the AD model in vitro. Cell viability was test by MTT method. Pro- and anti-apoptosis protein levels were investigated by Western blot., Results: After exposure to Abeta25-35, the cell viability decreased significantly, and the expression of pro-apoptosis protein--Bax, cleaved caspase 3, cytochrome C, caspase 8 was up regulated while the anti-apoptosis protein Bcl-2 was down regulated. However, the treatment of LIG (0.1, 1.0, 2.5, 5.0 microg/mL) significantly restored these changes., Conclusion: LIG has the protective effect against cytotoxicity induced by in SH-SY5Y cells via inhibit the apoptosis induced by Abeta25-35.

Objective: To study the metabolism of Z-ligustilide(Z-LIG) in vivo and in vitro in rats and the pharmacological activities of Z-LIG and metabolites in vitro., Methods: The biotransformation of Z-LIG in rats in vivo was tested. Z-LIG was also incubated with rat liver microsomes in vitro. The incubated product was extracted, separated and identified with high performance liquid chromatography (HPLC), high resolution mass spectrometry, nuclear magnetic resonance spectrum and UV. The effects of Z-LIG and its main metabolites on hydrogen peroxide (H1O2)-induced injuries were examined in cultured PC12 cells., Results: The HPLC analysis of the metabolites of Z-LIG was obtained. Senkyunolide I (SYL) isolated from in vitro incubation was identified as the main metabolite of Z-LIG. Both Z-LIG and SYL showed significant and concentration-dependent protection against H2O2-induced injuries in PC12 cells., Conclusion: SYL is the main metabolite of Z-LIG in rats. Z-LIG and SYL exert similar protective effects against oxidative damage in cultured PC12 cells.

Objective: To test the effects of combined use of dofetilide and verapamil on the action potential of papillary muscles in guinea pigs., Methods: Under the stimulation of different frequencies (0.2, 0.5, 1.0, 1.25 or 2.0 Hz), the action potential of papillary muscles in guinea pigs was recorded with the standard microelectrode techniques. The impacts of different concentrations of amiodarone (1, 5 or 10 micromol/L), dofetilide (10, 50, 100 nmol/L), and a combination of 100 nmol/L dofetilide and 1 micromol/L verapamil on the action potential were tested., Results: Amiodarone prolonged the action potential duration (APD) significantly, measured both at 50% (APD50) and 90% (APD90) of repolarization, in a concentration-dependent manner independent from stimulation frequencies. Dofetilide prolonged APD in a concentration-dependent manner, which was negatively dependent on stimulation frequencies. The frequency-dependent effect was ameliorated by adding 1 micromol/L verapamil to dofetilide., Conclusion: Both amiodarone and dofetilide prolong APD in a concentration-dependent manner. The class III antiarrhythmic compounds, amiodarone, has less frequency-dependent effect than the pure class III antiarrhythmic drug. A combined use of potassium and calcium antagonists may reduce the frequency-dependence of the pure class III antiarrhythmic drug.

Objective: To investigate the effect of low molecular weight potassium alginate (L-PA) on blood pressures in spontaneously hypertensive rats (SHRs) and its pharmacokinetics characteristics in mice., Methods: The systolic blood pressure (SBP) was measured by tail-cuff method in conscious SHRs. Forty rats were randomly assigned to the following five groups: control, hydrochlorothiazide (HCT, 6.25 mg/kg), L-PA in low, middle or high dose groups (100, 250, 500 mg/kg). SHRs were intragastrically (i. g.) administrated once daily for 28 days. The SBP was measured once weekly during drug treatment, and 3 and 6 days after drug with drawal. KM mice were i. g. administered with 100 mg/kg (74 MBq/kg) of 3H-L-PA. Ten microl blood samples were obtained from the tail vein at 2, 5, 10, 20, 30 min and 1, 2, 4, 6, 12, 24, 48, 72, 96, 120 or 144 h after drug administration for measuring radioactivities. Pharmacokinetics parameters of the oral administration of L-PA were analysed with DAS 2.0 software., Results: Twenty-one or 28 days after administration, the rats in the groups treated with HCT or L-PA at 100, 250 or 500 mg/kg had a significant decrease in SBP (P<0.01 vs control group). Three or 6 days after drug withdrawal, the antihypertensive effect of HCT disappeared (P>0.05), whereas the rats treated with 250 or 500 mg/kg L-PA still had lower SBP than the controls (P<0.01). The L-PA at a dose of 100 mg/kg also led to a significant decrease in SBP 3 days after drug withdrawal (P<0.05). The pharmacokinetics of L-PA (i. g.) was consistent with a two-compartment model, with 2.76 h of absorption half-life (t1/2, Ka), 42. 30 h of distributional half-life (t1/2alpha), 42. 31 h of elimination half-life (t1/2beta), and 36.28 h of terminal phase elimination half-life (t1/2z)., Conclusion: Oral administration of L-PA has significant anti-hypertensive effect, which can be maintained to 6 days after drug withdrawal. The sustaining anti-hypertensive effect of L-PA is probably associated with its slow elimination in vivo.