[LC-MS/MS method for determination of tripterine in plasma： pharmacokinetic study in Beagles].

To establish a LC-MS/MS method for determination of tripterine in Beagle plasma and study its pharmacokinetics after oral administration of tripterygium tablet. Plasma samples were extracted with dichloromethane and separated on a Phenomenex Luna C8 (2.0 mm×50 mm, 3 µm) column with methanol-acetonitrile isopropanol(1∶1)-1‰formic acid (15∶55 ∶30) as the mobile phase. Tripterine ([M+H] ⁺, m/z 451.3/201.1) and internal standard prednisolone ([M+H] ⁺, m/z 361.1/147.1) were monitored in multiple reaction monitoring (MRM). The concentration-time curves were simulated by drug and statistic software 1.0 and the pharmacokinetic parameters were calculated. There was a good linear relationship between peak area ratio and concentration of tripterine and internal standard prednisolone within range of 0.680 0-136.0 µg•L⁻¹. The limit of quantitation was 0.680 0 µg•L⁻¹ and the intra- and inter-day precision was within 6.15%. The absolute recovery rate was between 50.42% to 51.65%. The concentration-time curves were consistent with the one-compartment model(w=1/cc). The main pharmacokinetic parameters after a single dose were as follows： Cmax (35.64±9.540) µg •L⁻¹,Tmax(2.62±0.69) h,T1/2(2.93±0.29) h, CL (0.308±0.056) L•kg⁻¹â€¢h⁻¹, AUC0-12 (131.16±31.94) µg•L•h⁻¹, AUC0-∞ (142.83±37.57) µg•L•h⁻¹. The established LC-MS/MS method was proved to be sensitive, accurate and convenient, suitable for the pharmacokinetic study of Tripterygium tablet in Beagle dogs.

Systematic chemical profiling of Citrus grandis 'Tomentosa' by ultra-fast liquid chromatography/diode-array detector/quadrupole time-of-flight tandem mass spectrometry.

Citrus grandis 'Tomentosa', as the original plant of the traditional Chinese medicine "Huajuhong", has been used as antitussive and expectorant in clinic for thousands of years. The fruit epicarp and whole fruit of this plant were both literarily recorded and commonly used. In the present study, an ultra-fast liquid chromatography coupled with diode-array detection and quadrupole/time-of-flight mass spectrometry (UFLC-DAD-Q-TOF-MS/MS) based chemical profiling method was developed for rapid holistic quality evaluation of C. grandis 'Tomentosa', which laid basis for chemical comparison of two medicinal parts. As a result, forty-eight constituents, mainly belonging to flavonoids and coumarins, were unambiguously identified by comparison with reference standards and/or tentatively characterized by elucidating UV spectra, quasi-molecular ions and fragment ions referring to information available in literature. Both of the epicarp and whole fruit samples were rich in flavonoids and coumarins, but major flavonoids contents in whole fruit were significantly higher than in epicarp (P<0.5). The proposed method could be useful in quality control and standardization of C. grandis 'Tomentosa' raw materials and its products. Results obtained in this study will provide a basis for quality assessment and further study in vivo.

Electroacupuncture pretreatment prevents cognitive impairment induced by limb ischemia-reperfusion via inhibition of microglial activation and attenuation of oxidative stress in rats.

Limb ischemia-reperfusion (LI/R) is associated with high morbidity and mortality. Furthermore, critical trauma survivors can present cognitive impairment. Cognitive function, survival rate, oxidative stress and neuronal health were examined to elucidate (1) the magnitude of cognitive effects of prolonged reperfusion, (2) potential players in the mechanistic pathway mediating such effects, and (3) possible benefits of electroacupuncture (EA) pretreatment at Baihui (GV20), Yanglingquan (GB34), Taichong (LR3), Zusanli (ST36) and Xuehai (SP10) acupoints. LI/R was induced in rats by placing a rubber tourniquet on each hind limb for 3h, and the animals were evaluated periodically for 7d after LI/R. Rats subjected to LI/R had significantly lower survival rates, and displayed evidence of brain injury and cognitive dysfunction (as determined by the Morris water maze test) 1d and 3d after reperfusion compared to sham-operated controls. LI/R also resulted in higher levels of reactive oxygen species (ROS) and malondialdehyde (MDA), microglial activation, and decreased superoxide dismutase (SOD) activity within Cornu Ammonis area 1 (CA1) of the hippocampus. Depressed survival rates, microglial activation, oxidative damage, and histological changes, as well as cognitive dysfunction were partially or fully attenuated in rats that received 14d of EA prior to LI/R. These findings indicate that LI/R can result in cognitive dysfunction related to activated microglia and elevated oxidative stress, and that EA has neuroprotective potential mediated, at least in part, by inhibition of microglial activation and attenuation of oxidative stress.