Authors:Gao-Feng Shi, Guo-Ying Wang, and Xue-Fu Chen
To detect and identify natural antioxidants in Swertia chirayita with protective effect against cerebral infarction, a screening method, using column chromatography and cerebral ischemia-reperfusion injury in rat, was developed. Seventeen compounds were purposefully separated and identified by Nuclear Magnetic Resonance, Fourier Transform Infrared Spectroscopy, Ultraviolet Spectrum, and Mass Spectrometry. The purified compounds were further screened by radical scavenging activity and cerebral ischemia-reperfusion injury in rats. Two compounds showed apparent radical scavenging activity and neuroprotective activity. The two compounds were identified as 1-hydroxy-2,3,4,6-tetramethoxyxanthone and 1,5,8-trihydroxy-3-methoxy xanthone, and were preliminarily considered as primary natural neuroprotective antioxidants in Swertia chirayita. These two compounds (20 mg kg−1) markedly decreased infarct size to below 5%, and also caused a significant improvement of activities of superoxide dismutase (SOD) (92.90 ± 11.19 U ml−1), glutathione peroxidase (GSH-Px) (122.58 ± 12.31 μmol mg−1) and a decrease in the content of malondialdehyde (MDA) (3.98 ± 2.00 nmol ml−1) in serum. The two compounds showed strong capability for protective effects against cerebral damages induced by ischemia-reperfusion, and the protective effect may be related to the inhibition of lipid peroxidation. The use of the screening method based on tracing separation and ischemia reperfusion would provide a new way for detection of radical-scavenging and natural neuroprotective compounds from Swertia chirayita or complex matrices.
Authors:Y. Zhang, W. Zheng, Q.C. Ying, L.-E. Shi, Z.-L. Zhang, M.-Z. Shi, and Z.-X. Tang
The sub-acute toxicity of E. faecalis HZNU P2 was investigated in rats fed with different doses for 14 days. To evaluate the acute oral toxicity of E. faecalis HZNU P2, rats were fed with E. faecalis HZNU P2 at a high dose of 2×1011 CFU kg−1 for 10 days. Results showed that there were no abnormal clinical signs in any of the groups during the experiment. There were no significant differences in live weight gain among rats fed with E. faecalis HZNU P2, compared to those in control group. Macroscopic or microscopic examinations of organs revealed no abnormalities, indicating that E. faecalis HZNU P2 did not adversely affect the health of rats. Results of this study demonstrated that digestion of E. faecalis HZNU P2 in rats did not show any obvious signs of toxicity.