Objective: : To explore the effect of PD-1 gene knockout by CRISPR/Cas9 system on the proliferation and IFN-γ secretion in human T cells. Methods: : The sequence of sgRNA targeting PD-1 was designed. The PD-1-sgRNA and Cas9 mRNA were synthesized by T7 RNApolymerase in vitro, and then the mixture of PD-1-sgRNAand Cas9 mRNAwas delivered into activated T cells by nucleofection. The efficiency of gene knockout was confirmed by sequencing. The phenotypes of T lymphocytes and the expression of PD-1 after gene knockout were analyzed by Flow cytometry. The proliferation of T lymphocytes was calculated by trypan blue counting. The level of IFN-γ secreted by T lymphocytes was detected by ELISA. Results： ：PD-1-sgRNA and Cas9 mRNA were successfully synthesized in vitro and delivered into T cells by nucleofection. Sequencing technology confirmed that the PD-1 gene sequence was edited and the editing efficiency was 58.3%. The expression of PD-1 on T lymphocyte surface was down-regulated successfully by CRISPR/Cas9 system [(9.6±1.85)% vs (16.2±2.05)%, P<0.05]. The knockout of PD-1 gene did not affect the proliferation and phenotype of T lymphocytes(P<0.05); However, compared with the control group, the level of IFN-γ secreted by T lymphocytes in the PD-1sgRNA group was significantly increased (P<0.01). Conclusion: : CRISPR/Cas9 system can successfully ablate PD-1 gene in human T lymphocytes, which could block the negative regulation of PD-1／PD-L1 and further promote the IFN-γ secretion in T cells.

Polygona-polysaccharose is an important indicator to measure the quality of Polygonati Rhizoma. The polygona-polysaccharose has the effect of lowering blood sugar, regulating blood lipid, anti-fatigue, improving learning and memory ability. The Polygonati Rhizoma, as a Chinese herbal medicine with homology of medicine and food, has a good prospect and application value in the development of food and health products.

Objective To establish a HPLC method for the simultaneous determination of artemisinin,arteannuin B,chrysosplenetin and chrysosplenol-D in the water extract of Artemisia annua L.Methods The analysis was performed on Agilent ZORBAX SB-C18(250 mm×4.6 mm,5 μm)column with a mobile phase of acetonitrile(A)-water(B)and the flow rate of 0.8 mL·min-1 in a gradient elution manner.The column temperature was 30℃.The injection volume was 10 μL,and the detection wavelength was 210 nm.Results Artemisinin,arteannuin B,chrysosplenetin and chrysosplenol-D were correlated well linearly with peak area in their respective ranges 1.608 8-16.088 μg(r=0.999 9),0.014 1-0.141 4 μg(r=1),0.185 1-1.850 9 μg(r=0.999 9),0.144 1-1.441 4 μg(r=0.999 9),the average recovery rate(n=6)were 102.44%,97.82%,95.07%,95.55%,and the RSD values were 1.12%,1.44%,1.29%,1.53%.Conclusion This method is convenient and accurate.It has good stability and repeatability,and can be used to simultaneously determine the content of artemisinin,arteannuin B,chrysosplenetin and chrysosplenol-D in the water extract of Artemisia annua L.

OBJECTI VE To optimize the extraction technology of the leaves of Dimocarpus longan according to flavonoids and phenolic acids. METHODS The contents of gallic acid ，protocatechuic acid ，ethyl gallate ，quercetin，luteolin and kaempferol in the leaves of D. longan were determined by HPLC. Based on single factor test ，with the ethanol volume fraction ，solid-liquid ratio and extraction time as factors ，using comprehensive scores of the contents of above six components as indexes ，the extraction technology of the leaves of D. longan was optimized by Box-Behnken response surface methodology. RESULTS The optimal extraction technology included ethanol volume fraction of 100％，solid-liquid ratio of l ∶ 7（g/mL），extraction time of 90 min， extraction temperature of 80 ℃. After 3 times of validation tests ，the average comprehensive score was 97.54（RSD＝0.33％，n＝ 3），relative error of which with predicted score （99.05）was 1.55％. CONCLUSIONS Box-Behnken response surface methodology combined with multi-index comprehensive score can be used for the extraction technology of the leaves of D. longan ，and the optimized extraction technology is stable and feasible.

OBJECTIVE：To estab lish the fingerprint ，analyze the monosaccharide composition and content ，investigate the inhibitory effects of the polysaccharide from Desmodium styracifolium on α-glucosidase in vitro . METHODS ：Polysaccharide from D. styracifolium was prepared by water extraction and ethanol precipitation. After hydrolyzed by TFA and derived by PMP ，HPLC method was adopted to establish the fingerprint （using glucose peak as reference ），and analyze the constituent and content of monosaccharide. The content determination was performed on Phenomenex Luna C 18 column with mobile phase consisted of acetonitrile-0.05 mol/L potassium phosphate （pH adjusted to 6.8 with sodium hydroxide ）in gradient elution at the flow rate of 0.8 mL/min. The detection wavelength was set at 250 nm，and column temperature was set at 30 ℃. The sample size was 10 μL. Using acarbose as control ，PNPG assay was used to investigate the α-glucosidase inhibitory activity of polysaccharide from D. styracifolium. RESULTS ：There were 9 common peaks in HPLC fingerprints of 18 batches of samples ，and the similarity of 15 batches of samples was higher than 0.90. Totally 7 peaks were identified as mannose ，rhamnose，galacturonic acid ，glucose， galactose，xylose and arabinose. The contents of rhamnose ，galacturonic acid ，glucose，galactose and arabinose were 0.471-2.092， 1.379-8.919，2.560-35.679，1.194-6.905，0.566-4.158 mg/g，respectively. Based on rhamnose ，the molar ratios of the other four monosaccharides were 1.58-4.07，2.26-19.95，2.20-4.21 and 1.31-2.86，respectively. The inhibitory activity of polysaccharide from D. styracifolium on α-glucosidase increased with the increase of dose ，and the half inhibitory concentrations of it was 0.70 mg/mL， lower than 7.76 mg/mL of acarbose （positive control ）. CONCLUSIONS ：Glucose is the main component of D. styracifolium polysaccharide in different batches ，and the contents of monosaccharides are different. The polysaccharide from D. styracifolium have significant inhibitory activity on α-glucosidase，which is better than that of acarbose.

Stroke is considered a leading cause of mortality and neurological disability, which puts a huge burden on individuals and the community. To date, effective therapy for stroke has been limited by its complex pathological mechanisms. Autophagy refers to an intracellular degrading process with the involvement of lysosomes. Autophagy plays a critical role in maintaining the homeostasis and survival of cells by eliminating damaged or non-essential cellular constituents. Increasing evidence support that autophagy protects neuronal cells from ischemic injury. However, under certain circumstances, autophagy activation induces cell death and aggravates ischemic brain injury. Diverse naturally derived compounds have been found to modulate autophagy and exert neuroprotection against stroke. In the present work, we have reviewed recent advances in naturally derived compounds that regulate autophagy and discussed their potential application in stroke treatment.