Unraveling the serial glycosylation in the biosynthesis of steroidal saponins in the medicinal plant Paris polyphylla and their antifungal action

Sugar-sugar glycosyltransferases play important roles in constructing complex and bioactive saponins. Here, we characterized a series of UDP-glycosyltransferases responsible for biosynthesizing the branched sugar chain of bioactive steroidal saponins from a widely known medicinal plant Paris polyphylla var. yunnanensis. Among them, a 2'-O-rhamnosyltransferase and three 6'-O-glucosyltrasferases catalyzed a cascade of glycosylation to produce steroidal diglycosides and triglycosides, respectively. These UDP-glycosyltransferases showed astonishing substrate promiscuity, resulting in the generation of a panel of 24 terpenoid glycosides including 15 previously undescribed compounds. A mutant library containing 44 variants was constructed based on the identification of critical residues by molecular docking simulations and protein model alignments, and a mutant UGT91AH1Y187A with increased catalytic efficiency was obtained. The steroidal saponins exhibited remarkable antifungal activity against four widespread strains of human pathogenic fungi attributed to ergosterol-dependent damage of fungal cell membranes, and 2'-O-rhamnosylation appeared to correlate with strong antifungal effects. The findings elucidated the biosynthetic machinery for their production of steroidal saponins and revealed their potential as new antifungal agents.

Antitumor effect and mechanism of total alkaloids of Gelsemium elegans and sempervirine in vitro / 中国药房

OBJECTIVE To explore the antitumor effect and mechanism of total alkaloids of Gelsemium elegans （TA） and sempervirine （SPV） in vitro. METHODS The effects of low， medium and high concentrations of TA （50， 100， 200 μg/mL） and SPV （10， 30， 50 μmol/L） on the morphology of human hepatoma cells （HepG2， Bel-7402）， human lung cancer cells （A549） and human colon cancer cells （HCT-8） were observed， and the toxicity of TA and SPV to four tumor cells was monitored. The effects of TA and SPV on the contents of caspase-3 and caspase-9 in the supernatant of HCT-8 cells， the protein expressions of phosphorylated protein kinase B （p-Akt） （Thr308， Ser473）， B-cell lymphoma 2 （Bcl-2）， Bcl-2-related X protein （Bax）， survivin， C/EBP-homologous protein （CHOP）， immunoglobulin binding protein （Bip） and microtubule-associated protein 1 light chain 3Ⅱ （LC3Ⅱ） in HCT-8 cells were detected. RESULTS After the intervention of TA and SPV， the volume reduction and nuclear shrinkage were founded in four tumor cells； the cell activity decreased to varying degrees， among which TA and SPV had the best inhibitory effect on HCT-8 cells. After the intervention of TA and SPV， the contents of caspase-3 and caspase-9 in the supernatant of HCT-8 cells， the protein expressions of Bax， CHOP， Bip and LC3Ⅱ all increased to different degrees， while the protein expressions of p-Akt （Thr308， Ser473）， Bcl-2 and survivin in HCT-8 cells all decreased to different degrees. CONCLUSIONS TA and SPV have inhibitory effects on the above four tumor cells， and the inhibitory effect on HCT-8 cells is the best. The mechanism of their action on HCT-8 cells may be related to promoting apoptosis， activating endoplasmic reticulum stress and autophagy.

Study on Inhibitory Effects of Total Alkaloids of Gelsemium elegans on the Proliferation and Angiogenesis of Human Colon Cancer Cells / 中国药房

OBJECTIVE：To investigate the inhibitory effects of total alkaloids of Gelsemium elegans （TAG） on the proliferation and angiogenesis of human colon cancer cells. METHODS ：Human colon cancer cell line HT- 29 and HUVEC were cultured in vitro . After the intervention of low- ，medium-，high-dose TAG （40，80，120 μg/mL），the morphology of the two cells was observed by fluorescence inversion microscope. The survival rate of HT- 29 cells and HUVEC was detected by CCK- 8 assay. Flow cytometry was used to detect HT- 29 cell cycle. The migration rate ，invasion rate and tube number of HUVEC were observed by scratching test ，Transwell invasion experiment and tube formation experiment. RESULTS ：Compared with blank group ，HT-29 cells and HUVEC were decreased to different extents in TAG groups ；dead cells were observed ，and the survival rate of both decreased significantly （P＜0.05 or P＜0.01）. The proportion of HT- 29 cells at G 2/M phase in TAG groups as well as those at G 0/G1 phase in medium-dose group were increased significantly ；the proportion of HT- 29 cells at S phase in TAG groups as well as those at G 0/G1 phase in high-dose group were decreased significantly （P＜0.05 or P＜0.01）. Survival rate ，migration rate and invasion rate of HUVEC were decreased significantly in TAG groups ，and tube number was also decreased significantly at each time point during 4-24 h（P＜0.01）. CONCLUSIONS ：TAG have inhibitory effect on the proliferation of human colon cancer HT- 29 cells and HUVEC，can change HT- 29 cell cycle ，inhibit the migration ，invasion and tube formation of HUVEC.

Thinking and Suggestion on Positioning of Clinical TCM Pharmacists and the Cultivation of Post Service Ability / 中国药房

OBJECTIVE:To promote the work of clinical TCM pharmacists.METHODS:The problems faced by clinical TCM pharmacists were analyzed in respects of status quo of training in colleges and universities,status quo of hospital post training and status quo of continuing education.From the ability of post service,the ways to determine the duty orientation and improve the training quality of clinical TCM pharmacists were discussed theoretically.RESULTS & CONCLUSIONS:According to the nature of different types of medical institutions as TCM hospital,western medicine hospital,township community hospital and clinics,the responsibilities of clinical TCM pharmacists should be differentiated.TCM curriculum system of colleges and universities should be improved by adding social pharmaceutical education and TCM practical teaching.Based on the ability of post service,great importance should be attached to professional training of clinical TCM tablets after their employment.The theory,practice and research ability of clinical TCM talents should be improved by strengthening continuing education.The medical and pharmaceutical clinical TCM inter-disciplinary talent can be cultivated by improving rational drug use standard system.

Study on dynamic of chemical components of rhizoma alismatis and Evodia rutaecarpa in their compatibility / 中国中药杂志

This article studied the changes of chemical components in decoctions that made from the single medicinal herb of Rhizoma Alismatis or Evodia rutaecarpa, the co-decoctions made from different compatibilities of the two medicinal herbs, and that mixed decotions of two single medicinal herb decotions, by HPLC. The changes of chemical components of the codicotions were focused on. The relationships between the changes of chemical components of the codicotions and defferent compatibility ratios of medicinal herb were summarized.

Purification of a New Antibacterial Protein from Housefly(Musca domestica)Larvae / 中国生物工程杂志

Insects exhibit a particular resistance to infections.The activation of the innate immune response of insects is involved in the recognition of the infectious nonself and subsequent activation of cellular and humoral reactions.In humoral reactions,insect antibacterial peptides and lysozyme are very important in resistance to infections.Housefly(Musca domestica) is one of the most important kinds of insects and it has strong ability to adapt to the adverse circumstances.It is of momentous theoretical and practical significance to research the immunity system of housefly.The methods of inducement of housefly larvae were firstly studied.Then an antibacterial protein,whose molecular weight is 28kDa,was purified from housefly larvae,induced by 30% H2O2,through saltout,Sephadex G25 column,Sephadex G75 column and CMSepharose Fast Flow column.This antibacterial peptide had activities against most of Gram positive and Gram negative bacteria.