Three new bioactive flavonoid glycosides from Viscum album.

Two new flavonoid glycosides, named viscumneoside XII (1), and viscumneoside XIII (2); a new dihydrogen flavonoid glycoside product named viscumneoside XIV (3), were isolated from the aerial part of Viscum album, along with seven known compounds (4-10). Their structures were identified by analysis of spectroscopic data. In addition, cytotoxicity assay showed that 1, 2 and 3 possessed significant inhibitory activities against C6, A549 and MDA-MB-231 (the inhibition rate arrived about 50%, 70% and 74% respectively with IC50 ≤ 60.00 µmol·L-1), while the inhibition of TF-1 and Hela was not significant.

Two symmetrical unsaturated acids isolated from Viscum album.

In the present study, two new acetylene conjugate compounds, dibutyl (2Z, 6Z)-octa-2, 6-dien-4-yne dioate (1), and dibutyl (2E, 6E)- octa-2, 6-dien-4-yne dioate (2), were isolated from the dry stem leaves of Viscum album, along with nine known compounds (3 - 11). Their structures were confirmed on the basis of spectroscopic data. Compounds 1 and 8 showed antioxidant activity against xanthine oxidase (XOD) and 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydroxyl (DPPH), with the IC50 of 1.22 and 1.33 µmol·L-1, and the SC50 of 4.34 and 8.22 µmol·L-1, respectively.

Recent advances and safety issues of transgenic plant-derived vaccines.

Transgenic plant-derived vaccines comprise a new type of bioreactor that combines plant genetic engineering technology with an organism's immunological response. This combination can be considered as a bioreactor that is produced by introducing foreign genes into plants that elicit special immunogenicity when introduced into animals or human beings. In comparison with traditional vaccines, plant vaccines have some significant advantages, such as low cost, greater safety, and greater effectiveness. In a number of recent studies, antigen-specific proteins have been successfully expressed in various plant tissues and have even been tested in animals and human beings. Therefore, edible vaccines of transgenic plants have a bright future. This review begins with a discussion of the immune mechanism and expression systems for transgenic plant vaccines. Then, current advances in different transgenic plant vaccines will be analyzed, including vaccines against pathogenic viruses, bacteria, and eukaryotic parasites. In view of the low expression levels for antigens in plants, high-level expression strategies of foreign protein in transgenic plants are recommended. Finally, the existing safety problems in transgenic plant vaccines were put forward will be discussed along with a number of appropriate solutions that will hopefully lead to future clinical application of edible plant vaccines.