Optimization of Anthocyanin Production in Tobacco Cells.

Plant cell cultures have emerged as a promising tool for producing active molecules due to their numerous advantages over traditional agricultural methods. Flavonols, and anthocyanin pigments in particular, together with other phenolic compounds such as chlorogenic acid, are known for their beneficial health properties, mainly due to their antioxidant, antimicrobial, and anti-inflammatory activities. The synthesis of these molecules is finely regulated in plant cells and controlled at the transcriptional level by specific MYB and bHLH transcription factors that coordinate the transcription of structural biosynthetic genes. The co-expression of peach PpMYB10.1 and PpbHLH3 in tobacco was used to develop tobacco cell lines showing high expression of both the peach transgenes and the native flavonol structural genes. These cell lines were further selected for fast growth. High production levels of chlorogenic acid, anthocyanins (mainly cyanidin 3-rutinoside), and other phenolics were also achieved in pre-industrial scale-up trials. A single-column-based purification protocol was developed to produce a lyophile called ANT-CA, which was stable over time, showed beneficial effects on cell viability, and had antioxidant, anti-inflammatory, antibacterial, and wound-healing activities. This lyophile could be a valuable ingredient for food or cosmetic applications.

SiO(2) entrapment of animal cells: liver-specific metabolic activities in silicaoOverlaid hepatocytes.

Rat hepatocytes in a collagen-gel sandwich configuration were exposed to silicon alkoxides in a gas phase, yielding a 0.05 to 0.15 microm porous silica layer on the gel surface. Cell viability was unaffected by the procedure. After 24 h, bilirubin conjugation, ammonia removal, urea synthesis, and diazepam metabolism were unaffected by the procedure. However, both the ammonia removal rate and diazepam metabolism were increased after 48 hr, whereas urea synthesis was unaffected. These data indicate that silica overlay allows efficient metabolic activity of collagen-gel entrapped hepatocytes. The fact that the KM of bilirubin conjugation was unaffected by the presence of the silica membrane suggests that the transport of albumin-bound substrates is not decreased. The enhancement in some metabolic activities found 48 h after the entrapment procedure may be the result of favorable changes in the hepatocyte microenvironment. These characteristics might be useful for the development of organotypical bioartificial liver devices.