## 4 Plant Tissue and Organ Cultures in Bioreactors
### Temporary Immersion System
Other disadvantages include the possibility of occasional intensive foaming, the presence of shear forces in some types of reactors, or the provision of uniform culture conditions throughout the volume without unduly limiting the viability of the plant cells. Fortunately,the vast majority of these limitations can be overcome with an optimal bioreactor design and appropriate adjustment of the key parameters of the culture system [78]. Table 1 presents the selected examples of secondary metabolites obtained from transgenic plants that were cultured in bioreactors; including caffeic acid (CA) and chlorogenic acid (CHA) from _Leonurus sibiricus_; vincamine from _Vinca minor_; protopanaxadiol (PPD)-type ginseng from _Nicotiana tabacum_ (_N. tabacum_); geraniol from _N. tabacum_; swertiamarin, gentiopicroside, and sweroside from _Centaurium martiimum_; \(\beta\)-elemene from _Curcumae zedoariae_; and betulinic acid from _Senna obtusifolia_. The details about the vectors or genetic construct elements as well as the culture's conditions in bioreactors are also included. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Plant** & **Type of** & **Vector/Genetic** & **Type of** & **Bioeractor** & **Medium** & **Effect/Field** & **Ref. ** \\
**Species/Family** & **Culture** & **Culture** & **Culture** & **Culture** & **Culture** & **Culture** & **Culture** \\ \hline \multirow{4}{*}{ \begin{tabular}{c} _Nicotiana tabacum_ \\ L./Solanaceae \\ \end{tabular}  } & \multirow{4}{*}{ \begin{tabular}{c} suspension \\ culture \\ \end{tabular}  } & \multirow{4}{*}{ \begin{tabular}{c} _Pmax ginseng_ \\ fundamentalo-II \\ \end{tabular}  } & \multirow{4}{*}{ \begin{tabular}{c} triterpen \\ syngnues (PGD) and \\ Cytochrome \end{tabular}  } & \multirow{4}{*}{\ \begin{tabular}{c} supremation \\ (PPD), \\ \end{tabular}  } & \multirow{4}{*}{ \begin{tabular}{c} 5 L balloon-type \\ bioreactor 2 L of \\ Mongolia (MS) \\ medium \\ medium \\ medium \\ volume)} \\ \end{tabular}  & & & & & & \\  & & & & & & & \\  & & & & & & \\  & & & & & & &  
The presented examples showed that plant systems are good models for the production of secondary metabolites. According to Table 1, various classes of secondary metabolites are produced by transgenic plants cultured in bioreactors. The exploring of their biological activity show that all of them exert anti-cancer properties. PPD is a triterpenenoid saponin that belonged to ginsenosides, the major active component of ginseng. This compound could affect cell cycle distribution and pro-apoptotic signaling. Therefore, it is proposed that this compound might be a potent addition to the current chemotherapeutic strategy against cancer [135]. CA and CHA belong to the phenolic compounds. They possess a vulnerable activity for neutralizing reactive oxide species. Oxidative stress may activate a number of transcription factors, which lead to the differential expression of some of the genes involved in inflammatory pathways. Therefore, polyphenols have been proposed to be useful as an adjuvant therapy for their anti-inflammatory effects and may be helpful for the development of future antioxidant therapeutics and new anti-inflammatory drugs [136]. In addition, phenolic compounds have anti-cancer properties via modulating key processes such as oncogenic transformation of normal cells, growth and development of tumors, and angiogenesis and metastasis [137]. Betulinic acid is a pentacyclic triterpenoid with a wide range of biological properties, such as anti-inflammatory and anti-cancer. The activity of betulinic acid has been linked to the induction of the intrinsic pathway of apoptosis in cancer cells. In contrast to cancer cells, normal cells and tissues are relatively resistant to that compound. Given this, this compound seems to be a promising experimental cancer therapeutic [138; 139]. Another compound with anti-cancer activity is geraniol, a monoterpene alcohol.