## 2 Effects of Plant Extracts on In Vitro Dendritic Cell Biology and Its Effects in Cancer Cells
### Activation of T-Cells  
It has been found that several plant components stimulate mature DCs to induce T-cell proliferation [42], which are given in Table 2. The plant-derived polysaccharide _Angelica gigas Nakai_ (Angelin) activates DCs increases T-cell proliferation. It also increases Th1 cytokines such as IL-12 and IFN-\(\gamma\)[43, 44]. _Capparis spinosa_ polysaccharides induce DC maturation and increase the proliferation of CD8 and CD4 T-cells [45]. Another study showed that Safflower _Carthamus tinctorius_ enhances DC-mediated T-cell polarization and increases the cytotoxic activity against tumors [46]. Water extract of _Glycyrrhizia valensis_ stimulated DC maturation, enhanced HPV16 specific CD8+ T-cell proliferation and reduced tumor size [47]. _Dioscorea_ tuber phytoextracts confer immunomodulatory activities through DC-mediated activation of T-cell proliferation [18]. Immunomodulatory activity of plant extract (_Nicotiana benthamiana_) containing HPV16-E7 protein in human monocyte-derived dendritic cells induces HPV16-E7 specific cytotoxic activity [23]. Another report showed that plant-derived polysaccharides (PDPs) can induce DC maturation and  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Plant Name/Extracts** & \begin{tabular}{c} **Differentiation and** \\ **Maturation of DCs** \\ \end{tabular} & **Phenotypic Marker** & **References** \\ \hline _Polymodium leucotomos_ & Differentiation & - & [21, 29] \\ \hline _Polyporus umbellatus_ & Maturation & - & [32] \\ \hline _Pueraria lobata_ & Maturation & CD40, CD80 and MHC I/II & [27] \\ \hline _Dioscorea_ spp. & Maturation & - & [26] \\ \hline _Nicotiana benthamiana_ & \begin{tabular}{c} No differentiation, but \\ induce maturation \\ \end{tabular} & - & [23] \\ \hline Neem leaf glycoprotein & Maturation & CD83, CD80, CD86, CD40 and \begin{tabular}{c} \\ MHCs \\ \end{tabular} & [33] \\ \hline Astragalus polysaccharide & Maturation & CD11c and MHCII & [34, 35] \\ \hline Aged garlic extract & — & \begin{tabular}{c} Increase CD40, but no effect \\ on CD86 and MHCII \\ \end{tabular} & [36] \\ \hline Seed extract _Plantago asaatica_ & Maturation & CD80, CD86 and MHCII & [37] \\ \hline _Thymus vulgaris, Thymus daenensis, Zataria multifora_ & Maturation & CD40 & [38] \\ \hline Licorice roots containing 18-\(\alpha\) and 18-\(\beta\)-glycyrrhetinic acid & Maturation & - & [39] \\ \hline Lupine acetate of cortex periplocae, the aqueous & \begin{tabular}{c} Both maturation and \\ differentiation \\ \end{tabular} & - & [29] \\ \hline _Lycium bararum_ polysaccharide (LBP) & \
\begin{tabular}{c} Maturation \\ \end{tabular} & - & [40] \\ \hline \hline \end{tabular}
\begin{tabular}{c} Fermented mistletoe extract & Maturation & - & [41] \\ \hline \hline \end{tabular}
\end{table}
Table 1: Plant extracts on dendritic cells (DCs) differentiation and maturation.  
provide T cell immunity [21]. The butanol fraction of the stems and leaves of _Echinacea purpurea_ significantly influences BMDC maturation and T-cell proliferation [29]. It has been observed that uncarinic acid C, uncarinic acid D, and triterpene esters isolated from _Uncaria rhynchophyla_ plants were found to activate cytokine production of human DCs towards Th1 immune responses [48].