## 5 Biological Activities of Rice Phytolexins
### Bioactivities of Phenolic Phytoalexins
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Biological Activity** & **Experimental Model** & **References** \\ \hline \multirow{3}{*}{Antifungal} & _Magnaporthe grisea_ (syn. _M. oryzae_, _Pivicularia grisea/oryzae_)—Inhibition of spore germination and germ tube growth. & [70] \\ \cline{2-3}  & _M. grisea_—Fungal colony growth inhibition assay. & [95] \\ \hline \multirow{3}{*}{Antimutagenic} & _Salmonella typhimurium_ TA1535/pSK1002—Suppressive effect on _umu_ gene expression of SOS response against the mutagen AF-2. & [220] \\ \hline \multirow{3}{*}{Anticancer} & Multidrug-resistant Colo 320 human colon cancer cells—Growth inhibition by induction of apoptosis. & [221] \\ \cline{2-3}  & Colon carcinoma HCT-116 human cells—Cytotoxicity test through MTT assay. & [18] \\ \cline{2-3}  & B16 BL6 mouse melanoma cells—Dose-dependent stimulation of melanogenesis. & [222] \\ \hline \multirow{3}{*}{Antil allergic} & Blood flow decrease in the tail vein microcirculation of mice subjected to HEL-sensitization as a monitor—Measurement of platelet aggregation of whole blood induced by ADP through WBA analyzer. & [85] \\ \hline \multirow{3}{*}{Anti-inflammatory} & In vivo induction of acute inflammation by topical application of TPA to mouse ears or by subcutaneous injection of PLA2 into mouse paws. & \\ \cline{2-3}  & In vitro tests based on the effect of sakuranetin and other dihydroflavonols on arachidonic acid metabolism and release and/or activity of enzymes implicated in the inflammatory response like elastase, MPO, and PKC. & [223] \\ \hline \multirow{3}{*}{Adipogenesis induction—glucose uptake stimulation} & Differentiation of 3T3-L1 murine preadipocytes to adipocytes. Expression of genes involved in development of adipocyte phenotypes. Evaluation of basal- and insulin-stimulated glucose uptake. & [224] \\ \hline \multirow{3}{*}{Anti-inflammatory and antioxidant} & Murine model (male BALB/c mice) of chronic allergic pulmonary inflammation—Histopathological analysis: evaluation of extracellular matrix remodeling, inflammation, and oxidative stress in pulmonary vessels and lung parenchyma; quantification of the vascular wall thickness and the VEGF levels. & [225] \\ \hline \multirow{3}{*}{Anti-_Helicobacter pylori_} & Study of the interaction between sakuranetin and other flavonoids with HpFabZ protein from _H. pylori_ by enzymatic and crystalline structure analyses. & [226] \\ \hline \multirow{3}{*}{Antilieishmanial and antitrypanosomal} & In vitro antileishmanial and antitrypanosomal tests. & [227] \\ \cline{2-3}  & ADP: Adenosine diphosphate; AF-2: Furylfuramide; EC50: Half maximal effective concentration; HEL: Hen egg-white lysozyme; HpFabZ: \(\beta\)-hydroxyacyl-acyl carrier protein dehydratase from _Helicobacter pylori_; MPO: Myeloperoxidase; MTT: Thiazolyl blue tetrazolium bromide; PKC: Protein kinase C; PLA2: Phospholipid case A2; TPA: 12-O-Tetradecanoylphorbol-13-acetate; VEGF: Vascular endothelial growth factor; WBA: Whole blood aggregometer. & [226] \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Biological activities of sakuranetin. DNA synthesis. The \(umu\) assay was developed to evaluate the genotoxic effects of environmental mutagens and carcinogens by examining the expression of a gene from the SOS family to detect DNA-damaging agents. Sakuranetin has been shown to inhibit cancer growth both in vitro and in vivo. The induction of cell death by apoptosis appears to be the main mechanism involved in this bioactivity. As shown by [PERSON] et al. [18], sakuranetin inhibits the proliferation of human colon cancer HCT-116 cells with an IC\({}_{50}\) value of approximately 68.8 \(\upmu\)g/mL. According to [PERSON] and [PERSON] [222], sakuranetin strongly promotes melanogenesis in murine B16 BL6 melanoma cells by inhibiting ERK1/2 and PI3K/AKT signaling pathways, leading to increased expression of the Tyr family genes _TRP1_ and _TRP2_.