# A Review on Bioactive Compounds and Pharmacological Activities of _Citrus unshiu_
## 4 Pharmacological Activities of Satsuma Mandarin
### Anticancer  
According to an experiment, the bioactives of _C. unshiu_ (nobiletin, HMF, and tangeretin) inhibit 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine-induced cancer-associated mutations in the micronucleus test in vivo and the Ames test using the _Salmonella typhimurium_ TA98 strain in vitro [52]. _C. unshiu_ bioactives have shown therapeutic effects against a range of cancers through diverse activities and mechanisms of action. An experiment assessing the anticancer effect of _C. unshiu_ ethanolic and petroleum ether extracts on the proliferation of melanoma skin cancer (MSC) cells showed that nobiletin, but not hesperidin, strongly suppressed the proliferation activity, with a half-maximal inhibitory concentration (IC\({}_{50}\)) value of 35.65 \(\upmu\)g/mL [53]. Another experiment evaluated the anti-metastatic effects of _C. unshiu_ peel ethanolic extracts on MSC cells in vitro and in vivo. The extracts (hesperidin, naringin) demonstrated in vitro apoptosis induction in MSC cells through increasing the percentage of annexin V\({}^{+}\)/PI\({}^{+}\)/annexin V\({}^{+}\)/PI\({}^{-}\) cells and the expression of Bcl-2-associated X protein (Bax), while decreasing the expression of B-cell lymphoma-2 (Bcl-2). The extracts also increased mitochondrial dysfunction in MSC cells via enhancing intracellular reactive oxygen species (ROS) formation, but decreased the migration, invasion, and colony formation of MSC cells through the inhibition of metalloproteinase (MMP) and the upregulation of tissue inhibitor of matrix metalloproteinases (TIMP) expression. In vivo, oral administration of _C. unshiu_ peel extracts resulted in the inhibition of lung metastasis through reducing serum lactate dehydrogenase (LDH) activity and the expression of pro-inflammatory tumor necrosis factor-alpha (TNF-\(\alpha\)) in B16F10 cell-inoculated mice [54]. An in vitro experiment evaluated the anti-metastatic activity of hesperidin and naringin extracted from _C. unshiu_ peel in breast cancer (BRC) cells. The extracts inhibited invasion in cancer cells and adhesion to human umbilical vein endothelial cells induced by TNF-\(\alpha\) by downregulating vascular cell adhesion molecule-1 (VCAM-1) expression and protein kinase C (PKC) phosphorylation [55]. Hesperidin and naringin extracted from _C. unshiu_ peel suppressed BRC cell proliferation in vitro by activating apoptosis pathways, including cytosolic release of cytochrome \(c\) from mitochondria to cytoplasm, ROS-dependent AMP-activated protein kinase (AMPK) phosphorylation, as well as caspase-8/9, Poly(ADP-ribose) Polymerase (PARP), and Bax expression [56]. _C. unshiu_ peel aqueous extracts triggered apoptosis and inhibited BRC cell viability at different concentrations in vitro through upregulating caspase-8/9, PARP, and Bax expression; promoting mitochondrial membrane potential loss/ROS production; and increasing cytochrome c release to cytoplasm from mitochondria [57]. Treatment with _C. unshiu_ peel extracts (hesperetin, naringenin) inhibited pancreatic cancer (PaC) cell viability and migration in an in vitro and in vivo xenograft mouse model by downregulating the expression of proliferating cell nuclear antigen (PCNA) and upregulating the expression of cleavage caspase-3 through activating protein 38 (p38) and mitogen-activated protein kinase kinase 3/6 (MKK 3/6) signaling pathways [58]. Hesperitin combined with naringenin significantly induced apoptosis and suppressed PaCcell viability and migration when treated at different doses in both in vitro and in vivo xenograft mouse models through increasing caspase-3 cleavage and inhibiting the focal adhesion kinase (FAK) signaling pathway [59]. Oral administration of _C. unshiu_ peel extracts (hesperidin, narirutin) to tumor-bearing mice inhibited tumor growth and proliferation in renal cell carcinoma (RCC) through decreasing the protein levels of TNF-\(\alpha\) and increasing interferon-gamma (IFN-\(\gamma\)) expression [60]. _C.