**2.4 The anticancer effect of** *G. biloba* **flowers extract**

*G. biloba* is an ancient dioecious gymnosperm, which apply to worldwide for landscaping and medical usage. The male flowers with catkin blossom from late March to the middle of April for only three to seven days, varying in different areas of China [55]. The chemical constituents and bioactivities of the flowers contain high contents of nutritional and medicinally relevant components, such as amino acids, vitamins, unsaturated fatty acids, flavonoids, and lactones [56]. The extracts of ginkgo flowers can exhibit anticancer effects. Some phytochemical studies of *G. biloba* flowers enrich the diversity of Ginkgo chemical constituents and broaden its application in phytotherapy. The bioflavonoids from *G. biloba* male flowers promoted cell cycle arrest in the G2/M phase, inhibiting the proliferation of cervical cancer cells [57]. A study showed that biflavonoids bilobetin and isoginkgetin isolated from *G. biloba* flowers exhibited cytotoxic activities on cervical cancer, pancreatic cancer, lung cancer, Lymphoma, and ovarian cancer. The most sensitive cancer cell to these two compounds is cervical cancer. Furthermore, the morphological changes, apoptosis and cell cycle arrest were observed in cervical cancer cell. After treated with bilobetin and isoginkgetin, nuclear condensation together with the decrease on the ratio of Bcl2/BAX and the increase on cleavedcaspase 3, apoptosis rates were observed, indicating that apoptosis was triggered with these two compounds. In addition, cell cycle arrest via promoting G2/M phase arrest was also found in cervical cancer cell treated with bilobetin and isoginkgetin [55].
