**2.2 23,24-Dihydrocucurbitacin B (DHCB) (2′)**

 *C. tayuya* (Cucurbitaceae) is a climbing lignified plant with a large tuber that has long been used in folk medicine as an anti-inflammatory, antitumor, and antirheumatic agent. DHCB (**2′**) was isolated from the roots of *C. tayuya* and assessed in isogenic colon cancer cell lines HCT116 and Hke-3 by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. This compound induced apoptosis in both cell lines with IC50 values of 9.8 and 4.7 μM, respectively [15].

 DHCB inhibited the viability of human cervical cancer cell lines with an IC50 of 40–60 μM, but its cytotoxic effects were less pronounced in normal epithelial fr2 and HerEpiC cells, where the IC50 was 125 μM. The underlying mechanisms were studied, and the results showed that DHCB induced apoptosis in HeLa cells and caused ROS-mediated shifts in the ΔΨm. Additionally, DHCB caused cell cycle arrest in HeLa cells at the G2/M checkpoint. The phosphoinositide 3 kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR) cascade may play an important role in cancer tumorigenesis and progression and resistance to chemotherapy. The results indicated that DHCB decreased the expression of important proteins in the PI3K/Akt/mTOR cascade [16].
