**7. Cytotoxic activity of dioscoreaceae**

Several studies have been performed to examine the cytotoxic activity of constituents in *Dioscorea bulbifera*. Many studies have observed cytotoxic compounds, largely found as steroidal saponins. Isolated pennogenin-3-O-α-L-rhamnopyranosyl-(1 → 3)-[α-Lrhamnopyranosyl-(1 → 2)]-β-D-glucopyranoside and penogenin-3-O-α-Lrhamnopyranosyl-(1 → 4)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyrano-side demonstrated cytotoxic activity in two human hepatocellular carcinoma cell lines (Bel-7402; 99.1% and 92.6% inhibition, SMMC7721; IC50 value 4.54 μM and 4.85 μM) [47]. Diosgenin-3-O-[α-L-rhamnopyranosyl-(1 → 2)-[α-Lrhamnopyranosyl-(1 → 3)]-β-D-glucopyrano- side and diosgenin-3-O-[α-Lrhamnopyranosyl-(1 → 2)-[α-L-rhamnopyranosyl-(1 → 4)]-β-D-glucopyranoside were obtained from the rhizomes of *D. bulbifera* and displayed moderate cytotoxic activities against two human hepatocellular carcinoma cell lines (Bel-7402; IC50 values 10.87 and 19.10 μM, and SMMC7721; IC50 values 3.89 and 7.47 μM) [48]. In another study, spiroconazol A, penogenin-3-O-α-L-rhamnopyranosyl-(1 → 4)-α-Lrhamnopyranosyl-(1 → 4)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-glucopyranoside, and 26-O-β-D-glucopyranosyl-(25R)-5-en-furost-3β,17α,22α,26-tetraol-3- O-α-L- rhamno-pyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 4)-[α-Lrhamnopyranosyl-(1 → 2)]-β-D-glucopyrano-side were reported to have moderate activity against human urinary bladder carcinoma cell (ECV-304) [72]. In 2018, Wang and colleagues evaluated the cytotoxic activity of three new norclerodane diterpenoids (diosbulbin E acetate, diosbulbin R, and diosbulbin S) in the SMMC-7721 cancer cell line. These compounds were isolated from the ethanol extract of *D. bulbifera*. Interestingly, the isolates showed no inhibitory effects on SMMC-7721 (IC50 > 40 μM) [73]. Chloroform and methanol soluble fractions from *D. bulbifera* were
