*Cytotoxic Activity of Secondary Metabolite Compounds from Myanmar Medicinal Plants DOI: http://dx.doi.org/10.5772/intechopen.105153*

tested for their cytotoxic activity in T47D breast cancer cells by Rinto Muhammad Nur and Laurentius Hartanto Nugroho. The results revealed that the chloroform fraction displayed the highest activity with an IC50 value of 115.63 ± 86.01 μg/mL. They also screened the combined leaf chloroform fractions and the data showed that fractions F-5 (IC50: 14.55 ± 8.62 μg/mL) and F-6 (IC50: 14.55 ± 8.62 μg/mL) were found to be the most toxic fractions. Nevertheless, both fractions (F-5 and F-6) were very weak when compared with the cancer drug, Doxorubicin (IC50: 0.04 ± 0.02 μg/mL) [74]. Mainasara et al. reported that *D. bulbifera* has cytotoxic effects on MAD-MB-231 and MCF-7 breast cancer cell lines. The IC50 values for MAD-MB-231 were found to be 41.17, 15.71, and 11.53 μg/mL, at 24, 48, and 72 h of

#### **Figure 5.** *Cytotoxic compounds from* Dioscorea bulbifera*.*

incubation time. For MCF-7 cell lines, the IC50 values were 4.29, 1.86, and 1.23 μg/ mL, respectively, after 24, 48, and 72 h of incubation time. They also studied cycle analysis and apoptosis by using flow cytometry analysis. It was found that D. bulbifera induced apoptosis at various phases, with a considerable drop in viable cells after 24 h and significant improvements after 48 and 72 h of treatment [75]. Wang et al. observed the antitumor activity of various extracts and compound diosbulbin B from *D. bulbifera* in mice model [76]. In another study, two new phenolic derivatives (diosbulbiol A and diosbulbiol B) from the tubers of *D. bulbifera* were tested for their cytotoxic activity against SMMC7721, MCF-7, K562 and A549 cancer cell lines. Interestingly, these two compounds showed no inhibitory effect on all selected cell lines (IC50 > 40 μM) [77]. The chemical structures of some cytotoxic compounds are shown in **Figure 5**.
