Combinatorial Effects of Bitter Melon and Temozolomide on Glioma Cells

Glioblastoma tumors are the most common type in the brain and have shown to be difficult to treat. The current chemotherapeutic treatment is the drug temozolomide (TMZ); however, research has been done to investigate whether chemotherapeutic drugs demonstrate a synergistic effect when combined with a natural agent, such as the extract of a fruit or a vegetable. The purpose of this experiment was to assess whether bitter melon extract (BME) and TMZ would enhance each other in combination. The hypothesis of this experiment was that if the concentrations of BME and TMZ increase, then growth of glioma cells would decrease. Cell culture was performed on glioma cells and astrocytes, and they were treated with standard media (control), 2% BME, 200 µM TMZ, and a combination of 2% BME and 200 µM TMZ. After 72 hours, cell proliferation was measured using MTT assay, and western blot analysis was performed in order to assess the expression of P-STAT3 and cyclin D1. The combination treatment resulted in the most decrease in cell proliferation in both glioma cells and astrocytes (50% proliferation in glioma and 85% in astrocytes), as well as a synergistic effect. After the t-tests were performed, it was concluded that most of the data was significant, excluding BME only versus TMZ only in the glioma cells. Therefore, the hypothesis was supported. From the results of the western blot, it can be concluded that this is due to how BME decreased activation of P-STAT3, increasing cell death, and that BME and TMZ in combination more strongly decrease expression of cyclin D1, inhibiting cell growth.