Artemisinin: an alternative treatment for oral cancer

Artemisinin (AR), a sesquiterpene lactone, is a widely used antimalarial drug with minimal or no toxic side effects. Recently, additional uses for AR were discovered, including anticancer treatment for a number of in vitro cancer models. It is therefore possible that AR can kill human oral cancer cells through apoptosis. Using an HPV 16 immortalized/transformed human oral epithelial (IHOK) cell line, we evaluated the effect of AR and 5FU, a known chemotherapy agent. Using TUNEL, immunohistochemistry (IHS) markers, and flow cytometry techniques, we investigated the mechanism by which AR kills IHOK cells. Dose response was performed for optimal concentrations and time. A 400 μmol/L concentration over a 48-hour period yielded the optimal results. The results of TUNEL showed that AR-treated IHOK cells were over 80% strongly positive cells, while 5FU-treated cells were less than 20% positive. The majority of AR-treated cells maintained their integrity whereas 5FU-treated cells were mostly necrotic. The IHS markers demonstrated strong positive staining with Bax, p53, CD40, and CD40L in AR-treated cells and negative with Bcl2. 5FU-treated cells demonstrated a profile similar to AR but with less intensity. Control cells exhibited focal positive staining with all 5 antibodies. Cell cycle by flow cytometry results showed that cells treated with AR demonstrated a slight, but not statistically significant, increase in S phase: 21% compared to the control rate of 16%. 5FU-treated cells, however, demonstrated a significant increase in S phase of 45%. In conclusion, our results indicate that AR kills transformed oral epithelial cells and does so through apoptosis with no toxicity while 5FU kills mostly through toxicity. We therefore suggest that artemisinin may be useful as an alternative treatment for oral cancer. Artemisinin (AR), a sesquiterpene lactone, is a widely used antimalarial drug with minimal or no toxic side effects. Recently, additional uses for AR were discovered, including anticancer treatment for a number of in vitro cancer models. It is therefore possible that AR can kill human oral cancer cells through apoptosis. Using an HPV 16 immortalized/transformed human oral epithelial (IHOK) cell line, we evaluated the effect of AR and 5FU, a known chemotherapy agent. Using TUNEL, immunohistochemistry (IHS) markers, and flow cytometry techniques, we investigated the mechanism by which AR kills IHOK cells. Dose response was performed for optimal concentrations and time. A 400 μmol/L concentration over a 48-hour period yielded the optimal results. The results of TUNEL showed that AR-treated IHOK cells were over 80% strongly positive cells, while 5FU-treated cells were less than 20% positive. The majority of AR-treated cells maintained their integrity whereas 5FU-treated cells were mostly necrotic. The IHS markers demonstrated strong positive staining with Bax, p53, CD40, and CD40L in AR-treated cells and negative with Bcl2. 5FU-treated cells demonstrated a profile similar to AR but with less intensity. Control cells exhibited focal positive staining with all 5 antibodies. Cell cycle by flow cytometry results showed that cells treated with AR demonstrated a slight, but not statistically significant, increase in S phase: 21% compared to the control rate of 16%. 5FU-treated cells, however, demonstrated a significant increase in S phase of 45%. In conclusion, our results indicate that AR kills transformed oral epithelial cells and does so through apoptosis with no toxicity while 5FU kills mostly through toxicity. We therefore suggest that artemisinin may be useful as an alternative treatment for oral cancer.