Many  ROS-generating  natural  products  and  drugs  had  been  reported  but  their  selective  killing  effects  were  sometimes  not  investigated  [5-7].  It  was  warranted  for  further investigation about its possible selective killing effects. In contrast, it is noted that  the  ROS-generating  natural  products  and  drugs  are  not  always  displaying  the  selective killing effect.Some antioxidants were reported to have dual roles for cell survival and cell killing
in respective to different dosages [8], i.e., it displayed the survival effects at physiologic doses and the deleterious effects at high doses. In case of grape seed extracts, the famous natural  products  with  an  antioxidant  property,  it  was  found  to  be  healthy  to  normal  oral cells but inhibited the proliferation of oral cancer Ca9-22 cells at high doses [9].

Funding Support

References

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2.    Suzuki-Karasaki  Y,  Suzuki-Karasaki  M,  Uchida  M,  Ochiai  T.  Depolarization  controls  trail-sensitization and tumor-selective killing of cancer cells: Crosstalk with ros (2014) Front Oncol 4:128.
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5.    Yen YH, Farooqi AA, Li KT, Butt G, Tang JY, et al. Methanolic extracts of Solieria robusta inhibits proliferation  of  oral  cancer  ca9-22  cells  via  apoptosis  and  oxidative  stress  (2014)  Molecules 19:18721-18732.
6.    Yeh CC, Tseng CN, Yang JI, Huang HW, Fang Y, etal. Antiproliferation and induction of apoptosis in  ca9-22  oral  cancer  cells  by  ethanolic  extract  of  Gracilaria  tenuistipitata  (2012)  Molecules 17:10916-10927.
7. Yen CY, Chiu CC, Haung RW, Yeh CC, Huang KJ, etal. Antiproliferativeeffects of goniothalamin on ca9-22 oral cancer cells through apoptosis; DNA damage and ros induction (2012) Mutat Res 747:253-258.
8.    Bouayed J, Bohn T. Exogenous antioxidants - double-edged swords in cellular redox state: Health beneficial effects at physiologic doses
versus deleterious effects at high doses (2010) Oxid Med Cell Longev 3:228-237.
9.    Yen CY, Hou MF, Yang ZW, Tang JY, Li KT, et al. Concentration effects of grape seed extracts in anti-oral cancer cells involving differential apoptosis,
oxidative stress, and DNA damage (2015) BMC Complement Altern Med 15:94.

Keywords

Oral Cancer