Table 1.

The disadvantages of antioxidant therapy and chemotherapy / radiotherapy when administered alone.

Antioxidant therapy	Chemotherapy / radiotherapy
Only specific to one primary ROS, such as O2·- or H2O2. No antioxidant is specific against secondary ROS/RNS.	Non-targeting, not cancer cell specific.
Non-targeting; which may induce increasing dose of drugs to reach the high concentration in target site, leads to more side effects.	TACE is invasive treatment with more complication, and do not significantly improve the survival rate, with high possibility of recurrence.
Unstable structure leads to short half-life, susceptibility to be converted into inactive form or cleared by RES or renal clearance.	Can damage the hepatic-renal function, even bring about other dysfunction and chronic pain, fever, gastrointestinal discomfort, etc.
Little effect if administered orally	Cancer acquire resistance to radiation and chemotherapy after several rounds of treatment