The Protective Role of Antioxidants in the Defence against ROS/RNS-Mediated Environmental Pollution

Table 5

Studies demonstrating adverse or insignificant effects of antioxidant treatment after exposure to environmental pollutants.

Environmental pollutant	Antioxidants displaying adverse or insignificant effects	Study
Ozone (O3)	Vitamin E	Hackney et al. (1981) [240]
Cigarette smoke	Beta-carotene (synthetic)	Ruano-Ravina et al. (2006) [241]; Albanes (1999) [242]; Neuhouser et al. (2003) [243]
Asbestos	Beta-carotene	van Helden et al. (2009) [244]
UVR	Beta-carotene	Stahl et al. (2006) [124]
	Vitamin E and beta-carotene (no protective effect)	McArdle et al. (2004) [245]; Wolf et al. (1988) [246]; Garmyn et al. (1995) [247]
Bipyridinium herbicides (paraquat, diquat and difenzoquat)	Iron and copper	Korbashi et al. (1986) [248]; Kohen and Chevion (1985) [249]
Polychlorinated dibenzo-para-dioxins (dioxins) and polychlorinated dibenzofurans (furans)	Vitamin E (no protective effect)	Latchoumycandane and Mathur (2002) [250]
No extraexposure to environmental pollutants	Green tea catechins (enhanced colon carcinogenesis in rats)	Furukawa et al. (2003) [251]
	Melatonin (may exhibit carcinogenic potential)	Sakano et al. (2004) [252]