**6.3.2 Carotenoids**

An in vitro study using HeLa and Caco-2 cells reported that -cryptoxanthin increased rejoining of strand breaks induced by H2O2 and increase the repair of oxidised bases. However, increase of repair activity was not related with increase of hOGG1 or APE1expression (Lorenzo et al., 2009). The lack of correlation between activity and mRNA expression of OGG1 and APE1 has also been demonstrated in other studies (Collins *et al.*, 2003; Silva *et al.*, 2009). -carotene, lutein and lycopene also enhanced strand breaks rejoining in lymphocytes (Fillion *et al.*, 1998; Torbergsen and Collins, 2000). Paz-Elizur *et al.*, (2007) measured OGG1 activity and mRNA expression in 120 healthy individuals and a poor correlation between activity and mRNA was found.
