In summary, after treatment with citric acid, immortalized
human epidermal keratinocytes (HaCaT) exhibit apoptotic
features of DNA damage, apoptotic bodies, and an increase
of sub-G1 cells, resulting from activation of caspase-8, -9,
and -3 and the induction of AIF and Endo G release from
mitochondria. These findings are summarized in Figure 7.