Table 5 General cytotoxicity induced by different classes of phytochemicals and reported events taking place at the cellular level. ^a

EOs	Damage the cellular membrane and organelles Mitochondrial dysfunction-induced reactive oxygen species accumulation Decreased ATPase and dehydrogenase activities Causes nuclear and cytoplasmic mutagenicity
a Sources: Bakkali et al. (2008); Tripathi et al. (2009).
Most monoterpenes	Cause reduction in the number of intact mitochondria and Golgi bodies Impair respiration and photosynthesis
Hydrocarbons	Act as solvents of the cellular membrane compromising its integrity and increasing the movement of other molecules across the cell
Phenolics	Produce very reactive phenoxyl radicals when oxidized by contact with reactive oxygen species
Phenols, aldehydes, and alcohols	Act as prooxidants on proteins and DNA
Furocoumarins	Act as photoactive molecules; Produce radical reactions and oxygen singlet; Crosslink both strands of DNA by binding to pyrimidine bases, thereby inhibiting DNA replication and transcription.