NAPOLI, Italy—A new cosmetic cultured stem cell active ingredient—from Lycopersicon esculentum (tomato)—preserves nuclear DNA integrity from heavy metal damages by inducing genes responsible for DNA repair and protection, and neutralizes the effect of heavy metals on collagen degradation by inhibiting collagenase expression and inducing the synthesis of new collagen, according to a study published in the International Journal of Cosmetic Science (May 24, 2011). Heavy metals can cause several genotoxic effects on cells, including oxidative stress, DNA sequence breakage and protein modification. Among the body organs, skin is certainly the most exposed to heavy metal stress and thus, the most damaged by the toxic effects that these chemicals cause. Moreover, heavy metals, in particular nickel, can induce the over-expression of collagenases (enzymes responsible for collagen degradation), leading to weakening of the skin extracellular matrix.
Plants have evolved sophisticated mechanisms to protect their cells from heavy metal toxicity, including the synthesis of metal chelating proteins and peptides, such as metallothioneins and phytochelatins (PC), which capture the metals and prevent the damages on the cellular structures. To protect human skin cells from heavy metal toxicity, Italian researchers developed a new cosmetic active ingredient from Lycopersicon esculentum (tomato) cultured stem cells. Besides its high content of antioxidant compounds, the new active contained PC and was effective in the protection of skin cells toward heavy metal toxicity.