Parabens

Parabens used as a preservative in cosmetics. Methyl paraben work against bacteria and fungi whereas propyl paraben work against yeast and mould. Methyl paraben is water soluble and propyl paraben is oil soluble.

Dermal Exposure to Paraben

As we see in fig (A). when we apply cosmetic (lotion & cream) on skin Paraben gets highly absorbed into epidermis and dermis. The paraben which remains in stratum corneum/ epidermis stays there & not get metabolized. Because there is absence of enzyme esterase. Whereas the paraben which get absorbed deeper in dermis gets metabolized through the enzyme esterase by converting paraben to P-hydroxy benzoic acid get excreted by urine. The paraben remains in epidermis results in endocrine disruprion.

Endocrine disruption: Parabens are potential endocrine disruptors due to their ability to mimic estrogen.

Skin Cancer: when we apply cosmetic containing methyl paraben can lead to UV-induced damage of skin cells and disruption of cell proliferation (cell growth rate). Daily application, in particular, can lead to increased concentrations of methyl paraben because it is not completely metabolized. Parabens combined with other estrogenic chemicals may potentially influence the development of malignant melanoma, one form of skin cancer, through their estrogenic activity.

Developmental and Reproductive toxicity: Propyl and butyl parabens appear to reduce sperm production.

Oral Exposure to Paraben

Fig (B).Through oral route (in form of food/ medicine) paraben get converted to PHBA (P-hydroxy benzoic acid) by enzyme esterase and get excreted by urine.

Metabolism of paraben through skin and oral route

Link between Paraben and Breast Cancer

When paraben remain as it is in epidermis, it mimic as estrogen & affects on the estrogen receptor which results in cell growth and breast cancer occur.