Methylparaben Explained

Methylparaben (methyl paraben) one of the parabens, is a preservative with the chemical formula CH₃(C₆H₄(OH)COO). It is the methyl ester of p-hydroxybenzoic acid.

Natural occurrences

Methylparaben serves as a pheromone for a variety of insects^[1] and is a component of queen mandibular pheromone.

It is a pheromone in wolves produced during estrus associated with the behavior of alpha male wolves preventing other males from mounting females in heat.^{[2] [3]}

Uses

Methylparaben is an anti-fungal agent often used in a variety of cosmetics and personal-care products. It is also used as a food preservative and has the E number E218.

Methylparaben is commonly used as a fungicide in Drosophila food media at 0.1%.^[4] To Drosophila, methylparaben is toxic at higher concentrations, has an estrogenic effect (mimicking estrogen in rats and having anti-androgenic activity), and slows the growth rate in the larval and pupal stages at 0.2%.^[5]

Safety

There is controversy about whether methylparaben or propylparabens are harmful at concentrations typically used in body care or cosmetics. Methylparaben and propylparaben are considered generally recognized as safe (GRAS) by the USFDA for food and cosmetic antibacterial preservation.^[6] Methylparaben is readily metabolized by common soil bacteria, making it completely biodegradable.

Methylparaben is readily absorbed from the gastrointestinal tract or through the skin.^[7] It is hydrolyzed to p-hydroxybenzoic acid and rapidly excreted in urine without accumulating in the body.^[7] Acute toxicity studies have shown that methylparaben is practically non-toxic by both oral and parenteral administration in animals.^[7] In a population with normal skin, methylparaben is practically non-irritating and non-sensitizing; however, allergic reactions to ingested parabens have been reported.^[7] A 2008 study found no competitive binding for human estrogen and androgen receptors for methylparaben, but varying levels of competitive binding were seen with butyl- and isobutyl-paraben.^[8]

Studies indicate that methylparaben applied on the skin may react with UVB, leading to increased skin aging and DNA damage.^{[9] [10]}

External links

• Methylparaben at Hazardous Substances Data Bank
• Methylparaben at Household Products Database
• European Commission Scientific Committee on Consumer Products Extended Opinion on the Safety Evaluation of Parabens (2005) http://ec.europa.eu/health/ph_risk/committees/04_sccp/docs/sccp_o_019.pdf

Notes and References

1. Web site: Semiochemical - me-4-hydroxybenzoate . pherobase.com .
2. 10.1002/zoo.1430050103 . Wolf scent marking with raised-leg urination . Zoo Biology . 5 . 7–20 . 1986 . Mertl-Millhollen . Anne S. . Goodmann . Patricia A. . Klinghammer . Erich .
3. Book: Handbook of Applied Dog Behavior and Training, Adaptation and Learning . Steven R. Lindsay . John Wiley and Sons . 2013 .
4. Web site: Bloomington Drosophila Stock Center.
5. Toxicity and Estrogen Effects of Methyl Paraben on Drosophila melanogaster . Gu W, Xie DJ, Hour XW . Food Science . 2009 . 30 . 1 . 252–254 .
6. Web site: Parabens . 9 September 2020 . .
7. Soni MG, Taylor SL, Greenberg NA, Burdock GA . Evaluation of the health aspects of methyl paraben: a review of the published literature . Food and Chemical Toxicology . 40 . 10 . 1335–73 . October 2002 . 12387298 . 10.1016/S0278-6915(02)00107-2 .
8. Alan AF . Final amended report on the safety assessment of Methylparaben, Ethylparaben, Propylparaben, Isopropylparaben, Butylparaben, Isobutylparaben, and Benzylparaben as used in cosmetic products . International Journal of Toxicology . 27 Suppl 4 . Suppl 4 . 1–82 . 2008 . 19101832 . 10.1080/10915810802548359 .
9. Handa O, Kokura S, Adachi S, Takagi T, Naito Y, Tanigawa T, Yoshida N, Yoshikawa T . 6 . Methylparaben potentiates UV-induced damage of skin keratinocytes . Toxicology . 227 . 1–2 . 62–72 . October 2006 . 16938376 . 10.1016/j.tox.2006.07.018 .
10. Okamoto Y, Hayashi T, Matsunami S, Ueda K, Kojima N . Combined activation of methyl paraben by light irradiation and esterase metabolism toward oxidative DNA damage . Chemical Research in Toxicology . 21 . 8 . 1594–9 . August 2008 . 18656963 . 10.1021/tx800066u .