Comment on Balwierz et al. Potential Carcinogens in Makeup Cosmetics. 2023, , 4780.

We read with interest the article by Balwierz et al. [..

Toxicokinetic study following intratracheal instillation or oral gavage of two [Be]-tagged carbon black samples.

Background: The toxicokinetic behaviour of nanostructured particles following pulmonary or oral deposition is of great scientific interest. In this toxicokinetic study, following the general principles of OECD TG 417, the systemic availability of carbon black, a nanostructured material consisting of agglomerated aggregates was characterised.

Methods: Each of two grades of beryllium-7 labelled carbon black (Monarch® 1000, oxidized and Printex® 90; untreated) was administered either intratracheally or orally to adult rats.

Evaluating the evidence on genotoxicity and reproductive toxicity of carbon black: a critical review.

Carbon black is produced industrially by the partial combustion or thermal decomposition of gaseous or liquid hydrocarbons under controlled conditions. It is considered a poorly soluble, low toxicity (PSLT) particle. Recently, results from a number of published studies have suggested that carbon black may be directly genotoxic, and that it may also cause reproductive toxicity.

Translational toxicology in setting occupational exposure limits for dusts and hazard classification - a critical evaluation of a recent approach to translate dust overload findings from rats to humans.

Background: We analyze the scientific basis and methodology used by the German MAK Commission in their recommendations for exposure limits and carcinogen classification of "granular biopersistent particles without known specific toxicity" (GBS). These recommendations are under review at the European Union level. We examine the scientific assumptions in an attempt to reproduce the results.

Impact of quercetin and EGCG on key elements of the Wnt pathway in human colon carcinoma cells.

The flavonoids quercetin (QUE) and (-)-epigallocatechin-3-gallate (EGCG) are discussed as potential chemopreventive food constituents. Both compounds have been shown to affect a spectrum of different cellular signaling pathways. Glycogen synthase kinase-3beta (GSK3beta) is one of the key elements of the Wnt pathway, governing beta-catenin homeostasis.

Modulation of key elements of the Wnt pathway by apple polyphenols.

Glycogen synthase kinase-3beta (GSK3beta) is one of the key elements of the Wnt pathway involved in the regulation of beta-catenin homeostasis. The inhibition of GSK3beta kinase activity might lead to the onset of beta-catenin/TCF/LEF-mediated gene transcription, representing a potentially mitogenic stimulus. Apple polyphenols have been shown to mediate several biological effects that might be of interest with respect to chemoprevention.

Inhibitors of the epidermal growth factor receptor in apple juice extract.

The polyphenol-rich extract of a consumer-relevant apple juice blend was found to potently inhibit the growth of the human colon cancer cell line HT29 in vitro. The epidermal growth factor receptor (EGFR) and its subsequent signaling cascade play an important role in the regulation of cell proliferation in HT29 cells. The protein tyrosine kinase activity of an EGFR preparation was effectively inhibited by the polyphenol-rich apple juice extract.