Concentrations, influencing factors, risk assessment methods, health hazards and analyses of polycyclic aromatic hydrocarbons in dairies: a review

Nitrogen-doped hollow quadruple-shelled carbon-silicon nanosphere as a solid-phase microextraction adsorbent for the extraction of 19 polycyclic aromatic hydrocarbons in milk samples

In this study, nitrogen-doped hollow multi-shelled carbon-silicon nanospheres (NSiC-Homs-NS) were prepared using a template method and employed as a coating material for solid-phase microextraction (SPME) fibers. The extraction efficiency of single-, double-, triple-, and quadruple-shelled NSiC-Homs-NS coated fibers for polycyclic aromatic hydrocarbons (PAHs) were investigated, respectively. The NSiC-Homs-NS based SPME fiber coupled with gas chromatography-mass spectrometry was applied to detect 19 PAHs in milk samples. The extraction parameters of SPME were optimized using a central composite design methodology. Under the optimized conditions, the established method exhibited good linearity for the PAHs, ranging from 0.03 to 500 ng g-1, with coefficients of determination (r2) between 0.9952 and 0.9983. The limits of detection (S/N of 3) of the PAHs in milk samples ranged from 0.01 to 4.0 ng g-1. The relative standard deviations of the single-fiber repeatability (n = 5) and fiber-to-fiber reproducibility (n = 5) were all less than 12 %. The method recoveries of the PAHs in seven milk samples, evaluated at three different spiking concentrations, ranged from 80.4 % to 119 % with RSDs less than 12 %. The developed method exhibited good repeatability and accuracy.

Defective Homologous Recombination Repair By Up-Regulating Lnc-HZ10/Ahr Loop in Human Trophoblast Cells Induced Miscarriage

Human trophoblast cells are crucial for healthy pregnancy. However, whether the defective homologous recombination (HR) repair of dsDNA break (DSB) in trophoblast cells may induce miscarriage is completely unknown. Moreover, the abundance of BRCA1 (a crucial protein for HR repair), its recruitment to DSB foci, and its epigenetic regulatory mechanisms, are also fully unexplored. In this work, it is identified that a novel lnc-HZ10, which is highly experssed in villous tissues of recurrent miscarriage (RM) vs their healthy control group, suppresses HR repair of DSB in trophoblast cell. Lnc-HZ10 and AhR (aryl hydrocarbon receptor) form a positive feedback loop. AhR acts as a transcription factor to promote lnc-HZ10 transcription. Meanwhile, lnc-HZ10 also increases AhR levels by suppressing its CUL4B-mediated ubiquitination degradation. Subsequently, AhR suppresses BRCA1 transcription; and lnc-HZ10 (mainly 1-447 nt) interacts with γ-H2AX; and thus, impairs its interactions with BRCA1. BPDE exposure may trigger this loop to suppress HR repair in trophoblast cells, possibly inducing miscarriage. Knockdown of murine Ahr efficiently recovers HR repair in placental tissues and alleviates miscarriage in a mouse miscarriage model. Therefore, it is suggested that AhR/lnc-HZ10/BRCA1 axis may be a promising target for alleviation of unexplained miscarriage.

Oxygenated polycyclic aromatic hydrocarbons in food: toxicity, occurrence and potential sources

Oxygenated polycyclic aromatic hydrocarbons (OPAHs) are polycyclic aromatic hydrocarbons (PAHs) functionalized with at least one carbonyl group and are generally thought to be more toxic than PAHs. In this review, the physical-chemical properties, toxicity, occurrence, and potential sources of OPAHs in food were comprehensively discussed. The toxicities of 1,2-naphthoquinone, 1,4-naphthoquinone, 6H-benzo[cd]pyren-6-one, benzo[a]anthracene-7,12-quinone and 9,10-phenanthrenequinone were prominent among the OPAHs. Both 1,4-naphthoquinone and 1,2-naphthoquinone exhibited strong genotoxicity, cytotoxicity, and developmental toxicity. 6H-benzo[cd]pyren-6-one and benzo[a]anthracene-7,12-quinone showed high genotoxicity and cardiovascular toxicity. Although 9,10-phenanthrenequinone showed no genotoxicity, it exhibited almost the strongest cytotoxicity. For the majority of foods, the concentrations of OPAHs and PAHs were on the same order of magnitude. OPAHs tend to be positively correlated with the corresponding PAH concentrations in oil and fried food, while for barbequed food and seafood, no obvious correlation was found. In addition, 9-fluorenone, 9,10-anthraquinone, benzanthrone and 1,2-acenaphthenequinone had high abundance in food. Environmental pollution, food composition, storage conditions, heating methods, and other treatments influence the accumulation of OPAHs in food. Furthermore, oxygen and water played an important role in the transformation from PAHs to OPAHs. In short, this review guides the evaluation and further reduction of OPAH-related health risks in food.