Considering the global increase in fish consumption, the growing side-streams coming from the fish supply chain (e.g., skin, fins, tail, heads…), also including undersized or “unwanted catches”, have been recently proposed as source of high-value bioactive compounds (e.g., peptides and fatty acids). In this case study, hydrolyzed collagen peptides (HCPs) were extracted from different parts of Mugil cephalus L. using environmentally friendly techniques such as ultrasounds and enzymatic treatments. Both a mixed biomass derived from the skin, fins, and tail, and a whole fish, were considered as starting biomass, simulating the unsorted processing side-streams and an undersized/unwanted catch, respectively. The extracted HCPs were purified in fractions (3 KDa) whose yields (about 5% and 0.04–0.3%, respectively) demonstrated the efficiency of the hydrolysis process. The extraction protocol proposed allowed us to also isolate the intermediate products, namely the lipids (about 8–10%) and the non-collagenous proteins (NCs, 16–23%), whose exploitation could be considered. Each sample was characterized using Sircol, UltraViolet-Spectra, and hydroxyproline assay, and the viability of their collagen fractions was tested on human endothelial cells. Significant effects were obtained at a fraction of <3 KDa, in particular at a concentration of 0.13 µg/mL. The T-scratch test was also performed, with positive results in all fractions tested.

Aluminum is an element found in nature and in cosmetic products. It can interfere with the metabolism of other cations, thus inducing gastrointestinal disorder. In cosmetics, aluminum is used in antiperspirants, lipsticks, and toothpastes. The aim of this work is to investigate aluminum bioavailability after accidental oral ingestion derived from the use of a toothpaste containing a greater amount of aluminum hydroxide than advised by the Scientific Committee on Consumer Safety (SCCS). To simulate in vitro toothpaste accidental ingestion, the INFOGEST model was employed, and the amount of aluminum was measured through the ICP-AES analysis. Tissue barrier integrity was analyzed by measuring transepithelial electric resistance, and the tissue architecture was checked through light microscopy. The margin of safety was also calculated. Overall, our results indicate that the acute exposure to aluminum accidentally ingested from toothpastes is safe for the final user, even in amounts higher than SCCS indications.

Aluminum (Al³⁺) is a widespread environmental metal with potential effects on the intestinal epithelium. In this study, we evaluated the impact of dietary concentrations of aluminum on barrier integrity, histological organization, and gene expression in a 3D human intestinal tissue model. Tissues were exposed to increasing concentrations of aluminum (0, 5, 20, and 50 ppm) for 12 days to mimic environmental chronic exposure through ingestion. Transepithelial electrical resistance (TEER) measurements revealed a significant decrease only at the highest dose (50 ppm) on day 12, indicating a damage to the epithelial permeability. This was supported by a marked downregulation of OCLN and CLDN-5 expression, key genes involved in tight junction integrity. Aluminum permeation across the tissue was confirmed via Inductively Coupled Plasma—Atomic Emission Spectroscopy (ICP-AES), indicating dose-dependent penetration. Furthermore, gene expression analysis showed significant upregulation of MT-1E and MT-2A (markers of cellular response to metal exposure) while MT-1A remained unchanged. Histological analysis showed a vacuolated aspect in the tissue treated with 50 ppm. Confocal imaging revealed an apical accumulation of F-actin at the highest concentration of Al ³⁺ and transmission electron microscopy (TEM) demonstrated progressive shortening of apical microvilli in aluminum-treated tissues. The present data demonstrate that repeated exposure to 50 ppm of Al ³⁺ impacts intestinal barrier function and alters the tissue organization in the human intestinal epithelium.