Recent advances in ruminants’ milk-derived exosomes (EXO) have indicated a role of microRNAs (miRNAs) in cell-to-cell communication in dairy ruminants. The miRNAs EXO retain peculiar mechanisms of uptake from recipient cells, which enables the selective delivery of cargos, with a specific regulation of target genes. Although many studies have been published on the miRNAs contained in milk, less information is available on the role of miRNAs EXO, which are considered stable over time and resistant to digestion and milk processing. Several miRNAs EXO have been implicated in the cellular signaling pathway, as in the regulation of immune response. Moreover, they exert epigenetic control, as extenuating the expression of DNA methyltransferase 1. However, the study of miRNAs EXO is still challenging due to the difficulty of isolating EXO. In fact, there are not agreed protocols, and different methods, often time-consuming, are used, making it difficult to routinely process a large number of samples. The regulation of cell functions in mammary glands by miRNAs EXO, and their applications as genomic markers in livestock, is presented.

Reactive oxygen species (ROS) are normally produced in skeletal muscle. However, an imbalance in their regulatory systems can lead to their accumulation and ultimately to oxidative stress, which is one of the causes of the ageing process. Companion dogs share the same environment and lifestyle as humans, making them an excellent comparative model for the study of ageing, as well as they constitute a growing market for bioactive molecules that improve the quality of life of pets. The anti-ageing properties of oleuropein aglycone (OLE), a bioactive compound from olive leaves known for its antioxidant properties, were investigated in Myok9 canine muscle cell model. After incubation with OLE, senescence was induced in the canine cellular model by hydrogen peroxide (H₂O₂). Analyses were performed on cells after seven days of differentiation. The oxidative stress induced by H₂O₂ treatment on differentiated canine muscle cells led to a significant increase in ROS formation, which was reduced by OLE pretreatment alone or in combination with H₂O₂ by about 34% and 32%, respectively. Cells treated with H₂O₂ showed a 48% increase the area of senescent cells stained by SA-β-gal, while OLE significantly reduced the coloured area by 52%. OLE, alone or in combination with H₂O₂, showed a significant antioxidant activity, possibly through autophagy activation, as indicated by the expression of autophagic markers.

A gradual loss of muscle mass and strength increases the risk of falls, frailty and mortality. It is the result of a combination of intrinsic factors such as oxidative stress, mitochondrial dysfunction and extrinsic factors such as poor nutrition and inactivity. Oleuropein aglycone (OLE), a compound extracted from olive leaves, combats oxidative damage through its antioxidant and autophagy‐inducing properties. It activates AMPK and FOXO3a signaling pathways, autophagy, mitochondrial function and muscle health. OLE is investigated in the human immortalized myoblast cell line AB1079 for its protective effect against muscle oxidative stress. Oxidative stress was induced in the AB1079 cell line after 7 days of differentiation by hydrogen peroxide (H ₂ O ₂ ), leading to a significant increase in reactive oxygen species formation, which was reduced by approximately 43% by pretreatment with OLE. Cells treated with H ₂ O ₂ showed a 33% increase in stress‐induced senescent cells, while pretreatment with OLE significantly reduced the stained area of the X‐gal reaction by 12% compared to H ₂ O ₂ . OLE increased the expression of genes involved in antioxidant defense and influencing the autophagic process by inducing an oscillator AMPK phosphorylation, as well as the expression of the stress‐induced metabolic regulators SESN2 and SESN3. OLE has been shown to counteract the oxidative environment and promote autophagy‐related signaling in vitro, suggesting a potential role in preventing cellular mechanisms associated with muscle aging. Further in vivo studies are required to confirm functional anti‐aging effects.

Adipocyte whitening is a late-stage phenotypic transition that follows transient browning; however, its cellular and molecular basis remains incompletely understood. In particular, it is debated whether whitening reflects a passive loss of thermogenic identity or an actively regulated adaptive state. Late-stage whitening was investigated in human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes using an integrated approach combining quantitative mitochondrial morphology, lipid droplet remodelling, transcriptomics, protein analyses, and network-based bioinformatics. Whitening was characterised by coordinated suppression of thermogenic and oxidative gene programmes, together with enrichment of pathways associated with AMPK signalling, hypoxia response, and autophagy. Quantitative imaging analyses revealed stabilisation and remodelling of the mitochondrial network, with features consistent with mitochondrial quality control rather than degenerative loss of function. Transcriptomic and network analyses further supported the enrichment of autophagy-related processes and -adaptive signalling pathways during the late stages of differentiation. Overall, these findings indicate that adipocyte whitening is an actively regulated adaptive cellular state, integrating mitochondrial structural remodelling with metabolic and stress-responsive signalling. These results provide a conceptual framework for understanding adipocyte phenotypic plasticity during late differentiation.

Age-related loss of skeletal muscle is characterised by a progressive and generalised loss of muscle mass, function, and strength and is the main cause of disability and weakness in older people with a reduced quality of life. The diagnosis of sarcopenia is difficult due to its multifactorial component. The identification of biomarkers through rapid, non-invasive, and stress-free saliva sampling specifically related to skeletal muscle mass and strength could help in the early detection of sarcopenia and support the success of prevention. One hundred female and male volunteers with an average age of 64.0 ± 5.7 years were initially recruited for this study and took part in a physical training programme for one year. After six months, half of them received a dietary supplement containing 100 mg/d of oleuropein from olive leaf extract, a bioactive compound with antioxidant properties. Sestrin 1, sestrin 2, and interleukin 6 were detected in the saliva of volunteers at baseline (T0), after 6 months (T6), and at the end of the study, after 12 months (T12), and muscle strength and functional capacity were recorded. The concentration of sestrin 1 decreased in women and men from T6 to T12 regardless of the intake of oleuropein, while sestrin 2 and, in men, interleukin 6 increased at T12 after the intake of oleuropein. Muscle functionality was also significantly improved in both sexes at T12. These preliminary results are promising and pave the way for further studies to assess muscle functionality, also in the context of natural product intake.