Carnosine is a naturally occurring endogenous dipeptide composed by the ligation of β-alanine and L-histidine performed particularly by tissues with an increased oxidative metabolism such as muscles and brain. In the last 50 years different studies have assessed the role and function of carnosine through numerous in vitro, in vivo, and clinical studies, demonstrating the multimodal mechanism of action of this dipeptide that includes anti-aggregant, antioxidant, and anti-inflammatory activities. In particular its activity has been investigated in experimental models of cardiovascular disease (CVD), type 2 diabetes mellitus (T2DM), and neurodegenerative disorders, such as cerebral ischemia and Alzheimer's disease (AD). In the present review, we examined the protective role that carnosine could exert in the context of T2DM, CVD, and AD, which show common pathogenic mechanisms including oxidative stress, inflammation, and aggregation phenomena. Carnosine's pharmacodynamic profile is multimodal and combines the systemic anti-inflammatory and antioxidant activities with its anti-aggregant and neuroprotective efficacy in the central nervous system. This enlarged pharmacological activity opens a new path to explore the therapeutic potential of carnosine in all the three diseases, and in particular in patients with T2DM, who often show a history of CVD and also have an increased risk to develop mild cognitive impairment and AD.

Carnosine is an endogenous dipeptide composed of β-alanine and L-histidine, possessing a multimodal pharmacodynamic profile that includes anti-inflammatory and anti-oxidant activities. Carnosine has also shown its ability to modulate cell proliferation, cell cycle arrest, apoptosis, and even glycolytic energy metabolism, all processes playing a key role in the context of cancer. Cancer is one of the most dreaded diseases of the 20th and 21st centuries. Among the different types of cancer, breast cancer represents the most common non-skin cancer among women, accounting for an estimated 15% of all cancer-related deaths in women. The main aim of the present review was to provide an overview of studies on the anti-cancer activity of carnosine, and in particular its activity against breast cancer. We also highlighted the possible advantages and limitations involved in the use of this dipeptide. The first part of the review entailed a brief description of carnosine’s biological activities and the pathophysiology of cancer, with a focus on breast cancer. The second part of the review described the anti-tumoral activity of carnosine, for which numerous studies have been carried out, especially at the preclinical level, showing promising results. However, only a few studies have investigated the therapeutic potential of this dipeptide for breast cancer prevention or treatment. In this context, carnosine has shown to be able to decrease the size of cancer cells and their viability. It also reduces the levels of vascular endothelial growth factor (VEGF), cyclin D1, NAD⁺, and ATP, as well as cytochrome c oxidase activity in vitro. When tested in mice with induced breast cancer, carnosine proved to be non-toxic to healthy cells and exhibited chemopreventive activity by reducing tumor growth. Some evidence has also been reported at the clinical level. A randomized phase III prospective placebo-controlled trial showed the ability of Zn–carnosine to prevent dysphagia in breast cancer patients undergoing adjuvant radiotherapy. Despite this evidence, more preclinical and clinical studies are needed to better understand carnosine’s anti-tumoral activity, especially in the context of breast cancer.

The activity of microglia is fundamental for the regulation of numerous physiological processes including brain development, synaptic plasticity, and neurogenesis, and its deviation from homeostasis can lead to pathological conditions, including numerous neurodegenerative disorders. Carnosine is a naturally occurring molecule with well-characterized antioxidant and anti-inflammatory activities, able to modulate the response and polarization of immune cells and ameliorate their cellular energy metabolism. The better understanding of microglia characteristics under basal physiological conditions, as well as the possible modulation of the mechanisms related to its response to environmental challenges and/or pro-inflammatory/pro-oxidant stimuli, are of utmost importance for the development of therapeutic strategies. In the present study, we assessed the activity of carnosine on human HMC3 microglial cells, first investigating the effects of increasing concentrations of carnosine on cell viability. When used at a concentration of 20 mM, carnosine led to a decrease of cell viability, paralleled by gene expression increase and decrease, respectively, of interleukin 6 and heme oxygenase 1. When using the maximal non-toxic concentration (10 mM), carnosine decreased nitric oxide bioavailability, with no changes in the intracellular levels of superoxide ion. The characterization of energy metabolism of HMC3 microglial cells under basal conditions, never reported before, demonstrated that it is mainly based on mitochondrial oxidative metabolism, paralleled by a high rate of biosynthetic reactions. The exposure of HMC3 cells to carnosine seems to ameliorate microglia energy state, as indicated by the increase in the adenosine triphosphate/adenosine diphosphate (ATP/ADP) ratio and energy charge potential. The improvement of cell energy metabolism mediated by 10 mM carnosine could represent a useful protective weapon in the case of human microglia undergoing stressing conditions.

The burden of increasing cancer incidence among the population, and, in particular, of prostate cancer in men living in highly developed countries, brings with it, on one hand, the need for new devices that allow a faster and earlier diagnosis, ideally in a non-invasive way and with low consumption of expensive reagents, and on the other the need for the assessment of new in vitro models that allow a more reliable assessment of cancer features, including its microenvironment and sensibility to different drugs. At the crossroads of these features, microfluidic devices are found. These, taking advantage of the chemical-physical properties of cells and human samples, have demonstrated great sensitivity and sensibility at an on-chip scale. Many fields of biomedical sciences have tried to exploit all their potentialities: from the detection of antigens in the early phases of the disease (when they are very low concentrated, but the treatment is more effective) to isolation and characterization of circulating tumor cells. However, is in the building of in vitro 3D models to better assess and comprehend the fundamental dynamics occurring in the tumor microenvironment and metastasis that 3D bioprinting techniques come into play. The aim of the present review is to describe the potential of these two different cutting-edge technologies for the detection and treatment of prostate cancer, in the perspective of a possible future combination of them that allows scientists to fill the gaps present in the field to improve patient care and treatment.