Peoples' Friendship University of Russia

Aquaculture is developing in many countries to meet the rising protein demand associated with a rapidly growing human population. However, intensification of production brings with it challenges such as deteriorating water quality and increasing disease outbreaks. These conditions lead to an increased risk of infectious diseases and led to higher mortality rates, which causes economic losses. Lactococcosis, particularly that caused by the Gram-positive bacterium Lactococcus garvieae, is one of the most common of these problems and can cause significant losses in various fish species. The intensive use of antibiotics for control purposes creates additional risks in terms of antimicrobial resistance, environmental pollution, and food safety. Therefore, natural feed additives have gained importance in recent years. Certain additives that support immune responses and increase disease resistance in fish have become prominent. Among these, phytobiotics, probiotics, prebiotics, and synbiotics are the most well-known and effective. Their widespread availability, lower cost, and environmental safety make these additives considered an alternative approach to aquaculture. Studies show that these additives strengthen both innate and adaptive immune responses, reduce infection severity, and reduce mortality associated with L. garvieae infections. However, there are still gaps in knowledge regarding how these substances regulate mechanisms such as the immune system, inflammatory processes, antioxidant defenses, and interactions with pathogens. This review aims to clarify these mechanisms by bringing together scientific data obtained in recent years. It also discusses how the information obtained can contribute to the development of safer feed additive strategies and the development of new vaccine approaches. This aims to support the establishment of a more sustainable production structure in the aquaculture sector.

Selenium (Se) and selenoproteins play a significant role in preventing mitochondrial damage. Se regulates mitochondrial dynamics, biogenesis, and mitophagy, but the mechanisms by which it controls mitochondrial quality remain to be fully characterized. Thus, the objective of this review is to address the underlying mechanisms of Se in regulation of mitochondrial quality control upon exposure to endogenous and exogenous stressors. Contemporary data show that Se deficiency is associated with a shift from mitochondrial fusion to fission, inhibition of mitochondrial biogenesis via down-regulation of sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)/nuclear respiratory factor 1 and 2 (NRF1/2)/mitochondrial transcription factor A (TFAM) signaling, and alterations in PTEN-induced kinase 1 (PINK1)/Parkin-mediated mitophagy in vitro and in vivo. The role of Se in regulating mitochondrial quality control is mediated by specific selenoproteins, as evidenced from experimental selenoprotein knockout and overexpression models. Correspondingly, treatment with various forms of Se attenuates inhibitory effect of endogenous stressors (oxidative stress, ischemia, etc.), as well as exogenous agents like heavy metals, ammonia, fluoride, mycotoxins, and paraquat, on mitochondrial fusion/fission balance and biogenesis. Administration of Se mitigates the adverse effects of these stressors on mitophagy by recovering impaired mitophagy or by inhibiting mitophagy overactivation. Therefore, Se treatment might be considered a therapeutic approach to mitigate the adverse effects of various stressors on mitochondrial quality control and functioning, leading to prevention of liver, kidney, brain, and intestinal damage. However, the specific mechanisms, as well as dose-response and species-specific effects have yet to be investigated.

On March 19, 2026, in Moscow, an international interdisciplinary Expert Council convened during the III National Congress of Pediatric Neurologists to address the treatment of comorbid conditions associated with ADHD in children. It was observed that comorbid disorders, such as anxiety, sleep disturbances, and heightened nervous excitability, affect at least 70% of patients, exacerbating clinical symptoms of ADHD and diminishing treatment efficacy. The experts evaluated the evidence supporting the use of multicomponent low-dose formulations derived from plant extracts and minerals, specifically Nervoheel (for children aged 3 years and older) and Neurexan (for those aged 12 years and older). These formulations are approved in the Russian Federation as medical products and have demonstrated effectiveness in alleviating neurotic manifestations, anxiety, and sleep disorders, as well as improving focus and compliance. Following the Expert Council’s statement, these medications received a favorable evaluation regarding their effectiveness in managing anxiety, sleep disorders, and nervous. They were recommended for inclusion in the Ministry of Health of the Russian Federation’s clinical guidelines, with a strength of recommendation of C and a quality of evidence rating of 3.