Social isolation leads to mild social recognition impairment and losses in brain cellularity.

Chronic social stress is a significant risk factor for several neuropsychiatric disorders, mainly major depressive disorder (MDD). In this way, patients with clinical depression may display many symptoms, including disrupted social behavior and anxiety. However, like many other psychiatric diseases, MDD has a very complex etiology and pathophysiology. Because social isolation is one of the multiple depression-inducing factors in humans, this study aims to understand better the link between social stress and MDD using an animal model based on social isolation after weaning, which is known to produce social stress in mice. We focused on cellular composition and white matter integrity to establish possible links with the abnormal social behavior that rodents isolated after weaning displayed in the three-chamber social approach and recognition tests. We used the isotropic fractionator method to assess brain cellularity, which allows us to robustly estimate the number of oligodendrocytes and neurons in dissected brain regions. In addition, diffusion tensor imaging (DTI) was employed to analyze white matter microstructure. Results have shown that post-weaning social isolation impairs social recognition and reduces the number of neurons and oligodendrocytes in important brain regions involved in social behavior, such as the anterior neocortex and the olfactory bulb. Despite the limitations of animal models of psychological traits, evidence suggests that behavioral impairments observed in patients might have similar biological underpinnings.

Age-dependent memory impairment induced by co-exposure to nicotine and a synthetic cannabinoid in mice.

Co-use of marijuana and tobacco products is the second most common drug combination among adolescents. Nicotine (NIC) and cannabinoid use during adolescence induce similar detrimental changes, raising the hypothesis that simultaneous exposure could result in even more severe outcomes. Thus, we investigated whether the co-exposure to NIC and the synthetic cannabinoid WIN 55,212-2 (WIN) in adolescent mice causes behavioral outcomes different from those observed after exposure to a single drug. Male Swiss mice were exposed twice daily to NIC, WIN, or NIC + WIN during adolescence (PND28-47) or adulthood (PND70-89). Drug combination led to a greater reduction in weight gain in adolescent mice, while NIC-induced weight loss was observed in adults. During administration, NIC provoked hypothermia, and WIN produced hyperlocomotion in adolescent and adult mice. Animals exposed to NIC + WIN presented a profile of changes similar to those exposed to NIC. After drug exposure, changes in locomotion, thigmotaxis, social preference, prepulse inhibition, and working and recognition memory were evaluated. Adolescent but not adult mice exposed to NIC showed withdrawal-related hyperlocomotion unaffected by WIN co-administration. An age-specific impairment in object recognition memory was induced only by drug co-exposure during adolescence, which resolved spontaneously before reaching early adulthood. A transient decrease in hippocampal α7 nAChR subunit and CB1 receptor mRNA levels was induced by NIC exposure, which may be involved but is not enough to explain the memory impairment. Our work confirms the potential of NIC and cannabinoids association to aggravate some of the individual drug effects during critical neurodevelopmental periods.

Assessment of Salvia officinalis(L) hydroalcoholic extract for possible use in cosmetic formulation as inhibitor of pathogens in the skin / Avaliação do extrato hidroalcoólico de Salvia officinalis(L) para possível uso em formulações cosméticas como inibidor de patógenos da pele

Salvia officinalis (L.), or common sage, is an aromatic herb that has been used in medicine and cooking since ancient times and has been investigated for the treatment of various diseases, especially infections and skin inflammation. We conducted phytochemical prospecting and quality control with hydroalcoholic extracts of dried sage, to identify active compounds in the plant. The aim was to assess antibacterial and antifungal activity against Staphylococcus aureus, Streptococcus agalactiae, Candida albicans and Candida tropicalis. Antimicrobial susceptibility was investigated in vitro by agar-overlay and well-diffusion techniques, in which disc and well were used. Salvia officinalis (L.) was not effective against Streptococcus agalactiae, Candida albicans or Candida tropicalis, but best results were observed for antibacterial activity against Staphylococcus aureus. Considering the results of the inhibition tests presented here, we suggest that cosmetic formulations containing Salvia officinalis (L.) could contribute to inhibitor of pathogens in the skin microbiota.

A Salvia officinalis (L.) é uma planta com uso difundido, utilizada no tratamento de diversas patologias, principalmente para infecções e inflamações cutâneas. Neste trabalho foi realizada prospecção fitoquímica e controle de qualidade com a planta seca e extrato hidroalcoólico para identificação dos compostos ativos da sálvia, tendo como finalidade comprovar sua atividade antibacteriana e antifúngica frente à Staphylococcus aureus, Streptococcus agalactiae Candida albicans e Candida tropicalis. Os métodos de escolha para avaliação in vitro foram ensaios de sensibilidade antimicrobiana por difusão em ágar com discos e cilindros. Dentre os ensaios realizados a sálvia não se mostrou efetiva para Streptococcus agalactiae, Candida albicans e Candida tropicalis, sendo o melhor resultado obtido com Staphylococcus aureus, em que se pode verificar-se atividade antibacteriana. Diante dos resultados obtidos, propôs-se uma formulação de sabonete líquido com extrato hidroalcoólico de Salvia officinalis (L.), para atuar na higiene da pele.