The composition of intestinal microbiota is widely believed to not only affect gut health but also influence behaviour. This study aimed to evaluate the probiotic characteristics, antioxidant activity, and antidepressant- and anxiolytic-like activities of Lactococcus lactis subsp. cremoris LL95. This strain showed probiotic properties such as resistance in a simulated gastric tract model and survival at different concentrations of NaCl and bile salts. Moreover, antioxidant activity of LL95 was demonstrated through DPPH radical scavenging activity, scavenging of ABTS^•+ radical and ferric ion reducing antioxidant power (FRAP) assays. Female C57BL/6 mice received LL95 orally at a dose of 10⁹ UFC/day for 28 days. LL95 improved depressive- and anxiety-like behaviour, demonstrated by decreased immobility time in the tail suspension test and forced swim test and increased per cent of time spent in the open arms on the elevated plus maze. These findings indicate the potential antioxidant activity of LL95 and its role in behaviour, suggesting that probiotic may have therapeutic applications.

The aim of the present study was to compare the efficiency of vitrification and slow freezing techniques for the cryopreservation of zebrafish ovarian tissue containing immature follicles. In Experiment 1, assessment of cell membrane integrity by trypan blue exclusion staining was used to select the best cryoprotectant solution for each cryopreservation method. Primary growth (PG) oocytes showed the best percentage of membrane integrity (63.5 ± 2.99%) when SF4 solution (2 M methanol + 0.1 M trehalose + 10% egg yolk solution) was employed. The vitrification solution, which presented the highest membrane integrity (V2; 1.5 M methanol + 5.5 M Me₂SO + 0.5 M sucrose + 10% egg yolk solution) was selected for Experiment 2. Experiment 2 aimed to compare the vitrification and slow freezing techniques in the following parameters: morphology, oxidative stress, mitochondrial activity, and DNA damage. Frozen ovarian tissue showed higher ROS levels and lower mitochondrial activity than vitrified ovarian tissue. Ultrastructural observations of frozen PG oocytes showed rupture of the plasma membrane, loss of intracellular contents and a large number of damaged mitochondria, while vitrified PG oocytes had intact mitochondria and cell plasma membranes. We conclude that vitrification may be more effective than slow freezing for the cryopreservation of zebrafish ovarian tissue.

Objectives: Consumption of high-fat and high-sugar diets in Western countries has increased significantly causing major global health problems including metabolic syndrome and obesity. In addition, studies have suggested that obesity can lead to learning and memory deficits. In this context, the use of natural compounds with low costs, minor side effects and increased antioxidant activity, such as teas, could reduce the damages induced by obesity. We investigated the effect of white, green, red, and black teas (Camellia sinensis) and their possible neuroprotective mechanisms in an experimental obesity model induced by a cafeteria diet (CD). Methods: Female Swiss mice (20–30 g) were used; they received a normal diet or a hypercaloric diet (CD) during 8 weeks. Concomitantly, some mice received orally white, green, red, or black teas (1% dose) or water. Results: The mice subjected to CD showed weight gain, body fat accumulation, increased glucose, cholesterol, and triglycerides, associated to recognition memory deficits and increased reactive species (RS) levels and acetylcholinesterase (AChE) activity in the hippocampus. All teas significantly reduced AChE activity and partially reduced fat accumulation. Green and red teas reduced memory deficit. White, green, and black teas reduced RS levels, while only green and black tea reduced plasma triglyceride levels. Discussion: According to the results obtained it is possible to conclude that green tea was better than other teas in reducing effects of the CD model, being able to protect a greater number of parameters.