The effect of yeast Yarrowia lipolytica on the antioxidant indices and macro-and microelements in blood plasma of turkey hens.

The aim of the study was to assess the effect of different amounts of Yarrowia lipolytica yeast on the redox response and content of macro- and microelements in the blood plasma of turkey hens. The experiment was carried out on 240 turkey hens aged from 1 to 16 weeks. The birds were randomly assigned to 3 experimental groups of 80 birds each. Group I served as a control (K) and did not receive any experimental compounds. The turkey hens from the experimental groups (YL3 and YL6) were administered dried Yarrowia lipolytica yeast in their feed mixtures in the amount of 3% (YL3) or 6% (YL6). Yarrowia lipolytica yeast in the feed mixtures for the turkey hens did not induce oxidation reactions in the organism of the birds. However, an increase in catalase activity and a reduction in the level of LOOH, MDA and vitamin C were observed in the blood plasma of the turkey hens whose diet was supplemented with YL yeast. In the case of other indices, such as superoxide dismutase activity and total antioxidant potential (FRAP), the additive caused no significant changes. Administering Yarrowia lipolytica yeast to turkey hens may stimulate the enzymatic response of the antioxidant system (e.g. increasing catalase activity), mainly by increasing the concentration of iron in the plasma.

Unexpectedly strong effect of caffeine on the vitality of western honeybees (Apis mellifera).

We examined the influence of caffeine on honeybee lifespan, Nosema resistance, key enzyme activities, metabolic compound concentrations, and total DNA methylation levels. Caffeine slowed age-related metabolic tendencies. Bees that consumed caffeine lived longer and were not infested with Nosema spp. Caffeine-treated workers had higher protein concentrations. The levels increased with aging but they then decreased in older bees. Caffeine increased the activities of antioxidant enzymes (SOD, GPx, CAT, GST), AST, ALT, ALP, neutral proteases, and protease inhibitors, and the concentrations of uric acid, triglycerides, cholesterol, glucose, and Ca2+. Acidic and alkaline protease activities were lower in the bees treated with caffeine. Creatinine and Mg2+ concentrations were higher in the caffeine-treated workers but only up to 14 days of age. Caffeine significantly decreased DNA methylation levels in older bees. The compound could be considered as a natural diet supplement increasing apian resistance to stress factors. Our studies will enhance possibilities of using Apis mellifera as a model organism in gerontological studies.