Protective Effects of Kefir Against Unpredictable Chronic Stress Alterations in Mice Central Nervous System, Heart, and Kidney.

Kefir is a probiotic mixture with anxiolytic and antioxidant properties. Chronic stress can lead to anxiety disorders and increase oxidative damage in organs such as the heart and kidney. In this study, we examined whether kefir ameliorates the anxiety-like behavior of mice submitted to chronic unpredictable stress (CUS) by modulating brain-derived neurotrophic factor (BDNF) and corticosterone levels and whether kefir modifies the oxidative parameters in the heart and kidney of mice. Male Swiss mice received kefir (0.3 mL/100 g/day) or milk for 30 days (gavage). On the 10th day, the mice were submitted to CUS. Behavioral analysis was performed using the elevated plus maze and forced swimming tests. BDNF levels were analyzed in brain tissues. Heart and kidney superoxide dismutase (SOD), catalase, glutathione (GSH), thiobarbituric acid reactive substances (TBARS), 3-nitrotyrosine, metalloproteinase-2 (MMP-2), and plasma corticosterone were evaluated. Kefir reverted the CUS-induced decrease in the time spent in the open arms, the increase in grooming frequency, and decrease in the head dipping frequency, but not the reduced immobility time. CUS decreased the cerebellum BDNF levels and increased corticosterone levels, which were restored by Kefir. Neither catalase and SOD activities nor GSH, TBARS, 3-nitrotyrosine, and MMP-2 were modified by CUS in the heart. In the kidney, CUS increased 3-nitrotyrosine and MMP-2. Kefir increased the antioxidant defense in the heart and kidney of control and CUS mice. These results suggest that kefir ameliorated CUS-induced anxiety-like behavior by modulating brain BDNF and corticosterone levels. Kefir also increased the antioxidant defense of mice heart and kidney.

Antimicrobial potential, phytochemical profile, cytotoxic and genotoxic screening of Sedum praealtum A. DC. (balsam).

BACKGROUND: Sedum praealtum has been used for a long time in traditional medicine as an analgesic and anti-inflammatory agent. Its beneficial effects have been known since ancient times, when Latinos used it to treat sore and swollen eyes. This research evaluated the antimicrobial potential, the cytotoxic and genotoxic effects, and some chromatographic profiles of the hydroethanolic extract of leaves, stems and roots of S. praealtum. METHODS: The antimicrobial activities were carried out by broth microdilution and agar diffusion. In vitro cytotoxicity was evaluated by cell cultures of Aedes albopictus and the selectivity index (SI) was estimated: SI=CI50/MIC. Genotoxic and systemic toxic effects of S. praealtum leaves were analyzed by micronucleus assay in mice bone marrow. Chromatographic profiles and mass spectra were investigated by GC-MS. RESULTS: Gram-positive (B. subtilis, B. cereus, M. luteus, E. faecalis and S. aureus) and gram-negative (E. coli, E. aerogenes, S. marcescens, P. aeruginosa, P. mirabilis and S. typhimurium) bacteria exhibited MICs ranging from 12.5-50 and 0-50 mg/ml, respectively. Sedum praealtum showed no efficacy against M. tuberculosis and M. bovis. Cytotoxicity (CI50) of S. praealtum was 4.22 and 5.96 mg/ml for leaves and stems, respectively, while its roots showed no cytotoxicity. Micronucleated polychromatic erythrocytes (MNPCEs) analyzes showed no differences between treatment doses (0.5-2 g/kg) and negative control (NaCl), but the PCE/NCE ratio (polychromatic erythrocyte/normochromatic erythrocyte) showed significant differences. Phytochemical screening identified thirteen compounds in the leaves, stems and roots of S. praealtum potentially associated with their biological activities. CONCLUSIONS: This research comprises a first scientific study on genotoxicity, cytotoxicity and antimicrobial effects of S. praealtum (Balsam), and it provides an initial theoretical foundation for its comprehensive use. Results showed antibacterial action of S. praealtum against gram-positive bacteria and some gram-negative species (depending on the plant anatomical part), but ineffective antimycobacterial action. However, S. praealtum leaves and stems display potential cytotoxicity, contributing to the SI < 1 values. In addition, S. praealtum leaves exhibit no clastogenic and/or aneugenic effects, but it has systemic toxicity dose-independent.

In vitro mutagenicity assay (Ames test) and phytochemical characterization of seeds oil of Helianthus annuus Linné (sunflower).

The objective of this research was to investigate the genotoxic potential of the oil of H. annuus L. (sunflower) seeds via the Ames test as well as its oxidative properties and lipid composition. The pre-incubation method, system metabolic activation (S9 fraction) and five S. typhimurium strains (TA97, TA98, TA100, TA1535 and TA102) were employed for the Ames test. The oxidative stability and fatty acid composition were analyzed by standard methods and gas chromatography. A revertant analysis showed no significant differences between the treatment doses (10-200 µl/plate) and the negative controls, regardless of S9+ and S9-, and included all of the S. typhimurium strains. Chromatographic analysis showed high levels of polyunsaturated fatty acids, followed by monounsaturated, saturated and total trans-isomers. Among the polyunsaturated, monounsaturated and saturated fatty acids, linoleic, oleic and palmitic acids predominated. The results suggest that the sunflower oil is not genotoxic as indicated by frameshift mutations and base pair substitutions regardless of the treatment dose, but shows dose-dependent toxicity. The oxidative properties of the sunflower oil were consistent with the requirements of national and international standards. However, its composition could also indicate phytotherapeutic properties.

Evaluation of the mutagenicity and antimutagenicity of Ziziphus joazeiro Mart. bark in the micronucleus assay.

The aim of this study was to evaluate the mutagenicity (clastogenicity/aneugenicity) of a glycolic extract of Ziziphus joazeiro bark (GEZJ) by the micronucleus assay in mice bone marrow. Antimutagenic activity was also assessed using treatments associated with GEZJ and doxorubicin (DXR). Mice were evaluated 24-48 h after exposure to positive (N-nitroso-N-ethylurea, NEU - 50 mg.kg(-1) and DXR - 5 mg.kg(-1)) and negative (150 mM NaCl) controls, as well as treatment with GEZJ (0.5-2 g.kg(-1)), GEZJ (2 g.kg(-1)) + NEU and GEZJ (2 g.kg(-1)) + DXR. There were no significant differences in the frequencies of micronucleated polychromatic erythrocytes in mice treated with GEJZ and GEJZ + DXR compared to the negative controls, indicating that GEZJ was not mutagenic. Analysis of the polychromatic:normochromatic erythrocyte ratio revealed significant differences in the responses to doses of 0.5 g.kg(-1) and 1-2 g.kg(-1) and the positive control (NEU). These results indicated no systemic toxicity and moderate toxicity at lower and higher doses of GEZJ. The lack of mutagenicity and systemic toxicity in the antimutagenic assays, especially for treatment with GEZJ + DXR, suggested that phytochemical compounds in Z. joazeiro bark attenuated DXR-induced mutagenicity and the moderate systemic toxicity of a high dose of Z. joazeiro bark (2 g.kg(-1)). Further studies on the genotoxicity of Z. joazeiro extracts are necessary to establish the possible health risk in humans and to determine the potential as a chemopreventive agent for therapeutic use.