The Radioprotective Effect of Ascorbic Acid and Kefir against Genotoxicity Induced by Exposure in Mice Blood Lymphocytes

A medical and molecular approach to kefir as a therapeutic agent of human microbiota

The imbalanced microbial composition called dysbiosis constitutes a tendency related to different kind of human diseases. To overcome the disadvantages of dysbiosis, the consumption of probiotics is an emerging and promising topic of the last decade. Kefir is a probiotic fermented beverage produced from the fermentation of kefir grains with changing varieties of milk and displays a symbiotic association of bacteria and yeast. The discovery of the concept that fermented foods/beverages such as kefir could modify gut microbiota in humans has widened the borders of precision medicine and now microbiome therapeutics can be considered as a significant part of this field. Kefir seems to have potential to guide and manipulate future replacement/complementary therapies with a variety of beneficial biological/medical properties it has. The aim of this review was a comprehensive recapitulation of probiotic beverage kefir's significant properties mainly focusing of antioxidative, immunomodulatory, apoptotic, antitumor and neuroprotective properties. Apoptotic/antimetastatic effects are regulated at the molecular level by increases in TGF-β1, caspase-3, p53, Bax, Bax:Bcl-2 ratio, p21 and decreases in TGF-α, Bcl-2 and MMP polarization. Neuroprotective effects are revealed upon upregulation of SOD/catalase and anti-inflammatory Treg cells, decreases in repetitive behavior and modulation of apoptotic genes. Besides these significant features that may offer advantages in supplementary cancer therapies, the scope was also extended to recent emerging medical topics and also discussed and evaluated the concept of "psychobiotics". The therapeutic potential of psychobiotic effect is majorly attributed to the increased ratios of Clostridium butyricum, Lactobacillus and Bifidobacterium.

Nrf2-regulated antioxidant response ameliorating ionizing radiation-induced damages explored through in vitro and molecular dynamics simulations

This study aims to investigate the mechanism of natural antioxidant ferulic acid (FA) in reducing oxidative stress followed by its inhibitory effect on the Keap1-Nrf2 complex. FA was treated ex vivo with human blood for 30 min at 37 °C ± 1 °C and exposed to 1.5 Gy of γ- rays of 60Co (0.789 Gy/min) and allowed for repair for an hour at 37 °C ± 1 °C. FA's free radical scavenging capacity was measured using 2,7-dichlorofluorescein diacetate assay and cytogenetic assays. Further, a possible mechanism of protein-ligand interaction between FA and Keap1-Nrf2 pathway protein as a cellular drug target was studied using docking and molecular dynamics simulation. The 1.5 Gy of γ- rays exposed to pre-treated blood with FA showed a significant (p < 0.05) reduction in reactive oxygen species and DNA damage compared to the normal control blood group sample. The ligand-protein transient binding interaction in molecular dynamic simulation over a period of 100 ns was consistent and stable emphasizing complementary charge between the protein and ligand, speculating higher hydrophobic amino acid residues in the Keap1 active pocket. This might sway the Keap1 from interaction with Nrf2, and could lead to nuclear translocation of Nrf2 during radiation-induced oxidative stress. The present study emphasizes the radioprotective effect of FA against 1.5 Gy of γ- rays exposed to human blood and the application of in silico approaches helpful for the possible protective effect of FA.Communicated by Ramaswamy H. Sarma.

Kefir and Its Biological Activities

Kefir is a fermented beverage with renowned probiotics that coexist in symbiotic association with other microorganisms in kefir grains. This beverage consumption is associated with a wide array of nutraceutical benefits, including anti-inflammatory, anti-oxidative, anti-cancer, anti-microbial, anti-diabetic, anti-hypertensive, and anti-hypercholesterolemic effects. Moreover, kefir can be adapted into different substrates which allow the production of new functional beverages to provide product diversification. Being safe and inexpensive, there is an immense global interest in kefir’s nutritional potential. Due to their promising benefits, kefir and kefir-like products have a great prospect for commercialization. This manuscript reviews the therapeutic aspects of kefir to date, and potential applications of kefir products in the health and food industries, along with the limitations. The literature reviewed here demonstrates that there is a growing demand for kefir as a functional food owing to a number of health-promoting properties.