Abstract

Saccharomyces cerevisiae is a well known yeast used safely from ancient times in many biotechnological applications. Nowadays, there is an increasing interest in using yeast as probiotic. Dimethyl nitrosamine (DMN) has been used to induce liver fibrosis in rats. Yeast has been used side by side with the DMN to evaluate the role of its use as a probiotic in the protection against liver fibrosis. Six groups of rats have been used to represent negative and positive controls and other four groups which have been treated by DMN for two weeks and killed after 35 or 60 days. Two of the DMN treatment groups have been fed by yeast from the first 35 to 60 days, respectively. The results show that yeast has no side effect on each of glutamate-oxaloacetate-transaminase (GOT), glutamate-pyruvate-transaminase (GPT) and alkaline phosphatase (ALP) enzyme activities. DMN showed a significant effect on those enzymes. Feeding with yeast for 35 days showed a minor improvement, while feeding them for 60 days showed a significant improvement. Moreover, the expressions of interleukin 1-alpha (IL-1É‘) and interleukin-7 receptor (IL-7r) have been evaluated usingreverse transcription polymerase chain reaction (RT-PCR). The study includes also the analysis of liver histopathology. This study shows the importance of using yeasts as probiotics in the protection against liver injury.

Key words: Yeast, Saccharomyces cerevisiae, probiotic, dimethyl nitrosamine, IL-7r, IL-1É‘.

Abbreviation

DMN, Dimethyl nitrosamine; GOT, glutamate-oxaloacetate-transaminase; GPT, glutamate-pyruvate-transaminase; ALP, alkaline phosphatase;RT-PCR, reverse transcription polymerase chain reaction; IL-1É‘ interleukin 1-alpha;IL-7r, interleukin-7 receptor; LSD, least significant difference.