The effect of lactobacillus cell size on its probiotic characteristics.

Screening for probiotic characteristics is usually associated with a series of assays and a large number of isolates to be tested, which can be sometimes costly and frustrating. For this reason, finding some indicators to predict the probiotic potential would be of great significance. In this study, 10 Lactobacillus strains including L. sakei, L. reuteri, L. delbrueckii subsp. lactis, L. delbrueckii subsp. delbrueckii, L. plantarum, L. acidophilus, L. rhamnosus, L. paracasei, L. salivarius, and L. gasseri were characterized by cell morphology and growth properties. The strains were then examined in terms of some probiotic characteristics including resistance to acid and bile conditions, ability to adhesion to intestinal epithelial cells, antioxidant activity, aggregation characteristics, antibacterial activity, hemolytic activity, and resistance to different antibiotics. Correlations between different quantitative features were analyzed using Pearson's coefficient (r). Results of this study provided first-time evidence for the effects of cell length on probiotic features. Based on statistical analysis, long Lactobacillus strains had often higher antioxidant and aggregation activities. Moreover, these long strains were usually more sensitive to acid and bile conditions and resulted in a lower CFU yield compared to short strains. By conducting morphological tests at the first step of screening, some strains would gain higher priority because of predicting a high performance in some of the desired characteristics. Therefore, the cost and time required for the subsequent tests would be significantly reduced.

Knockdown of Sal-like 4 expression by siRNA induces apoptosis in colorectal cancer.

Colorectal cancer (CRC) is known as the third most common malignancies among men and women and is also the second leading cause of cancer-related deaths worldwide. It has been indicated that a variety of risk factors are involved in the pathogenesis of CRC. Spalt-like transcription factor 4 (SALL4) is known as a transcription factor that plays an important role in the proliferation of cancerous cells. In this study, using a specific sequence of small interfering RNA (siRNA) against the sequence of SALL4, its activity is investigated in the CRC cell line (sw742). The CRC cells (sw742) were cultured and then, using a specific anti-SALL4 siRNA, their toxic doses were determined. Then, the gene is transfected into the cell. Proliferation and expression of the SALL4 and Bcl-2 gene were measured using the real-time polymerase chain reaction method. Cell death was evaluated by propidium iodide staining and fluorescence-activated cell sorting analysis. Our results indicated that the specific concentration of siRNA of the SALL4 gene was 62.5 nmole. Gene expression of SALL4 and Bcl-2 results showed that expression of Bcl-2 gene in the siRNA group was significantly reduced. In conclusion, our finding indicated that it could be used as a therapeutic and diagnostic biomarker in the treatment of patients with CRC.