Evaluation of Lactobacillus delbrueckii Supernatant Effects on Cell CycleRegulation, Apoptosis Induction, and Gene Expression in HT-29 ColorectalCancer Cells

Document Type : Original Article

Authors
Mohammad Reza Majid Khoshkholgh Pahlaviani 1
Abbas Ali Rezaeian 2
Amir Emami 3
Seyed Mohammad Mehdi Mahmoodi 1
1 Department of Microbiology, Kaz.C, Islamic Azad University, Kazerun, Iran.
2  Department of Microbiology, Ja.C, Islamic Azad University, Jahrom, Iran.
3 Burn & Wound Healing Research Center, Shi.C, Shiraz, Iran.
10.22088/IJMCM.BUMS.14.3.872
Abstract
This study investigated the anti-tumor properties of Lactobacillus delbrueckii, a probiotic
bacterium, against HT-29 human colorectal cancer cells.
The primary objective was to evaluate the effects of Lactobacillus delbrueckii supernatant
on gene expression, cell viability, apoptosis, and cell cycle progression in HT-29 cells. In
Gilan Province, Iran, a native strain of Lactobacillus delbrueckii was identified from the
supernatant of local yogurt. After treating HT-29 cells with different doses of the
supernatant, the MTT test was used to calculate the IC50 value 24 hours later. Annexin V/PI
staining and flow cytometry were used to evaluate the induction of apoptosis, and real-time
PCR was used to measure changes in gene expression. The results showed that the
supernatant of Lactobacillus delbrueckii strongly and dose-dependently reduced the growth
of HT-29 cells. In addition to causing apoptosis and stopping the cell cycle in the G0/G1
phase, the therapy also increased the number of Sub-G1 cells, which is a sign of cell death.
According to gene expression study, anti-apoptotic genes (AKT, Bcl-2) were
downregulated while pro-apoptotic genes (PTEN, p53, and Bax) were upregulated.
Interestingly, the natural isolate outperformed a conventional strain in terms of anticancer
efficacy. These results demonstrate Lactobacillus delbrueckii's potential as a colorectal
cancer treatment.
Keywords
Keywords: Lac Antineoplast
Apoptosis
Colorectalneoplasms
Gene expression regulation
Cell cycle checkpoints.