Effects of Lactobacillus plantarum A7 with probiotic potential on colon cancer and normal cells proliferation in comparison with a commercial strain


1 Department of Biotechnology, Faculty of Pharmacy, Isfahan University of Medical Sciences, Isfahan, Iran

2 Department of Microbiology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran

3 Food Security Research Center, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran


Objective(s): Several beneficial effects have been attributed to the probiotic lactic acid bacteria. It was determined that lactobacilli can exert antiproliferative effects on the various cancer cell lines including colon cancer. Effects of lactic acid bacteria on colon cancer may vary from strain to strain and there is a need to find the new probiotic strains with tumor suppressing properties through         in vitro studies.
Materials and Methods: Anti-proliferative activities of heat-killed cells and cell-free supernatants of a native strain of Lactobacillus plantarum A7 and a commercial strain of lactobacillus  rhamnosus GG were assessed on human colon cancer cell lines (Caco-2 and HT-29) and normal cells (L-929), using MTT assay. Cells were seeded at 2×104 cells/mlin 96 well plates and incubated for 24 hr. Then heat-killed cells (OD620: 0.025, 0.0.05, 0.1) and cell-free supernatants of bacteria were added at concentration of 2.5, 5 and 10 mg/ml. After 48 hr incubation MTT (5 mg/ml) was added and the absorbance was measured at 540 nm using ELISA plate reader.
Results: Results showed that heat-killed cells and cell-free supernatants of both probiotic strains reduced the growth rate of cancer and normal cells. These results suggested that anti-proliferative effect may not be an exclusive characteris ticwhich is dedicated to officially approved probiotics.
Conclusion: L. plantarum A7 could be considered as colon cancer biological product, most likely due to its advantages in significant organic acid production.


1. FAO/WHO. Guidelines for the evaluation of probiotics in food. Joint FAO/WHO Working Group Report on Drafting Guide lines for the Evaluation of Probiotics in Food London, Ontario, Canada; 2002.

2. Suzuki C, Kimoto-Nira H, Kobayashi M, Nomura M, Sasaki K, Mizumachi K. Immunomodulatory and cytotoxic effects of various Lactococcus strains on the murine macrophage cell line J774.1. Int J Food Microbiol 2008; 123:159-165.

3. Salminen S, Bouley C, Boutron-Ruault MC, Cummings JH, Franck A, Gibson GR, et al. Functional food science and gastrointestinal physiology and function. Br J Nutr 1998; 80:S147-S171.

4. Kaur IP, Chopra K, Saini A. Probiotics: potential pharmaceutical applications.Eur J Pharm Sci2002; 15:1-9.

5. Liong MT. Roles of probiotics and prebiotics in colon cancer prevention: postulated mechanisms and in-vivo evidence. Int J Mol Sci 2008; 9:854-863.

6. Gupta V, Garg R. Probiotics. Indian J Med Microbiol 2009; 27:202-209.

7. Kumar M, Kumar A, Nagpal R, Mohania D, Behare P, Verma V, et al. Cancer-preventing attributes of probiotics: an update. Int J Food Sci Nutr 2010; 61:473-496.

8. Thirabunyanon M, Boonprasom  P, Niamsup P. Probiotic potential of lactic acid bacteria isolated from fermented dairy milks on antiproliferation ofcolon cancer cells. Biotechnol Lett 2009; 31:571-576.

9. Rafter J. The effects of probiotics on colon cancer development. Nutr Res Rev 2004; 17:277-284.

10. Fotiadis CI, Stoidis CN, Spyropoulos BG, Zografos ED. Role of probiotics, prebiotics and synbiotics in chemoprevention of colorectal cancer. World J Gastroenterol 2008; 14:6453-6457.

11. You HJ, Oh DK, Ji GE. Anticancer ogenic effect of a novel chiroinositol-containing polysaccharide from Bifidobacterium bifidum BGN4. FEMS Microbiol Lett 2004; 240:131-136.

12. Kim JY, Woo HJ, Kim YS, Kim KH, Lee HJ. Cell cycle dysregulation induced by cytoplasm of Lactococcus lactis ssp lactis in SNUC2A, a colon cancer cell line. Nutr Cancer 2003; 46:197-201.

13. Masood MI, Qadir MI, Shirazi JH, Khan IU. Beneficial effects of lactic acid bacteria on human beings. Crit Rev Microbiol 2011; 37:91-98.

14. Mirlohi M, Soleimanian-Zad S, Sheikh-Zeinodin M, Fazeli H. Enumeration of lactobacilli in the fecal flora of infant using two different modified de-Man Rogosa Sharpe media under aerobic and anaerobic incubation. Pak J Biol Sci 2008; 11:876-881.

15. Hentges DJ. The anaerobic microflora of the human body. Clin Infect Dis 1993; 16:S175-S180.

16. Choi SS, Kim Y, Han KS, You S, Oh S, Kim SH. Effects of Lactobacillus strains on cancer cell proliferation and oxidative stress in vitro. Lett Appl Microbiol 2006; 42:452-458.

17. KimY, Lee D, Kim D, Cho J, Yang J, Chung M, et al. Inhibition of proliferation in colon cancer cell lines and harmful enzyme activity of colon bacteria by Bifidobacterium adolescentis SPM0212. Arch Pharm Res 2008; 31:468-473.

18. Lam EK, Tai EK, Koo MW, Wong HP, Wu WK, Yu L, et al. Enhancement of gastric mucosal integrity by Lactobacillus rhamnosus GG. Life Sci 2007; 80:2128-2136.

19. Drisko JA, Giles CK, Bischoff BJ. Probiotics in health maintenance and disease prevention. Altern med Rev 2003; 8:143-155.

20. Yan F, Polk DB. Probiotic bacterium prevents cytokine-induced apoptosis in intestinal epithelial cells. J Biol Chem 2002; 277:50959-50965.

21. Orlando A, Messa C, Linsalata M, Cavallini A, Russo F. Effects of Lactobacillus rhamnosus GG on proliferation and polyamine metabolism in HGC-27 human gastric and DLD-1 colonic cancer cell lines. Immunopharmacol Immunotoxicol 2009; 31:108-116.

22. Kim JU, Kim Y, Han KS, Oh S, Whang KY, Kim JN,                et al. Function of cell-boundand released Exopoly saccharides produced by Lactobacillus rhamnosus ATCC 9595. J Microbiol Biotechnol 2006; 16:939-945.

23. Asha, Gayathri D. Synergistic impact of Lactobacillus fermentum, Lactobacillus plantarum and vincristine on 1,2-dimethylhydrazine-induced colorectal carcinogenesis in mice. Exp Ther Med 2012; 3:1049-1054.