Inhibitory Effect of Conjugated α‐Linolenic Acid from Bifidobacteria of Intestinal Origin on SW480 Cancer Cells

Abstract

In this study, we assessed the ability of six strains of bifidobacteria (previously shown by us to possess the ability to convert linoleic acid to c9, t11-conjugated linoleic acid (CLA) to grow in the presence of alpha-linolenic acid and to generate conjugated isomers of the fatty acid substrate during fermentation for 42 h. The six strains of bifidobacteria were grown in modified MRS (mMRS) containing alpha-linolenic acid for 42 h at 37 degrees C, after which the fatty acid composition of the growth medium was assessed by gas liquid chromatography (GLC). Indeed, following fermentation of one of the strains, namely Bifidobacterium breve NCIMB 702258, in the presence of 0.41 mg/ml alpha-linolenic acid, 79.1% was converted to the conjugated isomer, C18:3 c9, t11, c15 conjugated alpha-linolenic acid (CALA). To examine the inhibitory effect of the fermented oils produced, SW480 colon cancer cells were cultured in the presence of the extracted fermented oil (10-50 microg/ml) for 5 days. The data indicate an inhibitory effect on cell growth (p <or= 0.001) of CALA, with cell numbers reduced by 85% at a concentration of 180 microM, compared with a reduction of only 50% with alpha-linolenic acid (p <or= 0.01).

Mining bifidobacteria from the neonatal gastrointestinal tract for conjugated linolenic acid production

“…Microbial production of CLNA Bifidobacteria are able to produce different conjugated fatty acids including CLA, CLNA and conjugated stearidonic acid (CSA), when the relative substrates are freely present in the growth medium. 5,8,[18][19][20] All the F-6-PPK positive isolates were analyzed for CLNA production. After incubation for 72 h with 0.37 mg/ml of free linolenic acid, fatty acid profiles from all those isolates were analyzed via GC-MS. All of the isolates grew well in the mMRS broth plus linolenic acid, which means those isolates had better free fatty acid resistance, as in previous publications, some bifidobacteria strains could not grow in free fatty acid containing medium.…”

“…5 Microbial CLNA has been identified with anti-cancer activities in vitro in line with those isomers from plant seeds extract. 8 Additionally, most microbial CLNA was in the supernatant fluid which eliminates the process of further separation and purification.…”

Conjugated Linoleic Acid in Milk and Fermented Milks: Variation and Effects of the Technological Processes

“…Studies have shown that strains of B. breve could be used as starter cultures for the development of functional milk products with high concentrations of bioactive lipids such as CLA (61)(62)(63)(64)(65)(66). Conversions of linoleic acid into CLA up to 74% were obtained using three strains of B. breve (ZL12-28, 29M2 and M7-70) isolated from breast milk (62).…”

Chemical and physiological aspects of isomers of conjugated fatty acids

“…Nevertheless, synthetic CLNAs have proved to exert several physiological functions that are important and unique (KOBA; BELURY; SUGANO, 2007). Moreover, Coakley et al (2009) showed that five bifidobacteria strains from human intestinal origin converted LNA to CLNAs and speculated that the ability of bifidobacteria originated from the human intestine to biosynthesis biologically active lipids such as cis9, trans11 CLA and CLNA may be related to their suggested therapeutic effects.…”