Abstract
The metabolites of lactic acid bacteria (LAB) and bifidobacteria (Bb) have recently received a lot of attention due to their ability to protect interactions in blood and tissues, as well as their biodegradability and biocompatibility in human tissue. Exopolysaccharides (EPS) derived from bacteria have a long history of use in therapeutic and other industrial applications with no adverse effects. In this regard, EPSs were isolated and characterized from LAB and Bb culture supernatants to determine their antioxidant, antitumor, and periodontal regeneration properties. The antioxidant capacity of the EPSs varied with concentration (0.625–20 mg/ml). The highest antioxidant activity was found in LAB:
Streptococcus thermophiles
DSM 24731-EPS
1
,
Lactobacillus delbrueckii
ssp.
bulgaricus
DSM 20081
T
-EPS
5
,
Limosilactobacillus fermentum
DSM 20049-EPS
6
, and Bb;
Bifidobacterium longum
ssp.
longum
DSM 200707-EPS
10
. Human breast cancer cells (MCF7), human colon cancer cells (CaCo2), human liver cancer cells (HepG2), and human embryonic kidney 293 (HEK 293) cells were used as controls to assess the antitumor properties of the selected EPSs. According to the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) assay, EPS
5
had the highest cytotoxicity against MCF7, CaCo2, and HepG2, with IC
50
values of 7.91, 10.69, and 9.12 mg/ml, respectively. Lactate dehydrogenase (LDH) activity was significantly higher in cell lines treated with EPS
5
-IC
50
values compared to other EPSs-IC
50
values (
p
< 0.05). Real time (RT)-PCR results showed that EPS
5
treatment increased
Bax
,
Caspase 8
,
Caspase 3
, and
p53
gene expression. The expression of the
BCL2
,
MCL1
, and
Vimentin
genes, on the other hand, was reduced. The MTT test was used to examine the effect of EPS
5
on the viability of human periodontal ligament fibroblast cells (hPDLFCs), and it was discovered that EPS
5
increased hPDLFC viability. According to high-performance liquid chromatography (HPLC) analysis, galactose made up 12.5% of EPS
5
. The findings of this study pave the way for the use of EPS, which hold great promise for a variety of therapeutic purposes such as antioxidant, antitumor, and periodontal regeneration.
Therapeutic applications of exopolysaccharides derived from lactic acid bacteria and bifidobacteria.