Anti-inflammatory effect of lignans from flaxseed after fermentation by lactiplantibacillus plantarum SCB0151 in vitro

Lignan, a beneficial constituent of Flaxseed (Linum usitatissimum L.) showed great interest in
researchers because of its multiple functional properties. Nonetheless, a challenge arises due to
the glycosidic structure of lignans, which the gut epithelium cannot readily absorb. Therefore,
we screened 18 strains of Lactiplantibacillus plantarum, Lacticaseibacillus casei, Lactobacillus
acidophilus, Lacticaseibacillus rhamnosus, Pediococcus pentosaceus, Pediococcus acidilactici,
and Enterococcus durans to remove glycosides from flaxseed lignan extract enzymatically.
Among our findings, Lactiplantibacillus plantarum SCB0151 showed the highest activity of β-
glucosidase (8.91 ± 0.04 U/mL) and higher transformed efficiency of Secoisolariciresinol
(SECO) (8.21 ± 0.13%). The conversion rate of Secoisolariciresinol diglucoside (SDG) and the
generation rate of SECO was 58.30 ± 3.78% and 32.13 ± 2.78%, respectively, under the
optimized conditions. According to the LC-HRMSMS analysis, SECO (68.55 ± 6.57 µM), Ferulic
acid (FA) (32.12 ± 2.50 µM), and Coumaric acid (CA) (79.60 ± 6.21 µM) were identified in the
biotransformation products (TP) of flaxseed lignan extract. Results revealed that the TP
exhibited a more pronounced anti-inflammatory effect than the flaxseed lignan extract. SECO,
FA, and CA demonstrated a more inhibitory effect on NO than that of SDG. The expression of
iNOS and COX-2 was significantly suppressed by TP treatment in LPS-induced Raw264.7 cells.
The secretion of IL-6, IL-2, and IL-1β decreased by 87.09 ± 0.99%, 45.40 ± 0.87%, and 53.18 ±
0.83%, respectively, at 60 µg/mL of TP treatment. Given these data, the bioavailability of
flaxseed lignan extract and its anti-inflammatory effect were significantly enhanced by
Lactiplantibacillus plantarum SCB0151, which provided a novel approach to commercializing
flaxseed lignan extract for functional food.