Fermentative effects by probiotic Lactobacillus brevis B7 on antioxidant and anti-inflammatory properties of hydroponic ginseng

Abstract

Soil-cultivation presents environmental limitations and requires considerable labor, space, and water supply. Alternatively, hydroponically-cultured ginseng (HG) was improved its productivity, availability, and functionality. Improvement of bio-functionality by probiotic fermentation also has been studied. Therefore, in this study, HG was fermented using probiotics to enhance antioxidant and anti-inflammatory activities. Soil-cultivated ginseng (SG), 1 and 2-year HG (HG1, HG2) were extracted using 70% ethanol and fermented by Lactobacillus brevis B7. After fermentation, the phenolic and flavonoid contents, and antioxidant and NO scavenging activities were increased, and HG showed higher bioactivities than SG. Particularly, fermented HG2 showed the highest antioxidant and anti-inflammatory activities and significantly decreased the level of inflammatory mediators. Furthermore, fermented HG2 also effectively inhibited NF-κB signaling pathway. These results suggested that fermented HG significantly enhanced functionality compared to SG and non-fermented HG. This suggests that fermented HG is a potentially useful ingredient for developing health-functional foods or pharmaceutical materials.

Keywords: Anti-inflammatory activity; Antioxidant activity; Fermentation; Hydroponic ginseng; Probiotics.

Fig. 1

Changes in pH and growth characteristics of L. brevis B7 during fermentation of ginseng extracts. ○, Soil-cultivated ginseng extract; □, 1-year cultivated hydroponic ginseng extract; △, 2-year cultivated hydroponic ginseng extract

Fig. 2

HPLC analysis of non-fermented ginseng and fermented ginseng extracts. (A) Mixtures of ginsenoside standard materials; (B) soil-cultivated ginseng extract; (C) 1-year cultivated hydroponic ginseng extract; (D) 2-year cultivated hydroponic ginseng extract; (E) fermented 2-year cultivated hydroponic ginseng extract by L. brevis B7 for 1 day; (F) fermented 2-year cultivated hydroponic ginseng extract by L. brevis B7 for 7 days. 1. Re; 2, Rf; 3, Rb₁; 4, Rc; 5, Rb₂; 6, Rb₃; 7, Rd; 8, F₂; 9, Rg₃; 10, CK

Fig. 3

Antioxidant activity of non-fermented and fermented ginseng extracts. (A) DPPH radical scavenging assay; (B) ABTS radical scavenging assay; (C) reducing power assay; (D) FRAP assay. ■, 1.0 mg/mL; , 2.5 mg/mL; □, 5.0 mg/mL. NF non-fermented ginseng extract, F fermented ginseng extract by L. brevis B7, SG, soil-cultivated ginseng, HG1 1-year cultivated hydroponic ginseng, HG2 2-year cultivated hydroponic ginseng. All data have been represented as mean ± standard deviation with triplicate experiments. The different letters above error bars indicate significant differences within the same assay (p < 0.05)

Fig. 4

Downregulation of nitric oxide (A–C) and pro-inflammatory cytokines (D–G) production by treatment with non-fermented and fermented ginseng extracts in LPS-induced RAW 264.7 cells. (A) Soil-cultivated ginseng; (B) 1-year cultivated hydroponic ginseng; (C) 2-year cultivated hydroponic ginseng; (D) TNF-α; (E) IL-1β; (F) IL-6; (G) PGE₂. ELISA analysis (D–G) was performed by treatment with HG2. , without LPS treatment; , LPS treatment with 1 µg/mL concentration; ■, non-fermented ginseng extracts; □, fermented ginseng extracts by L. brevis B7. All data have been presented as mean ± standard deviation with triplicate analysis. The different letters above error bars indicate significant differences within the same ginseng type (p < 0.05)

Fig. 5

Downregulation of COX-2 and iNOS expression (A–C), and NF-κB signaling pathway (D–F) by treatment with non-fermented and fermented 2-year cultured hydroponic ginseng extracts in LPS-induced RAW 264.7 cells. (A, D) Immunoblotting results; (B) COX-2; (C) iNOS; (E) p-p65; (F) IκB-α. Relative band intensity was measured against β-actin. , without LPS treatment; , LPS treatment with 1 µg/mL concentration; ■, 0.2 mg/mL; □, 0.4 mg/mL. NF, non-fermented ginseng extracts; F, fermented ginseng extracts by L. brevis B7. Cells were subjected to treatments with non-fermented and fermented HG2 extracts (0.2 and 0.4 mg/mL) and inflammatory responses were induced using LPS for 30 min (A–C) and 24 h (D–F). The protein expression levels of pro-inflammatory mediators and β-actin were measured using western blotting. β-Actin was used as a loading control