Immunomodulatory effects of mixed Weissella cibaria JW15 with water extract of black soybean and burdock on Listeria monocytogenes infection in mice.

Abstract

The objective of this study is to assess immunomodulatory effects of mixed Weissella (W.) cibaria JW15 strain with water extract of black soybean (Glycine max) and burdock (Arctium lappa) on Listeria (L.) monocytogenes infection in mice. Female 7-9 week old BALB/c mice were given a daily dose of 1 × 109 CFU of viable JW15 and JW15 mixed with black soybean (BS) and burdock (BD) in 200 μL PBS for 2 weeks. The nomal control group (NC) and positive control group (PC) were given 200 μL PBS. After 2 weeks, mice were infected with L. monocytogenes (1.0 × 105 CFU/mouse) via the tail vein. The NC was injected with 100 μL PBS without L. monocytogenes. After 2 days, mice were euthanized and their body weights were determined. In addition, their livers and spleens were weighed, and serum were analyzed for cytokine (Interleukin-1β (IL-1β) and Tumor necrosis factor-α (TNF-α)) production. The survival rate was monitored using 5 mice in each group in the same way above until the mice died. Two days after infection with L. monocytogenes, mean spleen weight per body weight (g/kg) of JW15 (5.4 ± 0.88 g/kg), JW15 + BS (6.0 ± 0.64 g/kg), and JW15 + BD (5.3 ± 0.38 g/kg) group were significantly lower than that of the PC (6.8 ± 0.57 g/kg). The level of IL-1β in the serum of JW15 + BD (113.6 ± 31.03 pg/mL) was significantly higher than that of the JW15 (67.9 ± 15.15 pg/mL). Collectively, combination W. cibaria JW15 and water extract of BD and BD have ability to induce synergistic immunomodulative effects and are suitable for consideration as a functional food for humans and functional feed additives for companion animals.