Ethyl acetate extracts of alfalfa (Medicago sativa L.) sprouts inhibit lipopolysaccharide-induced inflammation in vitro and in vivo

摘要

This study aimed to investigate if food components that exert anti-inflammatory effects may be used for inflammatory disorders by examining alfalfa sprout ethyl acetate extract (ASEA). The cytokine profile and life span of BALB/c mice with acute inflammation after intra-peritoneal (ip) injection of 15 mg/kg BW lipopolysaccharide (LPS) were determined. The results showed that the life span of LPS-induced inflammatory mice were negatively correlated with serum levels of TNF-α, IL-6, and IL-1β at 9 hr after LPS-injection, which indicated that suppressing these cytokines in the late phase of inflammation may be beneficial for survival. The in vitro experiment then showed that ASEA significantly reduced IL-6 and IL-1β production and the NF-κB trans-activation activity of mitogen-stimulated RAW264.7 cells. To further evaluate the anti-inflammatory effects of ASEA in vivo, BALB/c mice were tube-fed with 25 mg ASEA/kg BW/day in 50 μl sunflower oil, while the control and PDTC (pyrrolidine dithiocarbamate, an anti-inflammatory agent) groups were tube-fed with 50 μl sunflower oil/day only. After one week of tube-feeding, the PDTC group was injected with 50 mg/kg BW PDTC and one hour later, all of the mice were injected with 15 mg/kg BW LPS. The results showed that the ASEA and PDTC groups had significantly lower serum TNF-α, IL-6, and IL-1β levels at 9 hr after LPS challenge, and significantly higher survival rates than the control group. This study suggests that ASEA supplementation can suppress the production of pro-inflammatory cytokines and alleviate acute inflammatory hazards.