The ethyl acetate extract of alfalfa sprout ameliorates disease severity of autoimmune-prone MRL-lpr/lpr mice

Abstract

Previous study showed that soy isoflavone supplement alleviates disease severity in autoimmune-prone mice. As the ethyl acetate extract of alfalfa sprout (AS) has selective oestrogenic and anti-inflammatory activity, this study evaluated the effects of alfalfa sprout ethyl acetate extract (ASEA) on disease severity of systemic lupus erythematosus, using autoimmune-prone female MRL-lpr/lpr mice. In Experiment 1, five groups of 12-week-old female mice were per oral treated with vehicle (control), lyophilized AS (550 mg wt/kg BW), ASEA (ASEA, 25 mg/kg BW), coumestrol (CUM, 0.075 mg/kg BW) and tamoxifen (TAM, 0.375 mg/kg BW) as the positive control. The onset of proteinuria was delayed, and the life span was significantly longer in the ASEA and TAM groups but neither in the AS nor in the CUM groups, compared to the control. To examine the changes in the immunological parameters related to disease process, three more groups of MRL-lpr/lpr female mice (control, ASEA and TAM) were fed in a similar manner for 6 weeks in the Experiment 2. Flow cytometric analysis of splenocytes showed a significantly lower percentage of activated T cells in the ASEA and TAM groups. The ex-vivo interferon-gamma and interleukin (IL)-4 production from splenocytes and tumour necrosis factor-alpha and IL-1beta production from peritoneal exudate cells were also significantly lower in the ASEA group compared with the control. The ASEA group also had less severe glomerulonephritis. Thus, ASEA attenuated cytokine and inflammatory responses of self-reactive lymphocytes, decreased the disease severity, increased survival and life span of the autoimmune-prone MRL-lpr/lpr mice, suggesting a potential of ASEA in the treatment of autoimmune diseases.