Dietary supplementation with Cyperus esculentus L (tiger nut) tubers attenuated atherosclerotic lesion in apolipoprotein E knockout mouse associated with inhibition of inflammatory cell responses

Atherosclerosis is a pathological process, where recruitment of mononuclear cells results in the growth of fibro-fatty plaques. Apolipoprotein E (ApoE) is a legend for the uptake of lipoproteins, and deficiency of ApoE leads to the accumulation of low-density lipoprotein. Utilizing ApoE^-/- mouse, which spontaneously develop atherosclerosis on low-fat chow diets, the present study showed that feeding these mice on a diet supplemented with the whole tubers of Cyperus esculentus L (tiger nut) resulted in attenuation of the development of atherosclerotic lesions. The anti-atherosclerotic effect was associated with a decrease in the number of monocytes, macrophages and dendritic cells in blood, and the expression of IL-2Rα and LFA-1 by these cells. Further, in vitro proliferation of blood and spleen cells from tiger nut-fed ApoE^-/- mice showed lower proliferation in responses to ConA and LPS, a T and B cell mitogen, respectively. Further, in vitro treatment of blood and spleen cells with water or ethanol extracts of tiger nut markedly increased their proliferation in response to ConA. Collectively, these data indicate that ingredients of tiger nut tubers exhibit anti-inflammatory properties upon inflammation, and immunostimulatory effects in immunocompetent hosts.