Chemoprevention of Tumor Metastasis by Liposomal .BETA.-Sitosterol Intake

Abstract

To investigate chemopreventive effect of liposomal b b-sitosterol on tumor metastasis, we prepared liposomal b b-sitosterol composed of egg yolk phosphatidylcholine for oral delivery. Although orally administered b b-sitosterol (4 m mmol as b b-sitosterol/mouse) was not absorbed into plasma, the amount of immune response cytokines such as IL-12 and IL-18 was increased in the small intestine after the liposome intake. Moreover, after daily oral administration of the liposome for 7 d, natural killer (NK) cell activity in the mice was increased, suggesting that the immune surveillance activity of mice was enhanced by the liposomal b b-sitosterol intake. Thus, we examined metastatic potential of B16BL6 melanoma cells, which were intravenously injected into mice after sequential administration of liposomal b b-sitosterol for 7 d. The number of metastatic colonies in the lungs was significantly less than that of control group two weeks after the injections of the cells. These results suggest that daily liposomal b b-sitosterol intake prevents tumor metastasis may be due to enhancement of gut immune surveillance systems.

Gene regulation in β-sitosterol-mediated stimulation of adipogenesis, glucose uptake, and lipid mobilization in rat primary adipocytes

“…SIT has been reported to elicit a multitude of bioactivities, which include, antioxidant [40], anticancer [5], antiinflammatory [6], angiogenic [11,28], chemopreventive [16], and immunomodulatory activities [8][9][10]. SIT is indicated for hypercholesterolemia [24] coronary heart disease [38], and benign prostate hyperplasia [39].…”

Critical Analysis on Characterization, Systemic Effect, and Therapeutic Potential of Beta-Sitosterol: A Plant-Derived Orphan Phytosterol

“…BS has poor absorptivity and therefore additives for enhancing its bioavailability or drug delivery with different dosage forms did not progress extensively even though its pharmacokinetic and bioavailability data was reported long ago [72,73,80]. Liposomal BS has been reported along with its ability to increase natural killer cell activity and decrease metastatic colonies in the lungs significantly in comparison to the control group [198]. BS has been reported to act as a model drug or substance for a novel formulation [199] and to test the efficacy in emulsion form [200].…”

Chemical composition and antiproliferative activity of Acalypha californica

“…Numerous experimental studies have demonstrated the antiproliferative effects of ␤-sitosterol and stigmasterol on colon, breast, prostate, stomach and lung cancers (Choon et al, 2009;Rubis et al, 2008;Younghuan et al, 2009). Also, has been studied the effect of reduction of metastasis presented by these compounds (Imanaka et al, 2008). The mechanisms of action by which is achieved the antitumor activity have also been elucidated, these substances can alter the membranes of tumor cells, can activate the sphingomyelin cycle, activate caspases, suppress the expression of bcl-2 and increase bax gene expression (Awad and Fink, 2000).…”