Beta-sitosterol and beta-sitosterol glucoside stimulate human peripheral blood lymphocyte proliferation: implications for their use as an immunomodulatory vitamin combination
Bouic, P.J.; Etsebeth, S.; Liebenberg, R.W.; Albrecht, C.F.; Pegel, K.; Van Jaarsveld, P.P.
International Journal of Immunopharmacology 18(12): 693-700
ISSN/ISBN: 0192-0561 PMID: 9172012 DOI: 10.1016/s0192-0561(97)85551-8
The phytosterols, beta-sitosterol (BSS), and its glucoside (BSSG) enhance the in vitro proliferative response of T-cells stimulated by sub-optimal concentrations of phytohaemagglutinin (PHA) several fold at extremely low concentrations (femtogram level). A 100:1 (mass:mass) ratio of BSS:BSSG (termed essential sterolin formulation, ESF) showed higher stimulation than the individual sterols at the same concentration. In vivo activity of ESF was also demonstrated when volunteers ingested ESF for 4 weeks. Proliferation of their T-cells, stimulated maximally with PHA, was significantly enhanced (20-920%) when compared to baseline values. In vitro, ESF (1 microgram.ml) was able to significantly enhance the expression of CD25 and HLA-Dr activation antigens on T-cells and increased the secretion, into the medium, of IL-2 and gamma interferon. NK-cell activity was also increased by BSS and BSSG alone, but with EST a higher activity was always found at different effector:target ratios (100:1 12:1).