Immune Modulation
Reference: Bouic PJD, Etsebeth S, Liebenberg RW, Albrecht CF, et al. Beta-sitosterol and beta-sitosterol glucoside stimulate human peripheral blood lymphocyte proliferation: implications for their use as an immunomodulatory vitamin combination. Int J Immunopharm 1996; 18:693-700.
Study: In this paper, the immunological actions of sterols/sterolins (Moducare®) were considered by both in vitro and in vivo experiments. In the first in vitro study, venous blood was drawn from healthy laboratory volunteers and employed as a source of T cells. These T cells were added to cell cultures and incubated along with 3H-thymidine and stimulated suboptimally with a mitogen for 72 hours. Varying concentrations of beta-sitosterol (BSS), beta-sitosterol glucosides (BSSG), and a 100:1 ratio of BSS/BSSG (Moducare®) were then added to these mixtures and laboratory markers of immune response such as T cell proliferation, CD25 and HLA-DR activation, IL-2 secretion, gamma interferon release, and natural killer (NK) cell activity were recorded.
In the in vivo portion of the trial, six volunteers ingested one capsule of Moducare® (20mg BSS and 0.2mg BSSG) 3 times a day for four weeks. Two volunteers were given placebo capsules at the same dosing schedule. Blood samples were collected at 0, 1, 2 and 4 weeks. The resulting T cells were incubated with 3H-thymidine and stimulated maximally with the PHA mitogen allowing the researchers to evaluate T cell proliferation at baseline and day 30.
Results: In vitro results demonstrated that although both phytosterols (BSS and BSSG) enhance the proliferative response of T cells to mitogen stimulation at very low concentrations, a 100:1 ratio of BSS to BSSG provided a larger stimulatory effect than could be achieved by the individual phytosterols and sterolins alone. Moducare® at a concentration of 1µg/ml was able to double the expression of CD25 and HLA-DR activation antigens on T cells, and increase the secretion of IL-2 (ranging from 17 to 23%) and gamma interferon (ranging from 36 to 41%) compared to controls. In addition, the combination of BSS/BSSG (100:1) at 1µg/ml was consistently more active at stimulating the lytic action of NK cells (effector) on a cancer K562 cell line (target) than BSS or BSSG on their own. Different effector:target ratios were tested ranging from 12,25,50 and 100:1 and for all these cell ratios the BSS/BSSG stimulated NK cells were the most effective.
In vivo results from the eight volunteers concluded that compared to baseline values, T cell proliferative responses increased from 20 to 920% in those taking Moducare® over 4 weeks compared to a relatively unchanged (-2 to 13%) reaction in the placebo group.
Clinical Summary: The unique combination of plant sterols/sterolins as found in the product Moducare® significantly enhances the laboratory markers of immunity both in vitro and in vivo.
