Specific Immunomodulatory and Secretory Activities of Stevioside and Steviol in Intestinal Cells

Abstract

Stevioside, isolated from Stevia rebaudiana, is a commercial sweetener. It was previously demonstrated that stevioside attenuates NF-kappaB-dependent TNF-alpha and IL-1beta synthesis in LPS-stimulated monocytes. The present study examined the effects of stevioside and its metabolite, steviol, on human colon carcinoma cell lines. High concentrations of stevioside (2-5 mM) and steviol (0.2-0.8 mM) decreased cell viability in T84, Caco-2, and HT29 cells. Stevioside (2 mM) potentiated TNF-alpha-mediated IL-8 release in T84 cells. However, steviol (0.01-0.2 mM) significantly suppressed TNF-alpha-induced IL-8 release in all three cell lines. In T84 cells, steviol attenuated TNF-alpha-stimulated IkappaB --> NF-kappaB signaling. Chloride transport was stimulated by steviol (0.1 mM) > stevioside (1 mM) at 30 min. Two biological effects of steviol in the colon are demonstrated for the first time: stimulation of Cl(-) secretion and attenuation of TNF-alpha-stimulated IL-8 production. The immunomodulatory effects of steviol appear to involve NF-kappaB signaling. In contrast, at nontoxic concentrations stevioside affects only Cl(-) secretion.

Chenodeoxycholic acid stimulates Cl− secretion via cAMP signaling and increases cystic fibrosis transmembrane conductance regulator phosphorylation in T84 cells

“…Iodide efflux studies were performed as we have described earlier (5) and are based on the original method of Venglarik et al (34) modified by Chappe et al (7). Briefly, T84 cells were grown in six-well plates.…”

Is Stevia rebaudiana Bertoni a Non Cariogenic Sweetener? A Review

“…The effects of stevioside and its metabolite, steviol, on human colon carcinoma cell lines were studied from Boonkaewwan et al [51] in 2008. Their results demonstrated two biological effects of steviol in the colon: the stimulation of Cl(´) secretion and the attenuation of TNF-alpha stimulated IL-8 production.…”

The major pathway by which polymeric formula reduces inflammation in intestinal epithelial cells: a microarray-based analysis

“…Prior to experiments, cells were washed twice with warm sterile 19 Dulbecco's phosphatebuffered saline (PBS; Gibco) and then treated with 100 ng/ ml of TNF-a in the presence or absence of PF (1:5 dilution) for 5 h (Boonkaewwan et al 2008;de Jong et al 2007). In each series of experiments, supernatants were collected following stimulation of the cells and stored at -80°C until required for subsequent analysis.…”