Premium
Specific immunomodulatory and secretory activities of stevioside (SVS) and steviol (SVO) in intestinal cells
Author(s) -
boonkaewwan chaiwat,
Ao Mei,
toskulkao chaivat,
Rao Mrinalini Chatta
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a1319-c
Subject(s) - interleukin 8 , chemistry , pharmacology , medicine , cytokine
SVS, isolated from Stevia rebaudiana, is used commercially as a sweetener. It is metabolized to SVO by colonic flora. We showed that SVS attenuates TNFα and IL1β synthesis in LPS‐stimulated THP1 monocytes by interfering with NFκB signaling. We hypothesize that SVS has similar immunomodulatory effects in the intestine. The effects of SVS and SVO on the biological activities of T84 and IEC18 cells were examined. Short‐term exposure (30 min) to either SVO (0.1 mM) or SVS (1 mM) increased I − efflux from T‐84 cells. Using an ELISA kit, IL8 release was measured in TNFα‐treated and control cells ± SVS or SVO (n > 3). As shown by others, TNFα caused a time‐ and dose‐dependent increase in IL8 release in T84 cells: maximally at 8 h and 100 ng/ml (2103 + 228 vs. 218 + 57 pg/ml). SVO (> 0.2 mM) or SVS (> 2 mM) for 8 h modestly increased IL8 release (483 + 33 and 586 + 184 pg/ml, respectively) in T84 cells. In contrast to THP1 cells where SVO had no effect, in T84 cells, SVO significantly inhibited (35% at 0.1 mM) and SVS potentiated (136% at 2 mM) TNFα‐mediated IL8 release. Neither TNFα, nor SVO, nor SVS caused IL8 release from IEC18 cells. However, as determined by the MTT assay, in both T84 and IEC18 cells, 0.1 mM SVO was not cytotoxic but > 2 mM SVS decreased cell viability (54 + 1%) suggesting that the IL8 response may be colon‐specific. Thus, long term utilization of SVS should take into consideration its important role in the inflammatory response of colonocytes.