Inhibitory Effects of Hot Water Extract of the Stevia Stem on the Contractile Response of the Smooth Muscle of the Guinea Pig Ileum
The effects of a hot water extract of the stem of <I>Stevia rebaudiana</I> on the smooth muscle of isolated guinea pig ileum were investigated. The butyl alcohol layer of the extract antagonized the contractions of the isolated guinea pig ileum induced by histamine (1×10<SUP>−5</SUP> <small>M</small>) and acetylcholine (1×10<SUP>−5</SUP> <small>M</small>) in a concentration-dependent manner. The butyl alcohol layer of the extract also showed inhibition of CaCl<SUB>2</SUB> (1×10<SUP>−3</SUP>–3.8×10<SUP>−1</SUP> <small>M</small>)-induced contractions. The antagonism of the extract was considered to be non-specific, but this action might be related to an influx of extracellular Ca<SUP>2+</SUP>.<BR>With column chromatography preparation, the active component was assumed to be as stevioside. The antagonistic effects exerted by the stem extract of <I>Stevia rebaudiana</I> contributed to the gastroprotective activity of the extract in animals fed dietary histamine.
- Bioscience, biotechnology, and biochemistry
Bioscience, biotechnology, and biochemistry 70(2), 489-494, 2006-02-23
Japan Society for Bioscience, Biotechnology, and Agrochemistry