[6]-Gingerol dose-dependent toxicity, its role against lipopolysaccharide insult in sea urchin (Paracentrotus lividus Lamarck), and antimicrobial activity

Ginger (Zingiber officinale, fam: Zingiberaceae) is a plant whose rhizome is used by humans as a spice or anti-inflammatory and antioxidant. It is composed of many constituents, though the majority are gingerols and shogaols. Although the bioactive components have been found, the mechanisms of action of the single components still need to be determined. Ginger compounds may be toxic at high doses, and therefore its use as a food/drug requires better guidelines. This study focuses on one of the major ginger compounds, the [6]-gingerol, and the relationships between the dosage used and the effects on sea urchin Paracentrotus lividus. Toxicity tests with morphological and viability evaluations were done on embryos and adult immune cells. A dose-dependent toxic effect of [6]-gingerol was observed. It increased the number of abnormal morphologies and reduced the size of embryos up to 100% with the dose of 100 ?M. Cell viability of immune cells gradually decreased over time, up to 40% with 50 ?M after 6 h. The expression of genes coding for inflammatory (Pl-NF-kB, Pl-Tlr4, Pl-tbk1, Pl-jun) and stress responsive (Pl-grp78, Pl-XPB-ERCC3) proteins were measured in immune cells stimulated with lipopolysaccharide after [6]-gingerol pre-treament. The results suggested that low doses of [6]-gingerol (10 and 20 ?M) might confer protection to sea urchin immune cells. Different doses of [6]-gingerol (10, 20, and 50 ?M) tested on three different non-pathogenic bacteria did not show any antimicrobial effects. The results suggested that [6]-gingerol might be beneficial as a functional food.