Sesquiterpenoid unsaturated dialdehydes increase the concentration of intracellular free Ca2+ in human neuroblastoma SH-SY5Y cells.

The effect of the three sesquiterpenoid unsaturated dialdehydes--polygodial, isovelleral, and epipolygodial--on intracellular free Ca2+ concentration, [Ca2+]i, was investigated in the human neuroblastoma cell line SH-SY5Y. [Ca2+]i was measured by the Fura-2 spectrophotofluorometric technique in multi-cell and single-cell experiments. Polygodial and isovelleral induced an increase in [Ca2+]i at low concentrations (0.1 and 0.5 micrograms/ml, respectively) but epipolygodial affected [Ca2+]i only at a high concentration (10 micrograms/ml). The results indicated that there was a relationship between the effect on [Ca2+]i and the pungency of the sesquiterpenes tested. Experiments in a Ca(2+)-free extracellular solution showed that Ca2+ was also released from intracellular calcium stores. Images from single-cell experiments indicated that polygodial induced fluctuations in the [Ca2+]i in some cells. The mechanism behind the sesquiterpene induced increase of the [Ca2+]i was not identified but a possible mobilization of inositol phosphates is considered.