n-Alkyl glucopyranosides completely inhibit ultrasound-induced cytolysis.
The mechanism(s) responsible for sudden cytolysis observed when cells are exposed to ultrasound could be mechanical and/or free radical in nature. Free radical reactions are initiated in the core and in the interfacial regions of collapsing acoustic cavitation bubbles. Because cyclic sugars are known to inhibit free radical chain reactions, we investigated the effects of n-alkyl-beta-d-glucopyranosides of varying hydrophobicity on ultrasound (1.057 MHz)-induced cytolysis of HL-60 cells in vitro. n-Alkyl glucopyranosides with hexyl- (5 mM), heptyl- (3 mM), or octyl- (2 mM) n-alkyl chains protected 100% of the cell population from ultrasound-induced cytolysis under a range of conditions that resulted in 35 to 100% cytolysis in the absence of glucopyranosides. The protected cell populations also possessed long-term reproductive viability. However, the hydrophilic methyl-beta-D-glucopyranoside could not protect cells, even up to a concentration of 30 mM. Furthermore, none of the glucopyranosides could prevent cytolysis of cells from a mechanically induced shear stress. Spin trapping and electron spin resonance experiments confirmed the presence of inertial cavitation in cell suspensions both in the presence and in the absence of the surfactants. It is concluded that surface-active glucopyranosides efficiently quench cytotoxic radicals and/or their precursors at the gas/solution interface of collapsing cavitation bubbles.
Sostaric
Joe Z
JZ
Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1002, USA. sostaric.2@osu.edu
Miyoshi
Norio
N
Riesz
Peter
P
DeGraff
William G
WG
Mitchell
James B
JB
D000818:Animals; D001555:Benzene Derivatives / Q000494:pharmacology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D006224:Cricetinae; D019610:Cytoprotection / Q000187:drug effects*; D005609:Free Radicals / Q000737:chemistry / Q000528:radiation effects; D005720:Gamma Rays; D005960:Glucosides / Q000494:pharmacology*; D018922:HL-60 Cells; D006801:Humans; D066298:In Vitro Techniques; D010316:Particle Size; D014465:Ultrasonics
D001555:Benzene Derivatives; D005609:Free Radicals; D005960:Glucosides; C007164:cumene hydroperoxide