Essential fatty acid deficiency in cultured human keratinocytes attenuates toxicity due to lipid peroxidation.
Wey-HE; Pyron-L; Woolery-M
Toxicol Appl Pharmacol 1993 May; 120(1):72-79
The relationship between toxicity due to lipid peroxidation and essential fatty acid deficiency (EFAD) was investigated using cultured human keratinocytes. Cryopreserved primary human epidermal keratinocytes were cultured in serum free medium to obtain EFAD cells. The model oxidant, tert-butyl-hydroperoxide (75912) (tBHP) was added. Results showed that at concentrations up to 2 millimolar tBHP did not result in toxicity as assessed by lactate-dehydrogenase (LDH) release. Only a minimum lipid peroxidation was indicated according to an assay for thiobarbiturate reactive substances (TRS). The phospholipid content was increased by addition of linoleic-acid (LA), with a resultant alleviation of the EFAD condition. When LA supplemented keratinocytes were subjected to tBHP, there was a significant increase in LDH and TRS release. The latter was also elevated when EFAD keratinocytes were exposed to tBHP. When the antioxidant alpha-tocopherol-succinate (TS) was added, tBHP induced LDH release was inhibited in the LA supplemented cultures. Supplementation with TS resulted in an attenuation of the tBHP effect on TRS release. This attenuation of TRS release was less marked in the LA supplemented cultures than in the EFAD cultures. The authors conclude that fatty acid and antioxidant nutrition of cultured keratinocytes are important parameters in the assessment of susceptibility to lipid peroxidation and toxicity, especially in cells grown in serum free medium. They stress the importance of the cell model toxic insult being similar to that experienced in-vivo.
NIOSH-Author; Cytotoxicity; Enzymes; Free-radicals; In-vitro-studies; Oxidative-processes; Phospholipids; Lipid-peroxidation; Fatty-acids; Peroxides; Toxic-effects
Toxicology and Applied Pharmacology