A Study of a Selection of Antidotes for Paraquat induced Skin Damage

ABSTRACT

BACKGROUND: Paraquat is a widely used herbicide, known to cause lethal toxicity in humans. Most studies about paraquat have concentrated on systemic toxicity, however several cases of paraquat-induced dermatitis have been reported. OBJECTIVE: The purpose of this study was to confirm the cutaneous toxic effect of paraquat and to select potential antidotes in paraquat-induced dermatitis. METHODS: Keratinocyte toxicity due to paraquat and the toxicity reduction capacity of several drugs were investigated in eitro. Topical effects of these drugs on paraquat-induced dermatitis in guinea pig skin was also investigated. RESULTS: Over 50% of keratinocytes failed to survive at a concentration of 2X10-4M paraquat by a neutral red uptake assay. Skin irritation by paraquat was observed at 2% concentration by non-invasive methods as well as a skin biopsy. Dexamethasone, glutathione and tocopherol showed some capacity to reduce paraquat-induced keratinocyte toxicity in vitro. Only dexamethasone, however, showed a reduction of cutaneous blood flow volume and dermal inflammatory cell infiltration in the guinea pig study. CONCLUSION: This result indicates the possible in eitro protective effect of paraquat toxicity in glutathione and tocopherol. Dexamethasone was capable of reducing paraquat-induced cytotoxicity and dermatitis both in vitro and in vivo.