Accidental ingestion of methyl ethyl ketone peroxide: N-acetylcysteine treatment and toxicological analysis.

INTRODUCTION: Methyl ethyl ketone peroxide (MEKP) is a highly toxic product which promotes tissue damage by uncontrolled free radical production. CASE REPORT: A man accidentally ingested 110 ml of MEKP (37%) at his workplace after mistaking it with a bottle of water. A loading dose of N-acetylcysteine (NAC) and subsequent maintenance doses were applied at the hospital for three consecutive days. Biochemical and hematological parameters showed significant alterations. Tracheal intubation, gastric lavage and hemodialysis were not performed. Methyl ethyl ketone (MEK) and MEKP were detected in EDTA-blood samples by GC-FID and LC-QTOF/MS respectively. An endoscopy exam identified tissue damage. The patient was admitted to the hospital for 10 days. No sequelae were reported after the MEKP poisoning. Oral administration of NAC was successful as an antidote without another approach. CONCLUSIONS: Although NAC treatment was successful, supervision after the hospitalization period was required according to the prognosis. Workplace conditions promoted anosmia, explaining the accident. MEKP and MEK were successfully detected in blood samples even with less-than-ideal storage conditions. Knowledge of MEKP dangerousness and good work practices can prevent accidental MEKP poisoning.

Chemical composition and evaluation of prolyl oligopeptidase and acetylcholinesterase inhibitory activities of Leonurus Sibiricus L. from Brazil.

Chemical investigation of the aerial parts of Leonurus sibiricus L. used in Brazilian folk medicine led to the identification of the following constituents: the labdane-type diterpenoid leojaponin, the phytosterols ß-sitosterol and ß-sitosterol glucoside and the alkaloid leonurine. The crude extracts obtained from methanol and methanol/1% HCl and pure compounds isolated from L. sibirius were investigated as acetylcholinesterase (AChE) and prolyl oligopeptidase (POP) inhibitors. Extracts obtained by maceration were active against POP (53-58%), but showed weak activity against AChE. The isolated leojaponin and leonurine were evaluated as POP inhibitors.