BACKGROUND: The mechanism of action of the ketogenic diet, a therapy for refractory epilepsy, is unknown. Our hypothesis is that acetone, one of three ketones elevated by the ketogenic diet, is directly responsible for the diet's anticonvulsant effects. This study examined the basic concepts of this hypothesis. MATERIAL/METHODS: Rats were acutely injected with acetone intraperitoneally at doses of 1 or 10 mmol/kg, or received acetone chronically in drinking water (1% v/v) for 10 days before being injected with a 1 mmol/kg dose of acetone. Controls consumed regular water and were injected with vehicle. A pentylenetetrazole seizure test was administered 15 min after the injections. Following the test, acetone was measured in the cerebrospinal fluid. RESULTS: A 10 mmol/kg injection of acetone suppressed seizures in 60% of rats (P<0.05). A chronic administration of acetone followed by a 1 mmol/kg injection suppressed seizures in 47% of rats (P<0.05). The acetone concentrations in these rats were 10.3±2.3 and 1.0±0.2 mmol/L, respectively. The effect of the acute 1 mmol/kg injection (without acetone pretreatment) was not statistically significant. This dose elevated acetone to 1.1±0.1 mmol/L in the cerebrospinal fluid.
Conclusions: Our findings suggest that acetone is an anticonvulsant and that chronic administration may enhance its action. Linking acetone to the effects of the ketogenic diet requires further research. In particular, it will be important to confirm that the ketogenic diet generates relevant concentrations of acetone.

Keywords: Acetone - administration & dosage, Acetone - therapeutic use, Anticonvulsants - administration & dosage, Anticonvulsants - therapeutic use, Cerebrospinal Fluid - chemistry, Convulsants - pharmacology, Diet, Epilepsy - diet therapy, Epilepsy - drug therapy, Fasting, Ketones - metabolism, Magnetic Resonance Spectroscopy, Pentylenetetrazole - pharmacology, Seizures - chemically induced