Crude preparations of Dioon spinulosum dyer neurotoxicity: methylazoxymethanol produces petil mal seizures in susceptible individuals.

Dioon spinulosum is a cycad prepared as an alternative food and consumed by Chinantecos from Veracruz and Oaxaca, México. Whether Dioon spinulosum possesses neurotoxic properties is unknown, therefore, we used wistar rats receiving several regimens of D. spinulosum. Semi-liquid diarrhea followed the ingestion of crude kernels of D. spinulosum (group-1). In group-2 we offered during 10 days, purine and water during 12 h/day, and kernel or sclerotesta during the remaining 12 h (8.00 p.m. to 8.00 a.m.). As a result, a significantly decreased ingestion of water and cycad was compensated by a higher ingestion of purine and water during the period for which they had access to their normal diet. In group-3 which received lyophilized powdered crude kernel through a displaceable oesophagic cannula during 80 days, the locomotor activity was significantly lowered (p<0.05), but their fine motor ability for swimming remained unaltered. In this group, the computerized analysis of the electroencephalogram illustrated a dominance of high-voltage, high-frequency waves as compared to a matched-age control group (p<0.05). In group-4, the active toxin of cycads, methylazoxymethanol-glucoside applied directly to the cerebral cortex (1 μl), produced an epileptic status (spike-wave activity: 3-6 Hz/200 μV) lasting more than six hours in 30% of the animals. In conclusion, D. spinulosum produced a decrease in gross locomotor activity, and an increased excitability of the central nervous system.