Anticonvulsant properties of Ipomoea stans

Ipomoea stans (IS) has long been used as an anticonvulsant. Although the use of HPLC and nuclear magnetic resonance techniques recently have allowed some of its compounds to be identified, the anticonvulsant properties of this Convolvulaceae remained to be tested. During the course of several weeks, mice (BALB/C) were given a normal infusion of the plant instead of clean water (IS-ad lib). They also were given total lyophilized powder (IS-T), and two mixtures of compounds (IS-A and IS-B) from the plant. Their convulsive thresholds were then tested with pentylenetetrazol (PTZ: 40, 60, 85 and 100mg/kg, s.c.) and electric shock (ECS: 0.1mAmp, 60 Hz). Results showed Ipomoea stans provides protection against ECS and a low dose of PTZ (40 mg/kg). However, some data from animals who died following ECS after receiving a high regimen of IS suggests they suffered mesenteric infarct. Similar results appeared after treatments with IS-T and IS-A. All IS preparations offered protection but IS-B in particular protected mice against seizures produced by a low dose of PTZ (40 mg/kg) and delayed the onset of seizures produced by ECS. In a second set of experiments, IS-ad lib and IS-T increased the threshold for amygdala discharges produced by the cortical electrical stimulation in Wistar rats. It is concluded that IS possesses some anticonvulsant properties similar to valproic acid, that are attributable to fraction B of the plant. Fraction A seems to possess a weaker anticonvulsant activity and some toxic properties.