Abstract
In a continuation of our studies of extracts of Combretum species, results obtained for C. hypopilium, C. verticillatum, C. sokodense and C. nigricans are presented and discussed. C. hypopilium is the least toxic (LD50 mice i. v. 2.3 gm/kg ± 0.3) while C. nigricans is the most toxic (LD50
mice i. v. 580 mg/kg ± 13). All the four species depress the CNS unlike C. paniculatum which was shown to stimulate the CNS at low doses. The extracts contain compounds which cause a fall in blood pressure both centrally and peripherally. They also stimulate respiration probably centrally. Work is in progress to identify and characterise the active compounds.
