Chemical and toxicological study of leaf extracts from Deinbollia boinensis Capuron (Sapindaceae), a malagasy medicinal plant

The aim of this study was to investigate the toxicity of Deinbollia boinensis, a Sapindaceae endemic to Madagascar. A purification process involving precipitation with 50% ethanol, dialysis and fractionation with n-butanol was used to obtain a partially purified toxic extract (PPE) from the cold crude aqueous leaf extract (LCE). The active compounds were thermostable and soluble in water, ethanol and n-butanol. They could be precipitated by neutral lead acetate and were adsorbed on activated charcoal. Phytochemical screening of LCE and PPE revealed the presence of tannins, polyphenols, saponins, deoxyoses, triterpenes and sterols. PPE caused symptoms in mice that suggested damage to the nervous system, as well as tissue lesions in some organs characterised mainly by capillary dilatation and hemorrhagic areas in the brain, lungs and kidneys. In the liver, architectural destruction was observed. The PPE LD₅₀ was in the order of 60.25 to 66.55 mg/kg of mice. PPE was also toxic to other warm-blooded animals such as guinea pigs, rats, chicks and cold-blooded animals including mosquito larvae, carp alvins and frog tadpoles. It caused lysis of sheep red blood cells. LCE inhibited the germination of seeds of some plants and the growth of young maize and cowpea bean seedlings. LCE had a stimulating effect on the development of axillary buds, while PPE had an inhibitory effect. LCE and PPE had no effect on the microorganisms tested.