Chemical and biological investigations of a toxic plant from Central Africa, Magnistipula butayei subsp. montana

Abstract

A4cigni. §/i.pw/cz b4iJciyei. subsp. mon/ancï (CAErysobcz/cïnczceOEe) is known, in the Great Lakes Region, to possess toxicological properties. In this paper, we investigated the acute toxicity (dose levels 50-1600 mgAEg) of its aqueous extract, administered orally to adult Wi. §/c]r rats.This study demonstrated that the freeze-dried aqueous extract (5%, w/w) possesses high toxicity. The extract caused hypothermia, neurological disorders, including extensor reflex of maximal convulsfve induced-seizures at about 2 h after the administered dose, and death occumed (LD5o = 370 mgn{g) in a dose dependent manner.Blood parameter evaluation revealed slight variations, but these might not have clinical relevance. Histological examination of intemal organs (lungs, liver, heart and kidneys) did not reveal any abnormality in the treated group compared to the control. Therefore, it can be concluded that Mcign!.s/!.pw/ci bwfczyc!. subsp. monfczncz aqueous extract, given oral]y, is toxic and that its target is the central nervous system.General phytochemical screening revealed that the plant did not contain significant amounts of products known to be toxic, such as alkaloids or cardioactive glycosides, but only catechic tannins, amino acids, saponins and other aphrogen principles in the three parts of the species (fruit, leave and bark).

Unusual Amino Acids and Monofluoroacetate from Dichapetalum michelsonii (Umutambasha), a Toxic Plant from Rwanda

“…Umutambasha is the vernacular name of a tropical tree from Rwanda which is well known by the local population for its toxicity [1,2]. Karangwa reported that aqueous decoctions of different parts of this plant were used to poison pests but also humans, especially during the 1994 genocide [3]. Although the convulsive action and the neurotoxicity induced by Umutambasha have been previously demonstrated [3,4], the toxic principle of this treeat first identified as Magnistipula butayei De Wild.…”

“…Since four plants correspond to the vernacular name Umutambasha (see l " Table 1), a new botanical identification was carried out, concluding that the species used in our previous studies was in fact D. michelsonii Hauman [5,6]. Firstly described on specimens from Kahuzi mount in DR Congo [7], D. michelsonii is considered as a synonym of D. stuhlmannii Engl.…”

“…The slight morphological differences observed between these two species should be the object of further in-depth taxonomic investigations. Apart from a qualitative screening [3], the phytochemical composition of D. michelsonii was never studied before, and, therefore, the identification of the plant is difficult. The aim of our present work was to study the chemical composition of D. michelsonii and to isolate and identify the compound responsible for its neurotoxicity.…”