Studies on Dieffenbachia picta Schott: Toxic effects in guinea pigs

Acute airway compromise after brief exposure to a Dieffenbachia plant

“…It most commonly affects children and unsuspecting adults who mistake the Dieffenbachia for an edible plant (2)(3)(4)(5)(6)(7)(8)(9)(10)(11) (Figure 1A and B). We present a case of an adult who mistook the stem of the Dieffenbachia for sugar cane.…”

Dieffenbachia: Uses, abuses and toxic constituents: A review

“…However, other workers (Ladeira et al, 1975) have suggested that the active principle is not similar to histamine.…”

“…More careful investigations suggested that calcium oxalate is probably not the major reason forthe toxicity and pointed to a "proteinaceous" agent (Pohl, 1964). Subsequent investigations have implicated the calcium oxalate crystals (perhaps merely as piercing agents), a proteolytic enzyme (named dumbcain), a cyanogenic glycoside, a substance which causes contraction of smooth muscles (Fochtman et al, 1969;Ladeira et al, 1975;Walter, 1967; for reviews, see : Arnold, 1978;Brodersen et al, 1979;Everist, 1962;Mitchell and Roor, 1979;Ricciuti, 1978;Tamplon, 1977), asparagine (Arena, 1974), and protoaenomoine which causes swelling of the pharynx and larynx (Morton, 1971). However, the exact cause for Dieffenbachia toxicity remains unknown and even pharmacological studies (Kubala and Anton, 1977) have not provided clarification.…”

“…If crystal-induced lacerations were required for entry by the toxic principle, toxicity would decrease with a drop in raphide and/or druse content. Second, only the precipitate of the stem juice obtained following " ... centrifugation at 3 °C at 10 000 rpm for 1 h ... '' contained the toxic principle which had no nitrogen in its molecule and apparently no protein (Ladeira et al, 1975). Third, treatments with proteolytic enzymes do not always eliminate toxicity.…”

“…Proteins were also isolated by other workers who have shown that trypsin digestion reduces or eliminates the toxic effects of Dieffenbachia extracts (Brodersen et al, 1979;Fochtman et al, 1969;Pohl, 1964;Occhioni and Rizzini, 1958;Rizzini and Occhioni, 1957). On the other hand, analyses of the active fraction of stem juice has shown that it contains no nitrogen, and incubation with trypsin or chymotrypsin did not hinder the usual effects (Ladeira et al, 1975;Pohl, 1955). Thus the role of protein and/or proteinaceous substance(s) in Dieffenbachia toxicity is not clear and remains subject to speculation.…”