Picrotoxanes as Therapeutics

In Western medicine, picrotoxanes have played but a marginal role therapeutically. Picrotoxin was described as analeptic. Porter recorded that picrotoxin was found to be an antidote against chloral hydrate and in consequence it was used also as an antidote against barbiturate intoxication (2). It was this activity that made biomedical researchers aware of its potential as research tool in neurochemistry. Due to its high toxicity, even its use as antidote is restricted, however. Picrotoxin is employed to treat vertigo and nausea in homeopathic preparations (25i). 

Several picrotoxane-containing plants are used in traditional medicines. Cor-iaria species play an important role in Chinese traditional medicine, notably against mental diseases. Coriaria nepalensis is used against numbness, toothache, traumatic injury, and conjunctivitis (252). In the traditional medicine of Taiwan, gastrointestinal disturbances, rheumatism, and uterine cancer are treated with extracts of Coriaria intermedia (255). C. sinica is used for treatment of schizophrenia (29), and extracts of the parasitic plant on C. nepalensis, L. parasiticus, were used as shock therapy in schizophrenia (27). Okuda et al. point to corianin (21) as the main active component (27). 

The only mention of a Picrodendraceae species as a remedy in folk medicine is the use of Celaenodendron mexicanum as antiseptic 48, 257). The only known Phyllanthaceae species containing picrotoxanes, M. floribunda, is used in Cameroon against filarial and stomach disorders 248) and its bark is used in Congo (Brazzaville) as remedy against leprosy 258). 

Since most of these traditional medicines are concoctions of plant extracts that contain biologically active substances of several structural classes, the effects of the picrotoxanes are somewhat obscure. 

The indirect influence that the picrotoxanes have on medicine as research tools in neurology far surpasses their therapeutic use. 

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