The devil's herb is a beautiful lady

It was a dull end of day, nothing special booked outdoors, work to be done the day after and that kind of sleepiness that makes you so yawning like a fat lion in the African Savannah. Three of us were there (myself, my wife, and a friend who needed a place to stay whilst writing her thesis), silent, bored, tired, waiting for the time to go to bed but eager to live a little more. Suddenly something for elders came up on TV. Initially I fought it, but then as the police intrigue started we decided to follow it. 

The unusual police chief was a mid-aged woman, fifty something I'd say. Her name was just a word, but not even that still resounds in my brain. I guess I remember stuff like who set the guy on fire, motivations and the alcoholism the main character was battling. But the star of the show was a berry I had known about in Portugal but which name was completely clueless to me, Missus Atropa belladona - for most, the star of the poison plants - the deadly nightshade. What a cool name!!! With a name describing some mythical stuff regarding shears and cut threads of life, some crazy thing like that, this beautiful lady ('Belladona' in Italian) is so dangerous as easy to be in contact with. In my country I recall 4 children having been intoxicated with it after a tea they've consumed, two of them having actually died due to the intoxication.

What is this Belladonna? I am talking about a herb that has been used for centuries on a range of physical issues like reducing pain associated with menstruation, headaches, ulcers, inflammation, motion sickness, in combination with barbiturates fighting irritable bowel syndrome [5], but there is yet a lot to know regarding medicinal applications of this herb.

Which are the responsible substances for the intoxication? The tropane alkaloid Atropine located in the berries of the Deadly Nightshade in the early Autumn. The toxic concentration for adults is not very well known, but Atropine can be fatal in children if taken to a concentration at around 10 mg, but apparently 0.5 mg will cause serious problems.

What are the most common effects? The most common effects are meaningless speech, heart problems like tachycardia, mydriasis (pupil dilation), flushing, acute psychosis [2].

Is there an antidote to atropine? Slow intravenous administration of physostigmine salicylate (e.g., Eserine) (0.5mg/Kg) available in 2mL ampules. Physistigmine acts very fast by inhibiting delirium. Pilocarpine is believed to contract the pupil after degeneration of the post-ganglionic fibres [4] however headaches can arise as a common side-effect. Physostigmine reduces the levels of acetylcholine [3] (a neurotransmitter in the autonomic nervous system). Diazepan is used to control excitement and convulsions in case of an overdose of atropine. Ice bags and alcohol sponges are used in children to reduce fever.

All clear, then let's summarise it all in this great video from Rhixxx1 I found on YouTube:

[1] The poison garden website - Atropa Belladonna (deadly nightshade), [http://www.thepoisongarden.co.uk/atoz/atropa_belladonna.htm], last visited on the 03rd October 2013, last update unknown. 

[2] Caksen, H., Odabas, D., Cesur, Y., Arslan, S., Uner, A., Oner, A. F. (2003). "Deadly nightshade (Atropa belladonna) intoxication: an analysis of 49 children". Human and Experimental Toxicology, 22(12), pp. 665-668.

[3] Karlen, B., Lundgren, G., Lundin, J., Holstedt, B. (1979). "Effect of physostigmine and atropine on acetylcholine turnover in mouse brain". Naunyn ScmiedebergsArch Pharmacology, 308(1), pp. 61-65.

[4] Cushny, A. R. (1901). "The action of atropine, pilocarpine and physostigmine". Unknown Journal (to me, at least).

[5] Helthline, Belladonna, [http://www.healthline.com/natstandardcontent/belladonna], last visited on the 03rd of October 2013, last update unknown.