Comfrey toxicity?

[DynamiteBob]

I've been reading about the many uses of comfrey and stumbled across some information about the plant producing pyrrolizidine alkaloids which are toxic to the liver. I know we aren't necessarily ingesting comfrey leaves, but I was wondering if our plants (along with vegetable/herb plants) can absorb the substance, seeing as comfrey is usually used in compost and mulch. Here's an article stating that some uptake in plants is noted:

https://www.omicsonline.org/open-access/horizontal-natural-product-transfer-a-so-far-unconsidered-source-ofcontamination-of-plantderived-commodities-2161-0525-1000287.pdf

Any thoughts??

 

[Rasta Roy]

It's been a healing herb for hundreds of years...so I would think it's fine. Don't let your dog eat it.

 

[greasemonkeymann]

I've been reading about the many uses of comfrey and stumbled across some information about the plant producing pyrrolizidine alkaloids which are toxic to the liver. I know we aren't necessarily ingesting comfrey leaves, but I was wondering if our plants (along with vegetable/herb plants) can absorb the substance, seeing as comfrey is usually used in compost and mulch. Here's an article stating that some uptake in plants is noted:

https://www.omicsonline.org/open-access/horizontal-natural-product-transfer-a-so-far-unconsidered-source-ofcontamination-of-plantderived-commodities-2161-0525-1000287.pdf

Any thoughts??

well shit, I sure hope not, cuz i'm fairly certain I use more comfrey than probably anyone else..
that's a very interesting thought, I did a lil research on the tests done on lab rats and here is a copy and paste, sorta reassuring considering..
but it looks as though one would have to consume a metric-fuck-ton of comfrey to do that... between 7 and 1040 kgs??!
that's like 15 lbs to us americans... or 1040kgs??
that's over a ton....
and that's actually eating it too, so I would speculate that it's alright in the cannabis, also considering that you have t literally ingest it via eating..
again, speculating here, but i'd say the alkaloids would likely be lessened, if not destroyed via the whole pyrolictic process of smoking
hope so anyways...
heres the copy/paste

In an experiment that ran for 21 weeks males rats were given 13 mg/kg i.p. twice weekly for 4 weeks and then once a week for 52 weeks. One rat out of twenty developed liver cell adenoma and three rats out of twenty developed hemanagioendothelial sarcomas of the liver. All of the animals displayed megalocytosis in the liver. In order to relate this to human risk an equivalent dose for a 60 kg human has been estimated (table 5). In order to receive an equivalent dose of symphytine one would need to consume between 7 and 1040kg of dry leaf, assuming 5% of comfrey PA is symphytine [65] and the variability of PA concentrations in leaf as given in Table 2. An alternate way of estimating the equivalent dose would be to consider all the alkaloids in comfrey to be of equal carcinogenic potential (not probable). The dose administered then would be equivalent to 350g to 52 kg dry leaf. Given a typical therapeutic dose to be about 5g/day it is easy to conclude that the results of this study can not be used it to determine human risk, as levels are 100 to 10,000 times greater in the rat study.

 

[Rasta Roy]

I was hoping you'd drop your two cents on this one @greasemonkeymann

 

[calliandra]

All things are poison, and nothing is without poison, the dosage alone makes it so a thing is not a poison. —Paracelsus

 

[Rasta Roy]

All things are poison, and nothing is without poison, the dosage alone makes it so a thing is not a poison. —Paracelsus

[Swoons]

 

[calliandra]

[Swoons]

Ohnooo! What did you just injest?! haha

 

[Wetdog]

[Swoons]

Haven't seen a good swoon in ages.

 

[Rasta Roy]

Ohnooo! What did you just injest?! haha

Your sweet poetry. Lol

 

[greasemonkeymann]

I was hoping you'd drop your two cents on this one @greasemonkeymann

yea, sorry, my shop has been slammed the last few weeks, haven't been roamin the forums much
so I did some more research, here is a much more conclusive study regarding it,
i'll link it, and copy/paste it
and it's a reputable scientific source as well (NIMH,I am a bit nerdy on them actually, I was fascinated by the social studies they did with rodents.. the overpopulation one in specific..fueled of course by the classic cartoon, which is badass by the way, it stood the tests of time fairly well considering it's an 80s cartoon-movie..)
anyways.. I digress..
heres the meat n' potatoes of it.
looks like us composters are alright, I do sorta have a teensy bit of apprehension in regards to my favorite shreddin n topdressing comfrey that I do like every damn ten days or so..
but as far as I understand, the alkaloids needs to be eaten..
also keep in mind that those are simply waste bags, it would be reasonable to assume that a composting procedure would accelerate the process much more
also many compost longer than 10 weeks anyways

The decomposition of toxic pyrrolizidine alkaloids in ragwort (Senecio jacobaea) on storage in waste bags has been evaluated by a new time-of-flight mass spectrometric detection method. The method makes progress in meeting the clear need for modern analytical methods for pyrrolizidine alkaloids and for studies into factors affecting the stability of the toxins in the uprooted plant, which might still be accessible to animals. The experiments demonstrated a rapid decomposition of the toxins in ragwort stored in bags, from 340 mg/kg to less than 40 mg/kg in four weeks and virtually complete loss after 10 weeks. The information obtained can guide effective ragwort removal procedures to safeguard grazing animals


https://www.ncbi.nlm.nih.gov/pubmed/19348474

 

[greasemonkeymann]

ah, and here is another copy and paste,
from our brothers and sisters across-the-pond

Degradability of grayanotoxin
In order to establish the ability of the composting process to degrade the toxin contained in this plant, several research and development projects were carried out. Recent research on degradability of grayanotoxins was undertaken by the Scottish Agricultural College. The results showed that this harmful compound present in rhododendron completely degrades during a typical, PAS100 compliant, composting process6. According to another project, which tested the decomposition of grayanotoxins, ‘estimates of exposure to grazing livestock coming into contact with source-segregated green waste compost containing up to 7% of rhododendron in the input to the composting process suggest that GTX III [one of the grayanotoxins] poses no appreciable risk.’ It is crucial to follow good practice composting, in accordance with the PAS100 standard, to ensure that grayanotoxins are fully degraded5.

heres the link if interested

http://www.qualitycompost.org.uk/upload/files/f43_31_ORG_information_sheet_on_composting_noxious_weeds.pdf

here's some more good info on the toxicity of it, interesting that mature leaves are waaay lower too,
I didn't know that at all

"Comfrey contains potentially dangerous compounds known as pyrrolizidine alkaloids. The roots contain higher levels of these compounds and mature leaves contain very little, if any, of these alkaloids. Fresh young leaves contain higher amounts (up to 16 times more than mature leaves) and should be avoided."
(K.A. Winship, Toxicity of Comfrey, Adverse Drug Reactions and Toxicological Reviews, 1991;10:47-59, cited by University of Michigan Health System, www.uofmhealth.org/ health-library/hn-2073000.)

 

[vostok]

I've been reading about the many uses of comfrey and stumbled across some information about the plant producing pyrrolizidine alkaloids which are toxic to the liver. I know we aren't necessarily ingesting comfrey leaves, but I was wondering if our plants (along with vegetable/herb plants) can absorb the substance, seeing as comfrey is usually used in compost and mulch. Here's an article stating that some uptake in plants is noted:

https://www.omicsonline.org/open-access/horizontal-natural-product-transfer-a-so-far-unconsidered-source-ofcontamination-of-plantderived-commodities-2161-0525-1000287.pdf

Any thoughts??

There's Russian comfrey ...GOOD even GREAT

and comfrey from the west

now banned by the Trump administration its poison even polluted

(https://en.wikipedia.org/wiki/Comfrey)

 

[DynamiteBob]

Good info! I'm going to just use comfrey in my compost then, and use the older leaves rather than younger. I'm more concerned about my food crops than anything. I wonder if the bud curing process would destroy any of the alkaloids? That is, if cannabis absorbs a traceable amount

 

[vostok]

Good info! I'm going to just use comfrey in my compost then, and use the older leaves rather than younger. I'm more concerned about my food crops than anything. I wonder if the bud curing process would destroy any of the alkaloids? That is, if cannabis absorbs a traceable amount

its been used for thousands of years

called Knitbone from the days of the Romans

you'd have to take in a shitload per day see above

to actually have any effect

even used today in winter salads

more chance of making Viag_ra outta cola

good luck

 

[Wetdog]

Hmmmmmm

Wonder how going through a worms gut affects this stuff. 90%+ of my comfrey is fed to the worms. I have 10 - 6YO+ plants and three more that are just over 2YO.

I know worms neutralize a good bit of nasty things and I guess I would have noticed something after all these years, but????

The comfrey isn't composted, just frozen for a bit right after harvesting. Hell, I don't even defrost the stuff, just put it on the surface of the bin and it's gone in 3 or 4 days.

 

[vostok]

I go to my comfrey patch chop out heaps

to a big pile

then run it all over with my lawnmower

I store the comfrey trims in trash bags

checking to dry it out then add it to my compost bin

I have in the past chop it out and hung to dry like tobbacco

then run it over then to compost bins

but it seemed unnecessary

good luck

 

[Trichometry101]

So if I can safely eat 10 lbs of poison, how much can I safely vaporize into my bloodstream via the lungs?

Food grade terpenes aren't safe to smoke,for example.. But its not poison? Lol.

Until scientists get their lips off each other and around a bong, there's really no knowing how bad smoking these substances are. It's not like people have been growing plants for thousands of years or anything. We should all stop smoking until Bill Nye offers approval.

 

[Big_Lou]

Comfrey toxicity? I'm much more concerned with covfefe toxicity.

 

[GreenSanta]

well shit, I sure hope not, cuz i'm fairly certain I use more comfrey than probably anyone else..
that's a very interesting thought, I did a lil research on the tests done on lab rats and here is a copy and paste, sorta reassuring considering..
but it looks as though one would have to consume a metric-fuck-ton of comfrey to do that... between 7 and 1040 kgs??!
that's like 15 lbs to us americans... or 1040kgs??
that's over a ton....
and that's actually eating it too, so I would speculate that it's alright in the cannabis, also considering that you have t literally ingest it via eating..
again, speculating here, but i'd say the alkaloids would likely be lessened, if not destroyed via the whole pyrolictic process of smoking
hope so anyways...
heres the copy/paste

In an experiment that ran for 21 weeks males rats were given 13 mg/kg i.p. twice weekly for 4 weeks and then once a week for 52 weeks. One rat out of twenty developed liver cell adenoma and three rats out of twenty developed hemanagioendothelial sarcomas of the liver. All of the animals displayed megalocytosis in the liver. In order to relate this to human risk an equivalent dose for a 60 kg human has been estimated (table 5). In order to receive an equivalent dose of symphytine one would need to consume between 7 and 1040kg of dry leaf, assuming 5% of comfrey PA is symphytine [65] and the variability of PA concentrations in leaf as given in Table 2. An alternate way of estimating the equivalent dose would be to consider all the alkaloids in comfrey to be of equal carcinogenic potential (not probable). The dose administered then would be equivalent to 350g to 52 kg dry leaf. Given a typical therapeutic dose to be about 5g/day it is easy to conclude that the results of this study can not be used it to determine human risk, as levels are 100 to 10,000 times greater in the rat study.

I probably use as much as you do. Ive started experimenting with using fresh comfrey in my soil mix. The comfrey is still green at transplant depending on how old my soil mix (generally 1-5 weeks old, a mix of vermicompost, compost, perlite, vermiculite, and now fresh comfrey)

Also, I have my worm farm setup next to my row of comfrey, that was probably the smartest thing I have ever done in my life lol.

 

[GreenSanta]

oh yeah and toxicity is for livestock that eat it fresh, one must be careful. I cant imagine it ever being a problem in your garden... one can never use too much comfrey!