Here in the UK snowdrops can be seen transforming woodlands, verges and banks. While they are a much-loved icon of spring, it can be surprising to find out that these dainty flowers have rather powerful therapeutic abilities.
Snowdrops are of the genus Galanthus, which translates literally to milk-white flowers, and the ancient Greeks noted the powerful mind-altering benefits from taking the extract of snowdrops.
Snowdrops themselves are inherently poisonous due to the alkaloids they contain which are concentrated mostly in their roots – namely lycorine and galantamine, both of which are also found in daffodils. While they don’t make eating these flowers fatal, they will cause vomiting and diarrhoea.
Despite being used for centuries as a remedial herb to ease headaches and migraines, the extract of snowdrops only became a commercial venture in the 1950s. To understand why we need to look into the chemical pathway that galantamine affects.
Acetylcholine (ACh) is a chemical messenger in the parasympathetic nervous system that plays an important role in brain and muscle function and was the first neurotransmitter discovered. It slows your heart rate and dilates blood vessels, plays an important role in learning and memory and is the main neurotransmitter responsible for contracting muscles.
When ACh binds to a receptor, it binds and causes a cascade on the other side. For example, when binding to a receptor in muscle tissue it causes the muscle to contract. After it’s passed on its message an enzyme called acetylcholinesterase (AChE) breaks it down, keeping ACh concentration levels balanced.
Galantamine is of interest as it has two key methods of effect:
1.By inhibiting the enzyme AChE, it stops the breakdown of ACh and increases its concentration. Low levels of ACh has been linked with chronic conditions like Parkinson’s and Alzheimer’s disease, and acetylcholinesterase are prescribed to alleviate symptoms. While there is currently no cure, Galantamine and other acetylcholinesterases are used to improve memory, thought processing and alleviate confusion.
2.By interacting with the nicotinic ACh receptors (named nicotinic as nicotine can also bind to them) it causes a conformational (shape) change of the receptor. This is believed to have a protective effect against β-amyloid cytotoxicity, which is important as β-amyloid forms plaques that settle between neurons and disrupt their function.
There are other studies that suggest galantamine sensitises the receptors to choline, causing a CA2+ influx and triggering the destruction of amyloid-β.
And it doesn’t stop there!
Antibiotic-resistant drugs and infectious diseases are one of the key threats to global health, which is becoming more worrying as current antimicrobial/bacterial/fungal/viral agents become less effective. Extracts of different snowdrop species have been shown to reduce the bacterial activity of various species, as well as being investigated for their antiviral potential against HIV, SARS-CiV among others.
Galantamine can also be used as an antidote immediately after organophosphate poisoning. Organophosphates are also acetylcholinesterases, but unlike galantamine, they tend to hold on to the AChE and inhibit its function for a long time. This causes ACh levels to skyrocket, causing breathing difficulties, vomiting, convulsions and is ultimately fatal. While the exact mechanisms aren’t known, it’s thought that galantamine competes with the organophosphates so AChE can still break down some ACh when galantamine lets them go, and in the meantime, another enzyme can be introduced that’ll break down the organophosphates, clever hey?
Plants are one of our key allies when it comes to drug discovery, who knew the snowdrops had so much potential?