Column: Doctor's Casebook with Dr Keith Souter

This week I have been looking at research concerning what happens when you give aspirin to plants.

This may have relevance at this time of the year when people are putting up cut Christmas trees in their homes, because there is a common belief that putting aspirin in to the water may help the tree to stay fresh and retain its needles.

Ever since the days of the ancient Egyptians it has been known that willow bark could be used as a painkiller.

But it was not until the early nineteenth century that it was discovered that the active agent in willow was salicylic acid.

Unfortunately, doctors found that many people suffered from significant bleeding problems, gastric irritation and stomach ulceration when they were given it in pure form.

In 1897, using the herb meadowsweet as the source for salicylic acid, the German chemist Felix Hoffman managed to produce acetylsalicylic acid.

The addition of the acetyl group significantly reduced the bleeding problem. Acetylsalicyclic acid is aspirin as we know it.

In 1899, Bayer patented the method of preparation of aspirin and obtained the trademark for it as Aspirin.

It is thought that the choice of name derived from ‘A’ for ‘acetyl’; ‘spir’ for Spiraea ulmaria (meadowsweet) and ‘in’, which was simply a common ending for a drug.

So back to the Christmas tree. It is known that when pathogens enter a plant the infected cells release methylsalicycic acid as a stress response. It also has an effect on how the plant functions and grows.

A group of scientists in Austria have investigated the effect of giving various painkillers, including aspirin, to plants.

They found that they affected the plants’ auxin transport.

That is the plant hormone that helps it open, grow upwards, open its shoots and leaves and grow roots downwards into the soil.

They also interfered with protein messenger chemicals in the plant cells, which affected development.

All in all, it looks at this time that the aspirin in the Christmas tree water is more likely to be a hindrance, rather than a help to the Christmas tree.