Chilli pepper (Capsicum annuum) is widely used as a spice. The active ingredient capsaicin, which makes chillies hot, also has medical applications. It is used in ointments to treat neuralgia, arthritis, rheumatism and chilblains and is being investigated for many other possible uses.
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# The healing power of plants

Information sheet

Many familiar garden plants were first grown for their healing properties rather than their appearance, and many common herbs were valued as much for medicinal uses as they were in the kitchen.

- School term:
  All year round

- Level of experience:
  No experience needed

- Subject(s):
  History, Social Studies



Plants with a herbal past often have ‘officinalis’ in their Latin name, derived from ‘officina’, the apothecary’s workshop. Today, over 80 percent of the world’s population still relies on traditional herbal medicine for its main source of health care and many modern drugs come directly or indirectly from plant extracts or are copies of plant compounds.

### Culinary herbs with medicinal uses

Most of the herbs commonly used in the kitchen also have herbal properties. As these are all edible, they are quite safe to grow in any school garden. However you should never try to self-medicate using herbs.

Coriander (Coriandrum sativum) is believed to be good for stimulating the appetite and helping digestion.

Dill (Anethum graveolens) is a constituent of gripe water used to soothe babies and is a popular remedy for an upset stomach, hiccups or sleep problems.

Garlic (Allium sativum) is effective against many fungal infections, is used to treat toothache, earache, coughs and colds and has been shown to reduce blood pressure.

Sage (Salvia officinalis) is used to make a gargle for sore throats, infected gums and mouth ulcers and a hot infusion for colds.

Lemon balm (Melissa officinalis) tea is used to relieve headaches and to aid digestion and is said to help improve the memory, and reduce anxiety, irritability and insomnia.

Peppermint (Mentha x piperata) is rather strong for cooking, but peppermint oil is used to flavour sweets. Its widespread use in toothpaste points to its antiseptic properties. It can also be used as a herbal tea for gastro-intestinal disorders and nervous headaches and in a rub to ease muscle pain.

### Plants with healing properties

All these plants are attractive enough to grow in an ornamental garden or in containers. Several are edible (as detailed below) and none of them are poisonous.

Aloe vera gel inside the leaves soothes and heals the skin, and extracts from the plant are used in everything from shaving cream to sun lotion.

Bergamot(Monarda) native Americans used the plant to treat colds and bronchial complaints. Now it makes a herbal tea to relieve nausea. Both leaves and flowers are edible and can be used in salad.

Camomile (Chamaemelum nobile) tea is believed to improve the appetite, and camomile oil is used to treat skin rashes or added to a relaxing bath to soothe the nerves.

Echinacea(Echinacea purpurea) was used by Native Americans for everything from snakebite to bronchitis. Now it is believed to stimulate the body’s immune system and help overcome infections such as coughs and colds and heal minor wounds.

Feverfew (Tanecetum parthenium) fresh leaves are used as a treatment for migraine though they are very bitter.

Lavender (Lavandula) has antiseptic and soothing properties. It is good for burns, stings and cuts, and as a massage oil to help overcome anxiety and insomnia as well as a variety of aches and pains.

Marigold(Calendula officinalis) petals are edible, and can be used to colour and decorate food. They also have antiseptic properties and are included in preparations to soothe and heal the skin and eyes.

### Plants used in modern medicine

Some of these plants, such as foxglove, were used in traditional remedies. Others have been recognised for their medicinal properties only recently. Not all these plants would be suitable for a school garden, as some are toxic.

Ammi(Ammi majus) seeds are edible and used as a spice in India. They also contain psoralen which is used in the treatment of skin disorders including psoriasis and vitiligo.

Deadly nightshade (Atropa belladonna) has glistening black berries which are highly poisonous. It provides the drug atropine which, until recently, was used to dilate the pupils for eye examinations and is now used to dry up bronchial secretions prior to operations.

Chilli pepper (Capsicum annuum) is widely used as a spice. The active ingredient capsaicin, which makes chillies hot, also has medical applications. It is used in ointments to treat neuralgia, arthritis, rheumatism and chilblains and is being investigated for many other possible uses.

Foxglove (Digitalis) our native foxglove D. purpurea contains digoxin, which stimulates the heart, though for commercial production the woolly foxglove (D. lantana) is grown as in contains higher levels of the drug. This plant is poisonous.

Ginkgo(Ginkgo biloba) has plum-like fruit which smells unpleasant, although the seeds are edible. When cultivated for medicinal use it is grown in closely planted rows and trimmed like a hedge. Ginkgo used to treat Alzheimer’s disease and circulatory problems, though its effectiveness is still a matter for dispute.

Opium poppy(Papaver somniferum) is the source of the powerful, illegal narcotics opium and heroin. The legitimate drugs morphine and codeine are both very effective painkillers produced from the plant. Papaverine is a drug which is used to treat cancer. For legal production the whole plant is cut, dried and then processed.

#### Willow (Salix)

Both the Ancient Greeks and Native Americans valued willow bark as a pain killer and the plant’s active ingredient, salicin, was one of the first therapeutic compounds to be isolated from plants, in 1852. It proved to be an effective pain killer, but irritated the stomach so a similar but safer compound was developed and is now manufactured as aspirin.

#### Yew (Taxus baccata)

The Pacific yew (T. brevifolia) from northwest North America was used by Native Americans to treat skin cancer. Scientific investigation found it to contain the drug taxol which has become an effective treatment for breast, ovarian and cervical cancer. Luckily English yews were found to have a similar compound in their leaves which could be converted into taxol, and yew hedge clippings are collected by pharmaceutical companies for this purpose.

#### Rosy periwinkle (Catharanthus roseus)

All parts of the plant are poisonous. Rosy periwinkle contains many compounds with therapeutic potential, two of which, vincristine and vinblastine, are important drugs in the treatment of leukaemia and some other cancers.

#### St John’s wort (Hypericum perforatum)

Wort means a medicinal herb in Anglo Saxon, and St John’s wort, flowering on St John’s day (24 June), was traditionally used on burns, bruises and crush injuries and to ease pain. It is now used to treat mild depression.

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