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Sixteen Active Plant Components Explained

Along with minerals and vitamins there are many other active components that originate in plants. As each serves a particular function, and some plants contain more of these elements or compounds than others, familiarity with each one offers insight into their combinatorial and physiological effects. This article will detail 16 plant constituents along with providing common sources of each.

The Top 16 Plant Components (in alphabetical order)

1) Alkaloids

The most active ingredient found in plants, these (normally nitrogen bearing) molecules have various medicinal and even cancer fighting effects on the body (e.g. Madagascar periwinkle - Vinca rosea) but are also toxic in high doses. Most plants contain some alkaloids. One of the most popular examples of an alkaloid is caffeine and is found in coffee, tea, and cocoa. Another alkaloid is solanine, a toxin found in the nightshade family (e.g. deadly nightshade - Atropa belladonna) and one reason why some people are sensitive to tomatoes, peppers and potatoes.

2) Anthocyanins

Antioxidant pigments that give fruits and flowers their blue, purple or red hue, anthocyanins help keep blood vessels healthy. Foods that contain large amounts of anthocyanins include grapes (Vitis vinifera) and blackberries (Rubus fruticosus).

3) Anthraquinones

Anthraquinones are natural laxative components in plants that relieve constipation, soften stool and cause peristaltic action. Sources of anthraquinones include senna (Cassia senna), cascara sagrada (Rhamnus purshiana) and Chinese rhurbarb (Rheum palmatum).

4) Bitters

An essential food group and something the human tongue is designed to detect, bitters have largely been factored out of the human diet due to their unpleasant taste. Bitters however are a key to digestion as they cause the secretion of salivary enzymes that nourish and strengthen the body. Some popular herbal products feature concentrated bitters. Examples of bitter foods include coffee, unsweetened chocolate, bitter melon and citrus peel. High levels of bitters can be found in chiretta (Swertia chirata) and wormwood (Artemisia absinthium).

5) Cardiac Glycosides

Natural diuretics that directly strengthen the heart by increasing the contraction rate, cardiac glycosides also improve circulation, lower blood pressure and relieve the urinary tract. Examples of plants containing cardiac glycosides are Digitalis lanata and Digitalis purpurea from which digoxin and digitoxin are derived. Caution: plants containing cardiac glycosides such as Foxglove are often poisonous. Consult your doctor before pursuing treatment with cardiac glycosides.

6) Coumarins

Coumarins offer widely divergent strengthening mechanisms that include sunscreen protection (e.g. celery - Apium graveolens ), blood thinning (e.g. melilot - Melilotus officinalis and muscle relaxant action (e.g. visnaga - Ammi visnaga). Found in many plants, popular examples include the tonka bean (Dipteryx odorata) and members of the Umbelliferae and Solanaceae families.

7) Cyanogenic Glycosides

Though based on highly poisonous cyanide, cyanogenic glycosides offer a sedative effect on the heart and muscles in small doses and are also used to sooth congestion and suppress a dry cough. Cyanogenic glycosides are found in Wild Cherry bark (Prunus serotina) and Elderflower (Sambucus nigra). Caution: Due to the risk of cyanide toxicity, consult your doctor before pursuing treatment with Cyanogenic glycosides.

8) Flavonoids

Flavonoids are antioxidants known as polyphenols which improve circulation and relieve tissues damaged by pathogens. Based on the Flavone molecular backbone which comes in various sizes and includes neoflavonoids and isoflavonoids, flavonoids play a role in pigmentation and also have anti-inflammatory properties. Good sources of flavonoids include onion (Allium cepa), garlic (Allium sativum), basil (Ocimum basilicum), spinach (Spinacia oleracea) and green leafy vegetables.

9) Glucosilinates

Glucosilinates have an irritant effect, causing inflammation and blistering of tissues. Used to increase blood flow to an affected area, glucosilinates facilitate waste removal, relieve joint problems and reduce thyroid function. Glucosilinates are found exclusively in the mustard family (Cruciferae). Radish (Raphanus sativus) and mustard (Sinapis alba) contain significant quantities of glucosilinates.

10) Minerals

Minerals are the basic elements from the Periodic Table. Examples include magnesium, iron and copper. Certain minerals are essential for certain life forms. Minerals are the building blocks of vitamins and are found in all foods. Plants high in minerals include Horsetail (Equisetum arvense - silica) and Dandelions (Taraxacum officinale  - potassium).

11) Mucilage

Mucilage is a component of many plants that contains polysaccharides (large sugar molecules). These retain water to produce a jelly like mass which offers protective and moisturizing effects. Soothing to the skin, throat, lungs and other organs, mucilage is found in aloe vera original, Slippery Elm (Ulmus rubra) and psyllium (Plantago affra) seed husks.

12) Phenols

A component of many compounds including salicylic acid (aspirin), phenols are antiseptic and anti-inflammatory components of plants. Phenols actually have an irritant effect when applied directly to the skin. Phenols are found in all foods, but high phenol foods that should be avoided by those with sensitive digestive tracts include food dyes, Vanillin flavor, oranges, tomato, peanuts, and chocolate. Salicylic acid can be found in many plants including: wintergreens (Gaultheria procumbers) and white willow (Salix alba). Thymol another phenol is found in thyme (Thymus vulgaris).

13) Saponins

A group of two expectorant elements that induce hormonal activity, saponins (including triterpenoid and steroidal) are similar to naturally occurring hormones found in the human body. Licorice ( Glycyrrhiza glabra ) is perhaps the most popular saponin while cowslip root (primula veris) may help in nutrient absorption.

14) Tannins

Familiar to wine drinkers as the ingredient that causes headaches, tannins are an astringent element found in bark and leaves of all plants and are there to repel life forms such as grazing animals, insects and pests. Used to `tan` leather, tannins cause tissue to contract the way Alum does. Sources include beer, wine, chocolate and citrus foods. Black catechu (Acacia catechu) and Oak bark (Quercus robur) are high in tannins.

15) Vitamins

Vitamins are the essential building blocks of life. More complex than minerals, vitamins are molecules versus atoms. Certain vitamins are required for proper cellular function, without which disease and disorder follow. For example, without vitamin C one will develop scurvy. Plants containing high levels of vitamins include: watercress (Nasturtium officinale - vitamin E), dog rose (Rosa canina - vitamin C).

16) Volatile Oils

Volatile substances are constantly breaking down through oxidation or other natural interactions with the environment. Volatile oils are the component of plants that offer the strong aroma to attract foraging wildlife, and these oils often provide concentrated medicinal benefits as well. Volatile oils are strongly antiseptic and normally have anti-inflammatory properties as well. Aromatherapy involves the use of volatile (essential) oils to alter moods and perception as well as to detoxify the body. Sources of volatile oils include tea tree (Melaleuca alternifolia), black seed (Nigella Sativa), peppermint (Mentha × piperita) and oregano (Origanum vulgare) oil.


Plant extracts such as the ones described in this article can be extremely potent. Note that all substances have what is called the Therapeutic Index or the ratio of the lethal dose over the effective dose. For example, one vitamin E is therapeutic while 25 vitamin E can be fatal. Thus, vitamin E has a toxic to therapeutic ratio of 25/1 or a therapeutic index of 25. With many of the substances covered in this article there is a fine line between a lethal and effective dose so use caution.




The Encyclopedia of Medicinal Plants - Dorling Kindersley and Andrew Chevallier.


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