The main groups of activfs components in native plants

Essential Oils 

Essential oils are volatile, fat-soluble plant compounds that are not miscible with water. They are produced in specific plant cells and stored in oil glands, trichomes (glandular hairs), or oil cells.

Many plants contain essential oil, sometimes only in trace amounts. Only plants containing 0.1–10% oil are considered aromatic.

Depending on their composition, essential oils have a distinct, characteristic scent and are often a signature of the plant.

They are extracted via steam distillation, solvent extraction, pressing, or CO₂ extraction.

Essential oils often contain over 100 individual components and vary greatly in composition and concentration — indicating their wide range of uses.

Note: pure essential oil is highly concentrated (10 to 1,000 times stronger than the plant itself) and must always be diluted before use.

External application may: 

– Increase blood flow to the skin, causing warmth and redness — useful in pain and rheumatism ointments (spruce needle, juniper berry, rosemary oils). Overuse can cause skin irritation or blistering.

– Have anti-inflammatory effects (chamomile, yarrow, sage oils)

– Be antibacterial, antifungal, and antiviral (thyme, lemon balm oils)

– Act as antiseptic, anti-inflammatory, and expectorant (used in diluted form for inhalation: peppermint, spruce, thyme oils)

Internal application
(only under medical supervision) may:

– Be expectorant (by irritating mucous membranes – thyme, wild thyme, anise oil)

– Be disinfectant (chamomile, sage, yarrow, thyme oils)

– Promote digestion (caraway, anise oils)

– Be antispasmodic (anise, fennel, coriander, chamomile, lemon balm oils)

– Be diuretic (lovage, juniper berry oils)

– Be calming (lavender, lemon balm, valerian oils)

Resins and Balms 

Like essential oils, resins are water-insoluble — but they are solid and non-volatile.

When dissolved in essential oils, they are called balms.

We focus here on coniferous plants like spruce, pine, larch — which produce turpentine resin.

Steam distillation removes the essential oil (turpentine oil), leaving behind the solid resin known as colophony, historically used in plasters, adhesives, and ointments.

Alkaloids

Alkaloids are nitrogen-containing, alkaline-reacting compounds with powerful effects, especially on the central nervous system.

They’re classified by their chemical structure or biosynthesis.

Plants with high alkaloid content are considered poisonous and should not be used without medical guidance.

Examples: broom, autumn crocus, tansy, hemlock, celandine, thorn apple, belladonna.

Among the most toxic: monkshood.

Other poisonous ornamental plants with alkaloids: yew, angel’s trumpet, laburnum, corydalis, larkspur.

Bitter Substances

These don’t form a distinct group chemically but share a common effect: they stimulate gastric juice secretion through their bitter taste and thereby aid digestion.

Appetite stimulants include: mugwort, yarrow, centaury, wormwood.

Caroténoïdes

Pigments jaunes à orange visibles dans les fleurs (ex. calendula), les fruits ou autres parties végétales.

Certains sont convertis en vitamine A (ex. bêta-carotène de la carotte).

Le lycopène (tomate) a des effets antioxydants.

La lutéine (présente dans les légumes verts foncés) est bénéfique pour la rétine.

Flavonoïdes

Souvent de couleur jaune (du latin *flavus*), ils colorent fleurs et fruits.

Structure chimique variée, très répandus dans les plantes.

Effets : protecteurs cellulaires (antioxydants), antispasmodiques (camomille, achillée), cardiotoniques (ex. aubépine), diurétiques (bouleau, ortie, verge d’or, ononis).

Autrefois utilisés pour teindre les fibres textiles naturelles.

Tanins (substances astringentes)

Ce sont des composés qui coagulent les protéines, notamment celles du collagène, transformant les peaux animales en cuir (tannage).

On distingue :

– tanins condensés (catéchiques)

– tanins hydrolysables (gallotanins, ellagitanins)

– tanins des lamiacées (acide rosmarinique)

Ils sont surtout présents dans les racines, l’écorce, les feuilles et les fruits immatures.

Effets : 

– protègent les tissus végétaux contre la pourriture et les prédateurs

– adstringents : forment une couche protectrice sur les muqueuses, réduisent inflammation et douleur

– utilisés en externe contre hémorroïdes, brûlures, plaies, inflammations buccales

– en interne : contre la gastrite, les diarrhées

– forment des complexes insolubles avec les alcaloïdes et métaux lourds → antidote en cas d’intoxication.

Exemples : ronce, origan, chêne, alchémille, potentille, lierre terrestre, myrtille, aigremoine, sauge, tormentille, noyer.

Glucosinolates (glycosides de moutarde) 

Molécules contenant soufre et azote, liées à une molécule de glucose.

Les plantes qui en contiennent possèdent aussi une enzyme (myrosinase) stockée à part dans les cellules.

En cas de dommage tissulaire (coupe, mastication), l’enzyme libère l’huile de moutarde à l’odeur piquante et au goût amer.

Effets : antibactériens, antifongiques, antiviraux (ex. capucine contre infections urinaires), stimulent la circulation locale (emplâtres à la moutarde).

Certains métabolites ont un effet anticancer potentiel.

Glycosides cardiotoniques

Dérivés stéroïdiens puissants.

Nécessitent un contrôle médical strict car la dose thérapeutique est proche de la dose toxique.

Utilisés uniquement par l’industrie pharmaceutique sous forme purifiée.

Effets : augmentent la force et la vitesse de contraction cardiaque, ralentissent la fréquence.

Indications : insuffisance cardiaque.

Plantes concernées : digitale, muguet, euonymus, adonide.

Iridoïdes

Composés bicycliques riches en oxygène, largement répandus dans les plantes.

Effets : antimicrobiens (ex. aucubine dans euphraise, molène, plantain), stimulants digestifs (amertume), sédatifs (racine de valériane).

Saponines

Composés hydrosolubles formant une mousse persistante dans l’eau.

Deux types : saponines stéroïdiennes et triterpéniques.

Effets thérapeutiques : expectorants (en cas de toux grasse – ex. lierre, primevère), diurétiques (par irritation rénale), anti-œdèmes (ex. aescine du marronnier).

Mucilages

Polysaccharides formant des gels visqueux au contact de l’eau.

Effets : 

– apaisants sur les muqueuses irritées (créent une couche protectrice)

– atténuent le réflexe de toux (ex. guimauve, tussilage, mauve, plantain, pensée sauvage, molène, lichen d’Islande)

– laxatifs doux (lin, psyllium)

Note
Les substances marquées d’un astérisque (*) n’existent pas sous forme libre dans la nature : elles sont majoritairement liées à un ou plusieurs sucres (ce sont des glycosides). 

L’effet thérapeutique dépend de la partie non sucrée appelée aglycone (ex. un flavonoïde est l’aglycone d’un flavonoïde glycoside).

Carotenoids

These hundreds of yellow-orange pigments appear in flowers (e.g., marigold), fruits, and other plant parts.

Some convert to vitamin A (e.g., beta-carotene from carrots).

Tomatoes contain lycopene (an antioxidant).

Lutein, found in leafy greens, is known to support eye health.

Flavonoids

Mostly yellow pigments (from *flavus*, Latin for yellow) that color flowers and fruits.

They share a basic structure but occur in many forms across the plant kingdom.

Depending on type and quantity, they are: 

– Cell-protective (antioxidants)

– Antispasmodic (chamomile, yarrow)

– Cardioprotective (notably in hawthorn, where compounds act synergistically)

– Diuretic (found in many herbal teas: birch leaves, nettle, goldenrod, restharrow)

Historically used as plant-based dyes for textiles.

Tannins

These plant compounds bind with proteins (especially collagen) to form insoluble compounds, turning animal hide into leather — the basis of tanning.

Types include:

– Condensed tannins (catechins)

– Hydrolyzable tannins (gallotannins, ellagitannins)

– Lamiaceae tannins (like rosmarinic acid), found mainly in the mint family

Found in roots, bark, leaves, immature fruits.

They protect plants from rot and herbivores (astringent taste).

Used for: 

– Tightening mucosal tissue (forms a protective barrier, reduces inflammation)

– Treating hemorrhoids, burns, wounds, oral inflammation (external use)

– Gastritis and diarrhea (internal use — though hydrolyzable tannins degrade in the stomach)

Also act as antidotes to alkaloids and heavy metal poisoning.

Examples: blackberry leaves, oregano, oak bark, lady’s mantle, cinquefoil, ground ivy, blueberry, agrimony, sage, tormentil, walnut.

Glucosinolates (Mustard Oil Glycosides)

These sulfur- and nitrogen-containing compounds are bound to glucose.

Plants also contain the enzyme myrosinase, stored separately in the cell.

When the plant is damaged (cut, chewed), the enzyme breaks the compound and releases pungent, bitter mustard oil — a defense mechanism.

Effects:

– Antibacterial, antifungal, antiviral (e.g., nasturtium for urinary infections)

– Skin irritant — stimulates local blood flow (e.g., mustard plasters)

– Some breakdown products may have cancer-preventive antioxidant effects

Cardioactive Glycosides

Steroid-based compounds with strong heart effects.

They require strict dosage and medical supervision, as therapeutic and toxic doses are close.

Used exclusively by pharmaceutical companies in purified, dosed medications.

Effects: strengthen heart contractions and reduce heart rate.

Used for chronic heart failure.

Examples: foxglove (digitalis glycosides), lily of the valley, spindle tree, pheasant’s eye.

Iridoids

Oxygen-rich, bicyclic compounds found widely in plants.

Depending on type, they may be:

– Antimicrobial (e.g., aucubin in eyebright, mullein, plantain)

– Bitter digestives (e.g., centaury)

– Calming (e.g., valerian root)

Those with digestive effects are also classified as bitter substances.

Saponins

Water-soluble compounds that foam when mixed with water, similar to soap (from Latin *sapo* = soap).

Two types: steroid saponins and triterpene saponins.

Used to: 

– Loosen mucus in bronchitis (liquefies phlegm — e.g., ivy leaves, primrose root)

– Promote urination (likely by irritating the kidneys)

– Reduce inflammation (with flavonoids — e.g., in goldenrod)

– Reduce swelling and vascular permeability (e.g., aescin in horse chestnut — used in anti-swelling gels)

Mucilages 

High-molecular-weight sugars that form thick gels when in contact with water.

Effects:

– Soothing — they coat mucous membranes, protecting against irritants

– Reduce cough reflex by decreasing sensitivity

– Used for throat inflammations and dry cough (e.g., marshmallow root, coltsfoot, mallow, plantain, pansy, mullein, Iceland moss)

– Mild laxatives — their bulk stimulates intestinal movement (e.g., flaxseed)

Note: All substances marked with an asterisk (*) occur in nature mainly bound to sugars (glycosides). The pharmacological effect comes from the non-sugar part, the aglycone. 

For example, a flavonoid is the aglycone of a flavonoid glycoside.*