Phytochemicals are secondary plant compounds that play a very important role in plant growth and defense against pathogens.
They are also useful for the human body, as they can reduce the risk of serious chronic diseases. Scientific studies have shown that a wide variety of phytochemicals is much more effective and therefore beneficial to health than the highly concentrated individual substances.
A diet rich in fruits and vegetables allows the necessary phytochemicals to enter our body. For external application, the active substances are first extracted in a solvent. For the substances written in bold in the table, special solvents are used (Quelle: Cowan, 1999). In water, already effective substances such as tannins, mucilages and saponins can be extracted from the plants and used directly for body care. As a solvent, water offers the great advantage that it has no negative effects on the skin.
|Functions of the plants||Effects for humans|
|Essential oils||Lure insects||Disinfectant; other plant-specific effects e.g., lavender: soothing|
|Mucilages||Water absorption||soothing and anti-inflammatory.|
|Bitter substances||Protective mechanism against herbivorous animals.||Relief of gastric discomfort, bilious and digestive problems.|
|Pungent||Defense mechanism against certain animals.||Antimicrobial|
|Saponins||Protection against fungi||Antibiotic and antiviral|
|Alkaloids||Not yet fully explored||Antibiotic and antiviral|
|Flavonoids||Flower coloration, UV filter, heat & frost tolerance.||Antibacterial, anti-inflammatory and antiviral|
|Tannins||Protective against animals, insects, fungi and rot.||Antibiotic and anti-inflammatory|
Essential oils: Volatile mixtures of substances consisting of several chemical compounds such as alcohols, esters, ketones and terpenes. They make up the typical smell and taste of the respective plant. Essential oils play an important role in plant survival: they can attract certain insects and improve the pollination process. In addition to their disinfectant effect, essential oils have other diverse functions from a medicinal point of view: Chamomile, for example, is anti-inflammatory, peppermint has an antispasmodic effect, and lavender has a calming effect.
Mucilages: they consist of multiple sugars and allow plants to absorb water. The mucilages are found in the roots of plants, on the surface of their seeds (mucilaginous or sticky seeds are easier to spread) and in their bark. We use the positive effect of mucilages to soothe and protect irritated tissues in the body, e.g. dry, irritated skin, wounds or inflamed mucous membranes. Most mucilages are not broken down by the human digestive system and are very important for the intestines because they absorb toxins.
Bitter compounds: Unclassified group of different phytochemicals characterized exclusively by your taste. The bitter substances represent a very important protective mechanism for plants against herbivorous animals. Bitterness is an inherent property of many toxic chemicals and even though they are mostly non-toxic, bitter tasting plants are avoided by animals. However, while some are actually poisonous and should not be ingested, many bitters are traditionally used to relieve stomach upset, biliousness, and digestive problems.
Pungent costituents: Develop a defense mechanism against certain animals. The pungent effect is based on the irritation of thermal and pain receptors in the mouth, falsely informing the brain that the affected area is burning. This startle effect is perceived only by mammals, while birds can eat pungent fruits without pain. Plants seem to prefer birds because they can disperse the seeds very far and they come out of their digestive system unharmed. On humans, pungents have some beneficial effects, including acting as antimicrobials.
Saponins: Are a group of plant glycosides that have surface-active properties and foam in water. Plants produce saponins as a protection against fungi. In the human body, saponins also have antifungal and anticarcinogenic effects. They possess expectorant properties, have antibiotic and digestive effects.
Alkaloids: Naturally occurring organic bases containing nitrogen. They have diverse and important physiological effects on humans and other animals. Alkaloids possess healing properties and are of great value in medicine. However, there are also alkaloids that are toxic. The purpose of the existence of alkaloids in plants is not yet fully understood. Some properties are listed below:
. - End products of secondary metabolism
. - Storage reservoirs for nitrogen
- Protective agents for the plant against attacks by predators
- Growth regulators
- Substitutes for potassium and calcium in plant metabolism
Flavonoids: Belong to the large group of polyphenolic compounds and represent one of the most common classes of compounds in fruits, vegetables, and plant beverages. They are divided into subclasses: Flavones, Flavanones, Flavanols, Isoflavones, Anthocyanidins and Flavanols. For plants, they are the most important color pigments for flower coloration. They produce yellow or red/blue pigments in the petals to attract pollinators. Flavonoids also protect plants from various biotic and abiotic stresses, act as UV filters, and play a role in plant heat acclimation and frost tolerance. They also have antibacterial, antiviral and anti-inflammatory effects and may reduce the risk of cardiovascular disease or cancer.
Tannins: Complex chemical substances derived from phenolic acids. They are present in the leaves, barks, fruits and seeds and condense the structure of leaves, barks and roots. The tannins have a protective function against animals, insect and fungal attacks and rot. They enable plants, such as carnation, to survive even in damp partial shade. In our body, they have antibiotic and anti-inflammatory effects. Many tannin molecules have been shown to reduce the activity of a number of mutagens.
Resins: lipid components that covered the areal parts of plants. Plants use them as barrier protection against environmental stress, including to control evaporation and hydration and not to dry out. Resins are hydrophobic and make plant parts water repellent. We humans use them mainly in industry as components of complex formulations, such as coatings.