Infusions and decoctions are ancestral preparations of dried plants that consist in extracting their water-soluble molecules. Just like a recipe with its various ingredients, the totality of the molecules of a plant, called "totum", and their concentration will be at the origin of very specific properties of this tea. Thus, the more the molecules are soluble in water, the more likely they are to be found in quantity in our herbal teas. The interactions between the molecules will give the herbal tea an activity of its own.
We speak of polar molecules to designate molecules that are soluble in water, while non-polar molecules are less soluble in water. Among the most water-soluble compounds, that we will qualify as polar or water-soluble, we find the famous polysaccharides, mineral salts, alkaloids or phenolic acids. Flavonoids, tannins and saponins are also found in many herbal teas. These molecules are generally linked to one or more bones: they are then called heterosides. Among the less soluble are essential oils, or terpene derivatives (diterpenic lactones, sesquiterpenic, iridoids, steroidal structures, etc.).
The oses correspond to simple sugar molecules such as glucose, fructose etc. They can associate and form complex sugars: holosides or heterosides.
The heterosides correspond to a molecule composed of one or more carbohydrates (also called oses) associated with a part that is called aglycone, that is to say, not a sugar. This unit is called the genin.
This genin generally corresponds to the part of the heteroside with pharmacological activity. It is generally less soluble than the oses. Among the genins often found in our plants, there are the saponins or flavonoids for example. Their name usually ends with "-oside". In summary, many molecules are in the form of heterosides in herbal teas.
The chemical reaction that takes place in our herbal tea is called "hydrolysis". This may sound a bit complex but don't panic, it's simple to understand! During this reaction, the heteroside will associate with a water molecule (H2O) to split into 2 molecules: genin and ose. They will have each captured a part of the atoms of H2O. The heterosides are more soluble in water than the genin alone. The genin is then absorbed by the intestines.
Mucilages are polysaccharides. This name, which may seem a bit barbaric, simply means a molecule containing more than 10 bones associated with each other. They are "complex sugars". They form chains capable of capturing water to form a gel.
The arabinogalactan in Marshmallow or Echinacea is a good example. The complex structure of this polysaccharide is immediately apparent. It would confer to Echinacea immunostimulant properties thanks to the activation of certain immune cells.
Since mucilage forms a gel that lines the intestinal mucosa, it is not advisable to drink herbal teas containing a lot of it at the same time as a meal or when taking medication. This leads to a modification of the absorption of nutrients and molecules.
Phenol compounds include several thousand substances. They include phenolic acids and polyphenols, among others. Phenol compounds have an antioxidant action, meaning that they will trap and neutralize free radicals. Nevertheless, depending on the plant's totum, the properties can vary widely.
Phenolic acids are molecules derived from cinnamic and benzoic acids in phytochemistry, which have at least one hydroxyl function (-OH) and one carboxylic function (-COOH). They have the following properties:
Rosmarinic acid from Rosemary for example is a derivative of cinnamic acid. Like all phenolic acids, it has antioxidant and anti-inflammatory properties, but it is also antiviral. Indeed, research has highlighted its ability to prevent the replication of viruses. It would also have anti-allergic properties thanks to its inhibiting action of the mediators of the allergy.
In herbal teas we find mainly tannins and flavonoids. Their basic structure is composed of several phenol rings (simple phenols). They confer to the plant the following properties:
Tannins are complexes of polyphenols. It is thanks to them that we have this astringent sensation in the mouth! They are contained in a large majority of plants but in different quantities. They precipitate proteins which allows them to tighten tissues locally, such as skin tissue, intestinal mucosa, etc. There are 2 types of tannins: hydrolyzable tannins and proanthocyanidols. Both will have this ability to tighten the skin tissue locally. They are said to be contact astringents. They also have anti-infective properties. Where proanthocyanidols really shine is that they are used internally instead for their action on all body tissues, including the intestinal mucosa for example! This gives them additional properties of :
Tannins being very astringent, they will tighten the intestinal mucosa and prevent certain nutrients and molecules from being absorbed by the intestinal cells. It is therefore generally recommended to take meals and medicinal treatments spaced from the infusion of plants containing a significant amount of tannins.
Plants such as Rose, Meadowsweet or Alchemilla offer properties that reflect their tannin content. In fact, the tannins in the Rose precipitate the proteins of the dermis such as elastin and collagen, thus allowing the skin to regain its tone and elasticity.
Isoflavones would be able to bind to estrogen receptors. They would thus have an influence on our hormonal system. Therefore, plants containing significant amounts of isoflavones may not be recommended for pregnant women and people with hormone-dependent diseases.
Kaempferol is a flavonoid of the flavonol type found in the bract of the lime tree. Like most flavonoids, it has antioxidant and antibacterial properties, but it is also neuroprotective. It would be recognized for its anxiolytic activity!
Saponosides are heterosides composed of molecules of oses and saponins. Saponosides are natural surfactants: they have a hydrophilic pole (oses) and a hydrophobic pole (genin) giving them foaming properties. This action allows them to increase the secretion of bronchial mucus and to fluidify the mucus by lowering their surface tension.
The verbascosaponosides contained in the white Broth have soft expectorant properties in case of fatty cough thanks to the formation of mucus which causes an expectorant mechanism. They are also emollient, the mucus formed will allow to soften the mucous membranes and to act as antitussive in case of dry cough.
Alkaloid plants are the most active plants in the plant pharmacopoeia. They are composed of a nitrogen molecule and are alkaline in nature. The name of the molecules ends with "-ine". Their properties are extremely versatile.
The properties of the alkaloids contained in the Fumeterrre grimpante have been studied. It has been demonstrated on mice that stylopine and protopine present in the plant, even in relatively small quantities, have an anti-inflammatory action thanks to the inhibition of inflammation mediators in the intestinal mucosa. These molecules would also have an immunomodulating and regenerating activity of the epithelium.
Mineral salts are chemical elements in ionic form. In herbal teas we generally find silica, calcium, potassium, iron, zinc or iodine. They are essential to the proper functioning of our body just like vitamins. Generally speaking, they are involved in all the enzymatic reactions of our body and will therefore contribute to its proper functioning, good health and thus good vitality. We say that remineralizing plants are therefore revitalizing.
Nettle contains iron, potassium, silica, zinc and has all the properties found in minerals. It is widely used in naturopathy as a "revitalization cure" thanks to the silicon it contains.
Sesquiterpene lactones, also known as "bitter principles", represent more than 3000 different structures. Lactones are also found in essential oils. Plants containing significant amounts of lactones are often used in detox treatments, but also have the following properties
At high doses they can tire the liver and kidneys. Plants containing them are therefore recommended over a discontinuous period. They can also be abortive.
Being small molecules, they can penetrate the skin tissue and are therefore used in creams, gels and lotions. They can have an action as well tranquilizing as stimulating according to the molecule.
The hypotensive action conferred by the Olivier, one owes it among others to the Oleuropéoside. Important Iridoid of this plant, it would have a vasodilator activity thanks to the interaction with other hypotensive molecules of the totum of this fruit tree.
The ursolic acid contained in the Sage for example, would be recognized for its anti-inflammatory action by inibition of the synthesis of the mediators of the inflammation. It would also support an immunomodulating and antiseptic activity by decreasing the bacterial resistance.
Some of these molecules are close to our steroid hormones. They could interact with our hormonal system. There is not yet enough scientific evidence to know at what level these molecules found in our herbal teas influence our hormonal functioning. It is therefore better to take a few precautions when using plants that contain significant quantities of them! They are generally not recommended for pregnant and breastfeeding women as well as for people with hormone-dependent diseases.
The essential oils of Fennel or Lemongrass, give the herbal teas based on these plants, their main properties.