What are the benefits of cornflower hydrosol for the skin?

Whilst oxygen is essential for life, it can also become harmful to the body under certain conditions. During cellular respiration, all aerobic living beings generate radical species, which are eliminated as they are produced. However, when these are in excess and surpass the cells' anti-radical defence capabilities, the body is no longer able to cope with all the assaults related to reactive oxygen species (oxidative stress).

Indeed, this overproduction of free radicals will cause alterations in the structure of many biological constituents, such as DNA, carbohydrates (glycation) and proteins (elastin, collagen). By producing radical species in large quantities, these components will then undergo damage, impacting their functioning.

Skin lipids, particularly those of the hydrolipidic film and cellular membranes, are also targeted, leading to lipid peroxidation. This chemical reaction, initiated by the presence of free radicals, results in the oxidation in vivo of polyunsaturated fatty acids. However, the products generated are toxic to the body, and the oxidation of cellular membranes can induce a change in their fluidity, thereby deteriorating the barrier function of the epidermis.

Exacerbated by pollution, sun exposure, smoking, and an unbalanced diet, oxidative stress can cause premature ageing by contributing to the degeneration of skin cells. This manifests as the early onset of wrinkles, a complexion that dulls more quickly, or a noticeable loss of firmness at an earlier stage.

However, cornflower hydrosol is capable of preventing oxidative damage induced by free radicals to cellular components (lipids, DNA, proteins). This anti-radical activity is correlated with its content of anthocyanins and flavonoids (rutin, quercetin, hesperidin, flavonols, myricetin...). Studies have revealed that the cornflower floral water combats radicals via two mechanisms:

• Inhibition of reactive oxygen species action through neutralisation;

• Formation of stable complexes with metallic ions.

Boasting numerous hydroxyl groups (-OH) in their structure, these polyhydroxylated phenolic compounds are capable ofintercepting and directly trapping free radicals, particularly peroxide or alkoxyl radicals, by acting as a hydrogen atom donor, thereby rendering them inactive. However, the potential for trapping radicals is linked to the number of hydroxyl groups on their benzene ring.

Other flavonoids have the ability to sequester iron, a metal involved in the formation of free radicals resulting in lipid peroxidation. In the presence of ferrous ions (Fe2+), hydrogen peroxide (H2O2) reacts by producing radical species (OH°, HO2°...) via the Fenton reaction, which attack most biological molecules. However, it has been demonstrated that cornflower hydrosol is capable of forming stable complexes with ferric ions. Rich in antioxidants, cornflower thus helps the skin to protect itself from the harmful effects of free radicals and therefore to prevent premature ageing.

Although there are currently no clinical studies confirming the anti-inflammatory properties directly derived from the blueberry, laboratory studies highlight this activity of the flowers, as well as their soothing effect. Various experiments conducted on rat serum have shown that the water-soluble extract obtained from the flower heads of the Centaurea cyanus has anti-inflammatory properties by interfering with the complement system, following the induction of various inflammatory states. The analysis of the composition of this aqueous fraction, which has the ability to soothe inflammation, revealed that this property is due to the presence of polysaccharides, mainly composed of galacturonic acid, arabinose, glucose, rhamnose, xylose, and galactose.

This action is explained by the ability of the carbohydrate fraction of cornflower hydrosol to inhibit the activity of anaphylatoxins, components produced during the activation of the complement system with roles in immune response and host defence. These fragments are notably capable of triggering the release of inflammation mediators, such as histamine or pro-inflammatory cytokines (TNF-α, IL-1α, IL-6), by endothelial cells, phagocytes (macrophages, dendritic cells) or mast cells, the first immune cells activated by stimuli. Anaphylatoxins also indirectly affect the dilation and permeability of blood capillaries.

In summary, the inhibition of anaphylatoxins activity by cornflower water allows for a significant decrease in the production of pro-inflammatory molecules. This property makes cornflower particularly suitable for sensitive skin to help soothe them. It thus helps to calm and reduce red patches (erythema), sensations of heat, itching and swelling (oedema) on sensitive skin.