What are the benefits of cornflower hydrosol for the skin?

While 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 defense 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 can cause changes 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 functionality.

Cutaneous 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, tobacco use, and an unbalanced diet, oxidative stress can lead to premature aging 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 through two mechanisms:

• Inhibition of reactive oxygen species action through neutralization;

• Formation of stable complexes with metallic ions.

Equipped with 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 aging.

While there are no clinical studies at this stage 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, after inducing different inflammatory states. The analysis of the composition of this aqueous fraction, which has the ability to calm 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 defense. 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 (edema) on sensitive skin.

For a long time, cornflower hydrosol has been primarily recognized and highlighted for its beneficial qualities on the eyes, eyelids, and periorbital areas. It is particularly mentioned for treating minor ocular inflammations (stye, conjunctivitis, etc.), and for soothing and revitalizing irritated, tired eyes, as well as congested eyelids caused by overexposure to screens and the effects of pollution. Indeed, its flowers are considered the symbol of "healthy eyes", hence one of its vernacular names "casse-lunette".

To date, no scientific study has rigorously validated the major role attributed to cornflower hydrosol. However, studies conducted by the Research and Innovation department of the L'Oréal group and relayed by Michel FAUCON in his book "Scientific and Medical Aromatherapy Treatise - Hydrosols" confirm these traditional facts long perceived about cornflower water regarding eye and eyelid care. First, tests in vitro on human cell cultures assessed the impact of the aqueous extract of cornflower on pigmentation at different concentrations (50% and 100%). After 10 days of daily application, a decrease in the amount of melanin pigments from melanocytes was observed compared to an untreated cell sample. These results indicate that cornflower can reduce contrast and dark color.

Subsequently, these results obtained in vitro (cell culture) were transposed and confirmed in vivo. Under the supervision of dermatologists, clinical studies were conducted on a panel of 41 women aged between 35 and 59 years. Eye baths of cornflower water at a concentration of 50%, or the application of compresses soaked in cornflower extract for 5 to 10 minutes on closed eyes, were performed daily (twice a day) over a period of one month. At the end of the evaluations, they demonstrated that cornflower water had a "anti-dark circle" effect deemed significant with a reduction in the visibility and intensity of the color of the dark circles, as well as a decongestant property with a reduction in the volume of under-eye bags.

Simultaneously, a study in vitro has demonstrated the ability of blueberries to significantly reduce edema in a dose-dependent manner. By facilitating blood circulation, blueberry hydrosol would stimulate the evacuation of accumulated fluids in the eye contour area. Additionally, the anti-inflammatory properties previously described would explain its soothing action on skin irritations and thus combat eye fatigue.

• ANGENOT L. & al. Anti-inflammatory and immunological effects of Centaurea cyanus flower-heads. Journal of Ethnopharmacology (1999).

• WILHELMOVA N. & al. Antioxidant and prooxidant properties of flavonoids. Fitoterapia (2011).

• GRANATO D. & al. Chemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract. Food and Chemical Toxicology (2018).

• FAUCON M. Traité d'aromathérapie scientifique et médicale - Les hydrolats. Sang de la Terre (2018).