Gentian: what are the benefits for the skin?

Glycation is a reaction that occurs between sugars and amino acids to produce glycoproteins. However, it can lead to the formation of glycotoxins or AGEs (Advanced Glycation End products). AGEs accumulate in the skin over time and accelerate skin ageing, particularly through an increase in oxidation reactions, i.e., the production of free radicals , and inflammation, related to tissue damage. Moreover, glycation results in a decrease and disorganisation of elastin and collagen fibres, vital tissue proteins for skin vitality. This leads to the appearance of wrinkles and skin folds. UV exposure can exacerbate this process.

However, the iridoids, photochemical constituents of certain plants, have shown anti-glycation activity in in vivo and in vitro studies. The gentiopicroside, found in gentian extract, is an iridoid that slows skin ageing by preventing the degradation and disorganisation of elastin, stimulating the synthesis of collagen, and blocking the formation of AGEs in the skin, among other things through the inhibition of the NF-kβ pathway, a transcription factor inducing inflammation and the production of reactive oxygen species (ROS). The skin will then be smoothed. However, the precise molecular mechanisms are little known to date.

A study on mice has demonstrated the effect of extracts from the roots and rhizomes of Japanese gentian (Gentiana scabra) on contact dermatitis. The topical application of the extract helped to alleviate skin lesions, such as surface roughness and crusts on the skin. It also prevented skin enlargement and reduced erythema, characterised by red skin spots, demonstrating the anti-inflammatory properties of gentian.

Furthermore, gentian has prevented hyperkeratosis and hyperplasia, processes of skin thickening and cell proliferation, respectively, potentially linked to skin conditions or as a result of repeated friction, through the inhibition of pro-inflammatory cytokine production (TNF-α, IFN-γ, IL-6 and MCP-1) in inflamed tissues, soothing the skin.

It has been demonstrated that gentian, through gentiopicroside, reduces the production of free radicals by impacting glycation. These species, which can also originate from UV rays, pollution or tobacco, cause oxidative stress on the skin, and this stress is implicated in the onset of skin damage and severe skin disorders, such as melanoma.

Its antioxidant properties are primarily derived from the flavonoids it contains. Thanks to their reducing power and chemical structure, flavonoids, with the help of a hydroxyl group, are able to trap free radicals, thus preventing oxidative stress. Gentian then helps to protect cells and prevent damage.

Research has proven that gentian extract has antimicrobial activity. Indeed, a study showed that extracts from the leaves and flowers of yellow gentian (Gentiana lutea) inhibited the growth of several tested pathogenic microorganisms.

The "minimum inhibitory concentration" values ranged between 0.12 and 0.31 mg/mL, and the most sensitive were, among others, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus epidermidis, Escherichia coli (with a minimum inhibitory concentration of 0.12 mg/mL), Salmonella typhymurium and Staphylococcus aureus.

The dry extract of Gentiana lutea roots has thus demonstrated significant efficacy against Streptococcus pyogenes, a bacterium responsible for infections, particularly skin infections, which are characterised by lesions on the face or lower limbs.

A study conducted using an extract of Gentiana lutea explored the effect of gentiopicroside on the appearance of the eye contour. Tests in vitro suggest that the gentian extract has a significant positive effect on the release of the protein VEGF-C.

VEGF-C is a mediator of lymphangiogenesis, that is, the synthesis of lymphatic vessels which are involved in the regulation of the inflammatory response by draining the fluid that accumulates under the eyes and causes the appearance of bluish dark circles, and by reducing the formation of eyelid oedema during acute skin inflammation.

These results suggest that gentian extract may have a protective effect against the formation of redness and dark circles under the eyes. Furthermore, gentian acts on the eye contour by slowing down the appearance of wrinkles, which in this case translates to "crow's feet" for example, by limiting skin folds, and thus making the skin smoother.

Typology has made the decision to incorporate yellow gentian extract (INCI: Gentiana Lutea Root Extract) into its smoothing eye contour mask. This treatment, with a balm-gel texture and enriched with polyglutamic acid and plant collagen, hydrates, plumps fine lines and brightens the eye contour. The reusable silicone patches enhance the absorption of the active ingredients.

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