This fern is typical of South America, although it can be easily cultivated in other environments as well, and was used in traditional medicine by the indigenous people of Ecuador and Bolivia under the name “Calaguala.” Studies have been carried out to assess whether the medicinal qualities attributed to it by folk tradition were based on real data, obtaining some really interesting results.[1]

P. leucotomos extract, in fact, turns out to be able to actively protect the skin from UVA and UVB radiation damage because the polyphenols in which it is rich absorb UV radiation preferentially over biological molecules and because it has a demonstrated tendency to accumulate in the dermis, thus forming a protective layer against cells and biological molecules.[2]

Such an extract has, moreover, also been successfully tested in the treatment of some dermatological diseases that cause pigmentation problems and, specifically, is useful in counteracting melasma and vitiligo, albeit in different ways.[3]

The therapeutic action carried out by the extract against melasma is due to its ability to absorb UV radiation preferentially over biological molecules, reducing the amount of UVB radiation that goes to interact with melanocytes and, therefore, reducing the facial hyperpigmentation typical of melasma.[4]

Towards vitiligo, on the other hand, P.leucotomos extract exerts a therapeutic action by virtue of its antioxidant action: it is, in fact, well known that at the basis of vitilitic pathology there is a defect in the endogenous antioxidant system, which then causes melanocyte necrosis. Melanocyte necrosis then causes lymphocyte activation for melanocyte antigens and gives rise to autoimmune responses against melanocytes, which prevent their normal function leading to the formation of vitilitic lesions. The antioxidant action of this fern extract prevents and counteracts damage to melanocytes and their necrosis, thus reducing their necrosis and autoimmune attack.[4]

In the extract, the main molecules with antioxidant action turn out to be ferulic acid and caffeic acid: these substances are known to have mild anti-inflammatory effects, inhibiting arachidonate 5-lipoxygenase and xanthine oxidase, responsible for gout in particularly susceptible individuals, in addition to their remarkable tendency to absorb UV-Vis radiation by undergoing photo-oxidation.[5]

However, there is also a specific focus to be made on what are the harms of sun exposure on the scalp and hair in general: in fact, it has been shown to be the main cause of telogen effluvium so called “actinic” telogen effluvium, that is, caused by follicle damage due to UV radiation, which is typical of the autumn period.[6]

Taking P. leucotomos extract per os is, therefore, an excellent therapeutic response for trichological patients who want to minimize potential hair loss due to photoexposure damage and for those with particularly light phototypes who cannot avoid sun exposure.