Air pollution is a rising problem in many metropolitan areas around the world. Airborne contaminants are predominantly derived from anthropogenic activities, and include carbon monoxide, sulfur dioxide, nitrogen oxides, volatile organic compounds, ozone and particulate matter (PM; a mixture of solid and liquid particles of variable size and composition, able to absorb and delivery a large number of pollutants). The exposure to these air pollutants is associated to detrimental effects on human skin, such as premature aging, pigment spot formation, skin rashes and eczema, and can worsen some skin conditions, such as atopic dermatitis.
Several cosmetic strategies can be adopted to protect human skin against environmental pollution. The very first step in an effective cosmetic anti-pollution routine is a proper cleansing of the skin to remove chemicals deposited on it. Another way to defend the skin against environmental stressors is the isolation of the epidermis through the formation of a cohesive and non-occlusive film on its surface, preventing the direct contact with airborne pollutants; this physical barrier can be obtained through the use of film-forming ingredients, both synthetic (silicones, acrylic acid copolymers) and naturally derived (peptides and polysaccharides extracted from plants or obtained by fermentation processes). The third approach is the inclusion in anti-pollution formulations of antioxidants, in order to protect against free radical effects, or ingredients able to up-regulate the antioxidant defenses of the epidermis cells.
Some cosmetic companies introduce in their anti-pollution cosmetics several ingredients with different complementary mechanisms of action, obtaining formulations designed to tackle as many pollutants as possible. Figure 1 presents schematically the action of environmental pollutants on human skin and the main mechanisms of antipollution cosmetic ingredients.
Most of the active anti-pollution ingredients present in formulations on the market are products of botanical origin. This reflects a more general trend in the today’s cosmetics and personal care industry.
Algae and Spermatophyte are most resource of botanical origin.
- Algae
Marine algae are eukaryotic organisms classified in microalgae (unicellular species present in phytoplankton) and macroalgae (found in coastal areas). Macroalgae (seaweeds) are in turn classified in Rhodophyceae (red algae), Chlorophyceae (green algae) and Phaeophycea (brown algae), according to their dominant pigment. Algae provide a great variety of metabolites (polysaccharides, lipids, phenolic compounds and pigments) and can be easily cultured on seashores in great volumes; moreover, they grow quickly, and it is possible to control the production of their metabolites by manipulating the culture conditions. For all these reasons, algae represent an attractive renewable source of bioactive compounds with potential applications in pharmaceutical, nutraceutical and cosmetics industries.
A number of bioactive compounds and extracts derived from macroalgae have proven to be useful in the treatment of some skin conditions like: photo-protective activity, skin whitening, antibacterial and anti-inflammatory activity, acne-affected skin, antioxidant potential
Brown algae have been reported to contain comparatively higher contents and more active antioxidants than red and green algae
Anti-Pollution Ingredients from Spermatophytae:
- Eriodictyon Californicum
Also known as “yerba santa” and “bear weed”, The leaves of E. californicum are covered by a resin containing flavonoids (such as eriodictyol and homoeriodictyol), which act as herbivore deterrents and UV screens; this plant is also a source of moisturizing compounds such as mucopolysaccharides and glycoproteins, which produce their moisturizing effects via hydrogen bonding of water by their sugar moieties. The extracts of E. californicum, due to the presence of flavonoids such as homoeriodictyol and eriodictyol, well known for their antioxidant activity, provide further benefits when added to cosmetic formulations.
- Camellia Sinensis
Green tea is obtained by roasting or steaming Camellia sinensis (Theaceae) leaves in order to inactivate polyphenol oxidase activity. Green tea extracts are complex mixtures of bioactive compounds, including tea polyphenols, primarily green tea catechins. Tea catechins include epicatechin, epicatechin-3-gallate, epigallocatechin and epigallocatechin gallate. These polyphenols have biological activities, including antimicrobial, anti-inflammatory, anticancer, antioxidant and radical scavenging activities.
On the basis of their biological properties, green tea polyphenols are generally accepted as having a protective effect against oxidative stress and DNA and cell structures damage induced by a number of environmental toxins/toxicants (pesticides, smoking, mycotoxins, PCB, arsenic.
2-3 -Marrubium Vulgare
It is a plant widely used in antipollution skincare products. M. vulgare is reported to possess several biological activities, among which the most interesting are antihepatotoxic, antihyperglicemic antibacterial, anti-inflammatory and antioxidant properties. In particular antioxidant properties may justify the widespread of Marrubium vulgare extracts, often prepared with peculiar extraction techniques, as natural cosmetic ingredients, with claims including anti-pollution, antioxidant, protective for irritated and stressed skin, detoxifying, soothing.
- Schinus Molle
Schinus molle (Anacardiaceae), also known as Peruvian pepper tree, false pepper or pink pepper, is an evergreen tree native to Peruvian Andes. Widely used in traditional medicine for its purported analgesic, antidepressant, antimicrobial, diuretic, astringent and antispasmodic properties, Schinus molle exhibits insect repellent, anti-inflammatory, antifungal and antioxidant effects. The antioxidant properties of leaf and fruit essentials oils of S. mole are approved.
In aqueous methanolic extracts of the leaves of S. molle a number of polyphenolic metabolites were found, including glycosides based on quercetin as an aglycone.
- Camellia Japonica
Camellia japonica, also known as Rose of winter, is a flowering tree or shrub belonging to the Theaceae family and naturally occurring in China, Japan and Korea.
It has been reported that C. japonica, whose flowers and flower buds were traditionally used in oriental medicine as an astringent, anti-hemorrhagic and anti-inflammatory remedy, exhibits a variety of biological activities, such as antiviral, anti-atherogenic, anti-hyperuricemic, anti-photoaging, antioxidant, radical scavenging and anti-inflammatory effects, and glycation inhibitory action. The ethanol extract of C. japonica flowers exhibits antioxidant properties , moreover, it is able to increase the protein expression of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase.
In an ex vivo model, it has been shown that it reduces piknotic nuclei and it prevents the detachment of the dermo-epidermal junction induced by pollutants such as heavy metals and hydrocarbons. The use of C. japonica flower extract in cosmetics support anti-aging and anti-pollution claims.
- Schisandra Chinensis
Schisandra chinensis Baill (Schisandraceae) is a plant native to China, Japan and Russia; its dried fruits are used in traditional Chinese medicine, where it is considered one of the 50 fundamental herbs. Modern studies show that this plant possesses several biological activities such as anti-hepatotoxic, antitumour, anti-inflammatory and antioxidant. Some recent studies have also shown the presence in fruits and leaves of S. chinensis of phenolic compounds with good antioxidant activity. The extract from S. chinensis fruits has beneficial effects on the skin and has been proposed as a cosmetic anti-pollution ingredient.
Several scientific investigations have established that the prolonged exposure to environmental pollutants can produce in human skin biochemical parameters modifications and impairment of barrier function, and can promote the mechanisms of skin aging; the visible results of these effects are dryness, wrinkles, dark spots, sagging and the aggravation of skin sensitivity. As the awareness of the impact of environmental stressors on the skin grows, there is an increasing consumer demand for cosmetics and personal care products able to provide anti-pollution benefits.
Source: Cosmetic Functional Ingredients from Botanical
Sources for Anti-Pollution Skincare Products
