The Uses of Phytochemicals in Skin-Care Products

Humanity's original skin-care products were plant- and animal-based salves, ungents and poultices. Although most modern cosmetics use petrochemicals instead of plant oils as their base as of 2011, most still make use of plant admixtures for their health-promoting phytochemicals. Whether used as a preventative or a treatment, phytochemicals are amongst the most widely used substances in dermatology.

Antioxidants

Many plants are rich sources of bioavailable antioxidants. In particular, the antioxidants lutein, lycopene, pycnogenol, resveratrol and epigallocatechin gallate are used in skin-care products that aim to slow the skin's aging process. Exposure to ultraviolet radiation and oxygen accelerates the skin's aging process. The topical application of powerful antioxidants may help the skin recover from these damaging environmental forces. Epigallocatechin gallate, the most powerful antioxidant of all green tea polyphenols, is more than 25 times as effective as vitamin E and 100 times as effective as vitamin C at preventing oxidative damage to cellular DNA. Only resveratrol, the phytochemical that gives red wine its color, approaches its efficacy.

Skin-Bleaching Agents

Many skin-care products incorporate the essential oils of several plant species to lighten the skin; citrus species, for example, have a high limonene content that allows them to serve this purpose. Limonene, a relatively harmless phytochemical that lighten the skin tone, can also increase the risk of skin damage upon exposure to the sun. The essential oil of chamomile makes a better choice for skin lightening; its rich angelic acid content decreases skin pigmentation, while its farnesene and carophyllene content can treat inflammation, eczema, rashes and allergic dermatitis.

Astringents

The vast majority of astringent skin care products contain phytochemicals as the primary active ingredients in their formulations. By far the most popular is tannin, found in witch hazel, oak bark and tea leaves. These mild astringents can close pores, cleanse the skin and treat minor shaving mishaps. More powerful astringents such as berberine and oxy-acanthine --- predominantly found in the roots of goldenseal and barberry plants --- can draw the moisture out of blisters and infected sores.

Antifungals

Melaleuca or tea tree oil can be effective as the synthetic antifungal drug Clotrimazole in the treatment of athlete's foot. Its powerful antimicrobial properties largely stem from the presence of the phytochemicals cineole and terpinen, two volatile terpenes that are also effective antibacterial agents. Unfortunately, melaleuca has an overpowering aroma some people find unpleasant. Manuka, on the other hand, has a mild odor and the same antifungal properties. Its high concentration of the triketones leptospermome, iso-leptospermome and flavesone make it effective not only against skin fungus but also gram-positive bacteria.