Peptides: Peptides are fragments or pieces of proteins, which have a variety of effects on cellular function. Many of the newer cosmeceutical preparations include both synthetic and naturally occuring peptides demonstrated in the laboratory to have a biologic effect on aging or damaged skin. Certain peptides may stimulate skin metabolism and repair, others inhibit the breakdown of collagen, and still others to decrease muscle movement, thus improving dynamic wrinkles.
Cosmeceutical peptides may act as "carrier" agents, to facilitate delivery of other agents into the skin, most notably copper, an important cofactor in collagen produbtion, as "signaling" molecules, by activating fibroblasts and inhibiting matrix metalloproteinases (MMP) which degrade collagen, and as inibitors of neuromuscular transmission by interfering with the activity of membrane proteins necessary for calcium dependent exocytosis and release of acetycholine.
Despite a better understanding of role of peptides in skin metabolism, repair, and aging, there's very little evidence that they have an actual effect on the appearance of skin, or even manage to get to the area in the skin or muscle to exert their physiologic activity.
Botanical Agents: Herbal remedies have been used since time immemorial, and a variety of botancial agents may be incorporated in skin care preparations.These agents are usually listed on the label as "extracts", and although there may be a rationale for their use based on folklore or in some cases in-vitro studies of the extract or its components, in most cases there is little if any scientific evidence that they are any more efficacious than placebo. Many of these may be toxic, or interact with other drugs when taken internally, and cause irritation, dermatitis, and/or photosensitivity when used topically. A lack of standardization of the various preparations further complicates any assessment of their efficacy.
Arnica Montana (arnica) has been used topically to reduce or minimize bruising and swelling, and and as a general soothing agent. Although studies have demonstrated these effects in the laboratory, rigourous clinical trials on patients have shown no significant effect.
Aloe Vera (aloe) has been demonstratede to enhance wound healing in patients with frostbite, and superfical abbraded wounds, although some studies have shown delayed wound healing, especially in deeper or complex wounds.
Berberis Aristata (barberry) extract contains berberine, a compound that has antiseptic and antinflammatory properties, but may also be a potent skin irritant in some patients.
Bromelain (pineapple) is an enzyme extracted from pineapple stems, which when taken internally, may help decrease swelling and speed the resolution of bruising when taken before a procedure.
Calendula officinalis (calendula) from the common marigold, has mild antinflammatory and antiseptic properties
Centella Asiatica (Hawaiian pennywort) extract or asiatic acid has known antinflammatory properties and may hasten wound healing.
Chamomile extract has been shown to have mild anti-irritant, soothing, and antioxidant properties.
Echinacea purpureae (purple coneflower)
Hammamelis (witch hazel)
Symphytum officiale (comfrey) Another traditional healing/soothing agent for swelling and bruising, comfrey has demonstrated liver toxicity and carcinocenicity in laboratory rats, and is not reccommended for internal use.
Mentha piperita (peppermint oil) is a mild antibacterial and antifungal agent, and can exert a cooling effect on the skin.
Melaleuca alternifolia (tea tree oil) may antibacterial and antifungal when used topically.
Solanum Dulcamara (bittersweet)
Thuja (red cedar) extract is a mild antiseptic and used as a "calming" agent because of mild vasoconstrictive properties.
Thyme extract, from the herb, contains potent antioxidants
Copper: Copper is found in most biologic systems, and acts as a cofactor in collagen and elastin production, production of new blood vessels, and deposition of glycosaminoglycans in the skin. Unlike copper salts, which are highly toxic, copper atoms are stabilized with peptide complexes (short lengths of protein molecules-see above) to assist delivery into the skin. Copper peptide complexes used topically have been shown to increase procollagen formation and may help retard some signs associated with skin aging.
Zinc: Zinc is an essential element for many biologic processes, and acts as a cofactor for collagen repair and remodeling, control of damaging free radicals in the skin, and proper expression and replication of DNA. Topical uses of zinc-containing preparations include wound healing, anti-inflammation, seborrhea (dandruff), and acne preparations. The two best known zinc containing preparations are zinc pyrithione (for dandruff) and zinc oxide ointment.
