A rewarding partnership

An important symbiotic relationship exists in the skin between vitamins C (L-ascorbic acid) and E (tocopherol). L-ascorbic acid is the only bioavailable form of vitamin C for the skin, delivering not only antioxidant value, but also multiple anti-ageing benefits including collagen formation. Vitamin E, in addition to its antioxidant action, has the ability to reduce oedema, erythema and sunburn cell formation⁵. Vitamin E also plays a role in healthy barrier function.

As free radicals are produced in the skin owing to UV exposure, they attack the lipid membrane of the cells in an attempt to reach DNA to cause mutations and cell damage. L-ascorbic acid is water-soluble, so it is unable to impede the action of these free radicals in a lipid environment. Tocopherol, however, is lipid-soluble, so it is the perfect candidate to neutralise the free radicals before they can cause damage to the cells.

Unfortunately, as a result of this free radical neutralisation, tocopherol itself becomes a free radical. L-ascorbic acid has the ability to react with the reduced tocopherol and turn it back into a stable molecule. This action of L-ascorbic acid makes it a co-antioxidant. For the best effect, formulations should contain lower percentages of tocopherol and higher percentages of L-ascorbic acid⁶.

C&E Strength and C&E Strength Max

C&E Strength and C&E Strength Max both contain ideal combinations of L-ascorbic acid and pure tocopherol to deliver excellent visible results in as little as 1 to 5 weeks.

Here is an overview of these finished products’ mechanisms of action:

• L-ascorbic acid directly stimulates the production of new collagen, starts the process of new collagen synthesis, and additionally works to ensure the chains are formed properly. It is an essential cofactor in the hydroxylation of proline and lysine (amino acids) into hydroxyproline and hydroxylysine the amino acids critical to the function of collagen. This action increases the secretion of procollagen (the precursor to collagen) from cells, as well as the processing and polymerisation of the precursors to collagen fibres. This results in the maximum stability of the triple helix that forms collagen. More abundant and more stable collagen minimises wrinkling and fine lines in the skin
• Both vitamins C and E are potent antioxidants, L-ascorbic acid in the water phase and tocopherol in the membrane or lipid phase. Together they make a potent antioxidant system across all components of the skin. They both also provide enhanced UV-protective benefits
• Vitamins C and E have also both exhibited anti-pigmentation effects. L-ascorbic acid interferes with the different steps of melanisation by interacting with copper ions at the tyrosinase active site, reducing DOPAquinone and blocking DHICA oxidation (DHICA: 5,6-dihidroxyindole-2-carboxylic acid). α-Tocopherol inhibits tyrosinase and melanogenesis in epidermal melanocytes. The antioxidant properties of α-tocopherol, which interfere with lipid peroxidation of melanocyte membranes and increase the intracellular glutathione content, could explain its depigmenting effect
• L-ascorbic acid regenerates α-tocopherol from its radical form, so using both vitamins C and E for treatment results is a more effective and long-lasting antioxidant response. Topical application of α-tocopherol and L-ascorbic acid has also shown the ability to decrease the tanning response, inhibiting the UV-induced melanogenesis and proliferation of melanocytes.

Although antioxidant vitamins provide important skin benefits on their own, when used in strategic combinations with other antioxidants and sunscreen, the protection quotient increases exponentially. By using vitamins C and E together daily in conjunction with a broad spectrum sunscreen with an SPF of at least 30, the skin is provided optimal protection. All formulations in the suite of PCA SKIN sunscreens also contain the antioxidants silybin and caffeine to provide even greater antioxidant protection.