The most important antioxidants in the skin increase in number as the need for protection becomes greater. This is a general principle in biology; when the stress level increases, cells are capable of compensating with increased protection. The immune system is therefore, within certain restraints, kept in balance. Antioxidants work in several ways: they may reduce the energy of the free radical, stop the free radical from forming in the first place, or interrupt an oxidizing chain reaction to minimise the damage caused by free radicals. A lack of antioxidants leads to conditions such as premature ageing, cell mutation, DNA damages, cancer, heart disease, etc.

There is a high level of antioxidants in the skin in relation to other organs of the body, and one finds both low molecular compounds (e.g. vitamins C and E, glutathione, ubiquinons, etc.), and enzymes (e.g. catalase, superoxide dismutase, glutathione reductase, etc.).

When skin is exposed to UV radiation, one might well expect that the antioxidants would protect our skin and be “activated”. The fact is, though, that most antioxidants get destroyed or remain inactive.

UV radiation causes oxidation of lipids in biological membranes, inactivates enzymes, disturbs the balance between metabolic processes and causes cross-linking among biopolymers, such as elastic fibres and collagen.

The below list provides an overview of the most important antioxidants in our skin. Those that become inactive due to UV radiation are coloured grey. Putrescine, Spermidine and Spermine are the only three antioxidants that are activated by UV light and that places them among the most UV resistant antioxidants.

Polyamines are found in all types of living tissue and in particularly high concentrations in sections of tissue that are under intense oxidative stress. Such sections of tissue include skin and epithelial cells, sperm cells, brain cells and lung cells. It is especially interesting to note that polyamines are the only antioxidants that are synthesised as a response to oxidative stress.

For quite some time, major research has been conducted in order to find the most effective antioxidants in the skin and in skin preparations. There is now increasing acceptance for the belief that polyamines are the most important antioxidants in the skin, and that these compounds are active in providing protection against sun-related damage and the repair of such damage.

Summary:

• The most important antioxidants in the skin increase in number as the need for protection becomes greater.
• Antioxidants may reduce the energy of a free radical, stop a free radical from forming in the first place or interrupt an oxidising chain reaction to minimise the damage caused by free radicals.
• A lack of antioxidants leads to conditions such as premature ageing, cell mutation, DNA damages, cancer, heart disease, etc.
• When the skin is exposed to UV radiation, most antioxidants get destroyed or remain inactive.
• Polyamines are the most important antioxidants in the skin, and these compounds are active in providing protection against sun-related damages and repair of such damage.