Eighty percent of skin dry weight is collagen which is
responsible for the tensile strength of the skin. Elasticity is
due to the elastin fibre network making up 2–4% of the
ECM and glycoaminoglycans (GAG's) are involved in the
hydration of the skin [2]. Collagen fibres, elastin fibres
and GAGs are produced by fibroblasts and are primarily
affected by photoageing resulting in visible changes in the
skin such as wrinkles, pigmentation and changes in thickness
[1,2]. ROS are also capable of inducing expression of
proteinases which are responsible for remodelling the
extracellular matrix such as matrix metalloproteinases
(MMPs) and serine proteases [10].