New coffee phytocomplex improves skin elasticity

These and other changes in the quality of the skin are partly the result of chronological ageing (i.e. they are intrinsic). Yet external influences (premature/extrinsic ageing) can also have a major impact on skin ageing. These external factors include smoking, pollution, toxic chemicals, and lifestyle (physical activity, diet, etc.). But the most significant factor (at a rate of 80%-90%) of all that contributes to the development of changes typical for premature ageing is UV rays.1 For this reason, extrinsic ageing is also sometimes referred to as photoageing. The dominant mechanism behind these changes is the excessive production of reactive oxygen species (ROS). ROS are generated and degraded by all aerobic organisms. If the intracellular mechanisms that break them down are working, ROS play a physiological role, for example, as signalling molecules in the regulation of the immune response, apoptosis or the regulation of pressure in the blood vessels.2 However, if production outweighs the degradation capacity, a condition called oxidative stress occurs.3 Free radicals, in cases of oxidative stress, cause lipid peroxidation, protein carbonylation and oxidative DNA damage, resulting in fracturing and other mutations, such as cyclobutane pyrimidine dimers and (6-4) photoproducts. The conditions of oxidative stress also have a negative impact on individual components of the extracellular matrix of the dermis, leading to their increased degradation or changes in functionality. In this way, oxidative stress contributes to the onset of wrinkles, decreased skin elasticity and reduced skin hydration. The extracellular matrix (ECM) of the dermis is composed mainly of collagen, elastin, proteoglycans and glycosaminoglycans. This structural component provides the skin with both the necessary strength and elasticity. The first mechanical properties supply the skin with collagen fibres, which make up 70% of the dry weight of skin.4 Another important part of the dermis is its elastic fibres. These fibres account for 1%-2% of the dry weight of the skin and are responsible for its elasticity and resilience.5 In the skin, there are three main types of elastic fibres, depending on the layer of the dermis in which they are to be found and the ratio of elastin and fibrillin forming them: the oxytalan fibres closest to the epidermis are composed solely of fibrillin and combine the dermal-epidermal junction (DEJ) with another type of fibre – elaunin fibres. These fibres are situated in the lower part of the papillary dermis and are made of elastin and fibrillin. The final component in this network is elastin-rich fibres in the reticular dermis. These fibres are parallel to the DEJ.6 It is evident from the function described and from the structure of the collagen and elastic fibres that the optimal production and organisation of collagen and elastin is absolutely essential to maintain the structure and mechanical properties of the skin. During photoageing, however, there is increased production of ROS to degrade the collagen,7 accompanied by the activation of signalling pathways for the expression of matrix metalloproteinase (MMP) 1, 3 and 9, which breaks down collagen further. In addition, the expression of procollagen I and III is reduced through the induction of the transcription factor activator protein 1 and the blocking of the effect of the transforming growth factor (TGF-).8 Similarly, the elastin network is disrupted during ageing by the decreased production of elastin and other related proteins, and the increased degradation of elastic fibres, such as by neutrophil or leukocyte elastase. These changes and the disruption of collagen structures lead to the formation of ‘solar elastosis’, also known as solar scars. These are areas deep in the dermis with structurally disorganised proteins of the elastic network.9 Coffee (coffea sp.) is a crop that has been known for a long time and used worldwide. Its effects countering the development of diabetes II, cardiovascular disease, or cancer of the colon are well known.10 Due to the high content of polyphenols, especially chlorogenic and caffeic acid, coffee has strong antioxidant properties and is able to protect cells against oxidative stress. It is also known to have positive effects on the conservation and production of the extracellular matrix, particularly collagen.11,12 On the other hand, low concentrations of these polyphenols or a high content of impurities can reduce these effects. Therefore, it is necessary to focus on a defined extract with a high proportion of these polyphenols and a minimum of impurities. Green coffee beans (Coffea arabica) were used to develop a new standardised phytocomplex with anti-ageing skin care properties. Its quality attributes were established in accordance with appropriate chemical and biological criteria. The fractionation method was reproducible and scalable. This design combined high throughput with high selectivity and ensured the enrichment of chlorogenic acid in the final cosmetic ingredient.

Materials and methods

Phytocomplex preparation