NATURALS 77
Plant-based cholesterol aids pro-ageing moisturisation
n Annika Schrader – Evonik, Germany Joe San Filippo – Wilshire Technologies, US
The sterol cholesterol is among the most widely distributed, naturally occurring organic compounds in the animal kingdom. Discovered in 1758 by Francois Pouletier de La Salle and later isolated and purified in 1815 by Michel Eugene Chevreul, the study of cholesterol has been the topic of two Nobel prizes during the 20th century (in 1927 by Windaus for clarification of its structure and in 1964 by Bloch for elucidation of its biosynthetic origins). Ensuing investigations have maintained an expansive interest in this ubiquitous sterol. Across the world, cholesterol continues
to garner increasing importance as a key ingredient in cosmetic products. According to Mintel’s Global New Product Database, the period between 2008 and 2017 saw an 8.7% compounded annual growth rate (CAGR) in new products containing cholesterol as part of their INCI declaration globally. Asia was the primary driver of this growth with a 13% CAGR over the same period. Other regions, especially Europe, have also contributed meaningfully to growing interest in this ingredient. The virtues of cholesterol are manifold. For example, it imparts excellent emulsifying properties to creams, lotions and other makeup formulations. This same quality also makes it an invaluable ingredient for the engineering of liposomal preparations used as delivery vehicles for the controlled release of cosmetic ingredients. Cholesterol, too, is frequently incorporated into cosmetic formulations because it adds emolliency without greasiness. Complimenting these virtues is the collective growing recognition of cholesterol’s role as an endogenous component in the skin. Additionally, there is the role which
cholesterol plays as a precursor to other cosmetic ingredients of which 7- Dehydrocholesterol (7-DHC) and cholesterol sulfate are just two examples. Undoubtedly, too, as the Pro-Ageing movement grows, future advances in other cholesterol-based products – e.g. the development of cholesterol conjugated
June 2018
amphiphiles of peptides, antioxidants and other ACIs – will further enhance the importance of this sterol.
Cholesterol and the skin Cholesterol is a simple sterol that is practically insoluble in water but soluble in most organic solvents, oils, and fats. It is essential for animal biology owing to the critical role it plays in the structural composition of animal cell membranes: cholesterol comprises nearly 30% of animal cell membranes and is important for its ability to retain cell membrane structural integrity while enabling membrane fluidity and flexibility.1
Because of
the critical role it plays in all animal life, cholesterol is biosynthesised by all animal cells at rates that vary based upon cell type and organ function. Cholesterol is the most abundant individual lipid in the stratum corneum, accounting for approximately 25% of the stratum corneum lipid mass.2
Along with
ceramides and fatty acids, cholesterol is a fundamental component of the lipid matrix lamellae structures surrounding corneocytes in the stratum corneum. Cholesterol lipids have ability to form tight,
semi-permeable barriers which play a critical role in maintaining skin hydration through the reduction of transepidermal water loss. An imbalance of these lipids has been linked with impaired barrier function.3 Studies have also found that cholesterol, whether formulated in alcohol, petrolatum, or wool fat, leads to an increased moisture retention by the skin.4
Given these facts, it
is not surprising that cholesterol has been found to effect only minimal to mild primary and cumulative skin irritation.4
Cholesterol
is neither a sensitiser nor photosensitiser.4 The multi-facetted role of cholesterol in maintaining healthy skin derives from its physical properties. Thus, for example, the pliability of skin results from the fluidity afforded by the overall lipid lamellae structure.2
Without cholesterol, our skin would otherwise be a rigid, somewhat brittle. As such, cholesterol levels in the skin are not only relevant to supporting skin hydration, but also to enabling the skin’s youthful, supple appearance. Unfortunately, as we age, the cholesterol levels in the skin invariably decrease until, by the time one reaches the age of 40, the cholesterol level in healthy skin has diminished by as much
PERSONAL CARE EUROPE
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88
