When a plant is formed it creates itself from sunshine or light energy. It gives a physical form to light energy taking a predetermined shape and substance from its genetic code or DNA. The initial impetus or stored energy of a seed from which a plant grows is its fat or lipid content.
The basic fibrous structure of a plant whether tree or grass they are formed by complex and simple sugars, starches and gums. Some of the names of these chemicals are well known such as glucose, fructose, galactose and cellulose. The group name for all these natural chemicals is polysaccharide. Certain plants produce specific polysaccharides with certain characteristics for example seaweeds yield fucose whilst lemon peel is richest in pectin.
The average person realise that these polysaccharides have certain characteristics that are very useful when it comes to textures. For example the gel consistency of jam derives from its glucose and pectin content. Fabric stiffeners rely on starches. In cosmetics a variety of textures can be obtained from polysaccharides to provide what we may call gels, serums or slurries.
In the latter case the key to their performance is their ability to hold moisture. As gelling agencies by their textural properties alone they can enhance the sensation of touch and well-being. Our initial contact with any substance on the skin is a sensorial one – what does it feel like? What does it smell like? Polysaccharides are touch improvers.
Fundamentally the skin requires moisture. About 70% of the skin is simply water. This moisture balance is crucial to the efficacy of any product applied to the skin. A cosmetic cream may be packed with the best ingredients of nature or science but they will not work if the substrate, the skin is not in a condition to use the materials or even receive the materials. Applied product must be bio compatible with the skin to be effective. They must have the right microenvironment in which to work to contribute lasting benefit. This means the skin must be brought to or maintained at its optimum level of moisture retention in other words hydration balance.
The water balance of skin is dependant upon a number of combined factors. Natural perspiration, local atmospheric conditions and the quantity of water in the cells of the stratum corneum itself are seen as the major factors. Often overlooked however is the hydrolipid film that overlays our skin that we call the skin acid mantle. This is a complex structure of substances that should provide a homogenous film covering our entire body.
It is this film combined with the corneal layer of the skin that determines skin comfort and sensitivity, the appearance of the skin, the efficacy of the epidermis as a barrier or coat and the perception of touch and even pleasure.
Polysaccharides seen for the moment simply as sugars can form moisture-retaining gels but this is not the story. For survival the originating plant via its roots secretes sugars into the soil in which it is planted. These provide food for the multitude of microorganisms existing in the soil, the bacteria which live in a symbiotic relationship with the living plant. Soil acids form other complex substances and enable the mineralisation of the plant to take place. The soil is full of odd substances some having a half life like yeasts and moulds which in their natural cycle with plant polysaccharides present ferment, yielding certain alcohols and yet more food for plant and bacteria.
Few realise that what goes on in the soil replicates itself on our skin. Such activity requiring sugars, acids, oils, and bacteria is fundamental to skin health. Today few live in a world conducive to skin well being. We are surrounded by pollution, dryness from air-conditioned or over heated environments. Our skin is stripped of its natural defences by alcohol-based toners, by detergents, shampoos, shower gels and soaps. This over cleaning is a killer for our skin and a primary cause of the signs of ageing.
Cosmetic scientists today can replicate many of these important natural processes especially fermentation. A combination of sugars, acids and alcohols can be combined under the loose heading of polysaccharides not only to moisturise by biofilm forming but actively support the natural processes of the skin acid mantle itself.
Looking even deeper into the microflora of the skin we see that each good bacterium secretes around itself a film or shell of polysaccharides. In turn the biofilm creates a consistent plane of protection for the skin or hair.
This moisturising film is however more than a mechanical protection. Our skin defence mechanism consisting of specialised cells forms a network of communication sending and receiving biological signals. Specialised polysaccharides are involved in the phenomena of cellular communication. Seaweeds and fungi in particular seem to have special affinity to the skin receptor sites. Padina pavonica has been recently highlighted as a specific seaweed with this capacity but it is present wherever the sugar fucose (from the Latin fucus=seaweed is present).
Polysaccharides should be seen as agents that reduce sensitivity and relieve inflammation and help to reduce allergic reactions. This is an especially useful concept if a cream contains excessively active materials such as AHA’s or enzymes. This is of course in addition to the previously made points about film forming and skin mantle nurturing moisturising properties. Polysaccharides always improve the texture of cosmetic formulations.
Unlike direct action moisturising materials such as hyaluronic acid or even petroleum gels polysaccharides show a build up of moisturising activity. This is the everse of direct action applications. This build up is due to the normalisation of the skin acid mantle and an increase in the skins own NMF’s (natural moisturising factors). This is a long lasting and not transient effect brought about by the skins own enzymatic activity breaking down the complex sugars into simple free sugars so trapping water molecules.
Another surprising benefit of these gel-forming materials is their ability to to enhance and increase the remanence of perfumes and essential oils. Polysaccharides intensify the perfume and makes it last longer on the skin but at the same time reducing the risk of skin intolerance.
Polysaccharides may be the unsung heroes of many gels and creams. Certainly they respect the skin and enhance its capacity to look its best and remain healthy and vital.