01.06.2018

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How to recognize a natural cosmetic? Let’s analyze the INCI!

Dr. Riccardo Matera

The consumer increasingly requests that a cosmetic reflects the naturalness requirements.

Generally, natural cosmetics contain ingredients of vegetable origin while they do not include substances such as silicones, petrolatum, mineral oils, polymers and synthetic preservatives.

How do we get to the bottom of the ingredient list?

The analysis of the ingredients or better of INCI (International Nomenclature of Cosmetic Ingredients) is not really in the public domain, but the answer to our questions always remains.

In this article we give you some advice to be able to read a label of a cosmetic product especially if we want to distinguish a traditional product from a natural one or even more organic.

We offer you an excerpt of one of our interviews with the cosmetologist Mara Alvaro of Cosmesidoc in which we clarify some important questions:

What are the useful indications on the label that allow you to understand if a cosmetic contains substances of natural origin or not?

All natural ingredients (waxes, vegetable oils, botanical extracts, essential oils) are described with the scientific name in Latin and with the English wording in brackets: for example Citrus medica limonum (Lemon) Peel Oil represents the essential oil of Lemon as well as the most common vegetable oils are easily recognizable especially by the English name for example. Almond, Jojoba, Avocado, Sunflower etc.

The structural products of a cosmetic (surfactants, emulsifiers, etc.) of natural derivation are generally described by elements that refer to the natural products from which they come, for example. coco-glucoside derivatives between glucose and coconut oil, glyceryl stearate citrate: glycerine derivatives between stearic and citric acid etc.

The petrochemical-based surfactants, on the other hand, are for example the famous SLES and SLS i.e. sulphate products such as Sodium laureth sulfate (recognizable by the suffix –eth which indicates a chemical reaction of ethoxylation) or non-ethoxylated as Sodium lauryl sulfate.

The most common rheological modifiers of natural origin are xanthan gums, carrageenans, cellulose of natural derivation, identifiable in INCI by the words Xanthan gum, Carrageenan, Cellulose and so on, which replace the most different acrylate-based polymers such as acrylates copolymer used in formulations not natural.

In shampoos, shower gel and green detergents, the silicones identifiable by INCI wordings with the suffixes -thicone, -xiloxane, for example cyclopentasiloxane, dimethicone are absent. Ingredients of petroleum origin such as mineral oils, paraffin (paraffinum liquidum) are absent in natural cosmetics and should not be present in green formulations.

Synthetic preservatives, formaldehyde cessors (e.g. Methylisothiazolinone, Imidazolidinyl urea) and parabens (Methylparaben and the like) should generally be absent in natural cosmetic formulas, where instead preservatives such as Potassium Sorbate and Sodium Benzoate, Benzyl Alcohol are used, synthetic products, but admitted by certification bodies for organic and natural products.

Furthermore, many ingredients can have both synthetic and natural derivations. The presence in formula of a derivative of natural origin can be accurately highlighted in INCI since they are obtained with greener production methods. Note the wording pentylene glycol of natural origin.

Sometimes the label reads “100% natural cosmetic”. Is it possible to have a cosmetic with such characteristics?

Natural cosmetics are complex mixtures of natural raw materials generally reworked, but few products can really be 100% formulated with entirely vegetable ingredients if some massage oils and body oils are excluded. But natural cosmetics don’t stop with oils! The different types of natural cosmetics include: creams, lotions, gels, serums and detergents.

Most of the structural raw materials of these products (e.g. emulsifiers, surfactants, rheological modifiers, etc.) are substances obtained by physical or chemical modification. The European regulations on natural cosmetic productions allow a series of ingredients that have different specifications in terms of “naturalness”. For brevity we distinguish three classes of ingredients allowed in natural cosmetics:

  1. The natural ingredients are substances of vegetable, inorganic origin and their mixtures obtained and processed with physical extraction procedures.
  2. Natural-identical substances found in nature, but synthesized with simple transformation methods.
  3. Natural-like substances of natural derivation are modified with chemical processes that do not leave toxic waste and contaminants.

All cosmetic products (not only natural ones) comply with European regulations. The national association of cosmetic companies Cosmetica Italia, provides useful information for the protection of consumer health. In addition, the ABC cosmetics website – developed for a greater awareness of the world of cosmetics – provides useful information about it and we often recommend it in case of doubts or questions.

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Do you want to know more about organic cosmetics?

Read the following article Why can’t cosmetics be 100% organic?

Cyclooxygenase, lipoxygenase and the inflammatory process

Cyclooxygenase and lipooxygenase are the two families of enzymes that are commonly involved in the inflammatory process, through a complex of reactions which is called arachidonic acid cascade. This complex of reactions develops as follows: a first enzyme, a phospholipase cleaves the phospholipids of biological membranes, releasing arachidonic acid, a polyunsaturated fatty acid with 20 carbon atoms (eicosa-5Z,8Z,11Z,14Z-tetraenoic acid ; C20:4; ω-6). The arachidonic acid is then transformed by two parallel enzymatic pathways, that is, by two families of enzymes: the cyclooxygenase which transforms it into prostaglandins and thromboxanes and the lipooxygenase which transforms it into hydroperoxides which in turn transform into leukotrienes .
There are two cyclooxygenase isoforms indicated with type 1 and type 2, briefly COX-1 and COX-2. COX-1 is the enzyme present in most cells (except red blood cells), and is constitutive, that is, it is always present. COX-2 is an inducible cyclooxygenase isoform: it is constitutively present in some organs such as brain, liver, kidney, stomach, heart and vascular system, while it can be induced (i.e. developed if necessary) following inflammatory stimuli on the skin, white blood cells and muscles.
There are various types of lipooxygenase that lead to different products, the most important in the inflammatory process is 5-lipooxygenase, 5-LOX.

Prostaglandins, Thromboxanes, and Leukotrienes

Prostaglandins, Thromboxanes, and Leukotrienes are chemical messengers or mediators, that is, molecules that bring a message to specific cells and activate or deactivate metabolic responses in these cells. They, therefore, have a function similar to hormones, only that, unlike what hormones do, the chemical message is carried only at a short distance, that is, only to the cells that are in the vicinity of the place where the mediators were produced. There are different prostaglandins, different thromboxanes and different leukotrienes that carry specific messages. In many cases these act as mediators of the inflammatory process , therefore they trigger all the events that are involved in inflammation:
– vasodilation with consequent blood supply (redness),
– increased capillary permeability with consequent fluid exudation (swelling or edema),
– stimulation of nociceptive nerve signals (pain),
– on-site recall of immune system cells that attack a possible invader (chemotactic action)
– activation of the biosynthesis of fibrous tissue to strengthen or repair the affected part (even if there is no need)
– generations of free radicals that can chemically destroy an invader (but also damage our tissues, i.e. they just “shoot in the middle”).
Prostaglandins and thromboxanes, however, also play important physiological roles in normal conditions, i.e. in the absence of inflammation. For example, they regulate the secretion of mucus that protects the walls of the stomach, they regulate the biosynthesis of cartilages and synovial fluid in the joints, they regulate vasodilation, hence the correct flow of blood in the various local districts, and more.

Triglycerides

Triglycerides are the main components of most oils and fats. These are heavy, non-volatile and little polar molecules, insoluble in water, made up of glycerol (or glycerin) esterified with three molecules of fatty acids: therefore, it is a tri-ester of glycerin, from which the name derives. Each fatty acid contains 8 to 22 carbon atoms (commonly 16 to 18) and can be saturated, mono-unsaturated or poly-unsaturated. The size of the fatty acids and their saturation determines the physical and sensorial properties of the triglycerides, which can appear as oils (liquids at room temperature) or fats (solid or semi-solid) and can have greater or less greasiness and smoothness on the skin. Unsaturated triglycerides or with shorter fatty acids are more fluid and have greater flowability.

Fatty acids (saturated, mono-unsaturated and poly-unsaturated)

The name fatty acids is commonly used to indicate those organic acids that are found in the composition of lipids, that is, in animal and vegetable oils and fats, both in the free form and in the form of esters with glycerol (e.g. in triglycerides), or they are esterified with “fatty” alcohols, that is, long chain alcohols, to form waxes. Fatty acids are carboxylic acids (formula R-COOH) which have a long carbon chain (R), unlike common organic acids such as acetic acid and propionic acid, which have 2 or 3 carbon atoms in total, respectively. Fatty acids are defined as saturatedif they do not have double carbon-carbon bonds, (called “unsaturations”), they are defined mono-unsaturated if they have only one, they are defined mono-unsaturatedpoly-unsaturated if they have two or more double bonds (see figure). The term omega-3 (ω-3) or omega-6 (ω-3), refers to the position of the first double bond starting from the bottom of the chain of carbon atoms: if the first double bond is encountered after 3 carbon atoms the fatty acid is classified as omega-3 , if after six carbon atoms omega-6 , as shown in the figure. The most common saturated fatty acids are palmitic acid (16 carbon atoms and no double bond, C16: 0) and stearic acid (18 carbon atoms, 18: 0), the most common mono-unsaturated is the oleic acid, typical of olive oil (18 carbon atoms and 1 double bond in position 9, C18: 1; ω-9), while the most common poly-unsaturated are linoleic acid and linolenic acid, progenitors respectively omega-6 and omega-3 (see figure).

Terpenes and terpenoids

Terpenes or terpenoids are a large family of natural molecules, typically containing 10 to 30 carbon atoms, which are biosynthesized from a common “brick”, isopentenyl pyrophosphate (IPP), containing 5 carbon atoms (see figure). The discovery that the repetitive brick consists of 5 carbon atoms is relatively recent, while it was once assumed that the entire family was created by repeating a brick of 10 carbon atoms, which was called “terpene”. Therefore, the molecules with 10 carbon atoms (such as limonene, see figure) were called mono-terpenes, i.e. composed of a single brick, diterpenes those with 20 carbon atoms (e.g. the cafestol that gives the aroma to the coffee), triterpenes those with 30 carbon atoms (e.g. beta-carotene). Since molecules made from 15 carbon atoms were also found (such as bisabolol), it was thought they contained a terpene and a half, and were called sesquiterpenes (from the Latin semis = half + atque = and). Today it is known that the repetitive unit is composed of 5 carbon atoms, therefore it is easy to understand how mono-terpenes contain two (see figure), sesquiterpenes three, diterpenes four, triterpenes six.