Cosmetics and their effects on skin
High doses of vitamin A (retinol) lead to reactions, as they are from vitamin A acid (retinoic acid) knows. While sodium lauryl sulfate is an example of a direct irritation offers, the reaction of vitamin A only indirectly by subsequent biochemical conversion into another substance. The strength of the irritation of many individual factors, such as skin thickness, the integrity of the barrier and the individual tolerance. For example, to ensure that children’s skin is much more permeable.
A connective tissue may be a general sensitivity for Hypertonic cause water phases. In this case, it is irrelevant what substances in the water phase. It plays physically seen only the resulting total concentration of a role. In rare cases, the tolerance limit even in hypotensive water phases achieved when released by evaporation of the drug contained in the water on the skin are concentrated.
How critical concentrations, is also in fruit acid treatments significantly. Here are the irritations even intends to create a regeneration of the skin to provoke. The threshold dose depends on the pH of the preparations from; at low pH is lower the threshold dose, with increasing pH with proportional increases fruit acid salts them.
Phototoxic operations
More or less unpredictable are the ingredients of plant extracts in people prone to allergies. Therefore, we recommend a test on the forearm when it is not safe. The culprit may proteins, biogenic amines and sharpness substances with the type of stimulus to capsaicin.
In contrast with other ingredients are predictable reactions when certain conditions occur. This is especially true for phototoxic inflammation, which in the case of natural and synthetic ingredients are observed. The allergenic Ascaridol, a terpene Endoperoxide, formed in the tea tree oil under the influence of atmospheric oxygen and ultraviolet radiation.
Figure: Ascaridol; in the middle are the two oxygen atoms of the endo-peroxide
Psoralens (furocoumarines) are also in lemon and orange peel, so it is imprudent for the removal of shells and related contamination in susceptible individuals phototoxischer dermatitis around the mouth can occur.
Even the Hypericin of St. John’s wort shows photosensitising properties. Accompanying a rather innocuous appearance later are stubborn.Phototoxic reactions are always to be observedSt. John’s wort is often administered orally and shows the need for unusual skin reactions, even after other factors than just the funds used skin care research. As a frequently occurring natural substance is still in mascara used to say, whose content in Abietic acid leads to contact allergy, the actual cause is not, however, the acid itself, but its reaction product with atmospheric oxygen.
Among the synthetic materials react especially polyether of ethylene glycol, also known as PEG, and their connections with long-alcohols – “ethoxylated alcohols” such as CETEARETH, Pareth (INCI) – under the influence of UV radiation with atmospheric oxygen.
Figure: formation of Hydroperoxide from PEG’s
(R1 and R2 symbolize different PEG chains remaining)
The educated Hydroperoxide are very aggressive and one of the causes of the dreaded Mallorca acne. It is therefore advisable to maintain fresh and perfumed not immediately suspend the sun, since the proportion of UV radiation, a variety of substances changed and dismantled, including antioxidant vitamins. The same applies to the use of deodorant products, if they are essential oils or synthetic chlorinated hydrocarbons contain. Since it comparatively more sensitive skin are applied, here is special caution.
Allergic reactions to preservatives are widely known and need at this point is not particularly emphasized. This applies without exception to all in the annex to the Cosmetics Regulation listed substances.
Anti inflammatory
Now there are substances in cosmetics, which can inhibit inflammation. These should be – it was said – not the sun Suspended, because of their sensitivity easily dismantled and thus may be ineffective. They work by different mechanisms:
Antioxidants inhibit depending on the structure of the above Photooxidation by:
by UV light generated hydrocarbon radicals defuse,
Activated oxygen molecules or intercept
formed with the oxidation products.
But they are no panacea, because they themselves are consumed, and therefore a limited capacity. The disadvantage is that they themselves naturally by the combination O2/UV be attacked. Moreover, they can not in any high concentrations, since then, such as vitamin E, own radical chain reactions, and thus become counter-productive. A sound basic forms of protection of this intact NMF of the skin. Detailed information about cosmetic practice in 2006 (2), 12-14 to find. Extracts & Co with their anti-inflammatory drugs to help the sun to treat erythema. These include aloe, sunhat and D-panthenol (see Cosmetic Practice 2006 (3), 8-9).
Not all the inflammatory processes in the skin by atmospheric oxygen and sunlight triggered. Other triggers are infections, injuries, chronic mechanical stimuli as well as barrier-and disorders. Regardless of the trigger inflammation cascade follows the same pattern multiples at which the body’s own enzymes are involved. An important key enzyme is 5-Lipoxygenase, the arachidonic acid to 5-Hydroperoxyeicosatetraensäure (5-HPETE) oxidized, from the subsequent proinflammatory Leukotrienes LTA4, LTB4, LTC4, LTD4 and LTE4 arise.
Picture: Education proinflammatory Leukotrienes
(Formulas from top to bottom: arachidonic acid, 5-HPETE, leukotrienes LTA4)
The skin with Bowellia nanoparticles in people who acne vulgaris, actinic keratosis, psoriasis and atopic tends, in practice has proved very good. The formation of the above is Leukotrienes including by omega-3-acids, such as α-linolenic acid (for example, comes in linseed oil and rosehips before) and Eicosapentaensäure (part of the fish oil) reduced.
Omega-3-acids and omega-6-acids (linoleic acid, γ-linolenic acid) are among the essential fatty acids and inhibit inflammation in terms of yet another interesting feature. They are in the skin by 15-Lipoxygenase to anti-inflammatory acids oxidized. Natural oils with a high proportion of essential fatty acids are bound, therefore, for skin care is of great value. Because of their sensitivity, they are best applied at night.
Among the anti-inflammatory extracts were representative of many other Calendula (active ingredients: terpenes), Spitzweg Erich (active ingredient: Acetosid), Mahonia (belongs to the substance: Berberine), chamomile (among other ingredients: aloe vera-α), willow bark (various phenolic Agents), Arnica (substances that are derived from Helenalin) to call. Arnica is just one example of the individual tolerance of different plant extracts. Apart from the healing effects may also opposite effects such as arnica allergy, dermatitis and eczema occur.
