A great snippet from an article, courtesy of Skin Inc. Magazine.

Skin Integrity, Inflammation and Sensitivity
Many individuals who experience irritated and inflamed skin such as rosacea and relative conditions seek “natural” alternatives other than medications to hopefully abate symptoms and find relief. From a topical perspective, cosmeceu­ticals and skin care products with anti-inflammatory ingredients will establish some degree of improvement. However, some may work temporarily, and symptoms may return.

It is important to observe the internal mechanisms of skin inflammation so that herbal skin care is chosen via efficacy and clinical validation rather than an experimental plea in desperation of attaining relief. Additionally, it should be noted that herbal products may also contribute to irritation if improperly selected, used out of compliance by either the technician or the client, not intended for use on the skin, or have not been manufactured under stringent guidelines for safety.

Inflammation of the skin is a complex process that involves a definitive source or antagonist—the release of vasoactivity, histamines, leukotrienes, pro-inflammatory prostagl­andins and lymphokines. These antagonists fuel capillary activity that may result in dilation and inflammation. Thus, applying any type of product topically without understanding the mechanism of both the functional and active ingredients and their potential sides effects may negate all worthy intentions. The alteration of the integrity of the stratum corneum via antagonists will be accompanied by a subsequent increase in transepi­dermal water loss (TEWL) and a decrease in skin hydration factors. Barrier dysfunction is associated with a substantial loss of ceramides from the stratum corneum, which corresponds with TEWL. The aim in management of sensitive skin is to restore the barrier function through the application of ceramides, nutritive lipids and carbohyd­rates.

The Power of Plants
The validation of the activity of botanical compounds lies within hundreds of specific phytochemical attributes much in the way essential oils function on human tissue. One plant may possess several characte­ristics, and various parts of the plant, stems or leaves may interact with the skin differently. Interest­ingly, botanicals provide almost any type of vehicle including surfactants, oils, butters, waxes and emulsifiers.

Gel polysacc­harides (Aloe vera).
Some of the most impressive plant compounds cited in countless studies are polysacc­harides such as those found in aloe vera gel, which have immunomo­dulatory properties. Polysacc­harides are complex carbohydrates found in most plants. They have potent therapeutic benefits and act as demulcents. Demulcents are natural plant skin hydrators and perform distinct barrier function capabilities. This is one of the most impressive natural mediated reactions that plants produce—having an affinity to act in defense of barrier function.

Mucilage (fenugreek).
Mucilage containing herbs work similarly to polysacc­harides in that they become sticky and “swell” when they come in contact with water. This allows them to act as a “plant bandage,” protecting dry or mildly inflamed skin. Botanicals such as marshmallow, mullein, slippery elm, flax and fenugreek are examples.

Phenolic compounds.
These bioactive substances found in plants are actually important constituents of the human diet. They include flavonoids such as anthocyanins, flavonols and flavones, and non-flavonoid classes including phenolic acids, lignins and stilbenes. Botanical and natural antioxidants work by scavenging and inhibiting the propagation of oxidative chain reactions, aiding in oxidative damage repair.

Phytomol­ecules (curcumin).
Phytomol­ecules include aloin, ginesenoside, curcumin, epicatechin, asiaticoside, ziyuglycoside I, magnolol, gallic acid, hydroxyc­havicol, and hydroxyc­innamic and hydrobenzoic acid. All scavenge free radicals from skin cells, prevent TEWL, include a sun protection factor (SPF) of 15 or higher and protect skin from wrinkles.