Generality
Azelaic acid is a saturated dicarboxylic acid, found naturally in wheat, barley, rye and olive oil (especially in the rancid). The interest in this substance - produced in large quantities by the fungus Malassezia furfur, which normally dwells on human skin - derives from some characteristics that are particularly useful in dermatology.
Property
Azelaic acid is a compound endowed with numerous properties and, for this reason, it is widely and effectively used in the dermatological field.
More in detail, azelaic acid possesses:
- Antibacterial properties.
- Inhibitory activity against keratinocyte proliferation.
- Anti-inflammatory and anti-radical activity.
- Depigmenting action.
uses
As mentioned, by virtue of its numerous properties, azelaic acid is used in the treatment of various skin disorders and is also used to combat hair loss.
Against acne
The anti-acne activity of azelaic acid probably derives from its bacteriostatic and bactericidal action against microorganisms that settle the superficial layers of the epidermis, causing skin lesions characteristic of acne vulgaris ( Propionibacterium acnes ).
This bacteriostatic and bactericidal action is due to the inhibitory activity of azelaic acid against enzymatic systems fundamental for the activation of the mitochondrial respiratory chain and for the synthesis of nucleic acids and proteins.
In addition to the aforementioned actions, azelaic acid has demonstrated a radical scavenger activity (anti free radicals), potentially useful in an anti-aging perspective, but also valuable for counteracting the inflammatory phenomena that accompany acne.
For all these reasons, azelaic acid is still considered one of the first-use drugs in modest forms of acne.
Against rosacea
Although the causes of rosacea have not yet been fully clarified, it is believed that the inflammatory processes nevertheless play a fundamental role in this pathology.
Thanks to its interesting anti-inflammatory properties, azelaic acid has proved very useful in the treatment of rosacea.
In detail, the effectiveness of azelaic acid in this area is due to its ability to modulate the inflammatory response at the level of keratinocytes through a series of mechanisms, such as:
- Inhibition of the synthesis of pro-inflammatory cytokines;
- Inhibition of the release of reactive oxygen species (free radicals or ROS) by neutrophils;
- A "scavenger" action of free radicals already formed (radical scavenger).
As depigmenting
Azelaic acid has an inhibitory action against tyrosinase, a key enzyme for melanin synthesis; in this sense, it is active above all in the hyperactive melanocytes, while it saves the normal ones. As such, it is widely used in the treatment of melasma.
Against hair loss
Androgenetic alopecia, the most common cause of hair loss in both men and women, is known to be linked to the action of androgenic hormones in a genetically predisposed medium. In this sense, the follicular concentration of the 5-alpha reductase enzyme, which converts testosterone into dihydrotestosterone, the main defendant in the genesis of baldness, plays a major role. The studies of Stamatiadis et al. (1987) showed that in vitro azelaic acid has a very strong inhibitory activity against the enzyme 5-alpha reductase; this effect is not direct (as in the case of progesterone), but derives from the inhibition of NADP reductase with blockade of the production of NADPH (key coenzyme of 5-alpha-reductase). Consequently, at the level of the hair bulb, the metabolic fate of testosterone is no longer oriented towards the synthesis of dihydrotestosterone, but towards oxidation to androstenedione and estrone (the latter with a positive activity on the health of the hair).
The association with pyridoxine and zinc appears to enhance the effects of azelaic acid in vitro.
Against skin aging
By virtue of its contrasting action against free radicals - hence its antioxidant properties - it is believed that azelaic acid can be an effective anti-wrinkle and anti-aging remedy.
Generally, when used as an anti-wrinkle and anti-aging treatment, azelaic acid is a creamy or oily formulation. However, in these cases, its concentration must necessarily be lower than that used to counteract the aforementioned disorders, in order to avoid unpleasant adverse reactions.
In fact, in anti-aging treatments, the concentration of azelaic acid should be around 3%, against 10-20% present in products for medical-dermatological use.
Side effects
Despite being an normally well tolerated active ingredient, azelaic acid is not however free from inducing side effects. For this reason, its use should be performed only with the advice of a doctor and under his supervision.
The main undesirable effect induced by azelaic acid is the skin irritation that can be associated with:
- Tingling;
- pricking;
- Redness;
- Dry skin.
In the most serious cases - and, above all, in the case of improper and / or excessive use of azelaic acid - real burns may also occur in the area of application.
Other side effects include:
- Urticaria;
- Burning or pain at the application site;
- Skin eruptions;
- Loss of sensitivity in the treated area;
- Exfoliation of the skin at the site of application;
- Erythema;
- Urticaria;
- Depigmentation of the treated area (this is to be considered an undesired effect when azelaic acid is used in the treatment of acne and rosacea, while it represents a desired effect when used against melasma).
Finally, in sensitive subjects, the use of azelaic acid can cause allergic reactions and sensitization.
