Acne: What can CBD contribute?

As the eighth most common disease (affecting approximately 9.4% of the global population), acne is one of the most frequently observed skin conditions in human dermatology, evolving in flare-ups. Associated with discomfort, permanent skin scarring, and negative self-perception and self-esteem, it is characterised by a mixed eruption of inflammatory skin lesions (papules, pustules, nodules and cysts) and non-inflammatory/retentional lesions due to hyperkeratinisation (open and closed comedones), primarily affecting the face, back and chest. Although acne is primarily a disorder of adolescence, current research indicates that the prevalence of acne in adults, particularly women, is on the rise.

It is well known that acne is a multifactorial disease: the accumulation of acne-causing strains of Cutibacterium acnes at the level of the pilosebaceous unit, the increase in sebum production (hyperseborrhoea) and the alteration of its consistency (dyseborrhoea), defective keratinisation and clogging of hair follicles, and inflammation of the sebaceous glands are elements commonly cited in the pathophysiology of acne. To date, guidelines recommend a combination of ingredients and conventional treatments (topical retinoids, benzoyl peroxide, oral antibiotics, isotretinoin, etc.) aimed at targeting the different stages of pathogenesis by acting through independent mechanisms.

However, most available acne treatments induce potential side effects (drying, itching, burning, etc.), not to mention the risk of antibiotic resistance which remains a limitation. Indeed, these effects can lead to a premature discontinuation of the treatment by the patient. This is why over the last decade, the growing interest in natural ingredients derived from plants as an alternative or adjunct to conventional treatments has led to the discovery and development of new therapies that offer good efficacy with a minimal risk of side effects.

Given the significant role of the endocannabinoid system in the skin, current research has focused on the role of phytocannabinoids as potential therapeutic options for various skin disorders, such as acne. Recently, cannabidiol (CBD) has been suggested as a new treatment option for acne. In addition to its known anti-inflammatory activity, it would simultaneously target the various pathological pathways underlying acne physiology, all with a notable side effect profile.

• CBD, a Sebostatic Agent: CBD has the ability to "normalise" the pathologically high sebum production from sebaceous glands observed in acne-prone skin. A study revealed that CBD administered to cultured human sebocytes and human skin organ cultures reduced the cellular proliferation of sebocytes via the activation of TRPV4 (Transient Receptor Potential Vanilloid-4) ion channels, without compromising viability, and thus significantly reducing sebum production due to the holocrine mechanism. It is also capable of inhibiting the lipogenic actions of various compounds, including arachidonic acid, linoleic acid, and testosterone.

• CBD and its complex anti-inflammatory effect: CBD also exerts anti-inflammatory actions in keratinocytes, which have been mediated by the increase of TRIB3 and the inactivation of NF-κB and MAPK signalling pathways. This is illustrated by a decrease in the expression levels of inflammatory mediators in skin cells, including TNF-α, IL-6, IL-8 and IL-1β. In the case of acne, it thus helps to modulate the inflammation of the sebaceous glands induced by C. acnes. It therefore allows to soothe and fade acne inflammations without presenting unpleasant effects. This anti-inflammatory action of CBD extends to the prevention of symptoms related to acne eruption such as redness.

• CBD and its bactericidal mechanism: CBD also exhibits antibacterial and antifungal actions. This phytocannabinoid can reduce the growth of several bacteria, including the Staphylococcus aureus which is highly resistant, the Streptococcus pneumoniae and the Clostridioides difficile, by altering the membrane.

• CBD in the face of hyperkeratinisation: finally, it has also been demonstrated that CBD inhibits the proliferation of hyperproliferative keratinocytes. These findings thus show that CBD can help prevent the build-up of epidermal cells that cause sebum retention and pore obstruction.

In close correlation with the results in vitro and ex vivo, several placebo-controlled clinical evaluations have been conducted and have shown that the topical application of a CBD-based formula statistically reduces the number of acne lesions (primarily inflammatory lesions), sebum production, and the onset of erythema. Collectively, the obtained results suggest that, thanks to its properties of regulating sebum overproduction, its anti-sebocyte, antibacterial, anti-proliferative, and anti-inflammatory effects combined, CBD has the potential to be a promising universal therapeutic agent in the fight against acne by thus influencing all aspects of this skin pathology.

CBD can be applied directly, locally to the affected skin areas. To promote its percutaneous penetration and distribution, CBD oils, balms, and creams are among the most effective means to benefit from its effects against acne, due to its lipophilic nature.

In order to optimise effectiveness, CBD is often combined with other active ingredients used in acne treatments, such as vitamins or other anti-inflammatory compounds (Centella asiatica, salicylic acid, etc.). Various clinical studies show that concentrations of 2.5 to 10 μg/mL of CBD are sufficient to observe a reduction in acne lesions and improve tolerance with reduced local side effects, and this for an application of twice a day for an average of one and a half months.

It is important to clarify that CBD currently serves as a therapeutic supplement against acne and it is advisable to discuss the subject in advance with your doctor, especially if you are concurrently taking any medication.

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• BIRO T. & al. Cannabidiol exerts sebostatic and antiinflammatory effects on human sebocytes. Journal of Clinical Investigation (2014).

• AKHTAR N. & al. The safety and efficacy of 3% Cannabis seeds extract cream for reduction of human cheek skin sebum and erythema content. Pakistan Journal of Pharmaceutical Sciences (2015).

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• JIMENEZ J. J. & al. The anti-inflammatory effects of cannabidiol (CBD) on acne. Journal of Inflammation Research (2022).

• XIANG L. & al. Cannabidiol inhibits inflammation induced by Cutibacterium acnes-derived extracellular vesicles via activation of CB2 receptor in keratinocytes. Journal of Inflammation Research (2022).

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