Skin is an important organ of human body with several functions, including the protection against different stressors, such as microbial pathogens, mechanical damage and UV irradiations. During cutaneous inflammatory diseases (such as psoriasis), keratinocytes, the most abundant cells in the epidermis, release a variety of pro-inflammatory mediators (for example IL-8 and MMP-9)1,2 to amplify and prolong the inflammatory process. IL-8 and MMP-9 expression in human keratinocytes is regulated through the activation of different transcription factors, including NF-κB.
Cannabidiol (CBD) is one of the lipophilic cannabinoids occurring in Cannabis sativa L.; although previous study has demonstrated that CBD exerts anti-inflammatory effects in an in vivo model of skin inflammation3, no studies on the anti-inflammatory and antioxidant effects in human keratinocytes have been reported so far.
The aim of this work was to evaluate the anti-inflammatory activity of the Cannabis sativa L. extracts, standardized in CBD and cannabidiolic acid (CBDA), in human keratinocytes.
Two Cannabis sativa L. extracts, each containing 1% or 50.8% CBD+CBDA, were prepared and standardized by LINNEA SA (Riazzino, Switzerland). IL-8 and MMP-9 release were analysed by ELISA assays, whereas NF-κB driven transcription was tested using a reporter plasmid.
Both extracts inhibited TNFα-induced MMP-9 secretion in a concentration dependent manner with an IC50 of 5.54 and 1.78 μg/mL respectively; considering IL-8 secretion, only 1% extract reduced the chemokine release (IC50: 34 μg/mL). The effect was ascribed to the impairment of the NF-κB pathway since both the extracts inhibited TNFα-induced NF-κB driven transcription (IC50: 37.8 μg/mL for 1% extract, and 2.7 μg/mL for 50.8% extract).
These results suggest that Cannabis sativa L. containing CBD and CBDA may possess beneficial effects against inflammatory skin diseases.
1Barker J.N.W.N. et al. J Clin Invest 1990. 85:605-08
2Majtan J. et al. Arch Dermatol Res 2013. 305(7):619-27
3Lodzki et al. J Control Release 2003. 93(3):377-387