When the skin is exposed to a triggering stimulus, keratinocytes, immune cells, antigen presentation cells, etc. produce a variety of inflammatory “hormones” called cytokines and chemokines. The end result of the initial triggering event is the amplification of a large inflammatory response that, while designed to help, can actually cause considerable damage to the skin.

We offer to assess anti-inflammatory or anti-redness activity of ingredients through:

- Inflammatory cytokine release (Il-6, TNF-a …)
- Cytolysis protection after inflammatory treatment (fibroblasts)
- Activation of transcription factors (NFKB, STAT-1, ERK)
- Activation of NF-E2-related factor – Nrf2 (anti-oxidant)
- Dendritic cells regulation (cytokine release)

Evaluation of anti inflammatory effects on fibroblast cytokine release

Fibroblasts (NHDF) were seeded in 96-well plates. Cells were treated with IL-17 for 24h or with Il-17 and a Anti-IL-17A neutralizing antibody. After treatment, IL-6 release was quantified in the supernatant of NHDF cells by ELISA. IL-6 release is dose-dependently increased in response to IL-17 treatment. This increase was strongly abolished in the presence of anti-IL17 antibody.

Anti inflammatory effects on fibroblast (cytotoxicity)

Fibroblasts (L929) were seeded in 96-well plates and after 24h, pre-treated with alpha-tocopherol (Vitamin E) or medium. After 1h of pre-treatment, TNF-alpha treatment was added. Cytolysis was kinetically monitored using our live cells analysis platform (for 16h) and a fluorescent marker that only enters cells with a compromised cell membrane (cytolytic). The number of cytolyzed cells was increased by TNF-alpha treatment over time and partially reversed using alpha-tocopherol as pre-treatment.

Anti inflammatory effects on primary human Langerhans cells cytokine release

Dendritic cells (DC) and their immature counterparts, Langerhans cells (LC), are highly specialized antigen-presenting cells located in the skin. DC and LC play a key role in the induction phase of contact allergenicity and other immunological reactions of the body. In skin infections, the local Langerhans cells take up and process microbial antigens to become fully functional antigen-presenting cells.

We offer a human primary dendritic cell model with high Langerhans cells purity, more than 75% of cells express the langerin marker (localized in the Birbeck granules, specific organelles present in the cytoplasm of Langerhans cells). Langerhans cells were able to respond to LPS and PMA stimuli by cytokine liberation (IL-6, IL-8 and TNFa) which was inhibited by the application of a TLR4 Inhibitor (Tak-242).