30 FORMULATING FOR MILDNESS molecules.6 These molecules induce an immune
response via the activation of naïve T cells which will specialise in the recognition and capture of foreign antigens. Keratinocytes play an important role in the initiation and persistence of the cutaneous inflammation. They contribute to these processes via the release of cytokines and chemokines which help in the recruitment and maturation of immune cells: the chemokine Interleukin 8 (IL8) for the attraction of neutrophils in the inflammatory areas.7 The objective of the study described below
is to evaluate the effect of Chlamydomonas Acidophila (CAP) extract on IL8 release by keratinocytes stimulated with Nickel.
Results CAP extract significantly reduced IL8 release induced by a Nickel stress, up to 65% (***) inhibition (Fig 5). Chlamydomonas acidophila (CAP) extract
inhibits the release of a major cytokine, IL8, in an inflammatory stress context induced by Nickel. Therefore, the extract could be of interest in a contact allergy or cutaneous hypersensitivity related to Nickel inflammatory stress context.
Modulation of the allergic response The potential anti-allergic effects of Chlamydomonas acidophila (CAP) extract were examined on two pathways involved in the allergy mechanisms: the activation of the basophils responsible for the release of histamine which provokes itching as well as on the Th2 pathway involved in the allergic type reaction in the case of atopic dermatitis. We have chosen to study these biological
activation pathways as models that mimic the cutaneous reactivity.
Inhibition of the basophil activation The immediate hypersensitivity reaction is characterised by an excessive allergic reaction
400.000 350.000 300.000 250.000 200.000 150.000 100.000 50.000 0.000
Control $$$
Figure 2: Biphasic flow horizontal tubular photobioreactor (PBR) - ©Microphyt.
upon contact with an allergen. This reaction may be mediated or non-mediated by antibodies from the immunoglobulin E (IgE) class. IgEs present on the surface of basophils are bound by the allergen, thus leading to the activation of an intracell signalling cascade and the activation of basophil cells. The last step of this activation is the degranulation which results in the release of histamine, which is responsible for the appearance of allergic reactions. During the degranulation step, the
cytoplasmic granules fuse with the plasma membrane of basophil cells, thus exposing the CD63 marker to the extracellular matrix. Therefore, CD63 is considered as a specific marker of activated basophils. The activation of basophils can be reproduced in vitro by incubating the cells with an anti-FCεRI antibody that mimics the binding of the allergen to the IgE (FCεRI) receptor or with a bacterial chemotactic peptide (fMLP; formyl-Met-Leu-Phe) that
-56% ***
-94% ***
PMA 10 µg/ml
Dexa 0.1 µM + PMA
CAP 0.01% dm +PMA
-80% ***
CAP 0.05% dm +PMA
1400.000 1200.000 1000.000 800.000 600.000 400.000 200.000 0.000
Control $$$
-87% ***
PMA 10 µg/ml
Indo 0.1 µM + PMA
-75% ***
CAP 0.01% dm +PMA
-61% ***
30.000 25.000 20.000 15.000 10.000 5.000 0.000
Control
CAP 0.05% dm +PMA
Figure 3: Anti-inflammatory effect of CAP extract following a PMA chemical stress (a) Effect on TNFa/(b) Effect on PGE2 ($$$ p<0.001 vs Control -; *** p<0.001 vs PMA - one-factor ANOVA followed by Tukey test, GraphPad Prism 5 software).
PERSONAL CARE April 2021
20 18 16 14 12 10 8 6 4 2 0
Control
+415% $$$
-35% *
-47% **
leads to an activation via an alternative IgE- independent mechanism. The activated basophil population is then identified by CD63 labelling among the total population of basophil cells identified by labelling of the chemokine receptor CCR3 expressed constitutively on the surface of basophils.8
Results
The stimulation by the fMLP peptide results in a very clear activation of basophils (40.1% of activated cells, i.e. 4527% stimulation - Fig 6). In the framework of this study, two potential
reference compounds were tested in the presence of fMLP: ■ SB202190, a p38 MAPkinase inhibitor; the activation of this kinase is essential in the basophil activation mechanism that leads to degranulation; ■ Cromoglycate, a known anti-allergic agent, whose mechanism of action involves the
+1235% $$$
-48% *
SDS 0.025%
CAP 0.05% dm +SDS
SDS 0.025%
CAP 0.01% dm +SDS
CAP 0.05% dm +SDS
Figure 4: Anti-inflammatory effect of CAP extract against TNFa following SDS-induced irritant stress in RHE (a) Gene expression in RHEs (qRT-PCR) (b) Protein expression in supernatants (ELISA) ($$$ p<0.001 vs Control -; * p< 0.05/ ** p<0.01 vs SDS - one-factor ANOVA followed by Tukey test, GraphPad Prism 5 software).
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PEG2 (pg/mL)
TNFalpha (pg/mL)
TNFalpha (pg/mL) Relative quantity
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