J. Cosmet. Sci., 71, 425–437 (November/December 2020) 425 Soothing Effect of Pogostemon cablin Extract (Patchouli), via Cannabinoid Receptor 2 Modulation in Human Skin FLORIAN LABARRADE, ARMELLE PERRIN, YOLENE FERREIRA, GILLES OBERTO, CATHERINE GONDRAN, CORINNE MOREL, and KARINE CUCUMEL , Ashland Specialties France, Global Skin Research Center, Nice 06904, France (F.L., A.P., Y.F., G.O., C.G., C.M., K.C.) Accepted for publication August 6, 2020 . Synopsis Skin functions as a neuro-immuno-endocrine tissue with well-defi ned neuronal networks and functions. The endocannabinoid system has been proven to be an important, homeostatic regulator for homeostatic and infl ammatory events. The system comprises endogenous or exogenous ligands and receptors (CB1 and CB2). In the present study, we evaluated the soothing properties of a Pogostemon cablin (patchouli) extract. Agonist AM1241 and antagonist AM630 were used for CB2 receptor activation/inhibition. Expression of CB2 receptor and β-endorphin was monitored by immunohistochemistry. Skin infl ammation was induced with ultraviolet B (UVB) or lipopolysaccharide (LPS), and the following markers were used to highlight the anti- infl ammatory properties of the extract: transient receptor potential vanilloid 1 (TRPV1), interleukin receptors 1 (IL1R1), and the interleukin 6 signal transducer (IL6ST). Our results demonstrated the implication of the CB2 receptor in the skin infl ammation process. The expression of CB2 receptor and β-endorphin was increased 48 hours after application of the extract. Furthermore, patchouli extract application helped to reduce IL1R1, IL6ST, and TRPV1 expression, in skin exposed to UVB or LPS. In conclusion, the application of the patchouli extract helps maintain skin integrity and reduce skin discomfort via modulation of CB2 receptor stimulation and the subsequent β-endorphin release. IN T RODUCTION Sk in serves as the fi rst protective barrier between the body and the environment, with both passive and active roles against chemical, physical, and microbial insults (1). Human skin produces numerous neuropeptides that play a role in various cutaneous functions and diseases, acting as neuromodulators, neurotransmitters, and hormones. Many different biologic actions of neuropeptides in skin have been demonstrated, such as infl ammatory, proliferative, and reparative processes after injury (2). Cannabinoids represent a broad class of chemical compounds derived from the cannabis plant. Cannabinoids are chemical Address all correspondence to Florian Labarrade at fl abarrade@ashland.com.

JOURNAL OF COSMETIC SCIENCE 426 compounds that are related to the main psychoactive ingredient in marijuana: Δ9- tetrahydrocannabinol (3). Phytocannabinoids are present in a large variety of plants and can interact with cannabinoid receptors or share chemical structure with cannabinoids, or both (4). The endocannabinoid system comprises endogenous ligands such as the anan- damide, enzymes, transporter apparatus, and two known receptors (CB1 and CB2). The various downstream effects of the cannabinoids are mediated through these two G protein– coupled receptors. The selective activation of cannabinoid receptor 2 is devoid of psycho- active side effects associated with cannabinoid receptor 1 stimulation. Skin infl ammatory reaction is characterized by redness, swelling, heat, and pain. Even if this is an important host defense mechanism against invading pathogens, persistent or over-infl ammation can result in skin damage. Distribution of CB1 and CB2 in human skin is described in many cell types and structures, and many studies have reported the promising role of canna- binoids in the treatment of dermatologic conditions, among them skin infl ammation (5–10). A downstream signaling mechanism of cannabinoid receptor 2 activation is the β-endorphin release, contributing to the peripheral analgesic effect (11). β-endorphin is a proopiomelanocortin (POMC)-derived opioid neuropeptide, and on a molar basis, β-endorphin is 18–33 times more potent than morphine (12). CB2 receptor activation alone is enough for attenuation of the neuropathic pain, by attenuating infl ammation, and changes in the interleukin signal (13). A large body of evidence now exists to sub- stantiate that certain endocannabinoids activate transient receptor potential vanilloid 1 (TRPV1). TRPV1 is a key receptor of various sensory phenomena (pain, heat, and itch). It is found in nonneuronal cell types, including human skin epidermal keratinocytes (14–17). TRPV1 also acts as a nociceptive sensor and can potentiate the infl ammatory process. Indeed, elevated TRPV1 expression was identifi ed in UV-irradiated photo-aged and intrinsically aged skin (18,19). Cannabinoids also exert potent anti-infl ammatory effect however, the mechanism by which cannabinoid receptor type 2 reduces infl amma- tion and promotes tissue repair in the course of human skin wound healing is still not completely clear. Several plants produce molecules with cannabinoid activity (20), such as β-caryophyllene (BCP), a phytocannabinoid with a strong affi nity to cannabinoid re- ceptor 2 (21), but not to cannabinoid receptor type 1 (22). BCP is one of the major active components of essential oils derived from a large number of spice and food plants. Patchouli oil has a variety of pharmacological activities, including anti-infl ammatory (23,24). BCP as a plant volatile compound is commonly found in patchouli leaves, with other sesqui- terpenes (25,26). Activity of BCP can be partially described as a cannabinoid receptor 2 agonist, suggesting its role as an anti-infl ammatory agent (27). In this study, we investigated the key functions of cannabinoid signaling to control local infl ammation responses in the skin, with CB2 receptor agonist AM1241, antagonist AM630, and a patchouli extract. Our fi ndings suggest that our patchouli extract possesses a soothing effect via the modulation of the CB2 receptor pathway. MATERIAL S AND METHODS PLANT MA TERIALS AND EXTRACTION The aeri al parts comprising the stem and leaves were collected in the fi eld from sustain- able farming in Colombia, dried, and ground by cryogenic grinding. Pure plant extract was obtained using a supercritical CO2 extraction technique, including ethanol as a cosolvent.