JOURNAL OF COSMETIC SCIENCE 430 PATCHOULI EXTRACT INCREASES CANNABINOID RECEPTOR 2 AND THE β-ENDORPHIN OPOID Several lines of evidence demonstrate that phytocann abinoids can exert various biological effects in the skin. Immunohistochemistry for cannabinoid receptor 2 on human skin sections (Figure 2A) showed primary localization of the receptor in the epidermis, although some Figure 1. Stimulation or inhibition of cannabinoid receptor 2 in UVB-irradiated human skin. (A) Hematoxylin– eosin staining of h u man skin sections of skin treated with PBS buffer, AM630, AM1241, 3 h before UVB irradiation. Biopsies were maintained in culture 48 h after UVB irradiation, and then formalin-fi xed and paraffi n-embedded. (B) Hematoxylin–eosin staining of human skin sections treated or not with AM630, 3 h before UVB irradiation. Topic application of placebo and patchouli extract was performed after the irradia- tion. Biopsies were maintained in culture 48 h after UVB irradiation, and then formalin-fi xed and paraffi n- embedded (objective ×20).

SOOTHING EFFECT OF POGOSTEMON CABLIN EXTRACT 431 cells of the dermis were also positive. Basal layers of the epidermis showed the strongest fl uorescent intensity (Figure 2A). The patchouli extract increased the expression level of the receptor (Figure 2C +22% *p 0.05). A downstream signal of the CB2 receptor is the release of the β-endorphin opioid. The patchouli extract signifi cantly increased the protein level of β-endorphin in skin (Figure 2B and C). Moreover, the β-endorphin re- lease could be observed in the cell interspaces (Figure 2B close-ups) compared with the Figure 2. Expression of cannabinoid receptor 2 and β-endorphin in normal skin. (A) Immunohistochemistry of cannabinoid r eceptor 2 (green) and DNA stained with DAPI (blue), 48 h after topic application of placebo or patchouli extract (×40 objective lens, scale bar = 16 μm). (B) Immunohistochemistry of β-endorphin (green) and DNA stained with DAPI (blue), 48 h after topical application of placebo or patchouli extract (×20 objective lens, scale bar = 31 μm). (C) Quantifi cation of the cannabinoid receptor 2 and β-endorphin immunohistochemistry. (D) Detection of β-endorphin expression in keratinocytes by ELISA, 24 h after patchouli extract addition in the culture media. (n = 3 mean ± Standard Error of the Mean ***p d 0.005 **p d 0.01 *p d 0.05).