RESUMO
Siegesbeckia glabrescens Makino (SGM) has been traditionally used to treat many disorders, including rheumatoid arthritis, hypertension, and acute hepatitis. However, the biological activities of SGM in skin remain unclear. The present study explored the effects of SGM flower absolute (SGMFAb) on skin-whitening-linked biological activities in B16BL6 cells. SGMFAb was extracted using hexane, and its composition was analyzed through gas chromatography/mass spectrometry analysis. The biological effects of SGMFAb on B16BL6 melanoma cells were detected via WST and BrdU incorporation assays, ELISA, and immunoblotting. SGMFAb contained 14 compounds. In addition, SGMFAb was noncytotoxic, attenuated the serum-induced proliferation of, and inhibited melanin synthesis and tyrosinase activity in α-MSH-exposed B16BL6 cells. SGMFAb also reduced the expressions of MITF (microphthalmia-associated transcription factor), tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 in α-MSH-exposed B16BL6 cells. Moreover, SGMFAb downregulated the activation of p38 MAPK, ERK1/2, and JNK in α-MSH-stimulated B16BL6 cells. In addition, SGMFAb reduced the expressions of three melanosome-transport-participating proteins (myosin Va, melanophilin, and Rab27a) in α-MSH-stimulated B16BL6 cells. These results indicate that SGMFAb positively influences skin whitening activities by inhibiting melanogenesis and melanosome-transport-related events in B16BL6 cells, and suggest that SGMFAb is a promising material for developing functional skin whitening agents.
RESUMO
The roots of Euphorbia kansui, which belong to the family Euphorbiaceae, have been used as a traditional medicine for the treatment of various diseases such as diabetes, ascites, and leukemia. Recently, it was reported that the methylene chloride fraction of E. kansui radix (EKC) regulated the differentiation of Th17 cells and alleviated the symptoms of Th17-related inflammatory bowel disease. Imiquimod (IMQ), a TLR7/8 agonist, has been used to induce psoriasis in a mouse model. In this study, we evaluated the effect of EKC in an IMQ-induced psoriasis model. EKC effectively inhibited the production of interleukin-17A and interferon-γ in vitro. On this basis, EKC was administered to an animal model of psoriasis. Acanthosis and the infiltration of inflammatory cells into the dermis were significantly reduced by EKC. EKC also inhibited the expression of IL-17A, IL-22, IL-23, IL-12, and RAR-related orphan receptor gamma t (RORγt) in the spleen, skin-draining lymph nodes, and the skin. Additionally, EKC inhibited the activity of dendritic cells but not that of keratinocytes. In conclusion, EKC ameliorated the symptoms of psoriasis through inhibition of Th17 differentiation and activation of dendritic cells. These effects are expected to be beneficial in the treatment and prevention of psoriasis.