Essential Oil of Thujopsis dolobrata Suppresses Atopic Dermatitis-Like Skin Lesions in NC/Nga Mice

Abstract

Atopic dermatitis (AD) is a multifactorial allergic infl ammatory skin disorder characterized by pruritic and eczematoid skin lesions. AD is commonly present in early infancy and childhood, although it can occur later in life and persist into adulthood (Barker et al., 2007;Brenninkmeijer et al., 2009). It results from interactions between susceptibility genes, the host's environment, skin barrier defects, bacterial and viral skin infections, and immunological factors (Leung and Bieber, 2003). Recent immunological analyses of the pathogenesis of AD have revealed that activated mast cells and an excess in the number of differentiated T-helper 2 (Th2) cells (caused by chemical mediators and cytokines) may play major roles in the development of dermatitis by elevating serum immunoglobulin E (IgE) levels (Leung, 1995). They may trigger the massive infi ltration of T cells, eosinophils, mast cells, and macrophages that characterizes AD (Alenius et al., 2002;Milgrom, 2002;Chen et al., 2005).We examined the effects of essential oil from Thujopsis dolobrata Sieb. et Zucc. var. hondai Makino (EOTD) (Cupressaceae) on atopic dermatitis (AD)-like skin lesions in NC/Nga mice. Treatment with EOTD twice daily for two weeks ameliorate AD-like skin lesions induced by DNCB (2,4 dinitrochlorobenzene), and clinical scores were reduced to 7.29, 7.07, and 4.5 points in the groups treated with 1.5%, 3.0%, and 6.0% extract (p<0.01) respectively, from the 15.0 score obtained using vehicle. EOTD inhibited the infi ltration of mast cells into the AD-like skin lesion in NC/Nga mice (p<0.01) and also reduced serum histamine and IgE levels (p<0.05). Furthermore, it dose-dependently inhibited the release of beta-hexosaminidase from rat basophilic leukemia RBL 2H3 cells. These results indicate that EOTD reduces AD-like skin lesions by inhibiting the production of IgE and histamine, and, thus, IgE-mediated degranulation.

Radical Scavenging Activity-Based and AP-1-Targeted Anti-Inflammatory Effects of Lutein in Macrophage-Like and Skin Keratinocytic Cells

“…Interestingly, this compound significantly suppressed the expression of IL-6 mRNA, a major cytokine involved in skin inflammation [33], as determined by quantitative (Figure 2(a), left panel) or semiquantitative (Figure 2(a), right panel) RT-PCR. Under the conditions, however, up to 30  μ M of lutein exhibited no cytotoxic activity in RAW264.7 cells (Figure 2(d) left panel).…”

Mast Cell Stabilizing Effect of (−)-Elema-1,3,11(13)-trien-12-ol and Thujopsene from <i>Thujopsis dolabrata</i> Is Mediated by Down-Regulation of Interleukin-4 Secretion in Antigen-Induced RBL-2H3 Cells

“…27) In our previous study, it was reported that essential oil from Thujopsis dolobrata reduced both serum levels of histamine and IgE in atopic dermatitis (AD)-like skin lesions induced by 2,4-dinitrochlorobenzene (DNCB) in NC/Nga mice, and furthermore it presented a mast cell stabilizing effect by inhibiting the release of β-hexosaminidase from antigen-induced RBL-2H3 mast cells. 29) In present study, two compounds, (−)-elema-1,3,11(13)-trien-12-ol (1) and thujopsene (2) isolated from essential oil of Thujopsis dolabrata were investigated for the inhibition of mast cell degranulation, IL-4 secretion, and IL-4 mRNA and protein expression in antigen-induced RBL-2H3 mast cells. Extraction and Isolation The wood part of Thujopsis dolabrata (10 kg) was steam distilled for 3 h using a Clevengertype apparatus, yielding 141 g of essential oil.…”

In vitro Na+/K+-ATPase inhibitory activity and antimicrobial activity of sesquiterpenes isolated from Thujopsis dolabrata

“…Sesquiterpenes 1, 5, and 8-11 exhibited potent antibacterial activity, and β-thujaplicin (12, hinokitiol) showed a broad spectrum of antibacterial and antifungal activity. Since the essential oil from T. dolabrata reduces atopic dermatitis (AD)-like skin lesions by inhibiting the production of IgE and histamine (Nam et al, 2011), studies on the antiallergic effects of the isolated compounds in mice are in progress, together with studies on the anti-AD mechanisms of these compounds.…”

“…Among them, hinokitiol (β-thujaplicin), the major component of this plant, has been found to show a broad spectrum of biological activities, including antimicrobial activity (Morita et al, 2003(Morita et al, , 2004, insecticidal effects, phytogrowth-inhibitory activity (Sakagami et al, 2000), cytotoxic effects on mammalian tumor cells (Inamori et al, 1993), and enzyme inhibitory activities such as those on catechol-O-methyltransferase and metalloproteases (Borchardt, 1973;Inamori et al, 1999). In a previous work (Nam et al, 2011), we had reported the effects of essential oil from T. dolabrata onatopic dermatitis (AD)-like skin lesions in NC/Nga mice. Our data indicated that the essential oil from T. dolabrata reduces AD-like skin lesions by inhibiting the production of IgE and histamine, and, thus IgE-mediated degranulation.…”