• The Journal of Korean Medicine
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• v.18 no.2
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• pp.167-186
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• 1997

The inhibitory activity of Aquillariae Lignum (Thymelaeaceae) on type Ⅰ immediate hypersensitivity of the anaphylactic type in the wistar rat model of passive cutaneous anaphylaxis, an IgE-mediated, mast cell-dependent reaction. Administered orally at 250, 500 mg/kg body weight 1 h before the challenge, Aquillariae Lignum potently inhibited PCA in rats which disodium cromoglycate showed poor inhibitory activity. Aquillariae Lignum inhibited compound 48/80-induced anaphylaxis 100% with a dose of 0.5 g/kg body weight at 1 h before or 5 and 10 min after injection of compound 48/80. Aquillariae Lignum (0.05-1.6 mg/ml) also exhibited the dose-related inhibitory effect on compound 48/80-induced histamine release from rat_peritoneal mast cells. Moreover, it was clearly demonstrated that Aquillariae Lignum and disodium cromoglycate disodium cromoglycate potently inhibited such type Ⅰ allergic reactions as anaphylactic shocks, suggesting that these drugs, at least in part, share the same mechanism of action It is suggested that Aquillariae Lignum may exert a stronger inhibition on the mast cell degranulation process. Since Aquillariae Lignum (1.0 mg/ml) inhibited about 90% of histidine decarboxylase activity, the inhibitory activity of Aquillariae Lignum for histamine release was considered to be derived from the inhibition of histidine decarboxylase activity. It results from increased expression of the mRNA coding for histidine decarboxylase, as assessed by Northern blot analysis after a 12 h incubation to P-815 cells with dexamethasone plus 12-O-tetradecanoylphorbol-13-acetate. The addition of Aquillariae Lignum to P-815 cells with dexamethasone plus 12-O-tetradecanoyl-phorbol-13-acetate, significantly inhibited the histidine decarboxylase gene expression. Tumor necrosis $factor-{\alpha}$ was not constitutively expressed in P-815 cells. Substance P selectively activates the tumor necrosis $factor-{\alpha}$ gene expression in P-815 cells. Aquillariae Lignurm inhibited substance P-induced tumor necrosis $factor-{\alpha}$ gene expression. Furthennore, The effect of Aquillariae Lignum on the mRNA expression of novel protein kinase C ${\delta}$ a major isoform of mast cells, was examined by Northern blot analysis. The expression of novel protein kinase C ${\delta}$ mRNA in the presence of Aquillariae Lignum was significantly lower than in the absence of Aquillariae Lignum. These results suggest the possibility that the inhibition of allergic reaction by Aquillanae Lignum should be regulated by tumor necrosis $factor-{\alpha}$ and novel protein kinase C ${\delta}$.