Compounds from Platycladus orientalis and their inhibitory effects on nitric oxide and TNF-α production.

Four new compounds: an abietane (1), two isopimarane (2 and 3) diterpenes, and a dihydrobenzofuran neolignan (5), together with a sesquiterpene glycoside (6) firstly isolated from a natural source, and a known phenol glycoside (4) were isolated from leaves of Platycladus orientalis. The structures and relative configurations of these compounds were assigned on the basis of MS, IR, 1D and 2D NMR data. The absolute configuration of compound 1 was determined via density functional theory calculations of its electronic circular dichroism. In addition, the results of bioassays indicated that compounds 4 and 6 showed a potent inhibitory effect on NO production with IC50 values of 24.4 and 11.9 µM, respectively. Meanwhile, compounds 1, 2, and 3 moderately inhibited TNF- α release.

Chemical constituents from Gnaphalium affine and their xanthine oxidase inhibitory activity.

Gnaphalium affine D. Don, a medicinal and edible plant, has been used to treat gout in traditional Chinese medicine and popularly consumed in China for a long time. A detailed phytochemical investigation on the aerial part of G. affine led to the isolation of two new esters of caffeoylquinic acid named (-) ethyl 1, 4-di-O-caffeoylquinate (1) and (-) methyl 1, 4-di-O-caffeoylquinate (2), together with 35 known compounds (3-37). Their structures were elucidated by spectroscopic data and first-order multiplet analysis. All the isolated compounds were tested for their xanthine oxidase inhibitory activity with an in vitro enzyme inhibitory screening assay. Among the tested compounds, 1 (IC50 11.94 µmol·L-1) and 2 (IC50 15.04 µmol·L-1) showed a good inhibitory activity. The current results supported the medical use of the plant.

The anti-inflammatory activities of an extract and compounds isolated from Platycladus orientalis (Linnaeus) Franco in vitro and ex vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: As a Chinese traditional herbal medicine, leaves of Platycladus orientalis (Linnaeus) Franco (LPO) are used to treat coughs, excessive mucus secretion, chronic bronchitis, bronchiectasis, and asthma, etc. The experiments were carried out to investigate their anti-inflammatory properties and mechanisms, which could support the Chinese traditional uses of treating inflammatory airway diseases. MATERIALS AND METHODS: The anti-inflammatory activities of the chloroform fraction (CHL) and pure compounds of LPO were evaluated for their abilities to inhibit pro-inflammatory enzymes in vitro, and production of tumor necrosis factor-α (TNF-α) and nitric oxide in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Furthermore, the arachidonic acid metabolites, stimulated by calcium ionophore A23187, were also determined by HPLC. RESULTS: For the first time, the assays of eicosanoids in intact cells showed that the CHL, hinokiol, and acacetin had significant inhibitory effects on 5-hydroxy-eicosa-tetra-enoic acid (5-HETE) and leukotriene B(4) (LTB4) formations. And cell-free enzyme assays (5-lipoxygenase, leukotriene A(4)-hydrolase, cyclooxgenase-2) demonstrated the potent inhibitory effects of the CHL, hinokiol and acacetin on 5-lipoxygenase (5-LOX). Then, the inhibitions of the CHL, hinokiol on NO biosynthesis and the inhibitions of the CHL, 8(14),15-pimaradien-3ß,18-diol, and hinokiol on TNF-α release were also confirmed in the RAW264.7 murine macrophages. CONCLUSION: The data indicate that the inhibitory effects of the CHL and its components (hinokiol and acacetin) on 5-LOX contribute to the anti-inflammatory activity of LPO. Moreover, the CHL and its components also show beneficial effects on NO and TNF-α production. Consequently, these results provide a rationale for LPO's traditional applications in the treatment of inflammatory airway diseases.