Plant growth regulatory effect and insecticidal activity of the extracts of the Tree of Heaven (Ailanthus altissima L.).
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BACKGROUND: There is an urgent need to explore and utilize naturally occurring products for combating harmful agricultural and public health pests. Secondary metabolites in the leaves of the Tree of Heaven, Ailanthus altissima L. have been reported to be herbicidal and insecticidal. The mode of action, however, of the active compounds in A. altissima are not understood. In this paper, we report the chemical characteristics of the herbicidal and insecticidal components in this tree, and will discuss the effect of light on the bioactivity of the active components. RESULTS: Extracts from the fresh leaves of A. altissima showed a strong plant germination/growth inhibitory effect in laboratory bioassays against alfalfa (Medicago sativa). The effect was dose-dependent. The growth inhibitory components were in the methylene chloride soluble fraction of the extract. The effect was greater in the light than in the dark. Other fractions had plant growth enhancing effect at lower concentrations. The extract was slightly insecticidal against yellow fever mosquito larvae (Aedes aegypti). CONCLUSIONS: The extract or its semi-purified fractions of A. altissima were strong plant growth inhibitors, therefore good candidates as potential environmentally safe and effective agricultural pest management agents. The finding that light affects the activity will be useful in the application of such natural products. (+info)
Three new quassinoids, ailantinol E, F, and G, from Ailanthus altissima.
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Three new quassinoids, ailantinol E (1), ailantinol F (2), and ailantinol G (3), and related compounds were isolated from Ailanthus altissima grown in Taiwan. Their structures were elucidated from spectral evidence. Each new quassinoid was evaluated for its antitumor promoting effects against Epstein-Barr virus early antigen activation introduced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells. The new quassinoids were found to show potent activity without showing any cytotoxicity. The screening for inhibitors against nitric oxide donor action was also conducted using the new quassinoids and some standard samples. (+info)
1-Methoxy-canthin-6-one induces c-Jun NH2-terminal kinase-dependent apoptosis and synergizes with tumor necrosis factor-related apoptosis-inducing ligand activity in human neoplastic cells of hematopoietic or endodermal origin.
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We investigated the effects of 1-methoxy-canthin-6-one, isolated from the medicinal plant Ailanthus altissima Swingle, on apoptosis in human leukemia (Jurkat), thyroid carcinoma (ARO and NPA), and hepatocellular carcinoma (HuH7) cell lines. Cultures incubated with the compound showed >50% of sub-G1 (hypodiploid) elements in flow cytometry analysis; the apoptosis-inducing activity was evident at <10 micromol/L and half-maximal at about 40 micromol/L 1-methoxy-canthin-6-one. The appearance of hypodiploid elements was preceded by mitochondrial membrane depolarization, mitochondrial release of cytochrome c, and Smac/DIABLO and procaspase-3 cleavage. We subsequently investigated the effect of 1-methoxy-canthin-6-one in combination with human recombinant tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in the four cell lines. Suboptimal concentrations (10 micromol/L 1-methoxy-canthin-6-one and 0.25 ng/mL TRAIL, respectively) of the two agents, unable to elicit apoptosis when used alone, induced mitochondrial depolarization, activation of caspase-3, and 45% to 85% of sub-G1 elements when added together to the cells. The synergism seemed to rely partly on the enhanced expression of TRAIL receptor 1 (TRAIL-R1; DR4), analyzed by immunofluorescence, by 1-methoxy-canthin-6-one. Cell incubation with 1-methoxy-canthin-6-one resulted in activating c-Jun NH2-terminal kinase (JNK), as revealed by Western blotting; induction of apoptosis and TRAIL-R1 up-regulation by 1-methoxy-canthin-6-one were >80% prevented by the addition of the JNK inhibitor (JNKI) SP600125JNKI, indicating that both effects were almost completely mediated by JNK activity. On the other hand, synergism with TRAIL was reduced by about 50%, suggesting that besides up-regulating TRAIL-R1, 1-methoxy-canthin-6-one could influence other factor(s) that participated in TRAIL-induced apoptosis. These findings indicate that 1-methoxy-canthin-6-one can represent a candidate for in vivo studies of monotherapies or combined antineoplastic therapies. (+info)
Anti-inflammatory activity of Ailanthus altissima in ovalbumin-induced lung inflammation.
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As part of an ongoing investigation to find bioactive medicinal herbs exerting anti-inflammation activity, the effect of an ethanol extract from the parts of Ailanthus altissima (Simaroubaceae) was evaluated in both in vitro and in in vivo system. The ethanol extract of A. altissima (EAa) inhibited generation of the cyclooxygenase-2 (COX-2) dependent phases of prostaglandin D2 in bone marrow-derived mast cells (BMMC) in a concentration-dependent manner with an IC50 value of 214.6 microg/ml. However, this compound did not inhibit COX-2 protein expression up to a concentration of 400 microg/ml in the BMMC, indicating that EAa directly inhibits COX-2 activity. In addition, EAa inhibited leukotriene C4 production with an IC50 value of 25.7 microg/ml. Furthermore, this compound inhibited degranulation reaction in a dose dependent manner, with an IC50 value of 27.3 microg/ml. Ovalbumin (OVA)-sensitized mice were orally pretreated with EAa before aerosol challenges. EAa reduced the eosinophil infiltration into the airway and the eotaxin, IL-4, and IL-13 mRNA expression levels. These results suggest that the anti-inflammation activity of A. altissima in OVA-induced lung inflammation may occur in part via the down regulation of T(H)2 cytokines and eotaxin transcripts as well as the inhibition of inflammatory mediators. (+info)
Quassinoid inhibition of AP-1 function does not correlate with cytotoxicity or protein synthesis inhibition.
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Antiasthmatic activity of luteolin-7-O-glucoside from Ailanthus altissima through the downregulation of T helper 2 cytokine expression and inhibition of prostaglandin E2 production in an ovalbumin-induced asthma model.
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Previously, we reported that an ethanol extract of Ailanthus altissima has antiinflammatory activity in an ovalbumin (OVA)-sensitized murine asthmatic model. To determine the biological compounds from this plant, luteolin-7-O-glucoside (L7G) was isolated and its antiasthmatic activity was evaluated in an in vivo murine asthmatic model. L7G (10 to 100 mg/kg, per os (p.o.)) reduced the amount of eosinophil infiltration in bronchoalveolar lavage (BAL) fluid in a dose-dependent manner. In comparison, dexamethasone (5 mg/kg, p.o.), which was used as a positive control, also strongly inhibited the number of infiltrating eosinophils. L7G inhibited both the prostaglandin E(2) (PGE(2)) and serum immunoglobulin E level in BAL fluid in a dose-dependent manner. In addition, L7G inhibited the transcript profiles of interleukin (IL)-4, IL-5, and IL-13 mRNA expression levels in the murine asthma model, as determined using reverse transcription-polymerase chain reaction (RT-PCR). These results suggest that the antiasthmatic activity of L7G in OVA-induced lung inflammation may occur in part via the downregulation of T helper 2 cytokine transcripts as well as the inhibition of PGE(2) production. (+info)
Human-mediated dispersal of seeds by the airflow of vehicles.
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