Effects of Different Doses of Eucalyptus Oil From Eucalyptus globulus Labill on Respiratory Tract Immunity and Immune Function in Healthy Rats.

Eucalyptol (1,8-cineole), the major constituent of eucalyptus oil (EO), was used in traditional medicine as a remedy for colds and bronchitis. This study aimed at clarifying the effect of eucalyptol on respiratory immune function of CD8 and CD4 cells, and alveolar macrophages (AM). Thirty male Sprague-Dawley rats were divided into experimental and control groups. The drug was given once a day for 3 weeks and the experimental group was divided according to the eucalyptol dose into: 30, 100, and 300 mg·kg-1 groups. Flow cytometry was used to detect the phagocytic function of CD4, CD8 cells, and AM in the bronchopulmonary lavage fluid. The 30 and 100 mg·kg-1 groups had an up-regulation effect on CD8 (p < 0.05), with no significant effect on macrophage phagocytosis. The 300 mg·kg-1 group had an inhibitory effect on CD8 and macrophage phagocytosis (p < 0.05), with no significant difference in CD4 between groups. Further investigation was conducted to evaluate the effect of EO on immune function in rats by detecting blood T, B, and NK cells using flow cytometry, and blood IgA, IgG, IgM, and IFN-γ levels by ELISA. High dosage of eucalyptol significantly reduced the proportion of blood B and NK cells (p < 0.05). IgA was decreased in the 100 and 300 mg·kg-1 groups (p < 0.05). There are no significant differences between the number of T cells and the IgG, IgM, and IFN-γ levels between experimental and control groups. Rational use of EO containing eucalyptol can improve the immune function of the respiratory tract and the body immunity, while high dose could have damaging effects, through modifying the phagocytic function of CD8 cells and reducing the proportion of blood B cells, NK cells, and IgA.

Cytotoxic Meroterpenoids from the Fungus Alternaria sp. JJY-32.

Two new meroterpenoids, tricycloalternarenes X and Y, together with one known meroterpenoid, tricycloalternarene I, were isolated from the fungus Alternaria sp. JJY-32. The structures including absolute configurations were established by the comprehensive spectroscopic data, electronic circular dichroism (ECD) spectral analyses, and biosynthesis consideration. Tricycloalternarene X showed cytotoxicity against the HL-60 and HO8910 cells with IC50 values of 7.54 and 20.32 µm.

Amphiphilic, hydrophilic, or hydrophobic synthetic bacteriochlorins in biohybrid light-harvesting architectures: consideration of molecular designs.

Biohybrid light-harvesting architectures can be constructed that employ native-like bacterial photosynthetic antenna peptides as a scaffold to which synthetic chromophores are attached to augment overall spectral coverage. Synthetic bacteriochlorins are attractive to enhance capture of solar radiation in the photon-rich near-infrared spectral region. The effect of the polarity of the bacteriochlorin substituents on the antenna self-assembly process was explored by the preparation of a bacteriochlorin-peptide conjugate using a synthetic amphiphilic bacteriochlorin (B1) to complement prior studies using hydrophilic (B2, four carboxylic acids) or hydrophobic (B3) bacteriochlorins. The amphiphilic bioconjugatable bacteriochlorin B1 with a polar ammonium-terminated tail was synthesized by sequential Pd-mediated reactions of a 3,13-dibromo-5-methoxybacteriochlorin. Each bacteriochlorin bears a maleimido-terminated tether for attachment to a cysteine-containing analog of the Rhodobacter sphaeroides antenna ß-peptide to give conjugates ß-B1, ß-B2, and ß-B3. Given the hydrophobic nature of the ß-peptide, the polarity of B1 and B2 facilitated purification of the respective conjugate compared to the hydrophobic B3. Bacteriochlorophyll a (BChl a) associates with each conjugate in aqueous micellar media to form a dyad containing two ß-peptides, two covalently attached synthetic bacteriochlorins, and a datively bonded BChl-a pair, albeit to a limited extent for ß-B2. The reversible assembly/disassembly of dyad (ß-B2/BChl)2 was examined in aqueous detergent (octyl glucoside) solution by temperature variation (15-35 °C). The energy-transfer efficiency from the synthetic bacteriochlorin to the BChl-a dimer was found to be 0.85 for (ß-B1/BChl)2, 0.40 for (ß-B2/BChl)2, and 0.85 for (ß-B3/BChl)2. Thus, in terms of handling, assembly and energy-transfer efficiency taken together, the amphiphilic design examined herein is more attractive than the prior hydrophilic or hydrophobic designs.

Versatile design of biohybrid light-harvesting architectures to tune location, density, and spectral coverage of attached synthetic chromophores for enhanced energy capture.

Biohybrid antennas built upon chromophore-polypeptide conjugates show promise for the design of efficient light-capturing modules for specific purposes. Three new designs, each of which employs analogs of the ß-polypeptide from Rhodobacter sphaeroides, have been investigated. In the first design, amino acids at seven different positions on the polypeptide were individually substituted with cysteine, to which a synthetic chromophore (bacteriochlorin or Oregon Green) was covalently attached. The polypeptide positions are at -2, -6, -10, -14, -17, -21, and -34 relative to the 0-position of the histidine that coordinates bacteriochlorophyll a (BChl a). All chromophore-polypeptides readily formed LH1-type complexes upon combination with the α-polypeptide and BChl a. Efficient energy transfer occurs from the attached chromophore to the circular array of 875 nm absorbing BChl a molecules (denoted B875). In the second design, use of two attachment sites (positions -10 and -21) on the polypeptide affords (1) double the density of chromophores per polypeptide and (2) a highly efficient energy-transfer relay from the chromophore at -21 to that at -10 and on to B875. In the third design, three spectrally distinct bacteriochlorin-polypeptides were prepared (each attached to cysteine at the -14 position) and combined in an ~1:1:1 mixture to form a heterogeneous mixture of LH1-type complexes with increased solar coverage and nearly quantitative energy transfer from each bacteriochlorin to B875. Collectively, the results illustrate the great latitude of the biohybrid approach for the design of diverse light-harvesting systems.

Meroterpenoids with diverse ring systems from the sponge-associated fungus Alternaria sp. JJY-32.

Fifteen meroterpenoids (1-15) with diverse ring systems including an unprecedented oxaspiro[5.5]nonane-fused cyclohexenone (1), hydrogenated benzofurans (2-5), hydrogenated chromans (6, 7), hydrogenated cyclopenta[b]chromans (8-11), and four monocyclic structures (12-15) were isolated from the sponge-associated fungus Alternaria sp. JJY-32. The structures were elucidated by detailed spectroscopic analysis, including 2D NMR and electronic circular dichroism (ECD) calculations, and assisted by chemical derivatizations. On the basis of supplementation experiments with specific enzyme inhibitors and putative precursors, a shikimate-isoprenoid hybrid biosynthetic pathway is proposed. The NF-κB inhibitory activities of 1-15 were tested, and all of them, except 6 and 7 (IC50 > 100 µM), showed activities with IC50 values ranging from 39 to 85 µM in RAW264.7 cells.

Toll-like receptor 4/nuclear factor-κB signaling pathway is involved in ACTG-toxin H-mediated anti-inflammatory effect.

ACTG-toxin H (AH) originates from Alternaria sp. In this study, we explored the molecular mechanism underlying the anti-inflammatory properties of AH. Treatment with AH inhibited lipopolysaccharide (LPS)-induced interleukin-6, IL-1ß, inducible nitric oxide synthase, and cyclooxygenase-2 expression and nitric oxide production. Furthermore, AH inhibited LPS-induced P38 MAPK and Akt activation in RAW264.7 cells. Electrophoretic mobility shift assays (EMSAs) showed that AH inhibited LPS-induced nuclear factor-κB (NFκB) DNA-binding activity. Using transfection assay and measurement of an NFκB-sensitive promoter region, we found that transfection of toll-like receptor 4 (TLR4) increased LPS-induced NFκB transcription activity in 293T cells. AH significantly blocked LPS-induced NFκB activation in TLR4-transfected cells. Taken together, our data indicated that anti-inflammatory properties of AH resulted from the inhibition of proinflammatory cytokines and enzyme production via the TLR4/NFκB signaling pathway.

Biohybrid photosynthetic antenna complexes for enhanced light-harvesting.

Biohybrid antenna systems have been constructed that contain synthetic chromophores attached to 31mer analogues of the bacterial photosynthetic core light-harvesting (LH1) ß-polypeptide. The peptides are engineered with a Cys site for bioconjugation with maleimide-terminated chromophores, which include synthetic bacteriochlorins (BC1, BC2) with strong near-infrared absorption and commercial dyes Oregon green (OGR) and rhodamine red (RR) with strong absorption in the blue-green to yellow-orange regions. The peptides place the Cys 14 (or 6) residues before a native His site that binds bacteriochlorophyll a (BChl-a) and, like the native LH proteins, have high helical content as probed by single-reflection IR spectroscopy. The His residue associates with BChl-a as in the native LH1 ß-polypeptide to form dimeric ßß-subunit complexes [31mer(-14Cys)X/BChl](2), where X is one of the synthetic chromophores. The native-like BChl-a dimer has Q(y) absorption at 820 nm and serves as the acceptor for energy from light absorbed by the appended synthetic chromophore. The energy-transfer characteristics of biohybrid complexes have been characterized by steady-state and time-resolved fluorescence and absorption measurements. The quantum yields of energy transfer from a synthetic chromophore located 14 residues from the BChl-coordinating His site are as follows: OGR (0.30) < RR (0.60) < BC2 (0.90). Oligomeric assemblies of the subunit complexes [31mer(-14Cys)X/BChl](n) are accompanied by a bathochromic shift of the Q(y) absorption of the BChl-a oligomer as far as the 850-nm position found in cyclic native photosynthetic LH2 complexes. Room-temperature stabilized oligomeric biohybrids have energy-transfer quantum yields comparable to those of the dimeric subunit complexes as follows: OGR (0.20) < RR (0.80) < BC1 (0.90). Thus, the new biohybrid antennas retain the energy-transfer and self-assembly characteristics of the native antenna complexes, offer enhanced coverage of the solar spectrum, and illustrate a versatile paradigm for the construction of artificial LH systems.