Ergosterol and its derivatives from Grifola frondosa inhibit antigen-induced degranulation of RBL-2H3 cells by suppressing the aggregation of high affinity IgE receptors

Grifola frondosa is an edible mushroom consumed as a health food and/or traditional medicine in Asia. However, the anti-allergic effects of G. frondosa are not yet understood. In this study, we demonstrated the effects of G. frondosa extract (GFE) on IgE-mediated allergic responses, using antigen-stimulated RBL-2H3 cells. Three active compounds: ergosterol, 6β-methoxyergosta-7,22-dien-3β,5α-diol (MEDD), and 6-oxoergosta-7,22-dien-3β-ol (6-OXO) were isolated from GFE and shown to inhibit the antigen-induced release of β-hexosaminidase and histamine. Among the three active components, we focused on ergosterol because of its high content in GFE. Ergosterol inhibited the aggregation of high-affinity IgE receptor (FcεRI), which is the first step in the activation of mast cells and antigen-induced tyrosine phosphorylation. Furthermore, ergosterol suppressed antigen-increased IL-4 and TNF-α mRNA. Taken together, our findings suggest that G. frondosa, including ergosterol and its derivatives as active components, has the potential to be a novel functional food that prevents type I allergies.     

Selected Allelochemicals

Extensive research work has been done on allelochemicals that are primarily plant secondary metabolites; in this review, some pathways of biosynthesis that are produced by higher plants are discussed as well as plant defense and the potential of the control of pests, diseases, and weeds. Benzoxazinoids, glucosinolates, and some sesquiterpenoids and phenolic compounds are discussed in more detail. Five genes, Bx1 through Bx5, have been analyzed and shown to be required for a typical benzoxazinoid, DIMBOA biosynthesis in maize, and their functions were demonstrated in vitro. Among those alleochemicals mentioned here, some isothiocyanates hirsutin and ω methylsulfonylalkyl (n=8, 9, and 10) isothiocyanates, sesquiterpenoids rugosal A and lettucenin A, and phenolic compounds emodin, physcion, p-hydroxybenzaldehyde, p-hydroxybenzoic acid, and oligostilbenes are emphasized from the viewpoint of plant defense.     

Disruption of DNA polymerase ζ engages an innate immune response

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Green Chromatographic Methods and in Vitro Pharmacological Analysis of Varronia curassavica Leaf Derivatives

Varronia curassavica displays anti-inflammatory, antiulcerogenic, and antioxidant activities. Herein, we employed new UHPLC –UV green chromatographic methods for the analysis of in vitro antioxidant and anti-inflammatory activities of V. curassavica and its embryotoxicity in Zebrafish. Cordialin A, brickellin, and artemetin were purified from the ethanol (EtOH) extract of V. Curassavica leaves and identified using spectrometric techniques. In line with Green Analytical Chemistry principles, the proposed UHPLC methods involve the use of ethanol as organic modifier with low mobile phase consumption, and without sample pretreatment (OLE-UHPLC-UV). The application of the Agree and HPLC-EAT tools for greenness assessment yielded this pattern: HPLC-UV (reference)<UHPLC-UV<OLE-UHPLC-UV. Zebrafish assay results showed that 70 % EtOH extract of V. Curassavica leaves exhibited lower toxicity compared to 100 % EtOH extract, with LC₅₀ of 164.3 and 122.9 μg/mL, respectively, in 24 h post fertilization. Some embryos exhibited malformation phenotypes in the heart, somites, and eyes, mainly in higher extract concentrations. Extracts and brickellin exhibited higher antioxidant activity in the DPPH⋅ assay, while brickellin+artemetin displayed higher antioxidant activity compared to the extracts and isolated flavones in the O₂⋅⁻ and HOCl/OCl⁻ scavenging assays. Cordialin A and brickellin exhibited low COX-1, COX-2, and phospholipase A₂ inhibition.     

Mitochondrial dysfunction in a novel form of autosomal recessive ataxia

Defects in the recognition and/or repair of damage to DNA are responsible for a sub-group of autosomal recessive ataxias. Included in this group is a novel form of ataxia with oculomotor apraxia characterised by sensitivity to DNA damaging agents, a defect in p53 stabilisation, oxidative stress and resistance to apoptosis. We provide evidence here that the defect in this patient's cells is at the level of the mitochondrion. Mitochondrial membrane potential was markedly reduced in cells from the patient and ROS levels were elevated. This was accompanied by lipid peroxidation of mitochondrial proteins involved in electron transport and RNA synthesis. However, no gross changes or alteration in composition or activity of mitochondrial electron transport complexes was evident. Sequencing of mitochondrial DNA revealed a mutation, I349T, in the mitochondrial cytochrome b gene. These results describe a patient with an apparently novel form of AOA characterised by a defect at the level of the mitochondrion.     

Identification of cellular proteins interacting with octaarginine (R8) cell-penetrating peptide by photo-crosslinking

Octaarginine (R8) is a representative cell-penetrating peptide. Lanthionine synthetase component C-like protein 1 (LanCL1) was identified as a potential intracellular target of R8 by using a photo-crosslinking assay that utilized a phenyl-trifluoromethyl diazirine moiety and peptide mass fingerprinting. Increased cellular uptake of R8 by LanCL1-overexpressing cells was observed.     

Enzymatic Reduction of Sorbic Acid to trans-4-Hexmol

The sex pheromone of the citrus mealybug (Pseudococcus cryptus), [(1R,3R)-3-isopropenyl-2,2-dimethylcyclobutyl]methyl 3-methyl-3-butenoate, was synthesized from (+)-α-pinene in five operational steps in a 43% overall yield. The synthetic pheromone was identical with the natural pheromone in ¹H-NMR and mass spectroscopic properties, and showed almost the same pheromonal activity as the natural pheromone.