Comparative transcriptomics provides insights into the pathogenic immune response of brown leaf spots in weeping forsythia.

Weeping forsythia is an important ornamental, ecological and medicinal plant. Brown leaf spots limit the large-scale production of weeping forsythia as a medicinal crop. Alternaria alternata is a pathogen causing brown leaf spots in weeping forsythia; however, its pathogenesis and the immune response mechanisms of weeping forsythia remain unclear. In this study, we identified two mechanisms based on morphological anatomy, physiological indexes and gene expression analyses. Our results showed that A. alternata induced leaf stomata to open, invaded the mesophyll, dissolved the cell wall, destroyed the cell membrane and decreased the number of chloroplasts by up-regulating the expression of auxin-activated signaling pathway genes. Alternaria alternata also down-regulated iron-ion homeostasis and binding-related genes, which caused an increase in the levels of iron ions and reactive oxygen species in leaves. These processes eventually led to programmed cell death, destroying palisade and spongy tissues and causing the formation of iron rust spots. Alternaria alternata also caused defense and hypersensitive responses in weeping forsythia through signaling pathways mediated by flg22-like and elf18-like polypeptides, ethylene, H2O2 and bacterial secretion systems. Our study provides a theoretical basis for the control of brown leaf spots in weeping forsythia.

[Determination of seven ingredients of different grades Alismatis Rhizoma by QAMS method].

The present study is to establish a quantitative analysis of multi-components by single marker(QAMS) for determining contents of seven compositions in Alismatis Rhizoma, alismoxide, alisol C 23-acetate, alisol A, alismol, alisol B, alisol B 23-acetate and 11-deoxy-alisol B. Six relative correction factors(RCFs) of alismoxide, alisol C 23-acetate, alisol A, alismol, alisol B and 11-deoxy-alisol B were established in the UPLC method with alisol B 23-acetate as the internal standard, which was to calculate the mass fraction of each. The mass fraction of seven effective constituents in Alismatis Rhizoma was calculated by the external standard method(ESM) at the same time. Compared with the content results determined by the ESM and QAMS, the feasibility and accuracy of QAMS method were verified. Within the linear range, the RCFs of alismoxide, alisol C 23-acetate, alisol A, alismol, alisol B, 11-deoxy-alisol B were 0.946, 4.183, 0.915, 1.039, 0.923 and 1.244, respectively, with good repeatability in different experimental conditions. There was no significant difference between the QAMS method and ESM method. Then, QAMS method was applied to determination of the different degree Alismatis Rhizoma from different areas. As a result, the concentrations of 7 components have differences in different areas, but no significant differences in different grades. The QAMS method is feasible and accurate for the determination of the seven chemical compositions, and which can be used for quality control of Alismatis Rhizoma.

Astragaloside IV attenuates inflammatory cytokines by inhibiting TLR4/NF-кB signaling pathway in isoproterenol-induced myocardial hypertrophy.

ETHNOPHARMACOLOGICAL RELEVANCE: Astragaloside IV (As IV) is one of the main effective components isolated from the traditional Chinese medical herb Astragalus membranaceus. The protective effect of Astragalus membranaceus on myocardial hypertrophy has been extensively proved. To test the hypothesis that Astragaloside IV can ameliorate the myocardial hypertrophy and inflammatory effect induced by ß-adrenergic hyperactivity, we carried out in vivo and in vitro experiments. MATERIAL AND METHODS: In in vivo study, the isoproterenol (Iso) (5 mg kg(-1) d(-1)) was used as a model of myocardial hypertrophy by intraperitoneal injection. SD rats were randomly assigned to following six groups: A: the control; B: Iso group; C: Iso plus As IV 20 mg kg(-1) d(-1); D: Iso plus As IV 40 mg kg(-1) d(-1); E: Iso plus As IV 80 mg kg(-1) d(-1); F: Iso plus Propranolol 40 mg kg(-1) d(-1). In in vitro study, cultured neonatal rat cardiomyocytes were pretreated with As IV (3, 10, 30 µ mol L(-1)), Propranolol (2 µ mol L(-1)) and BAY11-7082 (5 µ mol L(-1)) for 30 min, and then incubated with Iso (10 µ mol L(-1)) for 48 h. For the rats in each group, the heart mass index (HMI) and the left ventricular mass index (LVMI) were measured. To measure the transverse diameter of left ventricular myocardial cells (TDM), the hematoxylin-eosin (HE) staining method was applied. In addition, the volume and the total protein content of cardiomyocytes were measured, the mRNA expression of ANP and TLR4 were quantified by RT-PCR, the protein expression of TLR4, IκBα and p65 were quantified by Western blot, and the level of TNF-α and IL-6 were measured by ELISA. RESULTS: In vivo: Comparing the Iso group to the control, the HMI, LVMI, TDM were significantly increased; the protein expression of TLR4 and p65 were increased, while the IκBα were decreased; the expression of ANP, TLR4 mRNA, and TNF-α, IL-6 in serum were significantly increased. These changes could be partly prevented by As IV and Pro. In vitro: the over-expression of the cell size, total protein content could remarkably down-regulated by As IV and Pro, and the results of RT-PCR, Western blot and ELISA were similar to those of in vivo. CONCLUSIONS: The results of these studies indicate that Astragaloside IV has good protective effect on myocardial hypertrophy induced by isoproterenol. More specifically, the cardioprotection is related to inhibiting the TLR4/NF-кB signaling pathway and the attenuating inflammatory effect.