Search Results (5)

Background/Objectives: Metabolic-associated fatty liver disease (MAFLD) is one of the most common liver disorders associated with obesity and metabolic syndrome, and poses a significant global health burden with limited effective treatments. The aim of this study was to assess the protective effects of mulberry twig alkaloids (SZ-A) on MAFLD and to further investigate the underlying mechanisms including the specific targets or pathways. Methods: Diet-induced obesity (DIO) and normal mouse models were established by feeding C57Bl/6J mice with a high-fat diet (HFD) or common diet for 12 weeks. SZ-A, dapagliflozin, and placebo were administered to corresponding mouse groups for 8 weeks. Data of fasting blood glucose, glucose tolerance, insulin tolerance, and the body weight of mice were collected at the baseline and termination of the experiment. Serum liver enzymes and lipids were measured by ELISA. Western blotting, qPCR, and pathological section staining were implemented to evaluate the degrees of liver steatosis, fibrosis, and oxidative stress in mice. Results: In DIO mouse models, high-dose SZ-A (800 mg/kg/d) treatment significantly inhibited HFD-induced weight gain, improved insulin tolerance, and reduced serum alanine aminotransferase, total cholesterol, and triglyceride levels compared with placebo. In DIO mice, SZ-A could alleviate the pathological changes of hepatic steatosis and fibrosis compared with placebo. Lipid catabolism and antioxidant stress-related proteins were significantly increased in the livers of the high-dose SZ-A group (p < 0.05). Inhibition of PGC1α could inhibit the function of SZ-A to enhance lipid metabolism in hepatocytes. PGC1α might interact with NRF2 to exert MAFLD-remedying effects. Conclusions: By regulating the expression of PGC1α and its interacting KEAP1/NRF2 pathway in mouse liver cells, SZ-A played important roles in regulating lipid metabolism, inhibiting oxidative stress, and postponing liver fibrosis in mice with MAFLD. Full article

Leaf veins are the continuation of twigs, and the hydraulic system of a leaf is part of, and the continuation of, the hydraulic architecture of a tree. Previous studies have demonstrated that the vessel diameter of the widest part at the tree base is tightly related to the total stem length of a tree. Here, we demonstrate that: the vessel diameter of the narrowest part at the distal end of the tree (the terminal twigs) is closely correlated to the leaf size for an angiosperm tree. Consequently, the basic feature of the hydraulic system of an angiosperm tree may be predicted by two simple parameters: the stem length (or tree height) and the leaf size, with the tree height predicting the size of the widest vessel at the tree base and the leaf size predicting the size of the narrowest vessel at the terminal trig. Namely, there is an inherent coordination between the leaf size and the hydraulic architecture of the angiosperm tree. As leaves are replacing themselves every year, their responses to climate are direct and immediate, while the woody part of a tree is there for years and more, and thus can only respond passively to climate change. This may cause a mismatch between the woody part and leaf part of the hydraulic system, and thus endanger the hydraulic coordination between leaves and the woody part. Full article

Cytospora chrysosperma is the main causal agent of poplar canker disease in China, especially in some areas with poor site conditions. Pathogens secrete a large number of effectors to interfere the plant immunity and promote their infection and colonization. Nevertheless, the roles of effectors in C. chrysosperma remain poorly understood. In this study, we identified and functionally characterized a candidate effector CcSp84 from C. chrysosperma, which contained a nuclear localization signal motif at the C-terminal and was highly induced during infection stages. Transient expression of CcSp84 in Nicotiana benthamiana leaves could trigger cell death. Additionally, deletion of CcSp84 significantly reduced fungal virulence to the polar twigs, while no obvious defects were observed in fungal growth and sensitivity to H₂O₂. Confocal microscopy revealed that CcSp84 labeled with a green fluorescent protein (GFP) was mainly accumulated in the plant nucleus. Further analysis revealed that the plant nucleus localization of CcSp84 was necessary to trigger plant immune responses, including ROS accumulation, callose deposition, and induced expression of jasmonic acid and ethylene defense-related genes. Collectively, our results suggest that CcSp84 is a virulence-related effector, and plant nucleus localization is required for its functions. Full article

To discover new pharmacologically active natural products, here, we performed the phytochemical analysis of a Korean medicinal plant. Euonymus alatus (Thunb.) Sieb. is a traditional medicinal plant that has been used as a remedy for various diseases in Asian countries. In particular, the cork cambium on the twigs of E. alatus has been used to treat dysmenorrhea, tumors, diabetes, and wound. Phytochemical analysis of the methanolic extract of E. alatus twigs led to the isolation of a sterol, which was identified as (3β,16α)-3,16-dihydroxypregn-5-en-20-one (1) by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high-resolution electrospray ionization mass spectrometry. The stereochemistry of 1 was established with nuclear Overhauser effect spectroscopy (NOESY) analysis and comparison of electronic circular dichroism (ECD) data. To the best of our knowledge, the isolation of compound 1 from nature is first reported here, as well as the complete and revised NMR data assignment of 1. In lipopolysaccharide (LPS)-stimulated RAW-264.7 macrophages, compound 1 significantly inhibited nitric oxide (NO) production at an IC₅₀ value of 12.54 ± 0.05 μM as well as the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, the pre-treatment with compound 1 attenuated the LPS-induced phosphorylation of nuclear factor kappa B (NF-κB) p65 through the inhibition of the phosphorylation of IκB kinase alpha (IKKα), IKKβ, and inhibitor of kappa B alpha (IκBα). Compound 1 also inhibited the LPS-induced phosphorylation of p38, c-Jun NH₂-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK). Taken together, compound 1 may serve as an anti-inflammatory constituent of E. alatus twigs and its anti-inflammatory property is thought to be associated with the inhibition of NO production via suppression of iNOS and COX-2 expression through inhibition of IKKα/β, I-κBα and NF-κB p65 activation and downregulation of p38, JNK, and ERK mitogen-activated protein kinase signal pathways in RAW 264.7 macrophages. These findings also provide experimental evidence that compound 1 identified from E. alatus twigs could be a candidate for an anti-inflammatory agent. Full article

Studies on the essential oil of leaves and terminal twigs of Juniperus communis L. var. saxatilis Pall., isolated by steam and hydro distillation using Clevenger type apparatuses showed marked differences in the composition depending on whether the plant material was either comminuted or not prior to the distillation, as well as depending upon the duration of the distillation connected herewith. Full article