Wunorlactones A-G, seven undescribed 7/8/5 and 7/8/3 carbon skeleton schinortriterpenoids from the stems and leaves of Schisandra chinensis, and their neuroprotective activities.

Schisandra chinensis is an important traditional Chinese medicine and its main bioactive components are lignans and schinortriterpenoids (SNTs). The aim of this study was to explore the biologically rich SNTs from the stem and leaves of S. chinensis (SCSL). Here, seven previously undescribed 7/8/5 and 7/8/3 carbon skeleton SNTs (1-7) were reported. Their structures were determined by NMR, UV, MS, ECD, and X-ray diffraction analyses, and the neuroprotective activities of these compounds on corticosterone-induced PC12 cell injury were evaluated. The results showed that 1, 5, and 7 (25 µM) had neuroprotective effects, and the cell viability was increased by 20.07%, 14.24%, and 15.14% (positive control: 30.64%), respectively. These findings increased the number of described SNTs in SCSL, and the neuroprotective activities of all compounds indicated their potential application in neurodegenerative diseases.

An integrated network pharmacology approach reveals that Darutigenol reduces inflammation and cartilage degradation in a mouse collagen-induced arthritis model by inhibiting the JAK-STAT3 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Darutigenol (DL) is a natural active product derived from the Chinese herbal medicine Sigesbeckia glabrescens (Makino) Makino. It is administered as a traditional Chinese medicine (TCM) to dispel rheumatism, benefit the joints, and detoxify. However, its potential mechanism in the treatment of rheumatoid arthritis (RA) remains unknown. AIMS OF THE STUDY: The objectives of this research were to determine the effects and elucidate the modes of action of DL on RA-related joint inflammation. MATERIALS AND METHODS: Network pharmacology and molecular docking were used to screen and validate candidate DL targets for RA treatment, respectively. A DBA/1 mouse rheumatoid arthritis model was induced with bovine type II collagen. Intragastric DL administration was followed by the calculation of the clinical arthritis index. A section of the ankle joint was excised and stained and the pathological changes in it were observed. Enzyme-linked immunosorbent assays (ELISA) and western blotting (WB) were used to clarify the mechanisms of DL in RA treatment. RESULTS: DL effectively attenuated the inflammation, mitigated the articular cartilage degradation, and bone erosion, and alleviated the inflammatory joints associated with RA. Network pharmacology screened six key targets of DL while molecular docking revealed that it docked well with its protein targets. The DL treatment group presented with significantly less ankle joint redness and swelling, a lower arthritis index scores and serum and bone marrow supernatant IL-6 levels, more complete ankle joint surfaces, and less synovial inflammation, cartilage degradation, and bone erosion than the collagen-induced arthritis (CIA) group. The DL treatment also substantially downregulated the Janus kinase (JAK)1, JAK3, matrix metalloproteinase (MMP)2, MMP9, and phospho-signal transducer and activator of transcription (p-STAT)3 proteins in the joints. CONCLUSIONS: To the best of our knowledge, the present work was the first to demonstrate that DL has significant anti-inflammatory efficacy and reduces cartilage degradation and bone erosion. It also demonstrated that the anti-RA effect of DL may be explained by its ability to inhibit joint inflammation and reduce articular cartilage degradation through the interleukin (IL)-6/JAK1,3/STAT3 axis and downregulate MMP2 and MMP9. Hence, DL might play a therapeutic role in a mouse RA model.

Molecular cloning and characterization of three phenylalanine ammonia-lyase genes from Schisandra chinensis.

Phenylalanine ammonia-lyase (PAL), which catalyzes the conversion from L-phenylalanine to trans-cinnamic acid, is a well-known key enzyme and a connecting step between primary and secondary metabolisms in the phenylpropanoid biosynthetic pathway of plants and microbes. Schisandra chinensis, a woody vine plant belonging to the family of Magnoliaceae, is a rich source of dibenzocyclooctadiene lignans exhibiting potent activity. However, the functional role of PAL in the biosynthesis of lignan is relatively limited, compared with those in lignin and flavonoids biosynthesis. Therefore, it is essential to clone and characterize the PAL genes from this valuable medicinal plant. In this study, molecular cloning and characterization of three PAL genes (ScPAL1-3) from S. chinensis was carried out. ScPALs were cloned using RACE PCR. The sequence analysis of the three ScPALs was carried out to give basic characteristics followed by docking analysis. In order to determine their catalytic activity, recombinant protein was obtained by heterologous expression in pCold-TF vector in Escherichia coli (BL21-DE3), followed by Ni-affinity purification. The catalytic product of the purified recombinant proteins was verified using RP-HPLC through comparing with standard compounds. The optimal temperature, pH value and effects of different metal ions were determined. Vmax, Kcat and Km values were determined under the optimal conditions. The expression of three ScPALs in different tissues was also determined. Our work provided essential information for the function of ScPALs.

[A new norsesquiterpenoid from Schisandra chinensis].

This study investigated the chemical components from the leaves and stems of Schisandra chinensis. Three norsesquiterpenoids were isolated from S. chinensis by various column chromatographies(silica gel, Sephadex LH-20, and MCI), reversed-phase medium-pressure preparative, and semi-preparative high-performance liquid chromatography(HPLC). Their structures were identified based on physicochemical properties, mass spectrometry(MS), nuclear magnetic resonance(NMR), ultraviolet(UV), and electro-nic circular dichroism(ECD) as(3R,4R,5R,6S,7E)-3,4,5,6-tetrahydroxy-7-megastigmen-9-one(1),(3S,5R,6R,7E)-3,5,6-trihydroxy-7-megastigmen-9-one(2), and(3S,4R,9R)-3,4,9-trihydroxymegastigman-5-ene(3). Compound 1 was a new compound, and its absolute configuration was determined by ECD. Compounds 2 and 3 were isolated from the Schisandra plant for the first time.

[Cloning of AhWRKY33 from Asarum heterotropoides and its genetic transformation in Arabidopsis].

The WRKY family genes, which play an important role in plant morphogenesis and stress response, were selected based on the data of the full-length transcriptome of Asarum heterotropoides. Using AtWRKY33, which regulates the synthesis of the camalexin in the model plant Arabidopsis to compare homologous genes in A. heterotropoides, primers were designed to amplify the open reading frame(ORF) fragment of AhWRKY33 gene by RT-PCR using total RNA of A. heterotropoides leaves as template. Real-time PCR results showed that there was a significant difference between the aerial part and the underground part of A. heterotropoides, the toxic aristolochic acid content is highly expressed in the leaves higher than the root. After verification, the WRKY33 gene of A. heterotropoides is ORF long 1 686 bp, encoding 561 amino acids.AhWRKY33 had two conserved WRKYGQK domains. According to the classical classification, it belongs to group Ⅰ WRKY transcription factor. A. heterotropoides WRKY33 had some homology with amino acids of other species. The study successfully constructed the plant eukaryotic expression vector PHG-AhWRKY33 and transformed Arabidopsis thaliana, the transgenic Arabidopsis was obtained by PCR detection and hygromycin resistant plate screening. It found that the germination of transgenic Arabidopsis seeds was accelerated and the stress resistance was increased. It laid a foundation for further analysis of WRKY transcription factor in the growth and development of A. heterotropoides and the synthesis of secondary metabolites.