Identification of Three Viruses Infecting Mulberry Varieties.

Viruses-mediated genome editing in plants is a powerful strategy to develop plant cultivars with important and novel agricultural traits. Mulberry alba is an important economic tree species that has been cultivated in China for more than 5000 years. So far, only a few viruses have been identified from mulberry trees, and their application potential is largely unknown. Therefore, mining more virus resources from the mulberry tree can pave the way for the establishment of useful engineering tools. In this study, eight old mulberry plants were gathered in seven geographic areas for virome analysis. Based on transcriptome analysis, we discovered three viruses associated with mulberries: Citrus leaf blotch virus isolate mulberry alba 2 (CLBV-ML2), Mulberry-associated virga-like virus (MaVLV), and Mulberry-associated narna-like virus (MaNLV). The genome of CLBV-ML2 was completely sequenced and exhibited high homology with Citriviruses, considered to be members of the genus Citrivirus, while the genomes of MaVLV and MaNLV were nearly completed lacking the 5' and 3' termini sequences. We tentatively consider MaVLV to be members of the family Virgaviridae and MaNLV to be members of the genus Narnavirus based on the results of phylogenetic trees. The infection experiments showed that CLBV-ML2 could be detected in the inoculated seedlings of both N. benthamiana and Morus alba, while MaVLV could only be detected in N. benthamiana. All of the infected seedlings did not show obvious symptoms.

Integrative Analyses of Transcriptomics and Metabolomics in Sex Differentiation of Mulberry Flowers.

Sex determination and sex differentiation of plants are important physiological processes of plant development. Mulberry (Morus indica L.) is an important economic tree being cultivated in sericulture countries, and mulberry leaf is commonly used for sericulture. The transcriptomic and metabolomic differences between the staminate flowers (SFs) and pistillate flowers (PFs) of mulberry were investigated by RNA sequencing and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Overall, we uncovered 4,230 genes and 209 metabolites are significantly differentially expressed between the SFs and PFs of mulberry. The combined transcriptomic and metabolomic analysis revealed these differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) are involved in flavonoid biosynthesis, galactose metabolism, plant-pathogen interaction, and starch and sucrose metabolism, and these detected DEGs and DEMs may be associated with sex differentiation of mulberry through the regulation of the enrichment pathways, such as the MAPK pathway, flavonoid biosynthesis, galactose metabolism, plant-pathogen interaction, and starch and sucrose metabolism. This study will provide a rich source for the analysis of the molecular mechanism of mulberry sex differentiation processes.

Luteolin-4'-O-glucoside and its aglycone, two major flavones of Gnaphalium affine D. Don, resist hyperuricemia and acute gouty arthritis activity in animal models.

BACKGROUND: Gnaphalium affine D. Don is a folk medicine of China believed to be efficacious in the treatment of many ailments, including hyperuricemia and gout. PURPOSE: Based on a previous study, we isolated two flavones, luteolin and luteolin-4'-O-glucoside, from G. affine. Our aim was to assess the potential beneficial effects of treatment and mechanisms of these two flavones on hyperuricemia and acute gouty arthritis. METHODS: The model of potassium oxonate (PO)-induced hyperuricemia and monosodium urate (MSU) crystal-induced inflammation in mice has been established. We evaluated serum uric acid (Sur), xanthine oxidase (XO) activity, protein expression of urate transporter 1 (mURAT1) and glucose transporter 9 (mGLUT9) in renal and kidney protection in a hyperuricemia model. In addition, paw swelling and levels of interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) in serum were assessed in MSU crystal-induced mice. RESULTS: Luteolin and luteolin-4'-O-glucoside showed a potent clinical effect in treating hyperuricemia and gout. We observed that the two flavones possess potent effect in hyperuricemia mice by decreasing the level of mURAT1 and inhibiting XO activity, which contribute to enhancing uric acid (UA) excretion and improving hyperuricemia-induced renal dysfunction. In addition, luteolin and luteolin-4'-O-glucoside also alleviated paw swelling and inflammation induced by MSU crystals. Further investigation implied that luteolin and luteolin-4'-O-glucoside improved the symptoms of inflammation by decreasing the levels of IL-1ß and TNF-α. CONCLUSION: The present study suggests that luteolin and luteolin-4'-O-glucoside could be developed as therapeutics for treating hyperuricemia and gouty arthritis.

Effects of Gnaphalium affine D. Don on hyperuricemia and acute gouty arthritis.

ETHNOPHARMACOLOGICAL RELEVANCE: The Gnaphalium affine D. Don is used in China as a folk medicine to treat gout, anti-inflammatory, antitussive and expectorant activities. The aim of this study was to evaluate the potential of the extract of G. affine to treat hyperuricemia and acute gouty arthritis in animal model. MATERIALS AND METHODS: G. affine extract was evaluated in an experimental model with potassium oxonate (PO) induced hyperuricemia in mice which was used to evaluate anti-hyperuricemia activity and xanthine oxidase (XO) inhibition. Therapies for acute gouty arthritis was also investigated on monosodium urate (MSU) crystal induced paw edema model. RESULTS: G. affine extract showed expressive results on active in reducing serum uric acid (Sur) through effect renal mGLUT9 and mURAT1 mainly and inhibit XO activity in vivo. The extract of G. affine also showed significant anti-inflammatory activity and reduced the paw swelling on MSU crystal-induced paw edema model. Meanwhile, eight major compounds were identified by HPLC-ESI-QTOF-MS/MS. CONCLUSIONS: The extract of G. affine showed significant effect on evaluated models and therefore may be active agents for the treatment of hyperuricemia and acute gouty arthritis.

Screening of Potential Xanthine Oxidase Inhibitors in Gnaphalium hypoleucum DC. by Immobilized Metal Affinity Chromatography and Ultrafiltration-Ultra Performance Liquid Chromatography-Mass Spectrometry.

In this study, a new method based on immobilized metal affinity chromatography (IMAC) combined with ultrafiltration-ultra performance liquid chromatography-mass spectrometry (UF-UPLC-MS) was developed for discovering ligands for xanthine oxidase (XO) in Gnaphalium hypoleucum DC., a folk medicine used in China for the treatment of gout. By IMAC, the high flavonoid content of G. hypoleucum could be determined rapidly and efficiently. UF-UPLC-MS was used to select the bound xanthine oxidase ligands in the mixture and identify them. Finally, two flavonoids, luteolin-4'-O-glucoside and luteolin, were successfully screened and identified as the candidate XO inhibitors of G. hypoleucum. They were evaluated in vitro for XO inhibitory activity and their interaction mechanism was studied coupled with molecular simulations. The results were in favor of the hypothesis that the flavonoids of G. hypoleucum might be the active content for gout treatment by inhibiting XO.

Polysaccharide from Phellinus linteus induces S-phase arrest in HepG2 cells by decreasing calreticulin expression and activating the P27kip1-cyclin A/D1/E-CDK2 pathway.

ETHNOPHARMACOLOGY RELEVANCE: Our previous study showed that the proteoglycan P1 from Phellinus linteus (Mesima) exhibits significant anti-tumor activity against human hepatocellular carcinoma cells (HepG2); however, its molecular mechanism remains unknown. This study aims to provide insights into the mechanism of the anti-tumor activity of P1 against HepG2 cells. METHODS: We examined the effects of P1 on HepG2 cell proliferation in vitro and in vivo. Flow cytometry was used to analyze the cell cycle distribution and apoptosis. Proteomic analysis, real-time (RT)-PCR, and Western blot were carried out to observe the expression of several cell cycle control proteins in HepG2 cells. RESULTS: Both the volume and the weight of solid tumors were significantly decreased in P1-treated mice (200mg/kg) compared with the control. The HepG2 cells in the P1-treated tumors were significantly decreased, irregularly shaped, and smaller. P1 slightly increased the body weight of the tumor-bearing mice, which indicates that P1 is nontoxic to mammals at 200mg/kg. P1 also caused a significant dose-dependent increase in S phase arrest, but no apoptosis was observed in HepG2 cells. The results of the proteomic analysis, RT-PCR, and Western blot analysis showed that significantly downregulated expression of calreticulin, cyclin D1, cyclin E, and CDK2 and upregulated expression of P27 kip1 and cyclin A in the P1-treated HepG2 cells (200 µg/ml). CONCLUSION: These results suggest that calreticulin expression and the P27 kip1-cyclin A/D1/E-CDK2 pathway were involved in P1-induced S-phase cell cycle arrest in HepG2 cells.