Characterization of Fusarium species causing head blight of highland barley (qingke) in Tibet, China.

Most of the research on the characterization of Fusarium species focused on wheat, barley, rice, and maize in China. However, there has been limited research in highland barley (qingke). Recently, Fusarium head blight (FHB) of qingke was recently observed in Tibet, China, especially around the Brahmaputra River. To gain a better understanding of the pathogens involver, 201 Fusarium isolates were obtained from qingke samples in 2020. Among these isolates, the most abundant species was F. avenaceum (45.3 %), followed by F. equiseti (27.8 %), F. verticillioides (13.9 %), F. acuminatum (9.0 %), F. flocciferum (3.5 %), and F. proliferatum (0.5 %). The distribution of Fusarium species varied along the Brahmaputra River, with F. avenaceum being predominant in the midstream and downstream regions, while F. equiseti was more common in the upstream region. Chemical analyses of all the isolates revealed the production of different mycotoxins by various Fusarium species. It was found that enniatins were produced by F. acuminatum, F. avenaceum, and F. flocciferum, beauvericin (BEA) and fumonisins were produced F. proliferatum and F. verticillioides, and zearalenone (ZEN) and nivalenol (NIV) were produced by F. equiseti. Pathogenicity test showed that F. avenaceum was more aggressive in causing FHB compared to F. acuminatum, F. equiseti, and F. flocciferum. The disease severity, measured by the area under the disease progress curve (AUDPC), was significantly positively (P < 0.01) correlated with the concentration of total toxins produced by each species. Furthermore, all the Fusarium strains which were used for pathogenicity test were susceptible to carbendazim, and the 50 % effective concentration (EC50) ranged from 0.406 µg/mL to 0.673 µg/mL with an average EC50 of 0.551 ± 0.012 µg/mL.

Antiproliferative effects mechanism of beta-sitosterul in hepatoma HepG2 cells / 中国中药杂志

<p><b>OBJECTIVE</b>To study the antiproliferative effects of beta-sitosterul and its mechanism in hepatoma HepG2 cells.</p><p><b>METHOD</b>Cell proliferation was assessed by MTT assay. Cell cycle distribution, apoptosis and mitochondrial membrane potential were measured by high content screening (HCS). The protein expression of caspase-3, caspase-8, caspase-9, Bcl-2, Bax, tBid and cytochrome c in the HepG2 cells were evaluated by Western Blots.</p><p><b>RESULT</b>beta-Sitosterul exerted significant antiproliferative effects in HepG2 cells. Furthermore, beta-sitosterul also induced HepG2 cells apoptosis, lost mitochondrial membrane potential, activated caspase-3, caspase-8 and caspase-9, up-regulate Bax, tBid protein, down-regulation Bcl-2 protein. However, beta-sitosterul had hardly any effects on QSG7701 cells.</p><p><b>CONCLUSION</b>beta-Sitosterul exerted antiproliferative effects and induced HepG2 cells apoptosis via mitochondrial pathway and membrane death receptor pathway.</p>