Project description:Platelets are an important component of the initial response to vascular endothelial injury; however, platelet dysfunction induces the acute clinical symptoms of thrombotic disorders, which trigger severe cardiovascular diseases such as myocardial infarction, ischemia, and stroke. In this study, we investigated the Dryopteris crassirhizoma's antiplatelet activity. A water extract of D.crassirhizoma (WDC) was partitioned into dichloromethane (DCM), ethyl acetate, n-butyl alcohol, and water. Among these four fractions, the DCM fraction potently inhibited the collagen-stimulated platelet aggregation in a concentration-dependent manner. From this fraction, five different acylphloroglucinol compounds and one flavonoid were isolated by activity-guided column chromatography. They were identified by comparing their mass, 1H-, and 13C-NMR spectral data with those reported in the literature. Quantifying the six compounds in WDC and its DCM fraction by high-performance liquid chromatography (HPLC) revealed that butyryl-3-methylphloroglucinol (compound 4) was the most abundant in these samples. Additionally, butyryl-3-methylphloroglucinol showed the strongest inhibitory activity in the collagen- and arachidonic acid (AA)-induced platelet aggregation, with inhibition ratios of 92.36% and 89.51% in the collagen and AA-induced platelet aggregation, respectively, without cytotoxicity. On the active concentrations, butyryl-3-methylphloroglucinol significantly suppressed the convulxin-induced platelet activation. Regarding the structure-activity relationships for the five acylphloroglucinol compounds, our results demonstrated that the functional butanonyl, methoxy, and hydroxy groups in butyryl-3-methylphloroglucinol play important roles in antiplatelet activity. The findings indicate that acylphloroglucinols, including butyryl-3-methylphloroglucinol from D.crassirhizom, possess an antiplatelet activity, supporting the use of this species for antiplatelet remedies.
Project description:Dryopteris crassirhizoma Nakai is a fern plant with important evolutionary and medicinal values. Herein, we assembled the complete chloroplast genome of D. crassirhizoma by next-generation sequencing technology. The complete chloroplast genome of D. crassirhizoma was 153,355 bp in length, and the GC content was 42.86%; the genome consisted of a pair of inverted repeats (IRs, 23,470 bp), a small single copy region (SSC, 21,570 bp) and a large single copy region (LSC, 84,854 bp). The genome contained 111 genes, namely, 73 protein-coding genes, 34 tRNA genes and four rRNA genes. The phylogenetic analysis suggested that both D. crassirhizoma and D. decipiens from Dryopteridaceae were most closely related to Lepisorus clathratus from Polypodiaceae.
Project description:Dryopteris crassirhizoma rhizomes are used as a traditional medicine in Asia. The EtOAc extract of these roots has shown potent xanthine oxidase (XO) inhibitory activity. However, the main phloroglucinols in D. crassirhizoma rhizomes have not been analyzed. Thus, we investigated the major constituents responsible for this effect. Bioassay-guided purification isolated four compounds: flavaspidic acid AP (1), flavaspidic acid AB (2), flavaspidic acid PB (3), and flavaspidic acid BB (4). Among these, 1 showed the most potent inhibitory activity with a half-maximal inhibitory concentration (IC50) value of 6.3 µM, similar to that of allopurinol (IC50 = 5.7 µM) and better than that of oxypurinol (IC50 = 43.1 µM), which are XO inhibitors. A comparative activity screen indicated that the acetyl group at C3 and C3' is crucial for XO inhibition. For example, 1 showed nearly 4-fold higher efficacy than 4 (IC50 = 20.9 µM). Representative inhibitors (1-4) in the rhizomes of D. crassirhizoma showed reversible and noncompetitive inhibition toward XO. Furthermore, the potent inhibitors were shown to be present in high quantities in the rhizomes by a UPLC-QTOF-MS analysis. Therefore, the rhizomes of D. crassirhizoma could be used to develop nutraceuticals and medicines for the treatment of gout.