Multiple Mechanistic Models Reveal the Neuroprotective Effects of Diterpene Ginkgolides against Astrocyte-Mediated Demyelination via the PAF-PAFR Pathway.

Currently, therapies for ischemic stroke are limited. Ginkgolides, unique Folium Ginkgo components, have potential benefits for ischemic stroke patients, but there is little evidence that ginkgolides improve neurological function in these patients. Clinical studies have confirmed the neurological improvement efficacy of diterpene ginkgolides meglumine injection (DGMI), an extract of Ginkgo biloba containing ginkgolides A (GA), B (GB), and K (GK), in ischemic stroke patients. In the present study, we performed transcriptome analyses using RNA-seq and explored the potential mechanism of ginkgolides in seven in vitro cell models that mimic pathological stroke processes. Transcriptome analyses revealed that the ginkgolides had potential antiplatelet properties and neuroprotective activities in the nervous system. Specifically, human umbilical vein endothelial cells (HUVEC-T1 cells) showed the strongest response to DGMI and U251 human glioma cells ranked next. The results of pathway enrichment analysis via gene set enrichment analysis (GSEA) showed that the neuroprotective activities of DGMI and its monomers in the U251 cell model were related to their regulation of the sphingolipid and neurotrophin signaling pathways. We next verified these in vitro findings in an in vivo cuprizone (CPZ, bis(cyclohexanone)oxaldihydrazone)-induced model. GB and GK protected against demyelination in the corpus callosum (CC) and promoted oligodendrocyte regeneration in CPZ-fed mice. Moreover, GB and GK antagonized platelet-activating factor (PAF) receptor (PAFR) expression in astrocytes, inhibited PAF-induced inflammatory responses, and promoted brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) secretion, supporting remyelination. These findings are critical for developing therapies that promote remyelination and prevent stroke progression.

Baicalin Inhibits Coxsackievirus B3 Replication by Reducing Cellular Lipid Synthesis.

Baicalin is a flavonoid extracted from Scutellariae Radix and shows a variety of biological activities as reducing lipids, diminishing inflammation, and inhibiting bacterial infection. However, there is no report of baicalin against CVB3 infection. In this study, we found that baicalin can reduce viral titer in a dose-dependent manner in vitro at a dose with no direct virucidal effect. Moreover, we revealed that baicalin can also improve survival rate, reduce heart weight/body weight ratio, prevent virus replication, and relieve myocardial inflammation in the acute viral myocarditis mouse model induced by CVB3. Then, in order to explore the mechanism of baicalin inhibiting CVB3 replication, we respectively examined the expression of autophagosome marker LC3-II by Western blot, tested the concentration of free fatty acid (FFA) and cholesterol (CHO) by commercial kits, detected the mRNA levels of fatty acid synthase (Fasn) and acetyl coenzyme a carboxylase (ACC) by RT-PCR, and observed the lipid content of cells by fluorescence staining. The results showed that CVB3 infection increased autophagosome formation and lipid content in HeLa cells, but these changes were significantly blocked by baicalin. Finally, in order to confirm that baicalin inhibits viral replication and reduces autophagosome formation by reducing cellular lipids, we added exogenous palmitate to cell culture supernatants to promote intracellular lipid synthesis and found that palmitate did not alter LC3-II and CVB3/VP1 expression in HeLa cells with or without CVB3 infection. Interestingly, palmitate can reverse the inhibitory effect of baicalin on autophagosome formation and viral replication. In conclusion, our results indicated that lipids play an important role in CVB3 replication, and the effect of baicalin against CVB3 was associated with its ability to reduce cellular lipid synthesis to limit autophagosome formation.

New diterpenoid alkaloids from Aconitum coreanum and their anti-arrhythmic effects on cardiac sodium current.

Two new diterpenoid alkaloids, Guan-Fu base J (GFJ, 1) and Guan-Fu base N (GFN, 2) along with nineteen known alkaloids (3-21) were isolated from the roots of Aconitum coreanum (Lèvl.) Rapaics, which is the raw material of a new approval anti-arrhythmia drug "Acehytisine Hydrochloride". The structures of isolated compounds were established by means of 1D, 2D NMR spectroscopic and chemical methods. All isolates obtained in the present study were evaluated for their inhibitory effects on blocking the ventricular specific sodium current using a whole-cell patch voltage-clamp technique. Among these 21 compounds, Guan-Fu base S (GFS, 3) showed the strongest inhibitory effect with an IC50 value of 3.48 µM, and only hetisine-type C20 diterpenoid alkaloids showed promising IC50 values for further development.

Inhibitory effects of indigowoad root polysaccharides on porcine reproductive and respiratory syndrome virus replication in vitro.

BACKGROUND: Indigowoad root polysaccharide (IRPS) is a natural polysaccharide isolated from the traditional Chinese medicinal herb Radix Isatidis, and has many kinds of biological activities. However, the IRPS antiviral activity, especially the anti-porcine reproductive and respiratory syndrome virus (PRRSV) effect, has not been evaluated. METHODS: PRRSV was propagated in the MARC-145 cell line, and viral titre was determined by cytopathic effect and expressed as the 50% tissue culture infection dose (TCID(50)) in the current study. The cell cytotoxic effect of IRPS toward MARC-145 was evaluated by MTT assay firstly, then the inhibitory effects of IRPS on PRRSV replication in vitro were investigated by determining the effect of IRPS upon a single replicative cycle of PRRSV in MARC-145 cells. The effects of IRPS on viral RNA and protein synthesis in PRRSV-infected cells were investigated using real-time PCR and double-antibody (sandwich) ELISA. RESULTS: IRPS was able to effectively suppress the infectivity of the PRRSV in a dose-dependent manner, especially by adding IRPS during the PRRSV infection. IRPS could affect the attachment of PRRSV to MARC-145 cells, and also inhibit the viral RNA and protein synthesis. CONCLUSIONS: IRPS has an antiviral effect on PRRSV replication in MARC-145 cells and might be useful in medical development for antiviral research. However, the precise mechanism of the host and viral targets of IRPS are unknown, so further studies should be conducted to investigate the precise mechanism of IRPS inhibitory effect on PRRSV infection.

[Isolation and identification of hetisine-type alkaloids from Aconitum coreanum by high speed countercurrent chromatography].

AIM: To search for more bioactive compounds from the roots of Aconitum coreanum (Lèvl.) Rapaics. METHODS: High speed countercurrent chromatography was successfully applied to the separation of alkaloids from Aconitum coreanum. The structures were elucidated by their physicochemical properties and spectroscopic analysis. RESULTS: Two-phase solvent system composed of CHCl3-CH3OH-0.2 mol x L(-1) HCl (10:3:3, volume ratio) was used in this experiment, eight alkaloids were obtained from the roots of Aconitum coreanum, which were identified as: 2alpha-propionyl-11alpha,13beta-diacetyl-14-hydroxyhetisine (I), Guanfu base P (II), Guanfu base G (III), Guanfu base F (IV), Guanfu base Z (V), Guanfu base O (VI), Guanfu base A (VII), Guanfu base B (VIII). CONCLUSION: Compound I is a new alkaloid, named Guanfu base R.

[A new hetisine-type alkaloid from the stems and leaves of Aconitum coreanum].

AIM: To study the chemical constituents of the stems and leaves of Aconitum coreanum (Lèvl.) Rapaics. METHODS: The constituents of Aconitum coreanum were isolated by using various kinds of modern chromatographic methods. The new alkaloid was identified on the basis of spectral analysis. RESULTS: Two compounds were isolated and identified as: 13-dehydro-1beta-acetyl-2alpha,6beta-dihydroxyhetisine (I) and Guanfu base G (II). CONCLUSION: Compound I is a new alkaloid.

Antioxidative phenylethanoid and phenolic glycosides from Picrorhiza scrophulariiflora.

One new phenylenthanoid glycoside, scroside D (2), was isolated from the roots of Picrorhiza scrophulariiflora (Scrophulariaceae), together with nine known phenylethanoid and phenolic glycosides: 2-(3,4-dihydroxyphenyl)-ethyl-O-beta-D-glucopyranoside (1), 2-(3-hydroxy-4-methoxyphenyl)-ethyl-O-beta-D-glucopyranosyl (1-->3)-beta-D-glucopyranoside (3), scroside B (4), hemiphroside A (5), plantainoside D (6), scroside A (7), androsin (8), piceoside (9), and 6-O-feruloyl-beta-D-glucopyranoside (10). The structures of these compounds were elucidated using spectroscopic methods. The antioxidative activities of these isolated compounds were evaluated based on their scavenging effects on hydroxyl radicals and superoxide anion radicals, respectively. Compounds 1, 2, and 6 showed potent antioxidative effects as those of ascorbic acid and the structure-activity relationship is discussed.