Effects of 1,2,4,6-tetra-O-galloyl-β-D-glucose from P. emblica on HBsAg and HBeAg Secretion in HepG2.2.15 Cell Culture

A polyphenolic compound, 1,2,4,6-tetra-O-galloyl-β-D-glucose （1246TGG）, was isolated from the traditional Chinese medicine Phyllanthus emblica L. （Euphorbiaceae） and assayed for its potential as an anti-hepatitis B virus （HBV） agent. The cytotoxicity of 1246TGG on HepG2.2.15 as well as HepG2 cells was determined by observing cytopathic effects, and the effects of 1246TGG on secretion of HBsAg and HBeAg in HepG2.2.15 cells were assayed by enzyme immunoassay. Results indicates that treatment with 1246TGG （6.25 ~tg/mL, 3.13 ~tg/mL）, reduced both HBsAg and HBeAg levels in culture supernatant, yet the inhibitory effects tend to decline with the assay time. This study provides a basis for further investigation of the anti-HBV activity and possible mechanism of action of 1246TGG

1,2,3,4,6-penta-O-galloyl-β-D-glucose up-regulates heme oxygenase-1 expression by stimulating Nrf2 nuclear translocation in an extracellular signal-regulated kinase-dependent manner in HepG2 cells

AIM: To examine the potency of 1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG) as a hepatic heme oxygen-ase-1(HO-1) inducer and its regulation in HepG2 cells. METHODS: Expression of HO-1 and NF-E2-related factor 2 (Nrf2) and activation of mitogen-activated protein (MAP) kinases were analyzed by Western blot, immuno-fluorescence assay, and flow cytometry. Transfections of HO-1 gene, small interfering RNAs for HO-1 and Nrf2, and dominant-negative gene for MAP/extracellular signal-regulated kinase (ERK) were carried out to dissect the signaling pathways leading to HO-1 expression in HepG 2 cells. RESULTS: PGG up-regulated HO-1 expression and this expression conferred cytoprotection against oxidative injury induced by t-butyl hydroperoxide. Moreover, PGG induced Nrf2 nuclear translocation, which was found to be an upstream step of PGG-induced HO-1 expression, and ERK activation, of which pathway was involved in PGG-induced Nrf2 nuclear translocation, HO-1 expression and cytoprotection. CONCLUSION: PGG up-regulates HO-1 expression by stimulating Nrf2 nuclear translocation in an ERK-depen-dent manner, and HO-1 expression by PGG may serve as one of the important mechanisms for its hepatoprotective effects.

1,2,3,4,6-penta-O-galloyl-β-D-glucose Protects PC12 Cells from MPP^+-mediated Cell Death by Inducing Heme Oxygenase-1 in an ERK- and Akt-dependent Manner

This study examined the ability of 1,2,3,4,6-penta-O-galloyl-β-D-glucose (β-PGG) to induce the expression of heme oxygenase-1 (HO-1) in the PC12 cells and its regulation in the PC12 cells.One week before treatment with the drug,nerve growth factor (NGF) was added to the cultures at a final concentration of 50 ng/mL to induce neuronal differentiation.After drug treatment,HO-1 gene transcription was analyzed by reverse transcription polymerase chain reaction (RT-PCR).Expression of HO-1 and NF-E2-related factor2 (Nrf2) and activation of extracellular signal-regulated kinase (ERK) and Akt were detected by Western blotting.The viability of the PC12 cells treated with different medicines was examined by MTT assay.The oxidative stress in the PC12 cells was evaluated qualitatively and quantitatively by DCFH-DA.The results showed that β-PGG up-regulated HO-1 expression and this increased expression provided neuroprotection against MPP+-induced oxidative injury.Moreover,β-PGG induced Nrf2 nuclear translocation,which was found to be upstream of β-PGG-induced HO-1 expression,and the activation of ERK and Akt,a pathway that is involved in β-PGG-induced Nrf2 nuclear translocation,HO-1 expression and neuroprotection.In conclusion,β-PGG up-regulates HO-1 expression by stimulating Nrf2 nuclear translocation in an ERK-and Akt-dependent manner,and HO-1 expression by β-PGG may provide the PC12 cells with an acquired antioxidant defense capacity to survive the oxidative stress.

HPLC法同时测定赶黄草中4种成分

目的建立HPLC法同时测定赶黄草中乔松素-7-O-β-D-葡萄糖苷、pinocembrin-7-O-[4″,6″-(S)-hexahydroxydiphenoyl]-β-D-glucose、thonningianin A、pinocembrin-7-O-[3″-O-galloyl-4″,6″-(S)-hexahydroxydiphenoyl]-β-Dglucose的含量。方法赶黄草80%甲醇提取物的分析采用Agilent ZORBAX SB-C18柱(4.6 mm×250 mm,5μm)流动相乙腈-0.5%甲酸水,梯度洗脱;体积流量1.0 mL/min;柱温30℃;检测波长280 nm。结果4种成分在各自范围内线性关系良好(r≥0.9999),平均加样回收率100.90%~102.04%,RSD 0.82%~2.54%。结论该方法准确稳定,重复性好,可用于赶黄草的质量控制。

Metabolite characterization of Penta-O-galloyl-β-D-glucose in rat biofluids by HPLC-QTOF-MS

Objective： To understand the in vivo metabolic fate of 1,2,3,4,6-Penta-O-galloyl-β-d-glucose（PGG）naturally existed in many medicinal herbs and food plants such as Rhus chinensis,Paeonia suffruticosa,Paeonia lactiflora and Mango.Methods： The metabolites of PGG in rat biofluids were characterized using high performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry（HPLC-QTOF-MS）.Results： Ten metabolites in urine,five metabolites in feces and two metabolites in plasma,were observed when the rats were administrated with a single intravenous injection of PGG（20 mg/kg）.Conclusion： PGG is firstly metabolized to gallic acid,then gallic acid undergoes sulfation,glucuronidation and methylation by rat liver.The determination of metabolites and the proposed metabolic pathway of PGG in vivo will be benefit to gain deeper insights into its pharmacological activities.

Isolation of Antifungal Compound from Paeonia Suffruticosa and Its Antifungal Mechanism

Objective：To isolate antifungal compound from Paeonia suffruticosa,and to find the antifungal mechanisms by observing the ultrastructural modifications of yeasts in growth phase produced by 1,2,3,4,6-pentaO-galloyl-beta-D-glucose（PGG）.Methods：Peony（Paeonia suffruticosa） root bark（PRB） was separated by solvent extraction and purified by high performance liquid chromatography（HPLC） method using analytical and preparative reversed phase C18 column on the basis of bio-assay method.In order to investigate the antifungal mechanism of PGG,Yeasts were submitted to different concentrations[3×minimum inhibition concentration（MIC）,0.3×MIC]for 1 h under constant stirring at 30 ℃,and transmission electron microscopy was performed.Results：Based on the antifungal activity of PRB on Candida glabrata CBS138,the antifungal compound were isolated in ethyl acetate layer of PRB and identified as PGG by mass spectrometry,1H nuclear magnetic resonance（NMR） analyses,with molecular weight of 940 and molecular formular as C41H32O26.Transmission electron microscopy showed that PGG degraded the cell wall envelope.Conclusion：The results suggest that PGG may be responsible for the antifungal activity of PRB by disrupting the structure of cell wall directly.

A New Cyano-compound from Rhodiola kirilowii

Objective To study the chemical constituents of Rhodiola kirilowii.Methods The compounds were separated and purified by various chromatographic techniques and their structures were elucidated on the basis of physicochemical properties and spectroscopic methods.Results Five compounds were purified and their structures were identified as 4-(β-D-glucopyranosyloxy)-3-hydroxy-2-(hydroxymethyl)-butanenitrile(1),epicatechin(2), arbutin(3),rutin(4),andβ-D-glucose(5).Conclusion Compound 1 is a new cyano-compound and other compounds are isolated from the plant for the first time.