ABSTRACT
Physalin B (PB), one of the major active steroidal constituents of Solanaceae Physalis plants, has a wide variety of biological activities. We found that PB significantly down-regulated β-amyloid (Aβ) secretion in N2a/APPsw cells. However, the underlying mechanisms are not well understood. In the current study, we investigated the changes in key enzymes involved in β-amyloid precursor protein (APP) metabolism and other APP metabolites by treating N2a/APPsw cells with PB at different concentrations. The results indicated that PB reduced Aβ secretion, which was caused by down-regulation of β-secretase (BACE1) expression, as indicated at both the protein and mRNA levels. Further research revealed that PB regulated BACE1 expression by inducing the activation of forkhead box O1 (FoxO1) and inhibiting the phosphorylation of signal transducer and activator of transcription 3 (STAT3). In addition, the effect of PB on BACE1 expression and Aβ secretion was reversed by treatment with FoxO1 siRNA and STAT3 antagonist S3I-201. In conclusion, these data demonstrated that PB can effectively down-regulate the expression of BACE1 to reduce Aβsecretion by activating the expression of FoxO1 and inhibiting the phosphorylation of STAT3.
Subject(s)
Humans , Alzheimer Disease , Amyloid Precursor Protein Secretases/metabolism , Amyloid beta-Peptides/metabolism , Aspartic Acid Endopeptidases/metabolism , Down-Regulation , Forkhead Box Protein O1/genetics , Phosphorylation , STAT3 Transcription Factor/metabolism , SecosteroidsABSTRACT
Objective To investigate the steroidal chemical constituents from the whole plants of Physalis minima. Methods The chemical constituents were isolated and purified by repeated silica gel column chromatography, Sephadex LH-20 gel column chromatography, medium pressure ODS column chromatography and semi-preparative HPLC, and their structures were elucidated on the basis of physico-chemical properties and spectral analysis. Results Seven compounds were separated from the whole plant of P. minima, among them, two compounds were identified as physalins and named as 16,24-cyclo-13,14-secoergost-2-ene-18,26- dioicacid-14:17,14:27-diepoxy-5α,6β,13α,20α,22β,25β-hexahydroxy-1,15-dioxo-γ-lactone-δ-lactone (1) and physalin D (2); The other five compounds were identified as withanlides and named as physagulin L (3), physagulin M (4), physaminimin F (5), physagulin K (6), and withagulatin A (7). Conclusion Compound 1 is a new compound named 25-hydroxy-physalin D, at the same time, compounds 3, 4, and 7 were obtained from this plant for the first time.
ABSTRACT
Objective: To investigate the chemical constituents from whole herb of Physalis angulata and test their cytotoxic activity. Methods: Compounds were isolated by chromatography methods and LC-MS guided analysis, structures were determined by spectroscopic techniques of 1D- and 2D-NMR (HSQC, HMBC, 1H-1H COSY, and NOESY), cytotoxic activity experiments were conducted by MTT method. Results: Twelve compounds were identified as physalins A (1), B (2), C (3), D (4), F (5), H (6), I (7), O (9), 5α-ethoxy-6β-hydroxy-5,6-dihydrophysalin B (8), β-sitosterol (10), 2-carboxyoxanilic acid methyl ester (11), and acetaminobenzoic acid (12). Conclusion: Among these compounds, compound 11 is a new natural product. Compounds 1-3 and 9 are firstly obtained from P. angulata. All compounds are tested for their inhibitory activities against human lung adenocarcinoma strain A-549, with IC50 values of 1.9-20.2 μmol/L, which indicates good cytotoxic activity of these physalins.
ABSTRACT
Objective To study the in-vitro anti-tumor activities of physalin B (PhB) extracted from Physalis angulata L.. Methods Th e effect of PhB on the cell proliferation and the morphology changes of tumor cell strains HepG2 and SGC7901 was observed by methyl thiazolyl tetrazolium (MTT) assay and by phase contrast microscopy respectively, and the results were compared to positive control anti-cancer drug hydroxycamptothecine (HCTP) . Apoptosis of HepG2 and SGC7901 cells induced by PhB was determined by 4’ , 6-diamidino-2-phenylindole ( DAPI) staining method. Results MTT results showed that the growth of HepG2 and SGC7901 was significantly inhibited by PhB in dose-and time-dependent manner, and the inhibitory effect of high concentration of PhB was better than the positive control medicine HCTP. Phase contrast microscopy results showed that the cellular morphology was improved by PhB, which was accorded with the results showed by MTT assay. DAPI staining results showed that the apoptosis of HepG2 and SGC7901 was enhanced by PhB. Conclusion PhB extracted from Physalis pubescens L. exerts certain inhibitory effect on the proliferation of HepG2 and SGC7901 cells.
ABSTRACT
OBJECTIVE: To study the chemical constituents of whole plant of Physalis angulata L. METHODS: The constituents were isolated and purified by chromatographic methods and their structures were elucidated by spectroscopic methods and physio-chemical analysis. RESULTS: Thirteen known compounds was isolated and identified as physalin A (1), physalin B (2), physalin E (3), physalin P(4), stigmast-5-en-3β-ol (5), ergost-5, 24 (28) -diene-3β-ol (6), brassicaaterol (7), stigmasta-22-en-3, 6-dione (8), pregn-5-en-3-ol-20-carboxylic acid (9), ergost-5, 24 (28)-diene-3β, 23S-diol (10), ergosta-5, 25 (26)-diene-3, 24ξ-diol(11), n-hexade-canoic acid (12), and n-heptadecanoic acid (13). CONCLUSION: All of the compounds except 2 and 3 are isolated from this plant for the first time, and compounds 5-10 and 12-13 are isolated from Physalis for the first time.
ABSTRACT
Objective: To investigate the chemical constituents in persistent calyx of Physalis alkekengi var. franchetii. Methods: Various colume chromatographies over silica gel, Sephadex LH-20, and HPLC were used to separate the chemical constituents and their structures were elucidated by physicochemical property, 1H-NMR, 13C-NMR, and MS. Results: Four chemical constituents were obtained and identified as caffeic acid ethyl ester (1), 25, 27-dehydro-physalin L (2), physalin D (3), and cuneataside E (4). Conclusion Compound 2 is a new natural product, and compound 4 is isolated from the plant for the first time.
ABSTRACT
Objective To study the active constituents of Physalis alkekengi var. franchetii MethodsThe compounds were separated by silica gel and Sephadex LH-20 chromatography method, their structures were identified on the spectral analyses and physical data. Results Eleven compounds were isolated and identified as ?-sitosterol (Ⅰ), physalin A (Ⅱ), physalin B (Ⅲ), physalin O (Ⅳ), physalin L (Ⅴ), physalin M (Ⅵ), daucosterol (Ⅶ), ombuine (Ⅷ), 5, 4′, 5′-trihydroxy-7, 3′-dimethoxy-flavonol (Ⅸ), luteolin (Ⅹ), and luteolin-7-O-?-D-glucopyranoside (Ⅺ). Conclusion Compound Ⅸ is a new compound named physaflavonol.