Broad-spectrum antiviral activity of chebulagic acid and punicalagin against viruses that use glycosaminoglycans for entry.

BACKGROUND: We previously identified two hydrolyzable tannins, chebulagic acid (CHLA) and punicalagin (PUG) that blocked herpes simplex virus type 1 (HSV-1) entry and spread. These compounds inhibited viral glycoprotein interactions with cell surface glycosaminoglycans (GAGs). Based on this property, we evaluated their antiviral efficacy against several different viruses known to employ GAGs for host cell entry. RESULTS: Extensive analysis of the tannins' mechanism of action was performed on a panel of viruses during the attachment and entry steps of infection. Virus-specific binding assays and the analysis of viral spread during treatment with these compounds were also conducted. CHLA and PUG were effective in abrogating infection by human cytomegalovirus (HCMV), hepatitis C virus (HCV), dengue virus (DENV), measles virus (MV), and respiratory syncytial virus (RSV), at µM concentrations and in dose-dependent manners without significant cytotoxicity. Moreover, the natural compounds inhibited viral attachment, penetration, and spread, to different degrees for each virus. Specifically, the tannins blocked all these steps of infection for HCMV, HCV, and MV, but had little effect on the post-fusion spread of DENV and RSV, which could suggest intriguing differences in the roles of GAG-interactions for these viruses. CONCLUSIONS: CHLA and PUG may be of value as broad-spectrum antivirals for limiting emerging/recurring viruses known to engage host cell GAGs for entry. Further studies testing the efficacy of these tannins in vivo against certain viruses are justified.

Potential antioxidant properties and hepatoprotective effects of an aqueous extract formula derived from three Chinese medicinal herbs against CCl(4)-induced liver injury in rats.

The hepatoprotective effects of an aqueous extract formula (AEF) derived from Artemisia capillaris, Lonicera japonica and Silybum marianum (ratio 1:1:1) were evaluated by its antioxidant properties and its attenuation of carbon tetrachloride (CCl(4))-induced liver damage in rats. The antioxidant analyses revealed that the AEF showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide anion radical scavenging activities as well as ferric reducing antioxidant potential (FRAP) and Trolox equivalent antioxidant capacity (TEAC) compared with the individual herbs, suggesting a synergism in antioxidation between the three herbs. The animal experiments showed that the CCl(4) treatment increased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, but decreased triglyceride (TG) and glutathione (GSH) levels as well as glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activities. However, AEF administration can successfully lower serum ALT and AST activities, restore the GSH level, ameliorate or restore GPx and CAT activities as well as improve SOD action depending on AEF dosage. Histological examination of liver showed that CCl(4) increased the extent of bile duct proliferation, necrosis, fibrosis and fatty vacuolation throughout the liver, but AEF can improve bile duct proliferation, vacuolation and fibrosis, and restore necrosis. The present study demonstrated the hepatoprotective potential of AEF as an alternative to the traditional silymarin.

Hydrolysable tannins of tropical almond show antifibrotic effects in TGF-ß1-induced hepatic stellate cells.

BACKGROUND: Persistent activation of hepatic stellate cells (HSC-T6) has been known to cause liver fibrosis. In this study, our objective was to investigate the effects of chebulagic acid and chebulinic acid, two hydrolysable tannins of tropical almond (Terminalia chebula) fruits, on collagen synthesis and signal transduction in transforming growth factor-ß1-stimulated HSC-T6 cells. The expression of Smad2, Smad3, Smad4, collagen I(α1)/III, and plasminogen activator inhibitor 1 (PAI-1) mRNAs was determined by reverse-transcription polymerase chain reaction and their protein levels were assessed by western blotting. RESULTS: Results showed that chebulagic acid and chebulinic acid at 20 µmol L(-1) exhibited cytotoxic and anti-proliferative effects on HSC-T6 cells. They also significantly decreased the expression of Smd2, Smad3 and Smad4, and the synthesis of collagen, procollagen I (α1) and III, as well as suppressing the activation of PAI-1; these events consequently facilitated the resolution of fibrosis. CONCLUSION: These results indicate that both chebulagic acid and chebulinic acid possess antifibrotic activity, and their mechanism of action could be through the inhibition of the Smad pathway.

Evaluation of the optimal strategy for ex situ bioremediation of diesel oil-contaminated soil.

PURPOSE: Bioaugmentation and biostimulation have been widely applied in the remediation of oil contamination. However, ambiguous results have been reported. It is important to reveal the controlling factors on the field for optimal selection of remediation strategy. In this study, an integrated field landfarming technique was carried out to assess the relative effectiveness of five biological approaches on diesel degradation. The limiting factors during the degradation process were discussed. METHOD: A total of five treatments were tested, including conventional landfarming, nutrient enhancement (NE), biosurfactant addition (BS), bioaugmentation (BA), and combination of bioaugmentation and biosurfactant addition (BAS). The consortium consisted of four diesel-degrading bacteria strains. Rhamnolipid was used as the biosurfactant. The diesel concentration, bacterial population, evolution of CO(2), and bacterial community in the soil were periodically measured. RESULTS: The best overall degradation efficiency was achieved by BAS treatment (90 ± 2%), followed by BA (86 ± 2%), NE (84 ± 3%), BS (78 ± 3%), and conventional landfarming (68 ± 3%). In the early stage, the total petroleum hydrocarbon was degraded 10 times faster than the degradation rates measured during the period from day 30 to 100. At the later stage, the degradation rates were similar among treatments. In the conventional landfarming, contaminated soil contained bacteria ready for diesel degradation. CONCLUSION: The availability of hydrocarbon was likely the limiting factor in the beginning of the degradation process. At the later stage, the degradation was likely limited by desorption and mass transfer of hydrocarbon in the soil matrix.

Hydrolyzable tannins (chebulagic acid and punicalagin) target viral glycoprotein-glycosaminoglycan interactions to inhibit herpes simplex virus 1 entry and cell-to-cell spread.

Herpes simplex virus 1 (HSV-1) is a common human pathogen that causes lifelong latent infection of sensory neurons. Non-nucleoside inhibitors that can limit HSV-1 recurrence are particularly useful in treating immunocompromised individuals or cases of emerging acyclovir-resistant strains of herpesvirus. We report that chebulagic acid (CHLA) and punicalagin (PUG), two hydrolyzable tannins isolated from the dried fruits of Terminalia chebula Retz. (Combretaceae), inhibit HSV-1 entry at noncytotoxic doses in A549 human lung cells. Experiments revealed that both tannins targeted and inactivated HSV-1 viral particles and could prevent binding, penetration, and cell-to-cell spread, as well as secondary infection. The antiviral effect from either of the tannins was not associated with induction of type I interferon-mediated responses, nor was pretreatment of the host cell protective against HSV-1. Their inhibitory activities targeted HSV-1 glycoproteins since both natural compounds were able to block polykaryocyte formation mediated by expression of recombinant viral glycoproteins involved in attachment and membrane fusion. Our results indicated that CHLA and PUG blocked interactions between cell surface glycosaminoglycans and HSV-1 glycoproteins. Furthermore, the antiviral activities from the two tannins were significantly diminished in mutant cell lines unable to produce heparan sulfate and chondroitin sulfate and could be rescued upon reconstitution of heparan sulfate biosynthesis. We suggest that the hydrolyzable tannins CHLA and PUG may be useful as competitors for glycosaminoglycans in the management of HSV-1 infections and that they may help reduce the risk for development of viral drug resistance during therapy with nucleoside analogues.

Excoecarianin, Isolated from Phyllanthus urinaria Linnea, Inhibits Herpes Simplex Virus Type 2 Infection through Inactivation of Viral Particles.

Phyllanthus urinaria Linnea (Euphorbiaceae) is one of the traditional medicinal plants widely used by oriental people to treat various diseases. We have previously demonstrated that the acetone extract of P. urinaria inhibits herpes simplex virus type 2 (HSV-2) but not HSV-1 infection. In a continuing effort to clarify the antiviral mechanisms of P. urinaria, we isolated the pure compound excoecarianin from the whole plant of P. urinaria through acetone extraction, and investigated its anti-HSV-1 and HSV-2 activities. Our results indicated that excoecarianin protected Vero cells from HSV-2 but not HSV-1 infection, and its 50% inhibitory concentration (IC(50)) was 1.4 ± 0.1 µM. The antiviral effective concentration of excoecarianin did not affect the viability or the morphology of Vero cells. Although excoecarianin inhibited HSV-2 infection, the inhibitory effect, however, was most prominent when excoecarianin was concurrently added with the virus. Pretreatment of Vero cells with excoecarianin with removal of the drug prior to infection did not yield any antiviral effects, and the same observation was made for post viral entry treatment. Subsequent studies revealed that excoecarianin inactivated HSV-2 virus particles to prevent viral infection. A synergistic antiviral effect against HSV-2 was also observed when Vero cells were treated with a combination of acyclovir (ACV) and excoecarianin. These results suggested that excoecarianin merits to be further explored as an entry inhibitor against HSV-2 and could potentially be investigated for combinatorial drug treatment with nucleoside analogues such as ACV in therapeutic management of HSV-2 infection.

Ex situ bioremediation of oil-contaminated soil.

An innovative bioprocess method, Systematic Environmental Molecular Bioremediation Technology (SEMBT) that combines bioaugmentation and biostimulation with a molecular monitoring microarray biochip, was developed as an integrated bioremediation technology to treat S- and T-series biopiles by using the landfarming operation and reseeding process to enhance the bioremediation efficiency. After 28 days of the bioremediation process, diesel oil (TPH(C10-C28)) and fuel oil (TPH(C10-C40)) were degraded up to approximately 70% and 63% respectively in the S-series biopiles. When the bioaugmentation and biostimulation were applied in the beginning of bioremediation, the microbial concentration increased from approximately 10(5) to 10(6) CFU/g dry soil along with the TPH biodegradation. Analysis of microbial diversity in the contaminated soils by microarray biochips revealed that Acinetobacter sp. and Pseudomonas aeruginosa were the predominant groups in indigenous consortia, while the augmented consortia were Gordonia alkanivorans and Rhodococcus erythropolis in both series of biopiles during bioremediation. Microbial respiration as influenced by the microbial activity reflected directly the active microbial population and indirectly the biodegradation of TPH. Field experimental results showed that the residual TPH concentration in the complex biopile was reduced to less than 500 mg TPH/kg dry soil. The above results demonstrated that the SEMBT technology is a feasible alternative to bioremediate the oil-contaminated soil.

Detection of filamentous genus Gordonia in foam samples using genus-specific primers combined with PCR--denaturing gradient gel electrophoresis analysis.

A nested-PCR amplification combined with denaturing gradient gel electrophoresis (PCR-DGGE) approach was used to detect and identify Gordonia populations from wastewater treatment plant foam samples. The PCR-amplified region (position 722-1119) by specifically designed primers G699F and G1096R covered the hypervariable region of the Gordonia 16S rRNA gene sequence. This approach successfully distinguished Gordonia species to the interspecies level. The differential ability of PCR-DGGE analysis was effectively used to separate 12 Gordonia species belonging to different 16S rRNA gene-based phylogenetic lineages into 8 groups. Based on this method, the minimum limit of Gordonia detection was 5 x 10(4) CFU.g -1 in the seeded soil samples. The PCR-DGGE bands obtained were excised and identified by sequence analysis. Gordonia polyisoprenivorans, Gordonia amicalis, DGGE type II Gordonia species, and an uncertain Gordonia species dominated the activated sludge foam samples. Results of this study indicate that the detection and analyses of genus Gordonia within a complex microbial community could be accomplished using the PCR-DGGE approach to a larger extent, with certain limitations. Detection of diverse Gordonia populations in foam samples from wastewater treatment plants revealed the significant role of Gordonia in biological foaming during wastewater treatment. The nested-PCR amplification and DGGE can be used as a diagnostic tool for the early detection of foaming incidents in wastewater treatment plants using Gordonia as indicator organism.

Hippomanin A from acetone extract of Phyllanthus urinaria inhibited HSV-2 but not HSV-1 infection in vitro.

Phyllanthus urinaria Linnea (Euphorbiaceae) is a commonly used traditional medicinal plant in oriental countries and has been reported to possess various biological activities. Previously, the acetone extract and some pure compounds from P. urinaria were found to suppress herpes simplex virus (HSV). In this study, another two pure compounds were isolated from acetone extract of P. urinaria and were tested for their in vitro anti-HSV-1 and HSV-2 activities. The results showed that hippomanin A impeded HSV-2 but not HSV-1 infection. Corilagin, however, inhibited neither HSV-1 nor HSV-2 replication. The similarity between corilagin and hippomanin A in structure, but difference in antiviral activity, therefore, merit further investigation.

Induction of apoptosis in human breast adenocarcinoma MCF-7 cells by pterocarnin A from the bark of Pterocarya stenoptera via the Fas-mediated pathway.

Pterocarnin A, isolated from the bark of Pterocarya stenoptera (Juylandaceae), was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. To identify the anticancer mechanism of pterocarnin A, we assayed its effects on apoptosis, cell cycle distribution, and levels of p53, p21/WAF1, Fas/APO-1 receptor and Fas ligand. The results showed that pterocarnin A induced apoptosis of MCF-7 cells without mediation of p53 and p21/WAF1. We suggest that the Fas/Fas ligand apoptotic system is the main pathway of pterocarnin A-mediated apoptosis of MCF-7 cells. Our study reports here for the first time that the activity of the Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of pterocarnin A in MCF-7 cells.

Rugosin E, an ellagitannin, inhibits MDA-MB-231 human breast cancer cell proliferation and induces apoptosis by inhibiting nuclear factor-kappaB signaling pathway.

In this study, we first report the chemopreventive effect of rugosin E in human breast cancer cell line, MDA-MB-231. Treatment with rugosin E decreased the cell proliferation of MDA-MB-231 cells in a dose-dependent manner. Rugosin E treatment arrested MDA-MB-231 cells at G0/G1 phase. This effect was strongly associated with concomitant decrease in the level of cyclin D1, cyclin D2, cyclin E, cdk2, cdk4, and cdk6, and increase of p21/WAF1. In addition, rugosin E also induced apoptotic cell death. Rugosin E increased in the expression of Bax, Bak, and Bcl-Xs, but decreased the levels of Bcl-2 and Bcl-X(L), and subsequently triggered mitochondria apoptotic pathway (release of cytochrome c, activation of caspase-9, and caspase-3). In addition, pre-treatment of cells with caspase-9 inhibitor blocked rugosin E-induced cell proliferation and apoptosis, indicating caspase-9 activation was involved in rugosin E-mediated MDA-MB-231 cells apoptosis. Rugosin E inhibited the constitutively activated and inducible NF-kappaB in both its DNA-binding activity and transcriptional activity. Furthermore, rugosin E also inhibited the TNF-alpha-activated NF-kappaB-dependent reporter gene expression of cyclin D1, c-Myc, XIAP, Bcl-2, and Bcl-X(L) were all downregulated by rugosin E. Our results indicated that rugosin E inhibits the activation of NF-kappaB, and this may provide a molecular basis for drug development in the prevention and treatment of cancer by rugosin E.

The in vitro activity of geraniin and 1,3,4,6-tetra-O-galloyl-beta-D-glucose isolated from Phyllanthus urinaria against herpes simplex virus type 1 and type 2 infection.

Phyllanthus urinaria Linnea (Euphorbiaceae) is a widely used traditional medicinal plant by oriental countries and has been reported to possess various biological activities. Previously, the acetone extract from Phyllanthus urinaria was found to inhibit herpes simplex virus (HSV) infection. In this study, geraniin and 1,3,4,6-tetra-O-galloyl-beta-D-glucose (1346TOGDG), both of which were isolated from the acetone extract of Phyllanthus urinaria, were examined for their activity against HSV-1 and HSV-2 in vitro. Results showed that geraniin actively suppressed HSV-2 infection, whereas 1346TOGDG effectively inhibited HSV-1 infection. The 50% inhibitory concentration (IC(50)) was 18.4+/-2.0 microM for geraniin against HSV-2 infection, and 19.2+/-4.0 microM for 1346TOGDG against HSV-1. No toxic effect towards the host cell was observed at the antiviral concentrations. In conclusion, geraniin and 1346TOGDG were found to inhibit HSV-1 and HSV-2 multiplication at different magnitudes of potency.

ent-Epiafzelechin-(4alpha-->8)-epiafzelechin extracted from Cassia javanica inhibits herpes simplex virus type 2 replication.

Herpes simplex virus (HSV) is a ubiquitous organism that causes infections in human populations throughout the world. It causes a variety of diseases ranging in severity from mild to life-threatening. In this study, ent-epiafzelechin-(4alpha-->8)-epiafzelechin (EEE) extracted from the fresh leaves of Cassia javanica L. agnes de Wit (Leguminosae) was investigated for its in vitro anti-HSV-2 activity using XTT and plaque reduction assays. Results showed that EEE inhibited HSV-2 replication in a dose-dependent manner. The IC50 value was 83.8 +/- 10.9 and 166.8 +/- 12.9 microM for XTT and plaque reduction assays, respectively. EEE did not affect the viability and the proliferation of cells at antiviral concentrations. Mechanistic studies demonstrated that EEE prevented HSV-2 from penetrating the cell and also interfered with HSV-2 replication at the late stage of its life cycle. It also disturbed virus attachment but the inhibitory effect was minor. In summary, the conclusion of this study was that EEE exhibits various modes of action in suppressing HSV-2 multiplication.

Putranjivain A from Euphorbia jolkini inhibits proliferation of human breast adenocarcinoma MCF-7 cells via blocking cell cycle progression and inducing apoptosis.

Putranjivain A, isolated from the whole plant of Euphorbia jolkini Bioss (Euphorbiaceae), was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. The results showed that putranjivain A inhibited the proliferation of MCF-7 by blocking cell cycle progression in the G0/G1 phase and inducing apoptosis. Enzyme-linked immunosorbent assay showed that putranjivain A increased the expression of p21/WAF1 concomitantly as MCF-7 cell underwent G0/G1 arrest. An enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by putranjivain A. Our study reports here for the first time that the induction of p21/WAF1 and the activity of Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of putranjivain A in MCF-7 cells.

Determination of 19 rhubarb constituents by high-performance liquid chromatography-ultraviolet-mass spectrometry.

Rhubarb (Rhei rhizoma), a commonly used Chinese herb, contains anthraquinones, anthrones, galloylglucoses, stilbenes, and flavan-3-ols compounds, etc. as major constituents. Using 19 of these compounds as markers, an HPLC-UV-MS method was developed to estimate the quality of rhubarb samples within a period of 70 min. Extracts were analyzed with a Cosmosil 5C18-MS column and eluted with a gradient comprising an aqueous solution of acetic acid and methanol at a flow rate of 0.9 mL/min. Peaks were detected by absorbance measurements at 254 nm (6 and 8-19) and 280 nm (1-5 and 7), and the peaks of the marker substances were identified from their UV spectra and MS fragmentation patterns. The proposed method yielded a peak-area ratio RSD value with an intraday SD falling within 0.71-1.78% and an interday SD within 0.78-1.98% at a detection limit of 0.2-3.2 microg/mL. The ESI negative ion mode was used to collect data (molecular weight, CID fragments from MS and MS/MS spectra) for 19 compounds from four types of structure categories: anthraquinones, dianthrone glycosides, stilbenes, and galloylglucosides. The information gathered can be used to identify the structures of various peaks appearing in the LC chromatograms of rhubarb samples.

Characterization of floating activity of indigenous diesel-assimilating bacterial isolates.

Six diesel-degrading bacterial strains were isolated from oil-polluted sites located in central Taiwan. The floating activity of the isolates in an oil-supplemented liquid medium was monitored. Cell-surface hydrophobicity as well as cell-free and cell-residue emulsification activities were also investigated. Three isolates, identified as Gordonia alkanivorans CC-JG 39, Rhodococcus erythropolis CC-BC 04, and R. erythropolis CC-BC 11, were found to float and grow near the diesel layer on the surface. The other three isolates (namely, Comamonas testosteroni CC-CF3, Acinetobacter sp. CC-CF 5, and Sphingomonas yanoikuyae CC-CG 22) did not display floating activity, as they distributed uniformly in the liquid medium. Isolated cell walls of the floating strains appeared to settle at a lower sucrose density than the non-floating strains. The floating strains were also characterized by a higher cell-surface hydrophobicity and a higher cell-residue emulsification activity than the non-floating strains. In fact, the floating strains were thought to produce extracellular emulsifiers due to their higher supernatant emulsification activity than the non-floating strains. The floating activity of G. alkanivorans CC-JG 39 may be associated with the production of extracellular polymeric substances that formed an "air-bag" structure facilitating cell floating. The floating ability may also correlate with a high cellular hydrophobicity arising from unique cell wall compositions or cell-wall-bound surface active products.

Acetone, ethanol and methanol extracts of Phyllanthus urinaria inhibit HSV-2 infection in vitro.

Phyllanthus urinaria Linnea (Euphorbiaceae) is one of the traditional medicinal plants that are widely applied by oriental people, especially by Chinese and Indian, to ameliorate various kinds of ailments. Many biological activities, including anti-hepatitis B virus, anti-Epstein-Barr virus and anti-retroviral reverse transcriptase, of P. urinaria have been reported, but not against herpes simplex virus (HSV). In this study, the anti-HSV-1 and HSV-2 activities of different solvents extracted from P. urinaria were investigated in vitro by plaque reduction assay. Results showed that acetone, ethanol and methanol extracts of P. urinaria inhibited HSV-2 but not HSV-1 infection. The 50% inhibitory concentration against HSV-2 infection (IC50) of acetone, ethanol and methanol extracts was 4.3 +/- 0.5, 5.0 +/ -0.4 and 4.0 +/- 0.9 mcg/ml, respectively. All three extracts showed no cytotoxic effect against Vero cells at concentrations of 10.0 mcg/ml or below. The time-of-addition study demonstrated that these three extracts were only effective when added during the HSV-2 infection which, therefore, suggested that they disturb the initial stage of HSV-2 infection. Furthermore, they can diminish virus infectivity without significantly affecting incubation time and temperature. Therefore, the acetone, ethanol and methanol extracts of P. urinaria were concluded to likely inhibit HSV-2 infection through disturbing the early stage of virus infection and through diminishing the virus infectivity.

Euphorbia thymifolia suppresses herpes simplex virus-2 infection by directly inactivating virus infectivity.

1. The ethyl acetate (EtOAc) extract and 3-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-d-glucose (3OG46HG) of Euphorbia thymifolia Linnea have been shown to exhibit anti-herpes simplex virus (HSV)-2 activity in vitro. In the present study, we investigated the mode of action of these two compounds in suppressing HSV-2 multiplication. 2. The results demonstrated that the EtOAc extract and 3OG46HG affected virus infectivity in a dose-dependent manner. The EtOAc extract significantly reduced virus infectivity at a concentration of 4.0 microg/mL, whereas 3OG46HG obviously diminished virus infectivity at concentration of a 0.5 microg/mL. The virucidal ability of the EtOAc extract was affected by the incubation period, but not by the incubation temperature. In the case of the action of 3OG46HG against HSV-2, the effects of incubation time and temperature were negligible. 3. In summary, the EtOAc extract and 3OG46HG of E. thymifolia are concluded to inhibit HSV-2 multiplication by reducing virus infectivity.

Induction of cell cycle arrest and apoptosis in human non-small cell lung cancer A549 cells by casuarinin from the bark of Terminalia arjuna Linn.

Casuarinin, a hydrolyzable tannin isolated from the bark of Terminalia arjuna Linn. (Combretaceae), inhibits human non-small cell lung cancer A549 cells by blocking cell cycle progression in the G0/G1 phase and inducing apoptosis. Enzyme-linked immunosorbent assay showed that the G0/G1 phase arrest is due to p53-dependent induction of p21/WAF1. An enhancement in Fas/APO-1 and the two forms of Fas ligand (FasL), membrane-bound FasL and soluble FasL, might be responsible for the apoptotic effect induced by casuarinin. Our study reports here for the first time that the induction of p53 and the activity of the Fas/FasL apoptotic system may participate in the antiproliferative activity of casuarinin in A549 cells.

Casuarinin from the bark of Terminalia arjuna induces apoptosis and cell cycle arrest in human breast adenocarcinoma MCF-7 cells.

Casuarinin, a hydrolyzable tannin isolated from the bark of Terminalia arjuna L. (Combretaceae), was investigated for its antiproliferative activity in human breast adenocarcinoma MCF-7 cells. The results showed that casuarinin inhibited the proliferation of MCF-7 by blocking cell cycle progression in the G0/G1 phase and inducing apoptosis. An enzyme-linked immunosorbent assay showed that casuarinin increased the expression of p21/WAF1 concomitantly as the MCF-7 cells underwent G0/G1 arrest. An enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by casuarinin. Our study reports here for the first time that the induction of p21/WAF1 and the activity of Fas/Fas ligand apoptotic system may participate in the antiproliferative activity of casuarinin in MCF-7 cells.