Efficacy of ramosetron in the treatment of male patients with irritable bowel syndrome with diarrhea: a multicenter, randomized clinical trial, compared with mebeverine

BACKGROUND

The 5-HT(3) receptor antagonists are known to be effective for the treatment of diarrhea-predominant irritable bowel syndrome (IBS), but not widely used yet. The aim of this study was to compare the efficacy and safety of ramosetron, a 5-HT(3) receptor antagonist, and mebeverine in male patients with IBS with diarrhea (IBS-D).

METHODS

This study was performed in a multicenter, randomized, open-label design. Data of 343 male patients with IBS-D who were randomized to either a 4-week treatment of ramosetron 5μg once daily or a 4-week treatment of mebeverine 135 mg three times daily were analyzed by the intent-to-treat analysis. The primary efficacy parameter was the proportion of patients with adequate relief of IBS symptoms at the last week of treatment. The secondary endpoints were changes in each symptom score and the safety profiles.

KEY RESULTS

The responder rates for global IBS symptoms, abdominal pain/discomfort and abnormal bowel habits in the ramosetron and mebeverine groups significantly increased during the treatment period. The severity scores of abdominal pain/discomfort and urgency, the stool form score, and the stool frequency in both treatment arms were significantly reduced, compared with the baselines. There were no significant differences in the responder rates (37%vs 38% on ITT analysis) and adverse event profiles between the ramosetron and mebeverine groups. Neither severe constipation nor ischemic colitis was reported by ramosetron-treated patients.

CONCLUSIONS & INFERENCES

Ramosetron 5μg once daily is as effective as mebeverine three times daily in male patients with IBS-D.

A novel OmpY porin from Yersinia pseudotuberculosis: structure, channel-forming activity and trimer thermal stability

A novel OmpY porin was predicted based on the Yersinia pseudotuberculosis genome analysis. Whereas it has the different genomic annotation such as "outer membrane protein N" (ABS46310.1) in str. IP 31758 or "outer membrane protein C2, porin" (YP_070481.1) in str. IP32953, it might be warranted to rename the OmpN/OmpC2 to OmpY, "outer membrane protein Y", where letter "Y" pertained to Yersinia. Both phylogenetic analysis and genomic localization clearly support that the OmpY porin belongs to a new group of general bacterial porins. The recombinant OmpY protein with its signal sequence was overexpressed in porin-deficient Escherichia coli strain. The mature rOmpY was shown to insert into outer membrane as a trimer. The OmpY porin, isolated from the outer membrane, was studied employing spectroscopic, electrophoretic and bilayer lipid membranes techniques. The far UV CD spectrum of rOmpY was essentially identical to that of Y. pseudotuberculosis OmpF. The near UV CD spectrum of rOmpY was weaker and smoother than that of OmpF. The rOmpY single-channel conductance was 180 ± 20 pS in 0.1 M NaCl and was lower than that of the OmpF porin. As was shown by electrophoretic and bilayer lipid membrane experiments, the rOmpY trimers were less thermostable than the OmpF trimers. The porins differed in the trimer-monomer transition temperature by about 20°C. The three-dimensional structural models of the Y. pseudotuberculosis OmpY and OmpF trimers were generated and the intra- and intermonomeric interactions stabilizing the porins were investigated. The difference in the thermal stability of OmpY and OmpF trimers was established to correlate with the difference in intermonomeric polar contacts.

Various Quantum- and Nano-Structures by III-V Droplet Epitaxy on GaAs Substrates

We report on various self-assembled In(Ga)As nanostructures by droplet epitaxy on GaAs substrates using molecular beam epitaxy. Depending on the growth condition and index of surfaces, various nanostructures can be fabricated: quantum dots (QDs), ring-like and holed-triangular nanostructures. At near room temperatures, by limiting surface diffusion of adatoms, the size of In droplets suitable for quantum confinement can be fabricated and thus InAs QDs are demonstrated on GaAs (100) surface. On the other hand, at relatively higher substrate temperatures, by enhancing the surface migrations of In adatoms, super lower density of InGaAs ring-shaped nanostructures can be fabricated on GaAs (100). Under an identical growth condition, holed-triangular InGaAs nanostructures can be fabricated on GaAs type-A surfaces, while ring-shaped nanostructures are formed on GaAs (100). The formation mechanism of various nanostructures can be understood in terms of intermixing, surface diffusion, and surface reconstruction.

Size and density control of In droplets at near room temperatures

We report on the ability to control the size and density of In droplets on GaAs(100) substrates at near room temperatures using solid source molecular beam epitaxy. We specifically demonstrate the height, diameter and density control of In droplets as functions of substrate temperature (T(sub)) and monolayer (ML) coverage. For a range of density (approximately 10(9)-10(10) cm(-2)), the growth window is revealed to be between 20 and 70 degrees C. For a fixed ML coverage, the size and density of droplets can be controlled by controlling the T(sub). For a fixed T(sub), by controlling the ML coverage, droplet size and density can be controlled. Even at near room temperatures (20-70 degrees C), In atoms are extremely sensitive to surface diffusion and this enables the control of the size and density of droplets. This study provides an aid to understanding the formation of In droplets at near room temperatures and can find applications in the formation of quantum structures and/or nanostructures based on droplet epitaxy.

Transmissible infection of human 293T cells with porcine endogenous retroviruses subgroup a from NIH-miniature pig

In pig-to-human xenotransplantation, zoonotic infections have been an important barrier. The risk of zoonosis has been emphasized in xenotransplantation after finding that porcine endogenous retroviruses (PERVs) can infect human cells in vitro. Until now, transmissions of PERVs from PK15 cells have been studied in vitro and in vivo, but transmission of PERVs originating from miniature pigs have not been extensively reported. Peripheral blood mononuclear cells from miniature swine showed PERV transmission to human cells. In contrast, specific pathogen-free (SPF) pig islet cells showed no PERV transmission when co-incubated with 293T cells. To evaluate the risk of zoonosis with our experimental mini pigs, we tested the infectivity of PERVs from NIH-miniature pig primary ear cells for human 293T cells. As a result, all subgroups of infectious PERV virion (PERV-A, -B, and -C) were detected in the primary cell culture media. Unlike PERV-C, PERV-A and -B infected human 293T cells. Interestingly, only proviral PERV-A replicated in 293T cells to produce virions after infection. Our results suggested that a prevention study of PERV xenotransmission from experimental miniature pigs should concentrate on PERV-A control.

Roles of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase in apoptosis of human monoblastic leukemia U937 cells by lectin-II isolated from Korean mistletoe

The mitogen-activated protein kinase (MAPK) family members have been implicated in cell survival. We have previously demonstrated that cytotoxic lectin-II isolated from Korean mistletoe induces apoptotic cell death in the human monoblastic leukemia cell line, U937, via the activation of the stress-activated protein kinases/c-Jun N-terminal kinase (SAPK/JNK). In the present study, the roles of extracellular signal-regulated kinases (ERK1/2) and p38 MAPK in lectin-II-induced apoptosis have been investigated. Treatment of U937 cells with lectin-II resulted in apoptotic DNA fragmentation, which was preceded by the activation of ERK1/2, p38 MAPK and SAPK/JNK. This lectin-II-induced DNA fragmentation was significantly enhanced when ERK1/2 activation was selectively inhibited by PD098059. 12-O-tetradecanoylphorbol-13-acetate, which stimulates ERK activity in U937 cells, markedly reduced lectin-II-induced DNA fragmentation. Inhibition of p38 MAPK activity with p38-specific inhibitor, SB203580, partially inhibited lectin-II-induced DNA fragmentation. These results suggest that ERK1/2 and p38 MAPK may have opposite effects on cell survival in response to cytotoxic mistletoe lectin-II, which may contribute to the modulation of lectin-II-mediated cytotoxic activity.

Effect of rebamipide in treatment of Helicobacter pylori-associated duodenal ulcer: attenuation of chemokine expression and nitrosative damage

Production of cytokines along with increased activity of nitric oxide synthase has been implicated as one of the contributing mechanisms of Helicobacter pylori-mediated gastroduodenal diseases. We aimed to evaluate the effect of rebamipide in treating Helicobacter pylori-associated duodenal ulcers in terms of cytokine production and nitrosative damage of the gastric mucosa. In patients with duodenal ulcers, rebamipide or placebo were given randomly after eradication. Mucosal cytokine production was measured by enzyme linked immunoassay, and nitrotyrosine immunoexpression was measured by immunohistochemistry. The inflammatory activity and degree of neutrophil infiltration were graded accordingly. The mucosal production of RANTES, interleukin-8, and TNF-alpha showed a significant decrease after eradication in patients with rebamipide after-treatment. The nitrotyrosine immunoreactivity of gastric epithelium was significantly decreased in the rebamipide group. Rebamipide treatment after eradication resulted in a significant reduction in chemokine production along with nitrotyrosine immunoexpression in Helicobacter pylori-associated duodenal ulcers.

Diarylheptanoids with free radical scavenging and hepatoprotective activity in vitro from Curcuma longa

Assay-guided fractionation of the EtOAc soluble fraction of the rhizomes of Curcuma longa furnished three DPPH free radical scavenging diarylheptanoids, curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3). Compounds 1-3 showed the DPPH radical scavenging effects with IC(50) values of 2.8, 39.2, 308.7 microM, respectively. L-Ascorbic acid and resveratrol as positive controls exhibited IC(50) values of 22.5 and 25.0 microM, respectively. Compounds 1-3 showed significant hepatoprotective effects on tacrine-induced cytotoxicity in human liver-derived Hep G2 cells. The EC(50) values of 1-3 are 86.9, 70.7, and 50.2 microM, respectively. Silybin (EC(50) = 69.0 microM) and silychristin (EC(50) = 82.7 microM) were used as positive controls.

High prevalence and seasonality of cryptosporidiosis in a small rural village occupied predominantly by aged people in the Republic of Korea

The prevalence of Cryptosporidium parvum infection and its seasonality were studied in a small rural village occupied predominantly by aged people in Hwasun-gun, Chollanam-do, Republic of Korea. Fecal samples were collected monthly from November 1996 to October 1997 and examined for enteric parasites. To detect oocysts of C. parvum, the modified acid-fast stain was applied. To determine effects of climatic factors, local weather reports were collected. The overall oocyst prevalence during 1 year was 57.0% (77 of 135), and was significantly higher (P < 0.0001) in aged people--those aged 50-59 years (80.0%) and those aged 60-69 years (69.0%)--than in younger groups. No significant difference (P > 0.05) was noted between men and boys (53.6%) and women and girls (59.5%), but significant (P < 0.05) household clustering was recognized. People aged > 50 years tended to be more repeatedly positive than people in the younger group. The rate varied monthly from 7.8 to 20.0% (average, 12.6%), with significantly higher (P < 0.05) rates in spring than in summer and winter months. This seasonality had little relation with temperature (r = 0.04), but a weak correlation was found with rainfall (r = 0.4). It is of special interest that cryptosporidiosis is highly endemic among the aged population.

Seroepidemiological study of Helicobacter pylori infection in asymptomatic people in South Korea

BACKGROUND

Helicobacter pylori infection occurs throughout the world and causes gastroduodenal diseases in all age groups. The prevalence of H. pylori infection varies between countries and races. The aim of this study was to evaluate the seroprevalence of H. pylori infection in asymptomatic healthy people in South Korea.

METHODS

From March 1998 to October 1998, 5732 asymptomatic subjects who responded to the self-assessment questionnaires from 54 hospitals in South Korea were enrolled in this study. The serum levels of antibodies for H. pylori immunoglobulinG were measured by using an ELISA test.

RESULTS

The overall seroprevalence of H. pylori infection was 46.6% and there was no statistical difference between males (47.2%) and females (45.9%). In adults, a significant difference was observed between genders. According to the geographic areas, the high prevalent provinces were Kangwon (53.4%), Cheju (52.9%) and Cholla province (50.6%); Seoul (41.9%) was the lowest prevalent area. The seroprevalence increased with age and was highest when patients were aged in their 40s (78.5%). The characteristic feature of our study was that the infection rate was steeply increased in three age groups (10-12 year olds, 16-19 year olds and those aged in their 20s). In Seoul, there was no difference in the prevalence rate among the districts studied.

CONCLUSIONS

This nation-wide seroprevalence of H. pylori infection in South Korea was 46.6%, which showed the transition from a developing country to a developed country. More studies on the epidemiological factors and the route of transmission of H. pylori infection should be warranted.

4-Acetyl-12,13-epoxyl-9-trichothecene-3,15-diol isolated from the fruiting bodies of Isariajaponica Yasuda induces apoptosis of human leukemia cells (HL-60)

The fruiting bodies of Isaria fungi have been traditionally used in Korea to treat cancer. An apoptosis-inducing compound, 4-acetyl-12,13-epoxyl-9-trichothecene-3,15-diol, was isolated from the methanol extract of fruiting bodies of Isaria japonica Yasuda by bioassay-guided fractionation. The apoptosis of the human leukemia cells (HL-60) by the compound was accessed by propidium iodide-staining flow cytometric analysis, and apoptosis-inducing activity at IC50 concentration (10 nmol/l) was further confirmed by a nuclear morphological change, a ladder pattern of internucleosomal DNA fragmentation, and an activation of caspase-3.

Effect of an extract of the root of Scutellaria baicalensis and its flavonoids on aflatoxin B1 oxidizing cytochrome P450 enzymes

The inhibition of aflatoxin B1 (AFB1) metabolism by a water extract of the root of Scutellaria baicalensis and its flavonoids was examined in liver microsomes. AFB1 is known to be metabolized to aflatoxin M1 (AFM1), aflatoxin Q1 (AFQ1), and AFB1-8,9-epoxide (AFBO). The water extract potently inhibited the production of AFM1 by cytochrome P450 (CYP)1A1/2 and slightly reduced AFBO formation by CYP1A1/2, CYP2B1, CYP2C11 and CYP3A1/2 in TCDD-treated rat liver microsomes. IC50 values for AFM1 and AFBO formation were 6.8 and 122.4 microg/ml, respectively. Wogonin showed the highest inhibitory activity towards AFM1 formation among the flavonoids isolated from the extract. On the other hand, the extract had no effects on the formation of AFBO and AFQ1 in human liver microsomes, and on the activities of CYP2B1, CYP2C11 and CYP3A1/2 which were detected by hydroxylation patterns of testosterone. These results demonstrated that the extract of the root of Scutellaria baicalensis has a specific inhibitory effect on CYP1A1/2 among CYP enzymes involved in AFB1 metabolism by rat and human microsomes.

Inhibitory effects of methanol extract of Cyperus rotundus rhizomes on nitric oxide and superoxide productions by murine macrophage cell line, RAW 264.7 cells

The rhizomes of Cyperus rotundus (C. rotundus) have been used in oriental traditional medicines for the treatment of stomach and bowel disorders, and inflammatory diseases. Nitric oxide (NO) and superoxide (O2-) are important mediators in the pathogenesis of inflammatory diseases. This study was undertaken to address whether the metanol (MeOH) extract of rhizomes of C. rotundus could modulate NO and O2- productions by murine macrophage cell line, RAW 264.7 cells. The MeOH extract of rhizomes of C. rotundus showed the inhibition of NO production in a dose-dependent manner by RAW 264.7 cells stimulated with interferon-gamma plus lipopolysaccharide. The inhibition of NO production by the extract was due to the suppression of iNOS protein, as well as iNOS mRNA expression, determined by Western and Northern blotting analyses, respectively. In addition, the MeOH extract suppressed the production of O2- by phorbol ester-stimulated RAW 264.7 cells in dose- and time-dependent manners. Collectively, these results suggest that the MeOH extract of rhizomes of C. rotundus could be developed as anti-inflammatory candidate for the treatment of inflammatory diseases mediated by overproduction of NO and O2-.

The aqueous extract of Rhodiola sachalinensis root enhances the expression of inducible nitric oxide synthase gene in RAW264.7 macrophages

In the present study, we examined the effects of the aqueous extract of Rhodiola sachalinensis root (RSE) on the expression of inducible nitric oxide (NO) synthase (iNOS) gene in RAW264.7 macrophages. RSE synergistically increased NO synthesis in interferon-gamma-primed macrophages. Reverse transcriptase polymerase chain reaction and Northern blotting analysis revealed that RSE may provide a second triggering signal for the synergistic induction of iNOS mRNA expression. Thus, iNOS-mediated NO synthesis in response to RSE may be one mechanism whereby this herbal medicine elicits its therapeutic effects.

Binocularity and spatial frequency dependence of calcarine activation in two types of amblyopia

OBJECTIVE AND BACKGROUND

Strabismus and anisometropia early in life frequently causes monocular amblyopia. Activation of the visual cortex is compared between the two types of amblyopia to elucidate differences in the pathogenetic mechanism of the disease.

METHODS

Using an EPI gradient echo sequence in 1.5T MRI, calcarine activation by monocular viewing of checkerboard patterns with reversal was examined in terms of binocularity of the activation and dependence on the spatial frequency of the stimuli.

RESULTS

First, the proportion of voxels activated by both normal and amblyopic eye monocular stimulations is lower in the strabismic group than in the anisometropic group. Second, the activation by higher-spatial-frequency stimuli is reduced in the anisometropic group, but not in the strabismic group.

CONCLUSIONS

These findings from the human visual cortex are consistent with the view proposed based on animal research that the loss of binocular interaction and the undersampling of high-spatial-frequency components of visual stimuli are each one of the underlying changes in strabismic and anisometropic amblyopia, respectively.

Butein, a plant polyphenol, induces apoptosis concomitant with increased caspase-3 activity, decreased Bcl-2 expression and increased Bax expression in HL-60 cells

In the present study we have investigated whether butein could induce apoptosis in human leukaemic HL-60 cells. The treatment of HL-60 cells with butein induced apoptotic cell death as determined by morphological and biochemical changes. Apoptotic DNA fragments in the butein-treated HL-60 cells were increased gradually as determined by flow cytometric analysis. The caspase-3 activity was increased during butein-induced apoptosis. However, caspase-3 inhibitor abrogated the butein-induced DNA fragmentation. Furthermore, the treatment of HL-60 cells with butein decreased the expression of Bcl-2 protein, but increased the expression of Bax protein. These results suggest that butein-induced apoptosis is mediated through the activation of caspase-3 and it is associated with changed expression of Bcl-2 and Bax proteins.

Capsazepine, a vanilloid receptor antagonist, inhibits the expression of inducible nitric oxide synthase gene in lipopolysaccharide-stimulated RAW264.7 macrophages through the inactivation of nuclear transcription factor-kappa B

High amounts of nitric oxide (NO) production following the induction of inducible NO synthase (iNOS) gene expression has been implicated in the pathogenesis of inflammatory diseases. Capsaicin, a vanilloid receptor agonist, is known to have an inhibitory effect on NO production in macrophages. In the present study, we have found that capsazepine (CAPZ), a vanilloid receptor antagonist, also inhibited NO and iNOS protein syntheses induced by lipopolysaccharide in RAW264.7 macrophages via the suppression of iNOS mRNA. The mechanistic studies showed that CAPZ inhibited the expression of iNOS mRNA through the inactivation of nuclear transcription factor-kappa B (NF-kappa B). Thus, capsazepine may be a useful candidate for the development of a drug to treat inflammatory diseases related to iNOS gene overexpression.

Induction of granulocytic differentiation in acute promyelocytic leukemia cells (HL-60) by water-soluble chitosan oligomer

Water-soluble chitosan oligomer (WSCO) has been reported to have anticancer activity, immuno-enhancing effect and antimicrobial activity. However, other biological activities are unknown. Herein, we have shown that WSCO is able to inhibit proliferation of human leukemia HL-60 cells and induce these cells to differentiate. Treatment with WSCO for 4 days resulted in a concentration-dependent reduction in HL-60 cell growth as measured by cell counting and MTT assay. This effect was accompanied by a marked increase in the proportion of G(0)/G(1) cells as measured by flow cytometry. WSCO also induced differentiation of the cells as measured by phorbol ester-dependent reduction of NBT, morphological changes as examined by Wright-Giemsa staining and expression of CD11b but not of CD14 as analysed by flow cytometry, indicating differentiation of HL-60 cells toward granulocyte-like cells. A combination of low dose of WSCO with all-trans retinoic acid, a differentiating agent toward granulocyte-like cells, exhibited a synergistic effect on the differentiation. In addition, treatment of HL-60 cells with WSCO for 6 or 8 days resulted in the induction of apoptosis as assayed qualitatively by agarose gel electrophoresis and quantitatively by Annexin V technique using flow cytometry. Collectively, there is a potential for WSCO in the treatment of myeloid leukemia.

Rhodiola sachalinesis induces the expression of inducible nitric oxide synthase gene by murine fetal hepatocytes (BNL CL.2)

We have examined the effect of the aqueous extract of Rhodiola sachalinensis root (RSE), a traditional herbal medicine, on nitric oxide (NO) synthesis in murine fetal hepatocytes (BNL CL.2) by measuring the stable end-product nitrite and the mRNA of inducible NO synthase (iNOS). Interferon-gamma (IFN-gamma) by itself failed to induce NO synthesis in BNL CL.2 cells. RSE also did not elicit NO synthesis at concentrations up to 1,000 microg/ml, but dose- and time-dependently induced NO synthesis in the presence of IFN-gamma in BNL CL.2 cells. Whereas RSE or IFN-gamma failed to induce detectable levels of iNOS mRNA, a combination of RSE and IFN-gamma markedly induced iNOS mRNA in BNL CL.2 cells. Thus, we found that RSE triggered IFN-gamma-primed BNL CL.2 cells to synthesize NO by inducing iNOS gene expression. The capability of RSE to induce NO synthesis might be related to the therapeutic efficacy of RSE on the liver diseases.

Inhibitory effects of butanol fraction of the aqueous extract of Forsythia koreana on the nitric oxide production by murine macrophage-like RAW 264.7 cells

The aim of this study was to investigate the effect of butanol fraction of the aqueous extract of Forsythia koreana fruits on the nitric oxide (NO) production and inducible nitric oxide synthesis (iNOS) gene expression in murine macrophage-like RAW 264.7 cells. Butanol fraction alone affected neither NO production nor iNOS gene expression in macrophage-like RAW 264.7 cells. However, the butanol fraction inhibited NO production and iNOS gene expression in RAW 264. 7 cells stimulated with interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS). These findings suggest that inhibition of NO production by this butanol fraction in RAW 264.7 cells stimulated with IFN-gamma plus LPS was due to the suppression of iNOS gene expression.

Synergistic cooperation between water-soluble chitosan oligomers and interferon-gamma for induction of nitric oxide synthesis and tumoricidal activity in murine peritoneal macrophages

The effects of water-soluble chitosan oligomers (WSCO) on the synthesis of nitric oxide (NO) by murine peritoneal macrophages and on macrophage-mediated cytotoxicity towards murine fibrosarcoma Meth A cells were investigated. WSCO alone had no effect on NO synthesis and killing of tumor cells. However, treatment of macrophages with a combination of WSCO and interferon-gamma (IFN-gamma) synergically increased NO synthesis and enhanced killing of tumor cells. The synergism between IFN-gamma and WSCO in NO synthesis and tumoricidal activity was mainly dependent on increased secretion of tumor necrosis factor-alpha by WSCO.

Pentoxifylline potentiates nitric oxide production in interleukin-1beta-stimulated vascular smooth muscle cells through cyclic AMP-dependent protein kinase A pathway

In the present study, we observed that pentoxifylline (PTX) significantly augmented the nitric oxide (NO) production and the iNOS gene expression by interleukin-1beta (IL-1beta)-stimulated vascular smooth muscle cells (VSMCs). The enhancing effects of PTX on the IL-1beta-induced NO production was associated with an increased intracellular cyclic AMP (cAMP) levels, and the synergistic effects of PTX on the IL-1beta-induced NO production was blocked by cAMP-dependent protein kinase A (PKA) inhibitors. PKA inhibitors, KT5720 and H89, markedly decreased the augmented expression of iNOS gene whereas ODQ, a soluble guanylate cyclase inhibitor, did not affect the enhancing effect. In addition, the pretreatment with KT5720 or H89 abolished the increased translocation of the p65 subunit of NF-kappaB into the nucleus by PTX in the IL-1beta-stimulated VSMCs. These results suggest that enhancing effects of PTX on the iNOS gene expression in the IL-1beta-stimulated VSMCs is mediated predominantly through the activation of NF-kappaB via cAMP-dependent PKA pathway.

Lavandulylflavonoids: a new class of in vitro apoptogenic agents from Sophora flavescens

The root of Sophora flavescens has been reported to possess antitumor activity in Sarcoma 180, lymphoid leukemia 1210 and melanotic melanoma. We have isolated four cytotoxic flavonoids with a lavandulyl side-chain at C8 and tested for their effects on human myeloid leukemia HL-60 cells and human hepatocarcinoma HepG2 cells, in terms of inhibition of proliferation and induction of apoptosis. They showed potent antiproliferative effects with IC(50) values from 11.3 microM to 18.5 microM in HL60 cells and from 13.3 microM to 36. 2 microM in HepG2 cells. Treatment of HL-60 cells with the lavandulylflavonoids induced apoptosis in a dose-dependent manner. Apoptosis was judged by the detection of DNA fragmentation by agarose gel electrophoresis and the degree of apoptosis was quantified by a sandwich enzyme immunoassay. The hydration of C4"'C5"' double bond with or without C3 hydroxylation caused a complete loss of cytotoxicity. These results suggest that the lavandulyl side-chain is essential for the activity of the flavonoids isolated from S. flavescens which may be used as cancer chemotherapeutic and chemopreventive agents.

Polymethoxyflavonoids from Vitex rotundifolia inhibit proliferation by inducing apoptosis in human myeloid leukemia cells

Three polymethoxyflavonoids from the fruit of Vitex rotundifolia, namely 2',3',5-trihydroxy-3,6,7-trimethoxyflavone (Vx-1), vitexicarpin (Vx-5) and artemetin (Vx-6), were tested for their antiproliferative activity in human myeloid leukemia HL-60 cells. They showed a dose-dependent decrease in the growth of HL-60 cells. The concentrations required for 50% inhibition of the growth (IC50) after 96 h were 4.03 microM, 0.12 microM and 30.98 microM for Vx-1, Vx-5 and Vx-6, respectively. Treatment of HL-60 cells with the flavonoids induced morphological changes that are characteristic of apoptosis. We judged the induction of apoptosis by the detection of DNA fragmentation in agarose gel electrophoresis and the degree of apoptosis was quantified by a double-antibody sandwich ELISA and by flow cytometric analysis. The C-3 hydroxyl and C-8 methoxyl groups were found not to be essential for the activity, but the C-3' methoxyl instead of hydroxyl group lowered the antiproliferative and apoptosis inducing activity. These results suggest that the polymethoxyflavonoids isolated from V. rotundifolia may be used as potential chemopreventive and chemotherapeutic agents.