The antioxidant activity of daidzein metabolites, O‑desmethylangolensin and equol, in HepG2 cells

Daidzein and its glycoside form daidzin, are known to have potential health benefits and are metabolized to O‑desmethylangolensin (O‑DMA) and equol following consumption. In the current study, the antioxidant activity and cytotoxicity of O‑DMA, equol, daidzein and daidzin was investigated and their effects on HepG2 human hepatocelluar carcinoma cells were compared. For cytotoxicity assays, lactose dehydrogenase (LDH) release and 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide‑based cell viability, cells were exposed to various concentrations of each compound (5‑200 µM) for 24, 48 or 72 h. O‑DMA and equol did not affect LDH release, but higher concentrations (<75 µM) showed inhibition of cell growth. By contrast, daidzein and daidzin (200 µM) increased LDH release and cell growth. All compounds stimulated catalase and total superoxide dismutase (SOD) (CuZn‑ and Mn‑SOD) activity, and mRNA and protein expression. This phenomenon was most pronounced for O‑DMA and equol, as their effects were similar. These data suggested that O‑DMA and equol possess greater antioxidant properties compared with daidzein and may, thus, be beneficial for human health.

O-desmethylangolensin inhibits the proliferation of human breast cancer MCF-7 cells by inducing apoptosis and promoting cell cycle arrest

The aim of the present study was to investigate the anticancer effect of O-desmethylangolensin (O-DMA) by assessing cell proliferation, apoptosis and cell cycle distribution, as well as exploring the mechanisms underlying these effects in breast carcinoma MCF-7 cells. The cells were exposed to O-DMA (5–200 μM) for 24, 48 and 72 h. The results revealed that cell proliferation was significantly inhibited in a dose-dependent manner following treatment for 48 and 72 h, but not after 24 h, and resulted in the significant induction of apoptosis and the promotion of cell cycle arrest at the G₁/S and G₂/M phases. To elucidate these effects of O-DMA, the expression levels of cell cycle regulators were measured in the cells exposed to O-DMA at 150 μM for 72 h. Of the G₁/S phase-related proteins, O-DMA modulated the cyclin-dependent kinases (CDKs), with a decrease in CDK2 and CDK4 and an increase in CDK6, and downregulated cyclin D and E. With respect to the G₂/M-related proteins, O-DMA caused a reduction in CDK1, together with a slight increase in cyclin A and B. In addition, O-DMA downregulated p21^Cip1 and p27^Kip1, but not p16^INK4a and p15^INK4b, and interacted with the CDK6-cyclin D and CDK1-cyclin B complexes. In conclusion, these results indicate for the first time that the regulation of the CDK4/6-cyclin D and CDK1-cyclin B complexes may participate in the anticancer activity pathway of O-DMA in MCF-7 cells.

Antiproliferative activity of daidzein and genistein may be related to ERα/c-erbB-2 expression in human breast cancer cells

In this study, we investigated the antiproliferative activity of the isoflavones daidzein and genistein in three breast cancer cell lines with different patterns of estrogen receptor (ER) and c‑erbB‑2 protein expression (ERα‑positive MCF‑7 cells, c‑erbB‑2‑positive SK‑BR‑3 cells and ERα/c‑erbB‑2‑positive ZR‑75‑1). After treatment at various concentrations (1‑200 µM for 72 h), the effect of daidzein and genistein on the proliferation of different cell types varied; these effects were found to be associated with ERα and c‑erbB‑2 expression. Daidzein and genistein exhibited biphasic effects (stimulatory or inhibitory) on proliferation and ERα expression in MCF‑7 cells. Although 1 µM daidzein significantly stimulated cell growth, ERα expression was unaffected. However, genistein showed marked increases in proliferation and ERα expression after exposure to <10 µM genistein. Notably, the inhibition of cell proliferation by 200 µM genistein was greater compared to that by daidzein at the same concentration. Daidzein and genistein significantly inhibited proliferation of SK‑BR‑3 and ZR‑75‑1 cells in a dose‑dependent manner. In addition, ERα and c‑erbB‑2 expression was reduced by daidzein and genistein in both SK‑BR‑3 and ZR‑75‑1 cells in a dose‑dependent manner. However, the effect of genistein was greater compared to that of daidzein. In conclusion, the isoflavones daidzein and genistein showed anti‑breast cancer activity, which was associated with expression of the ERα and c‑erbB‑2 receptors.

Infrared conductivity and carrier mobility of large scale graphene on various substrates

It is known that low-field mobility of graphene depends largely on the substrate material on which it is transferred. We measured Drude optical conductivity of graphene on various substrates and determined the carrier density and carrier scattering rate. The carrier density varies widely depending on the substrate material. However the scattering rate is almost constant, approximately 100 cm(-1), for 5 different substrates. We calculate carrier mobility of graphene using the two quantities, i.e., carrier density and scattering rate, to find that it agrees with the mobility measured from dc transport experiment. We conclude that substrate-depent mobility of graphene originates from different carrier density but not from the scattering rate.

Routine pulmonary function test can estimate the extent of tuberculous destroyed lung

Tuberculous destroyed lung (TDL) is diagnosed by a clear past history of tuberculosis with findings of parenchymal destruction verified by chest X-ray. Despite the resultant deterioration of lung function and quality of lives seen in TDL patients, the exact mechanism or characteristics of pulmonary function worsening have not been clearly studied. We investigated the feature of respiratory impairment of TDL patients, and studied whether extent of destroyed lung measured with chest CT has any correlation with routine lung function. To evaluate the degree of destruction, the Goddard classification scoring system was modified into a novel scoring system (destroyed lung score, (DLS)) with a score from 0 to 4. Twenty-five subjects were enrolled. TDL predominantly manifested as an obstructive pattern (64%, 16/25). Median value of DLS of the entire lung was 2.6 (1.7–3.9). Absolute values of FEV1 and FVC were both negatively associated with DLS (r = −0.78, P = 0.001, and r = −0.61, P = 0.021). Percentage of predicted value of FEV₁ and FVC were also negatively associated with DLS (r = −0.62, P = 0.019, and r = −0.76, P = 0.002). Our study shows that lung function of TDL patients were notably correlated with the extent of destroyed lung measured with chest CT scan.

Quercetin acts as an antioxidant and downregulates CYP1A1 and CYP1B1 against DMBA-induced oxidative stress in mice

We investigated the effects of quercetin on 7,12-dimethylbenz(a)anthracene (DMBA)-induced oxidative stress and the expression of CYP1A1 and CYP1B1 in mice. Quercetin was administered orally to mice at 100 or 250 mg/kg BW for 18 days, after which DMBA (34 mg/kg BW) was administered intragastrically twice. Quercetin showed side effects such as increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in DMBA-untreated mice. Also, quercetin induced AST and ALT in DMBA-treated, although this was not significantly different from levels in DMBA-treated controls. The thiobarbituric acid reactive substances (TBARS) value showed a tendency to decrease following quercetin treatment; these decreases were significantly greater in the DMBA-treated compared to the untreated groups. Also, catalase and superoxide dismutase (SOD) activities as well as their mRNA expression were increased by quercetin; this increase was more pronounced in DMBA-treated compared to untreated mice. DMBA induced CYP1 activity as well as expression of CYP1A1 and CYP1B1. Each of these effects was significantly reduced by quercetin; however, this reduction was observed for CYP1A1 at only the higher dose and for CYP1B1 at both doses. These data suggest that quercetin shows antioxidant activity against DMBA-induced oxidative stress. Moreover, its regulation of CYP1A1 and CYP1B1 suggests the potential of quercetin as an anticancer supplement.

The effects of methane and hydrogen gases produced by enteric bacteria on ileal motility and colonic transit time

BACKGROUND

Gases produced by intestinal flora may modulate intestinal motor function in healthy individuals as well as those with functional bowel disease. Methane, produced by enteric bacteria in the human gut, is associated with slowed intestinal transit and constipation. The effects of hydrogen, another main gas produced by bacterial fermentation in the gut, on small bowel and colonic motor function remains unrecognized. Therefore, we set out to investigate whether intestinal gases including methane and hydrogen could influence the small bowel motility and colonic transit.

METHODS

Guinea pig ileum was placed in the peristaltic bath with tension transducers attached to measure velocity and amplitude of peristaltic contraction before and after the infusion of control, hydrogen, and methane gases. Also, changes in the intraluminal pressures were monitored before and after the gas infusions.

KEY RESULTS

Methane decreased peristaltic velocity and increased contraction amplitude significantly of guinea pig ileum (P < 0.05). The AUC of intraluminal pressure was significantly increased with methane in guinea pig ileum (P < 0.05). In a second experiment, guinea pig colon was placed in the peristaltic bath to measure transit time before and after control, hydrogen, methane, and methane-hydrogen mixture gas infusions. Hydrogen shortened colonic transit time by 47% in the proximal colon, and by 10% in the distal colon, when compared with baselines (P < 0.05).

CONCLUSIONS & INFERENCES

Methane delayed ileal peristaltic conduction velocity by augmenting contractility. Hydrogen shortened colonic transit, and that effect was more prominent in the proximal colon than distal colon.

Effects of 4',7-dimethoxyflavanone on cell cycle arrest and apoptosis in human breast cancer MCF-7 cells

The present study was designed to investigate the anticancer activity of 4,7-dimethoxyflavanone in vitro. When human breast cancer MCF-7 cells were treated with 4',7-dimethoxyflavanone at various concentrations (1-200 μM) for 24 h, antiproliferative effects were first observed at 1 μM and the IC(50) was 115.62 μM. Conversely, 4',7-dimethoxyflavanone was not cytotoxic (measured as lactate dehydrogenase release in CHO-K1 cells) under the same conditions. MCF-7 cells exposed to the 4',7-dimethoxyflavanone at the IC(50) concentration showed cell cycle arrest and apoptosis. Compared to the respective control level, exposure to 4',7-dimethoxyflavanone resulted in a remarkable increase of small DNA fragments at the sub-G1 phase and an increase in the G2/M phase cell population. Moreover, when 4',7-dimethoxyflavanone treatment caused G2/M phase arrest, an increase in CDK1 together with an increase in cyclin B was observed. Based on these results, 4',7-dimethoxyflavanone may be a useful anticancer agent.

Pharmacokinetic characterization of decursinol derived from Angelica gigas Nakai in rats

Decursinol is a major coumarin derived from the roots of Angelica gigas and has various pharmacological effects against inflammation, angiogenesis, nociceptive pain and Alzheimer's disease. In vitro and in vivo studies were conducted to characterize the metabolism and pharmacokinetics of decursinol. Decursinol exhibited high stability to oxidative and glucuronic metabolism in human and rat liver microsomes. In Caco-2 cell monolayers, decursinol showed high permeability (>14 × 10(-6) cm/s) at all tested concentrations in the absorptive direction, which saturated at 100 μM. Secretion increased in a concentration-dependent manner, with an efflux ratio of more than 2 at 50 μM, indicating the participation of an active efflux transporter such as P-glycoprotein, multidrug resistance protein 2 or breast cancer resistance protein. The fraction of decursinol not bound to plasma proteins was 25-26% in the rat and 9-18% in humans. In human plasma, but not rat plasma, the percentage of unbound decursinol was concentration dependent. Following intravenous administration in rats, non-linear elimination of decursinol was observed with K(m) and V(max) values of 2.1 μg/mL and 2.5 mg·h(-1)·kg(-1), respectively. Following oral administration, decursinol exhibited high oral bioavailability (>45%) and rapid absorption (T(max), 0.4-0.9 h) over the dose range studied. In addition, dose-dependent absorption and elimination were observed at 20 mg/kg.

Anticancer mechanism of equol in 7,12-dimethylbenz(a)anthracene-treated animals

This study investigated the anticancer effects of equol, the major metabolite of the antioxidant phytochemical daidzein, on 7,12-dimethylbenz(a)anthracene (DMBA)-treated animals and explored its anticancer mechanism. The experiment consisted of two parts. In the first part, Sprague-Dawley rats were given equol daily at 5 and 25 mg/kg body weight (BW) for 8 weeks after a single dose of DMBA (100 mg/kg BW). As a control, rats were divided into vehicle alone and DMBA alone groups. Equol administration at a higher dose effectively suppressed tumor formation and PCNA over-expression. The activation of p53 by equol subsequently affected the cyclin-dependent kinase inhibitor p21Cip1. This was associated with equol-induced apoptosis in mammary gland tumors, as evidenced by the decreased Bcl-2 expression and increased Bax expression, together with the activation of caspase-3 and poly(ADP-ribose) polymerase (PARP). In the second part, oral pre-administration of equol to mice which received DMBA intragastrically twice a week for 2 weeks significantly decreased their levels of biomarkers (thiobarbituric acid-reactive substances, carbonyl content and serum 8-hydroxy-2-deoxyguanosine) of DMBA-induced oxidative stress. Although several antioxidant enzymes were down-regulated in mice treated with DMBA alone, pre-administration of equol blocked much of this effect, increasing catalase and superoxide dismutase activity in a dose-dependent manner. Although equol did not affect the ratio of oxidized to reduced glutathione, it activated the glutathione peroxidase and glutathione reductase enzymes, and this effect was significant at a dose of 25 mg equol/kg body weight. DMBA treatment induced apoptosis, as shown by a decrease in the Bcl-2 levels and an increase in the levels of Bax, cleaved caspase-3 and poly(ADP-ribose) polymerase. These apoptotic effects were also reversed by equol at all doses tested. Based on these results, equol possesses anticancer activity that suppresses tumor formation via apoptosis induction in rats with DMBA-induced mammary gland tumors. In addition, equol showed a hepatic protective effect by acting as an antioxidant and by reducing apoptosis.

Anti-/pro-apoptotic effects of hesperetin against 7,12-dimetylbenz(a)anthracene-induced alteration in animals

This study investigated the anticancer effects of hesperetin on 7,12-dimethylbenz(a)anthracene (DMBA)-treated animals and explored its anticancer mechanism. The experiment consisted of two parts. First, Sprague-Dawley rats were given hesperetin daily at a dose of 50 mg/kg for 8 weeks after a single dose of DMBA (100 mg/kg). As controls, rats were divided into vehicle alone and DMBA alone groups. Secondly, ICR mice were given hesperetin daily at a dose of 10 and 50 mg/kg BW/day for 7 weeks before a single dose of DMBA (34 mg/kg/week). In rats with DMBA-induced mammary gland tumors, hesperetin pretreatment significantly reduced the tumor burden and PCNA overexpression. The administration of hesperetin significantly inhibited mammary gland carcinoma from developing by restoring the decreased Bcl-2 and increased Bax expression. By contrast, in the livers of mice treated with DMBA, obvious DNA fragmentation was observed. Moreover, apoptosis-related gene expression in the livers of the mice differed from that in mammary gland carcinomas in rats. These changes were restored in mice treated with hesperetin, indicating the inhibition of apoptosis. Based on these results, hesperetin may act not only as a proapoptotic agent, but also as an antiapoptotic agent, depending on the circumstance.

Quercetin accumulation by chronic administration causes the caspase-3 activation in liver and brain of mice

Quercetin is an excellent antioxidant that has a variety of side effects. This study investigated whether the chronic administration of quercetin in mice induces apoptosis. Mice were divided randomly into three treatment groups. Quercetin was administered orally to two of three groups at 100 and 250 mg/kg body weight (BW) for 18 days. The serum quercetin level increased in a dose-dependent manner, although the quercetin levels in the liver and brain were lower than in serum. Nevertheless, quercetin induced apoptosis in both the liver and brain, as evidenced by increased caspase-3 expression and activity. Quercetin-induced apoptosis seems to be associated with quercetin accumulation. Moreover, with quercetin accumulation, the brain was more susceptible to apoptosis than the liver. In conclusion, quercetin administration at a high dose may lead to apoptosis in the liver and brain of mouse.

Anti-carcinogenic effect of a new analogue 4'-chloroflavanone from flavanone in human breast cancer cells

We investigated the antiproliferative effects of synthetic flavanone derivatives using an MTT assay in MCF-7 and MDA-MB-453 cells. When cells were treated with synthetic flavanone derivatives in concentrations ranging from 1 to 200 microM for 48 h, cell growth decreased at concentrations >50 microM. 4'-Chloroflavanone is more potent than flavanone among the synthetic flavanone derivatives. Exposure to 4'-chloroflavanone at 50 microM for 48 h caused cell cycle arrest in both MCF-7 and MDA-MB-453 cells. In addition, when 4'-chloroflavanone caused G1/S phase arrest, a decrease in CDK4 and cyclin D, together with an increase in p21Cip1, was observed in the cells. The p21Cip1 is a downstream target of p53 that may be affected by the activation of p53 by 4'-chloroflavanone. These results indicate that activation of p53 played some role in 4'-chloroflavanone-induced cell cycle arrest of human breast cancer cells. 4'-Chloroflavanone increased cytochrome c expression and decreased the expression of caspase-3, but did not change the expression of Bcl-2 and Bax. Activation of cytochrome c and its downstream target, caspase-3, is suggested to be an important inducer of the apoptosis process by 4'-chloroflavanone. 4'-Chloroflavanone inhibits cell proliferation through G1/S phase disruption and may induce apoptosis. Based on our findings, we propose that 4'-chloro-flavanone is useful as an anticancer drug.

Partial pericardial defect incidentally discovered during coronary bypass surgery

A 71-yr-old male patient with three vessel coronary artery disease underwent a coronary artery bypass graft. The patient was found to have a large pericardial defect at the apex of the heart that measured approximately 18 cm in circumference. The edge of the pericardial defect impinged on the epicardial coronary arteries. The left phrenic nerve descended via the dorsal boundary of the pericardial defect. Following coronary artery bypass grafting, the pericardial defect was repaired with a polytetrafluorethylene patch. The patient had an uncomplicated postoperative course.

Evaluation of equol function on anti- or prooxidant status in vivo

The present study was performed to investigate the effects of equol on oxidative stress and the antioxidant defense system in the livers of mice. Mice were orally administered equol at either 5 or 25 mg/kg body weight/day for 1, 3, or 7 wk. Equol administration significantly inhibited biomarkers of oxidative stress (thiobarbituric acid-reactive substances value, carbonyl content, and serum 8-OH-dG) at all doses and for all durations of administration, and this phenomenon was most pronounced at 3 wk. Moreover, catalase and total superoxide dismutase (SOD) activities and their mRNA expression were significantly increased by equol. Although equol increased the glutathione peroxidase (GSH-px) activity in mice treated with equol for 1 wk, long-term administration of equol (7 wk) caused a decrease in the ratio of reduced/oxidized glutathione (GSH/GSSG) and the activities of GSH-px and glutathione reductase (GR). Taken together, these results suggest that equol may act as an antioxidant through an inhibition of oxidative stress and stimulation of catalase and SOD, but can also cause prooxidant effects such as reduction of the GSH/GSSG ratio, depending on the treatment period.