Inhibitory activity of berberine on DNA strand cleavage induced by hydrogen peroxide and cytochrome c

The oxidative nuclease activity of human cytochrome c with mutations in Ω-loop C/D

Natural and artificial nucleases have extensive applications in biotechnology and biomedicine. The exploration of protein with potential DNA cleavage activity also inspires the design of artificial nuclease and helps to understand the physiological process of DNA damage. In this study, we engineered four human cytochrome c (Cyt c) mutants (N52S, N52A, I81N, and I81D Cyt c), which showed enhanced DNA cleavage activity and degradation in comparison with WT Cyt c, especially under acidic conditions. The mechanism assays revealed that the superoxide (O₂^•-) plays an important role in the nuclease reaction. The kinetic assays showed that the peroxidase activity of the I81D Cyt c mutant enhanced up to 9-fold at pH 5. This study suggests that the mutations of Ile81 and Asn52 in Ω-loop C/D are critical for the nuclease activity of Cyt c, which may have physiological significance in DNA damage and potential applications in biomedicine.

A Review of Fibraurea tinctoria and Its Component, Berberine, as an Antidiabetic and Antioxidant

Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia caused by resistance to insulin action, inadequate insulin secretion, or excessive glucagon production. Numerous studies have linked diabetes mellitus and oxidative stress. People with diabetes usually exhibit high oxidative stress due to persistent and chronic hyperglycemia, which impairs the activity of the antioxidant defense system and promotes the formation of free radicals. Recently, several studies have focused on exploring natural antioxidants to improve diabetes mellitus. Fibraurea tinctoria has long been known as the native Borneo used in traditional medicine to treat diabetes. Taxonomically, this plant is part of the Menispermaceae family, widely known for producing various alkaloids. Among them are protoberberine alkaloids such as berberine. Berberine is an isoquinoline alkaloid with many pharmacological activities. Berberine is receiving considerable interest because of its antidiabetic and antioxidant activities, which are based on many biochemical pathways. Therefore, this review explores the pharmacological effects of Fibraurea tinctoria and its active constituent, berberine, against oxidative stress and diabetes, emphasizing its mechanistic aspects. This review also summarizes the pharmacokinetics and toxicity of berberine and in silico studies of berberine in several diseases and its protein targets.

Rescuing Dicer expression in inflamed colon tissues alleviates colitis and prevents colitis-associated tumorigenesis

Chronic inflammation is known to promote carcinogenesis; Dicer heterozygous mice are more likely to develop colitis-associated tumors. This study investigates whether Dicer is downregulated in inflamed colon tissues before malignancy occurs and whether increasing Dicer expression in inflamed colon tissues can alleviate colitis and prevent colitis-associated tumorigenesis. Methods: Gene expression in colon tissues was analyzed by immunohistochemistry, immunoblots, and real-time RT-PCR. Hydrogen peroxide or N-acetyl-L-cysteine was used to induce or alleviate oxidative stress, respectively. Mice were given azoxymethane followed by dextran sulfate sodium to induce colitis and colon tumors. Berberine, anastrozole, or pranoprofen was used to rescue Dicer expression in inflammatory colon tissues. Results: Oxidative stress repressed Dicer expression in inflamed colon tissues by inducing miR-215 expression. Decreased Dicer expression increased DNA damage and cytosolic DNA and promoted interleukin-6 expression upon hydrogen peroxide treatment. Dicer overexpression in inflamed colon tissues alleviated inflammation and repressed colitis-associated carcinogenesis. Furthermore, we found that anastrozole, berberine, and pranoprofen could promote Dicer expression and protect cells from hydrogen peroxide-induced DNA damage, thereby reducing cytosolic DNA and partially repressing interleukin-6 expression upon hydrogen peroxide treatment. Rescuing Dicer expression using anastrozole, berberine, or pranoprofen in inflamed colon tissues alleviated colitis and prevented colitis-associated tumorigenesis. Conclusions: Dicer was downregulated in inflamed colon tissues before malignancy occurred. Decreased Dicer expression further exaggerated inflammation, which may promote carcinogenesis. Anastrozole, berberine, and pranoprofen alleviated colitis and colitis-associated tumorigenesis by promoting Dicer expression. Our study provides insight into potential colitis treatment and colitis-associated colon cancer prevention strategies.

Lifespan-extending and stress resistance properties of brazilin from Caesalpinia sappan in Caenorhabditis elegans

This study contributes to the continual discovery of lifespan-extending compounds from plants, using the Caenorhabditis elegans model system. An ethyl acetate soluble fraction of methanol extract from the heartwood of Caesalpinia sappan showed a significant lifespan-extending activity. Subsequent activity-guided chromatography of the ethyl acetate-soluble fraction led to the isolation of brazilin. Brazilin showed potent 2,2-diphenyl-1-picrylhydrazyl radical scavenging and superoxide anion quenching activities and also revealed a lifespan-extending activity in C. elegans under normal culture conditions. Brazilin also exhibited the protective effects against thermal, oxidative and osmotic stress conditions to improve the survival rate of the nematode. Furthermore, brazilin elevated superoxide dismutase (SOD) activity and decreased intracellular reactive oxygen species accumulation in C. elegans. Further studies showed that brazilin-mediated increased stress tolerance of worms could be due to increased expressions of stress resistance proteins such as heat shock protein (HSP-16.2) and superoxide dismutase (SOD-3). Besides, there were no significant, brazilin-induced changes in aging-related factors, including progeny production, food intake, and growth, indicating brazilin influences longevity activity independent of affecting these factors. Brazilin increased the body movement of aged worms, indicating brazilin affects the healthspan and lifespan of nematode. These results suggest that brazilin contributes to the lifespan of C. elegans under both normal and stress conditions by increasing the expressions of stress resistance proteins.

Barberry administration and pro-oxidant-antioxidant balance in patients with metabolic syndrome

Background:

Metabolic syndrome is the constellation of several cardiometabolic risk factors, and is associated with a heightened risk of coronary heart disease (CHD). The pro-oxidant–antioxidant balance (PAB) is a measure of factors that promote and control oxidative stress. PAB may also be associated with the risk factors of CHD.

Objectives:

This study aimed to explore the impact of supplementation with barberry, a fruit rich in antioxidants, on PAB in patients with metabolic syndrome.

Patients and Methods:

A total of 106 patients diagnosed with metabolic syndrome were randomized in two groups: case and control. The case group received three capsules of barberry and the control group received three capsules of placebo for 6 weeks. Serum PAB was measured in all patients before and after the intervention.

Results:

There was no significant difference between the groups regarding their baseline PAB values (P = 0.32). A significant decrease in PAB was observed in the barberry group (P = 0.022), whilst there was no significant change in the control group (P = 0.18). The magnitude of change in PAB during the study was significantly greater in the case group compared to the control group (P = 0.01).

Conclusions:

Barberry supplementation reduces oxidative burden in patients with metabolic syndrome.

Hepatoprotective Effect ofShidagonglaoon Acute Liver Injury Induced by Carbon Tetrachloride

This study investigates the hepatoprotective activity of ethanol extract from Shidagonglao roots (SDGLEtOH). The hepatoprotective effect of SDGLEtOH(20, 100 and 500 mg/kg) was analyzed on carbon tetrachloride ( CCl4)-induced acute liver injury. Rats pretreated orally with SDGLEtOH(100 and 500 mg/kg) and silymarin (200 mg/kg) for 3 consecutive days prior to the administration of a single dose of 50% CCl4(0.10 ml/100 g of bw, ip) significantly prevented the increases in the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in CCl4-treated rats. Histological analysis also showed that SDGLEtOH(100 and 500 mg/kg) and silymarin reduced the incidence of liver lesions including vacuole formation, neutrophil infiltration and necrosis of hepatocytes induced by CCl4in rats. Moreover, the SDGLEtOH(100 and 500 mg/kg) increased the activities of anti-oxidative enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRd) and decreased malondialdehyde (MDA) level in liver, as compared to those in the CCl4-treated group. Furthermore, SDGLEtOH(100 and 500 mg/kg) and silymarin attenuated the increased levels of tumor necrosis factor-α (TNF-α) in serum and nitric oxide ( NO ) in liver as compared to the CCl4-treated group. The hepatoprotective mechanisms of SDGLEtOHare likely related to inhibition of TNF-α, MDA and NO productions via increasing the activities of antioxidant enzymes (SOD, GPx and GRd). These experimental results suggest that SDGLEtOHcan attenuate CCl4-induced acute liver injury in rats.

Effects of Sanionia uncinata extracts in protecting against and inducing DNA cleavage by reactive oxygen species

When mosses are exposed to increased quantities of ultraviolet (UV) radiation, they produce more secondary metabolites. Antarctica moss Sanionia uncinata (Hedw.) Loeske has presented high carotenoid contents in response to an increase in UVB radiation. This moss has been recommended as a potential source of antioxidants. In the present work, the protective and enhancing effects of aqueous (AE) and hydroalcoholic (HE) extracts of S. uncinata on the cleavage of supercoiled DNA were evaluated through topological modifications, quantified by densitometry after agarose gel electrophoresis. Total phenolic contents reached 5.89 mg/g. Our data demonstrated that the extract does not induce DNA cleavage. Furthermore, both extracts showed antioxidant activity that protected the DNA against cleavage induced by (i) O(2)(•-), 89% (AE) and 94% (HE) (P<0.05), and (ii) (.)OH, 17% (AE) and 18% (HE). However, the extracts intensified cleavage induced by Fenton-like reactions: (i) Cu(2+)/H(2)O(2), 94% (AE) and 100% (HE) (P<0.05), and (ii) SnCl(2), 62% (AE) and 56% (HE). DNA damages seem to follow different ways: (i) in the presence of Fenton-like reactions could be via reactive oxygen species generation and (ii) with HE/Cu(2+) could have also been triggered by other mechanisms.

Selective regulation of multidrug resistance protein in vascular smooth muscle cells by the isoquinoline alkaloid coptisine

When the biological activites of hydrophobic drugs or xenobiotics are studied, it is important to clarify their effects on expression and function of multidrug resistance (MDR) protein. We therefore evaluated the effects of coptisine on MDR in comparison with the structurally related isoquinoline alkaloids berberine and palmatine. To achieve this, we investigated the effects of the three alkaloids on the expression and function of P-glycoprotein/MDR1, MDR1 gene products, in vascular smooth muscle cells (VSMCs). In A10 cells (a rat VSMC line), coptisine upregulated the mRNAs of Mdr1a and Mdr1b, rodent homologues of human MDR1, and these effects were completely abrogated by actinomycin D. Coptisine also induced Mdr1a/1b protein expression and enhanced the efflux of rhodamine 123 from A10 cells. In contrast, berberine and palmatine slightly upregulated the mRNAs of Mdr1a and Mdr1b, but failed to induce Mdr1a/1b protein expression or stimulate rhodamine 123 efflux. To clarify whether these effects occurred in other cells, the effects of the three alkaloids on Mdr1a/1b function were examined in 3Y1, dRLh-84 and B16 cells. Coptisine and berberine enhanced rhodamine 123 efflux in all three cell types, while palmatine inhibited it, based on the finding that palmatine efficiently activated the Mdr1a ATPase activity as a good substrate for Mdr1a. Therefore, the three isoquinoline alkaloids regulated MDR differently in cell type-specific manners. In particular, only coptisine induced Mdr1a/1b in A10 cells and stimulated rhodamine 123 efflux. Taken together, coptisine appears to exert VSMC-selective effects on Mdr1a/1b induction in contrast to berberine and palmatine.

Protective role of Coptidis Rhizoma alkaloids against peroxynitrite-induced damage to renal tubular epithelial cells

A study was conducted to elucidate and compare the protective activity of alkaloids from Coptidis Rhizoma (berberine, coptisine, palmatine, epiberberine, jatrorhizine, groenlandicine and magnoflorine) using an LLC-PK1 cell under peroxynitrite (ONOO−) generation model. Treatment with 3-morpholino-sydnonimine (SIN-1) led to an increase in cellular ONOO− generation in comparison with non-treated cells. However, Coptidis Rhizoma extract and its alkaloids, except for berberine, reduced the cellular ONOO− level. In addition, DNA fragmentation induced by SIN-1 was significantly decreased by the extract, and also by coptisine, epiberberine, jatrorhizine, groenlandicine and magnoflorine. Moreover, treatment with berberine, coptisine, palmatine and epiberberine exerted a protective effect against G0/G1 phase arrest of cell cycle induced by SIN-1. The increase in cellular ONOO− generation, DNA damage and disturbance of the cell cycle by SIN-1 resulted in a decrease in cell viability. However, Coptidis Rhizoma extract, epiberberine, jatrorhizine, groenlandicine and magnoflorine significantly increased cell viability even at a concentration as low as 10μg mL−1. These findings demonstrate that Coptidis Rhizoma extract and its alkaloids can ameliorate the cell damage associated with ONOO− generation in renal tubular LLC-PK1 cells, and that the various alkaloids have distinctive mechanisms of action, such as ONOO− scavenging, protection from DNA damage and control of the cell cycle. Furthermore, the data suggest that among the Coptidis Rhizoma alkaloids, coptisine is the most effective for protection against SIN-1-induced cellular injury in terms of its potency and content.

Evidence-Based Efficacy of Kampo Formulas in a Model of Non Alcoholic Fatty Liver

Data on the efficacy of herbal compounds are often burdened by the lack of appropriate controls or a limited statistical power. Treatments to prevent the progression of non alcoholic fatty liver disease (NAFLD) to steatohepatitis (NASH) remain unsatisfactory. A total of 56 rabbits were arrayed into 7 groups fed with standard rabbit chow (SRC), SRC with 1% cholesterol, or each of the five experimental treatments (Kampo formulas 1% keishibukuryogan [KBG], 1% orengedokuto [OGT], and 1% shosaikoto [SST]; vitamin E [VE]; or pioglitazone [PG]) in a 1% cholesterol SRC. We analyzed changes after 12 weeks in plasma and liver lipid profiles, glucose metabolism, adipocytokines, oxidative stress, and liver fibrosis. Data demonstrated that all five treatments were associated with significant amelioration of lipid profiles, oxidative stress, and liver fibrosis compared to no supplementation. KBG was superior to VE and PG in the reduction of liver total cholesterol ( P < 0.01) and lipid peroxidase levels ( P < 0.05), urinary 8-hydroxy-2′-deoxyguanosine ( P < 0.05), hepatic α-smooth muscle actin positive areas ( P < 0.01) and activated stellate cells ( P < 0.01). In conclusion, there was a statistically significant benefit of Kampo formulas (KBG in particular) on a dietary model of NAFLD/NASH. Future studies need to be directed at the mechanisms in the treatment of NASH.

Free radical scavenging activity and lipoxygenase inhibition of Mahonia aquifolium extract and isoquinoline alkaloids

Roots and stem-bark of Mahonia aquifolium (Oregon grape) (Berberidaceae) are effectively used in the treatment of skin inflammatory conditions.

In the present study, the effect of Mahonia aquifolium crude extract and its two representative alkaloid fractions containing protoberberine and bisbenzylisoquinoline (BBIQ) alkaloids on activity of 12-lipoxygenase (12-LOX), was studied. The reactivity with 1,1-diphenyl-2-picryl-hydrazyl (DPPH), a free stable radical, was evaluated to elucidate the rate of possible lipid-derived radical scavenging in the mechanism of the enzyme inhibition.

The results indicate that although the direct radical scavenging mechanism cannot be ruled out in the lipoxygenase inhibition by Mahonia aquifolium and its constituents, other mechanisms based on specific interaction between enzyme and alkaloids could play the critical role in the lipoxygenase inhibition rather than non-specific reactivity with free radicals.

Oxidative damage of DNA induced by the cytochrome C and hydrogen peroxide system

To elaborate the peroxidase activity of cytochrome c in the generation of free radicals from H2O2, the mechanism of DNA cleavage mediated by the cytochrome c/H2O2 system was investigated. When plasmid DNA was incubated with cytochrome c and H2O2, the cleavage of DNA was proportional to the cytochrome c and H2O2 concentrations. Radical scavengers, such as azide, mannitol, and ethanol, significantly inhibited the cytochrome c/H2O2 system-mediated DNA cleavage. These results indicated that free radicals might participate in the DNA cleavage by the cytochrome c and H2O2 system. Incubation of cytochrome c with H2O2 resulted in a time-dependent release of iron ions from the cytochrome c molecule. During the incubation of deoxyribose with cytochrome c and H2O2, the damage to deoxyribose increased in a time-dependent manner, suggesting that the released iron ions may participate in a Fenton-like reaction to produce dOH radicals that may cause the DNA cleavage. Evidence that the iron-specific chelator, desferoxamine (DFX), prevented the DNA cleavage induced by the cytochrome c/H2O2 system supports this mechanism. Thus we suggest that DNA cleavage is mediated via the generation of dOH by a combination of the peroxidase reaction of cytochrome c and the Fenton-like reaction of free iron ions released from oxidatively damaged cytochrome c in the cytochrome c/H2O2 system.

Photochemical and phototoxic activity of berberine on murine fibroblast NIH-3T3 and Ehrlich ascites carcinoma cells

The present study demonstrates photoinduced generation of superoxide anion radical and singlet oxygen upon UVA irradiation of berberine chloride, and its cytotoxic/phototoxic effects on murine fibroblast non-cancer NIH-3T3 and Ehrlich ascites carcinoma (EAC) cells. The EPR spectra monitored upon photoexcitation of aerated solutions of berberine evidenced the efficient activation of molecular oxygen via Type I and II mechanisms, as the generation of superoxide anion radical and singlet oxygen was observed. The EAC cell line was more sensitive to the effect of non-photoactivated and photoactivated berberine than the NIH-3T3 cell line. UVA irradiation increased the sensitivity of EAC cells to berberine, while the sensitivity of NIH-3T3 cells to photoactivated berberine was not changed. Berberine significantly induced direct DNA strand breaks in tested cells, oxidative lesions were not detected, and the effect of irradiation of cells after berberine treatment did not affect the increase of DNA damage in EAC and NIH-3T3 cells. The DNA damage generated by a combination of berberine with UVA irradiation induced a significant blockage of EAC cells in the S and G(2)/M phases and the stopping/decrease of cell proliferation after 24h of influence. On the other hand, after 36h or 48h of berberine treatment, the DNA damage induced necrotic or apoptotic death of EAC cells. Whether these divergences are caused by differences in the properties of two non-isogenic cell lines or by different berberine uptake and cell localization will be analyzed in our further investigations.

Activation of the aryl hydrocarbon receptor by berberine in HepG2 and H4IIE cells: Biphasic effect on CYP1A1

Berberine has long been considered a candidate for an antimalarial drug. It exerts a plethora of biological activities and has been used in the treatment of diarrhea and gastro-enteritis for centuries. Here we provide evidence that berberine activates the aryl hydrocarbon receptor (AhR) in human hepatoma (HepG2) and rat hepatoma cells stably transfected with a dioxin responsive element fused to the luciferase gene (H4IIE.luc). AhR was activated by high doses of berberine (10-50 microM) after 6 and 24 h of incubation as revealed by CYP1A1 mRNA expression (HepG2) and AhR-dependent luciferase activity (H4IIE.luc). Berberine induced nuclear translocation of AhR-GFP chimera transiently transfected to Hepa1c1c7 cells. In contrast, low doses of berberine (<1 microM) and prolonged times of the treatments (48 h) failed to produce any activation of AhR in H4IIE.luc cell line. HPLC analysis ruled out the hypothesis that the loss of berberine capacity to activate AhR in H4IIE.luc cells is due to metabolic inactivation of the alkaloid. We demonstrate that berberine is a potent inhibitor (IC50=2.5 microM) of CYP1A1 catalytic activity (EROD) in HepG2 cell culture and in recombinant CYP1A1 protein. Collectively, our results imply that while berberine activates the Ah receptor, it is accompanied by inactivation of the catalytic activity of CYP1A1 and occurs at concentrations that exceed those predicted to occur in vivo. Given these data, it appears that activation of the AhR pathway by berberine has a low toxicological potential.

Oxygen activation by photoexcited protoberberinium alkaloids fromMahonia aquifolium

Protoberberinium salts, i.e. berberine (I), palmatine (II) and jatrorrhizine (III) prepared from Mahonia aquifolium (Pursh) Nutt. belong to isoquinoline alkaloids possessing interesting biological activity (e.g. antibacterial, antimalarial, antitumor). The characteristic UV/Vis absorption band maxima of I-III iodide salts were found in regions 350 and 425 nm in dimethylsulfoxide (DMSO) and ethanol solvents, and were only negligibly influenced by substitution changes on the C-2 and C-3 positions. The fluorescence intensity of protoberberinium salts monitored in ethanol solutions was significantly lowered by iodide counter-ions, and decreased in the order berberine > palmatine > jatrorrhizine. EPR spectroscopy supplied evidence of the formation of super-oxide anion radicals and singlet oxygen upon irradiation of berberine in oxygenated DMSO solvent. The photochemical generation of O(2) (.-) and (1)O(2) in DMSO solutions of palmatine and jatrorrhizine was substantially lower, and probably reflected the replacement of a photolabile methylenedioxy group at C-2 and C-3 positions in the berberine molecule by two methoxy groups in palmatine, and methoxyl (C-2) and hydroxyl (C-3) substitution in jatrorrhizine. Additionally, the powder EPR spectra of protoberberinium iodides I-III measured at 290 K revealed the presence of single-line EPR signals (g(eff) = 2.0044), which were attributed to hydroperoxidic structures produced by the autoxidation process. The photochemical reactions of protoberbenium salts producing reactive oxygen species after UVA excitation should be integrated in biological activity investigations, as well as in their applications in skin disorder treatment.

Effect of Oren-gedoku-to (Huanglian-Jie-Du-Tang) extract on disruption of hepatic antioxidant defense systems in rats treated with D-galactosamine

We have indicated that the antioxidant action of Oren-gedoku-to (Huanglian-Jie-Du-Tang) extract (TJ-15), a traditional Chinese herbal medicine, may contribute to its preventive effect on the progression of D-galactosamine (GAL)-induced liver injury in rats. Herein, we examined a possibility that TJ-15 exerts this preventive effect by attenuating the disruption of hepatic antioxidant defense systems in GAL-treated rats. TJ-15 (500 mg/kg) was orally administered to rats injected with GAL (500 mg/kg, i.p.) at 6 h after hepatotoxin treatment. In the liver of rats treated with GAL alone, the concentration of thiobarbituric acid-reactive substances (TBARS), an index of lipid peroxidation, increased at 24 h, but not at 6 h, while reduced glutathione (GSH) and ascorbic acid concentrations and superoxide dismutase (SOD), catalase, and Se-glutathione peroxidase (Se-GSH-px) activities decreased at 24 h, but not at 6 h. Post-administered TJ-15 prevented all these changes observed at 24 h after GAL treatment. TJ-15 administered to GAL-untreated rats in the same manner did not affect the hepatic TBARS, GSH, and ascorbic acid concentrations and SOD, catalase, and Se-GSH-px activities. These results indicate that post-administered TJ-15 attenuates the disruption of hepatic antioxidant defense systems in GAL-treated rats, which may contribute to its preventive effect on the progression of GAL-induced liver injury.

Coptidis Rhizoma: protective effects against peroxynitrite-induced oxidative damage and elucidation of its active components

We have investigated the protective effects of Coptidis Rhizoma against peroxynitrite (ONOO(-))-induced oxidative damage and have elucidated the active components of this preparation. In an in-vitro system, Coptidis Rhizoma extract scavenged ONOO(-) and its precursors, nitric oxide (NO) and superoxide anion (O(2)(-)). This scavenging activity was more marked for ONOO(-) than its precursors. In addition, against 3-morpholinosydnonimine-induced cellular damage, this extract significantly reduced cellular ONOO(-) formation and increased cell viability. In an in-vivo lipopolysaccharide plus ischaemia-reperfusion system that generated ONOO(-), the administration of Coptidis Rhizoma extract at 50 and 100 mg kg(-1)/day for 30 days exerted greater inhibition of ONOO(-) than NO and O(2)(-). This suggested that it acted as a direct scavenger of ONOO(-) rather than as a scavenger of its precursors. Moreover, the suppression of the activities of the antioxidative enzymes superoxide dismutase, catalase and glutathione peroxidase was significantly attenuated by the administration of Coptidis Rhizoma extract. Furthermore, the extract ameliorated renal dysfunction judged by decreasing serum urea nitrogen and creatinine levels. To elucidate the active components of Coptidis Rhizoma extract, we evaluated and compared the effects of the phenol plus alkaloid and alkaloid fractions on ONOO-induced damage. We found that the alkaloid fraction consisting of berberine, palmatine and coptisine was the most effective at protecting against ONOO(-). We confirmed that berberine (10 and 20 mg kg(-1)/day for 10 days), the main and most active alkaloid in Coptidis Rhizoma extract, was also protective, exerting NO-, O(2)(-)- and ONOO(-)-scavenging activities. This study suggested that Coptidis Rhizoma could protect against ONOO(-)-induced oxidative damage and that this effect was mainly attributable to the constituent alkaloids, especially berberine. This study is the first to demonstrate an antioxidative effect of alkaloids, including berberine, against ONOO(-)-induced damage.

Inhibition of tumor-induced angiogenesis and matrix-metalloproteinase expression in confrontation cultures of embryoid bodies and tumor spheroids by plant ingredients used in traditional chinese medicine

Tumor-induced angiogenesis is a prerequisite for excessive tumor growth. Blood vessels invade the tumor tissue after degradation of the extracellular matrix scaffold by matrix metalloproteinases (MMPs). Inhibition of MMPs has been therefore suggested to be a useful tool to abolish neoangiogenesis of solid tumors. In the present study, antioxidative plant ingredients used in traditional Chinese medicine were investigated for their capacity to down-regulate MMP expression and to inhibit angiogenesis in embryonic stem cell-derived embryoid bodies and tumor-induced angiogenesis in confrontation cultures consisting of embryoid bodies and multicellular DU-145 prostate tumor spheroids. Embryoid bodies transiently expressed MMP-1, MMP-2, and MMP-9 during the time of differentiation of capillary-like structures. In confrontation cultures, MMP expression was increased compared with control tumor spheroids and embryoid bodies cultivated separately. The increased expression of MMPs in confrontation cultures was a result of elevated levels of reactive oxygen species (ROS) upon confrontation culture and was totally abolished in the presence of the free radical scavenger vitamin E. Incubation of embryoid bodies with baicalein, epicatechin, berberine, and acteoside, which are herbal ingredients used in traditional Chinese medicine, significantly inhibited angiogenesis in embryoid bodies and decreased intracellular ROS levels. Tumor-induced angiogenesis in confrontation cultures was totally abolished in the presence of the free radical scavenger vitamin E. Because herbal ingredients down-regulated MMP expression, we conclude that ROS generated during confrontation culture induce the expression of MMPs that are necessary for endothelial cell invasion into the tumor tissue.