Evaluation of antigenotoxic activity of isoliquiritin apioside from Glycyrrhiza glabra L

Sensitive sensing of GLA and ISL based on highly conductivity nitrogen-doped carbon synergistic dual-template molecularly imprinted ratiometric electrochemical sensor

A novel ratiometric Molecularly Imprinted Electrochemical sensor for the specific marker of Glycyrrhiza glabra L. was developed in this work. To achieve simultaneous detection of two analytes on one sensor, we constructed a double template molecular imprinted electrochemical sensor with glabridin (GLA) and isoliquiritin (ISL) as templates. Further, Ferrocene/ZIF-8 (Fc/ZIF-8) composites were prepared via a one-pot solvothermal reaction and coated on the surface of a glassy carbon electrode (GCE), and the oxidation of Fc was presented as the internal reference signal. Nitrogen-doped carbon (NOC) with high conductivity was further loaded on the modified GCE. Based on theoretical exploration and computer directional simulation of density functional theory (DFT), the optimal functional monomer and the best ratio of double template molecules to functional monomer were screened. Under optimal conditions, the sensor produced electrochemical curves when exposed to a solution containing GLA and ISL. As the concentration of GLA and ISL increased, the peak current intensity of GLA and ISL (IGLA and IISL) also increased, while the peak current intensity of Fc (as a reference signal) remained relatively constant. The values of IGLA/IFc and IISL/IFc showed excellent linear relationships with GLA and ISL concentrations in the range of 0.1-160 μM and 0.5-150 μM, respectively. The detection limits were 0.052 μM and 0.27 μM (S/N = 3), respectively. Due to the imprinting effect of MIP and the existence of a reference signal, the sensor exhibited excellent selectivity and anti-interference ability and was successfully applied to the quality evaluation of Glycyrrhiza glabra L.

Neuroprotective Effects of Glycyrrhiza glabra Total Extract and Isolated Compounds

Glycyrrhiza glabra L. is a plant commonly utilized in herbal medicine and stands out as one of the more extensively researched medicinal plants globally. It has been documented with respect to several pharmacological activities, notably, neuroprotective effects, among others. However, the neuroprotective activity of pure phenolic compounds has not been reported yet. The chromatographic of a methanolic extract yielded twenty-two compounds, viz.: naringenin 4'-O-glucoside (1), 3',4',7-trihydroxyflavanone (butin) (2), liquiritin (3), liquiritin apioside (4), abyssinone (5), glabrol (6), isoliquiritin (7), neoisoliquiritin (8), isoliquiritin apioside (9), licuraside (10). 3'[O], 4'-(2,2-dimethylpyrano)-3,7-dihydroxyflavanone (11), glabrocoumarin (12), glabrene (13), isomedicarpin (14), 7-hydroxy-4'-methoxyflavone (formononetin) (15), ononin (16), glycyroside (17), (3S)-7,4'-dihydroxy-2'-methoxyisoflavan (18), glabridin (19), neoliquiritin (20), 3,11-dioxooleana-1,12-dien-29-oic acid (21), and 3-oxo-18β-glycyrrhetinic acid (22). The results of the neuroprotection evaluation showed that G. glabra total extract (TE) and compounds 1, 7, 11, 16, and 20 protected SH-SY5Y cells by inhibiting the depletion of ATP and elevated caspase 3/7 activities induced by MPP+. Indeed, this study reports for the first time the structure and activity of compound 11 and the neuroprotective activity of some phenolic constituents from G. glabra.

Green Synthesis of Gold Nanoparticles Using Liquiritin and Other Phenolics from Glycyrrhiza glabra and Their Anti-Inflammatory Activity

Phenolic compounds are the main phytochemical constituents of many higher plants. They play an important role in synthesizing metal nanoparticles using green technology due to their ability to reduce metal salts and stabilize them through physical interaction/conjugation to the metal surface. Six pure phenolic compounds were isolated from licorice (Glycyrrhiza glabra) and employed in synthesizing gold nanoparticles (AuNPs). The isolated compounds were identified as liquiritin (1), isoliquiritin (2), neoisoliquiritin (3), isoliquiritin apioside (4), liquiritin apioside (5), and glabridin (6). The synthesized AuNPs were characterized using UV, zeta sizer, HRTEM, and IR and tested for their stability in different biological media. The phenolic isolates and their corresponding synthesized NP conjugates were tested for their potential in vitro cytotoxicity. The anti-inflammatory effects were investigated in both normal and inflammation-induced settings, where inflammatory biomarkers were stimulated using lipopolysaccharides (LPSs) in the RAW 264.7 macrophage cell line. LPS, functioning as a mitogen, promotes cell growth by reducing apoptosis, potentially contributing to observed outcomes. Results indicated that all six pure phenolic isolates inhibited cell proliferation. The AuNP conjugates of all the phenolic isolates, except liquiritin apioside (5), inhibited cell viability. LPS initiates inflammatory markers by binding to cell receptors and setting off a cascade of events leading to inflammation. All the pure phenolic isolates, except isoliquiritin, neoisoliquiritin, and isoliquiritin apioside inhibited the inflammatory activity of RAW cells in vitro.

Discovery, structural characterization, and functional insights into a novel apiosidase from the GH140 family, isolated from a lignocellulolytic-enriched mangrove microbial community

OBJECTIVES

Apiosidases are enzymes that cleave the glycosidic bond between the monosaccharides linked to apiose, a branched chain furanose found in the cell walls of vascular plants and aquatic monocots. There is biotechnological interest in this enzyme group because apiose is the flavor-active compound of grapes, fruit juice, and wine, and the monosaccharide is found to be a plant secondary metabolite with pharmaceutical properties. However, functional and structural studies of this enzyme family are scarce. Recently, a glycoside hydrolase family member GH140 was isolated from Bacteroides thetaiotaomicron and identified as an endo-apiosidase.

RESULTS

The structural characterization and functional identification of a second GH140 family enzyme, termed MmApi, discovered through mangrove soil metagenomic approach, are described. Among the various substrates tested, MmApi exhibited activity on an apiose-containing oligosaccharide derived from the pectic polysaccharide rhamnogalacturonan-II. While the crystallographic model of MmApi was similar to the endo-apiosidase from Bacteroides thetaiotaomicron, differences in the shape of the binding sites indicated that MmApi could cleave apioses within oligosaccharides of different compositions.

CONCLUSION

This enzyme represents a novel tool for researchers interested in studying the physiology and structure of plant cell walls and developing biocatalytic strategies for drug and flavor production.

Polyphenols as novel interventions for depression: exploring the efficacy, mechanisms of action, and implications for future research

Numerous animal and human studies have assessed the relationship between polyphenols and outcomes related to depression. However, no comprehensive synthesis of the main findings has been conducted. The aim of this manuscript was to systematically review the available evidence from animal and human studies on the association and the effects of dietary polyphenols on depression and provide recommendations for future research. We based our review on 163 preclinical animal, 16 observational and 44 intervention articles assessing the relationship between polyphenols and outcomes related to depression. Most animal studies demonstrated that exposure to polyphenols alleviated behaviours reported to be associated with depression. However, human studies are less clear, with some studies reporting and inverse relationship between the intake of some polyphenols, and polyphenol rich foods and depression risk and symptoms, while others reporting no association or effect. Hence, while there has been extensive research conducted in animals and there is some supporting evidence in humans, further human studies are required, particularly in younger and clinical populations.

Underlying Anticancer Mechanisms and Synergistic Combinations of Phytochemicals with Cancer Chemotherapeutics: Potential Benefits and Risks

Cancer therapies are associated with various challenges including the emergence of multidrug resistant tumors, toxicological issues, severe side effects, and economic burden. To counteract these effects, natural products as substitutes and adjuvant therapies have received considerable attention owing to their safety, efficacy, and economic aspects. Various preclinical and clinical studies revealed that natural products and their combinations with chemotherapeutics mediate their anticancer effects via modulation of various signaling pathways implicated in promoting apoptosis, inhibiting excessive cellular proliferation, and mobilizing the immune system. Several lead phytochemicals including curcumin, resveratrol, quercetin, and cannabinoids synergistically act with cancer chemotherapeutics reducing cell proliferation and inducing apoptosis and cell cycle arrest. However, clinical studies on the subject matter are limited and need further extensive studies. It has been observed that patients undergoing chemotherapy use alternative therapies to ameliorate the symptoms associated with the use of chemotherapeutic agents. Nevertheless, some of the patients inform their physicians regarding herbal medicine during chemotherapy while others do not, and even most of the patients do not know the composition of herbal medicine they consume during chemotherapy. Herbal interactions with chemotherapeutics are associated with both beneficial and harmful aspects, but the beneficial aspect overweighs the harmful ones in terms of controlling the symptoms associated with the chemotherapy. Nonetheless, a large number of herbal medicines have been demonstrated to have synergistic effect with chemotherapy and alleviate the side effects of chemotherapeutic agents. The concomitant use of the majority of herbal medicines with chemotherapy has been demonstrated to be beneficial in multiple malignant tumors like cancer of blood, lungs, kidneys, liver, skin, and gastrointestinal tract. However, herbal medicines which possess positive interaction and improve the quality of life of patients should be sorted out and integrated with the chemotherapy. There should be a quality control system for the appraisal of herbal medicine, and there should also be an appropriate system of patient-doctor communication to counsel the patients regarding the beneficial and deleterious effects of the herbal medicine in combination with chemotherapy.

The genus Glycyrrhiza (Fabaceae family) and its active constituents as protective agents against natural or chemical toxicities

Licorice is the dried roots and rhizomes of various species of the genus Glycyrrhiza (Fabaceae) that have been used in folk medicine from ancient times. Many important research projects have established several beneficial effects for this medicinal herb, including antiinflammatory, antimicrobial, antiviral, antiprotozoal, antioxidant, antihyperglycemic, antihyperlipidemic, hepatoprotective, and neuroprotective. Licorice contains important bioactive components, such as glycyrrhizin (glycyrrhizic, glycyrrhizinic acid), liquiritigenin, liquiritin, and glycyrrhetinic acid. The protective effects of licorice and its main chemical components against toxins and toxicants in several organs including the brain, heart, liver, kidney, and lung have been shown. In this comprehensive review article, the protective effects of these constituents against natural, industrial, environmental, and chemical toxicities with attention on the cellular and molecular mechanism are introduced. Also, it has been revealed that this plant and its main compounds can inhibit the toxicity of different toxins by the antioxidant, antiinflammatory, and anti-apoptotic properties as well as the modulation of Inhibitor of kappaB kinase (IKK), Extracellular signal-regulated protein kinase1/2 (ERK1/2), p38, inducible nitric oxide synthase, and nuclear factor-κB (NF-κB) signaling pathways. More high-quality investigations in both experimental and clinical studies need to firmly establish the efficacy of licorice and its main constituents against toxic agents.

Glycoside Compounds From Glycyrrhiza uralensis and Their Neuroprotective Activities

This paper concerns the study of the roots and rhizomes of Glycyrrhiza uralensis where one new alkaloid glycoside, 3,4-dihydroxyquinoline 4- O-β-d-glucopyranoside, along with 13 known compounds (12 phenolic glycosides and one triterpene glycoside) were isolated and identified. The structure of the new compound and the known ones were identified on the basis of nuclear magnetic resonance (NMR) and mass spectrometric (MS) analysis. All the glycosides were tested for their anti-neuroinflammatory activities by inhibiting nitric oxide (NO) release in lipopolysaccharide (LPS)-induced murine microglial BV-2 cells. Several compounds were tested for their antioxidant activities in rat adrenal pheochromocytoma PC12 cells. A structure–activity relationship (SAR) analysis was carried out and revealed that the position and amount of sugar moieties have significant impact on antioxidant activities.

Effect of Jakyakgamcho-Tang Extracts on H2O2-Induced C2C12 Myoblasts

Oxidative stress is a major contributor to muscle aging and loss of muscle tissue. Jakyakgamcho-tang (JGT) has been used in traditional Eastern medicine to treat muscle pain. Here, we compared the total phenolic and flavonoid contents in 30% ethanol and water extracts of JGT and tested the preventive effects against oxidative stress (hydrogen peroxide)-induced cell death in murine C2C12 skeletal muscle cells. The total phenolic content and total flavonoid content in 30% ethanol extracts of JGT were higher than those of water extracts of JGT. Ethanol extracts of JGT (JGT-E) had stronger antioxidant activities of 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2′-diphenyl-1-picrylhydrazyl-scavenging activity (DPPH) than water extracts of JGT (JGT-W). JGT-E contained 19–53% (1.8 to 4.9-fold) more active compounds (i.e., albiflorin, liquiritin, pentagalloylglucose, isoliquiritin apioside, isoliquiritin, liquiritigenin, and glycyrrhizin) than JGT-W. The ethanol extracts of JGT inhibited hydrogen peroxide-induced cell death and intracellular reactive oxygen species generation more effectively than the water extract of JGT in a dose-dependent manner. For the first time, these results suggest that ethanol extract of JGT is relatively more efficacious at protecting against oxidative stress-induced muscle cell death.

MS-based metabolite analysis of two licorice chalcones in mice plasma, bile, feces, and urine after oral administration

Isoliquiritigenin (ILG) and isoliquiritin (ILQ), two kinds of major flavonoids in licorice, are biological active substances with antioxidant, anti-inflammatory, and tumor-suppressive effects. However, their in vivo metabolites, possible material basis of this two licorice chalcones for the treatment of diseases, have not been studied completely. To determine the metabolism of ILG and ILQ, after oral administration of 100 mg/kg/day of these compounds for consecutive 8 days, the metabolites of these two licorice chalcones in mice plasma, urine, feces, and bile were determined using liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry in this study. The structures of those metabolites were tentatively identified according to their fragment pathways, accurate masses, characteristic product ions, metabolism law, and reference standards-matching. As a result, a total of 25 and 29 metabolites of ILG and ILQ were identified, respectively. Seven main metabolic pathways, oxidation and reduction, deglycosylation and glycosylation, dehydroxylation and hydroxylation, demethoxylation and methoxylation, acetylation, glucuronidation, and sulfation, were summarized to tentatively explain how the metabolites were biologically transformed. These results provide the important information on the metabolism of ILG and ILQ, which may be helpful for the further research of their pharmacological mechanism.

Serotonergically dependent antihyperalgesic and antiallodynic effects of isoliquiritin in a mouse model of neuropathic pain

Chronic neuropathic pain poses a significant health problem worldwide, for which effective treatment is lacking. The current work aimed to investigate the potential analgesic effect of isoliquiritin, a flavonoid from Glycyrrhiza uralensis, against neuropathic pain and elucidate mechanisms. Male C57BL/6J mice were subjected to chronic constriction injury (CCI) by loose ligation of their sciatic nerves. Following CCI surgery, the neuropathic mice developed pain-like behaviors, as shown by thermal (heat) hyperalgesia in the Hargreaves test and tactile allodynia in the von Frey test. Repetitive treatment of CCI mice with isoliquiritin (p.o., twice per day for two weeks) ameliorated behavioral hyperalgesia to thermal (heat) stimuli and allodynia to tactile stimuli in a dose-dependent fashion (5, 15 and 45 mg/kg). The isoliquiritin-triggered analgesia seems serotonergically dependent, since its antihyperalgesic and antiallodynic actions were totally abolished by chemical depletion of spinal serotonin by p-chlorophenylalanine, whereas potentiated by 5-HTP (a precursor of 5-HT). Consistently, isoliquiritin-treated neuropathic mice showed escalated levels of spinal monoamines especially 5-HT, with depressed monoamine oxidase activity. Moreover, isoliquiritin-evoked antihyperalgesia and antiallodynia were preferentially counteracted by the 5-HT_1A receptor antagonist WAY-100635 delivered systematically or spinally. Of notable benefit, isoliquiritin was able to correct co-morbid behavioral symptoms of depression and anxiety evoked by neuropathic pain. Collectively, these findings demonstrate, for the first time, the therapeutic efficacy of isoliquiritin on neuropathic hypersensitivity, and this effect is dependent on the spinal serotonergic system and 5-HT_1A receptors.

Specific NDM-1 Inhibitor of Isoliquiritin Enhances the Activity of Meropenem against NDM-1-positive Enterobacteriaceae in vitro

NDM-1-positive Enterobacteriaceae have caused serious clinical infections, with high mortality rates. Carbapenem was the ultimate expectation for the treatment of such infections in clinical practice. However, since the discovery of plasmid-mediated New Delhi metallo-β-lactamase-1 (NDM-1), the efficient therapeutic effects of carbapenems have been increasingly restricted. Here, we identified isoliquiritin, a novel specific inhibitor of the NDM-1 enzyme that restored the activity of carbapenem against NDM-1-producing E. coli isolates and K. pneumoniae isolates without affecting the growth of bacteria. A checkerboard test, growth curve assays and time-kill assays confirmed the significant synergistic effect of isoliquiritin combined with meropenem in vitro. It is worth noting that isoliquiritin only inhibited the activity of NDM-1 and had no obvious inhibitory effect on other class B metallo-β-lactamases (VIM-1) or NDM-1 mutants (NDM-5). The FIC indices of meropenem with isoliquiritin on NDM-1-positive E. coli and K. pneumoniae were all less than 0.5. Isoliquiritin had no influences on the expression of NDM-1-positive strains at concentrations below 64 µg/mL. Collectively, our results show that isoliquiritin is a potential adjuvant therapy drug that could enhance the antibacterial effect of carbapenems, such as meropenem, on NDM-1-positive Enterobacteria and lay the foundation for subsequent clinical trials.

Natural Chalcones in Chinese Materia Medica: Licorice

Licorice is an important Chinese materia medica frequently used in clinical practice, which contains more than 20 triterpenoids and 300 flavonoids. Chalcone, one of the major classes of flavonoid, has a variety of biological activities and is widely distributed in nature. To date, about 42 chalcones have been isolated and identified from licorice. These chalcones play a pivotal role when licorice exerts its pharmacological effects. According to the research reports, these compounds have a wide range of biological activities, containing anticancer, anti-inflammatory, antimicrobial, antioxidative, antiviral, antidiabetic, antidepressive, hepatoprotective activities, and so on. This review aims to summarize structures and biological activities of chalcones from licorice. We hope that this work can provide a theoretical basis for the further studies of chalcones from licorice.

Seven new flavonoid glycosides from the roots of Glycyrrhiza uralensis and their biological activities

As part of our ongoing investigation of the bioactive constituents from the roots of Glycyrrhiza uralensis Fisch., seven new flavonoid glycosides (1-7) were obtained along with 19 known compounds (8-26). All of the isolates possessed one or more sugar moieties. Their structures, as well as the absolute configurations, were elucidated on the basis of spectroscopic data (UV, IR, HRESIMS, 1D and 2D NMR, and CD). In the in vitro assay, compounds 3 and 7 showed moderate antioxidant activities at a concentration of 0.1 μM; compound 2 showed hepatoprotective activity at a concentration of 10 μM.

Renoprotective Effects Of Isoliquiritin Against Cationic Bovine Serum Albumin-Induced Membranous Glomerulonephritis In Experimental Rat Model Through Its Anti-Oxidative And Anti-Inflammatory Properties

Background

Membranous glomerulonephritis (MGN) is a nephrotic syndrome which shows the symptoms of heavy proteinuria and immune complex deposition in glomerular sub-epithelial space and finally leads to chronic kidney disease. Isoliquiritin (ILQ) is a flavonoid with a wide range of pharmacological properties, including antioxidant and anti-inflammatory activity. The present study was undertaken to investigate the possible mechanisms by which ILQ ameliorates cationic bovine serum albumin (C-BSA) induced MGN in rat model.

Methods

The MGN condition was confirmed by the 24 hr proteinuria and ILQ (10 mg/kg/bw/day) or TPCA-1 (10 mg/kg/bw/day; IKKβ inhibitor) was administered to successfully induce rats for 4 weeks.

Results

The present study revealed that MGN rats treated with ILQ showed significantly ameliorated kidney dysfunction and histopathological changes in kidneys. ILQ treated MGN rats alleviated the oxidative stress and were presented with increased anti-oxidative status in kidneys. Furthermore, ILQ treatment to MGN rats showed anti-oxidative effects through the prominent stimulation of Nrf2 signaling pathway and inhibition of Keap1, which consequently increases the Nrf2 nuclear translocation and thereby induces expression of NQO1 and HO-1. In addition, ILQ-treated MGN rats demonstrated anti-inflammatory effects by inhibiting NF-κB signaling pathway through decreased mRNA and protein expressions of NF-κB p65, IKKβ, COX-2, iNOS, p38-MAPK, p-p38-MAPK, TNF-α, IL-1β, IL-8, ICAM-1, E-selectin and VCAM-1 and reduced the nuclear translocation of NF-κB p65.

Conclusion

The protective effect of ILQ on MGN can be explained by its anti-oxidative and anti-inflammatory activities, which in turn due to the activation of Nrf2 and downregulation of NF-κB pathway.

Reaction mechanism of β-apiosidase from Aspergillus aculeatus

Apiosidases are glycosidases relevant for aroma development during fermentation of wines and black tea. Reaction mechanism of apiosidase from Aspergillus aculeatus in commercial glycanase Viscozyme L was studied by ¹H NMR technique. Study of hydrolysis of 4-nitrophenyl β-D-apiofuranoside revealed that this reaction proceeds with inversion of hydroxyl group in the anomeric center, which confirms inverting mechanism of the enzyme and its inability to catalyze transapiosylation in syntheses of apiosides.

Isoliquiritin Apioside Suppresses in vitro Invasiveness and Angiogenesis of Cancer Cells and Endothelial Cells

Several components isolated from Glycyrrhizae radix rhizome (GR), including glycyrrhizin, liquiritin, and liquiritigenin, have been shown to induce cancer cell death and inhibit cancer metastasis. Isoliquiritin apioside (ISLA), a component isolated from GR, has been effective for treating tetanic contraction and genotoxicity. However, the effects of ISLA on the metastasis and angiogenesis of malignant cancer cells and endothelial cells (ECs) have not been reported. In this study, we found that up to 100 μM ISLA did not affect cell proliferation but efficiently suppressed the metastatic ability of HT1080 cells, as assessed by scratch-wound migration, Transwell^® migration, scratch-wound invasion, Transwell^® invasion, and three-dimensional spheroid invasion. ISLA significantly decreased phorbol 12-myristate 13-acetate (PMA)-induced increases in matrix metalloproteinase (MMP) activities and suppressed PMA-induced activation of mitogen-activated protein kinase as well as NF-κB, which are involved in cancer metastasis. In addition, ILSA treatment reduced the production of pro-angiogenic factors in HT1080 cells, including MMP-9, placental growth factor, and vascular endothelial growth factor under normoxia as well as hypoxia conditions, by impairing the hypoxia-inducible factor-1α pathway. We also found that the abilities of human umbilical vein ECs to migrate across the Transwell^® and to form tube-like structures were significantly reduced by ISLA treatment. Moreover, using the chorioallantoic membrane assay, vessel formation with or without vascular endothelial growth factor was significantly suppressed by ISLA. These results suggested that ISLA possesses anti-metastatic and anti-angiogenic abilities in malignant cancer cells and ECs, with no cytotoxicity. ISLA may therefore be a safe and effective lead compound to develop anti-cancer drug for limiting the spread of primary tumors to distant organs to form secondary tumors.

Ionic liquids-ultrasound based efficient extraction of flavonoid glycosides and triterpenoid saponins from licorice

Flavonoid glycosides and triterpenoid saponins are the main chemical constituents of licorice. In this study, an ionic liquids-ultrasound based extraction (IL-UAE) method was established to simultaneously extract liquiritin (LQ), liquiritin apioside (LA), isoliquiritin (ILQ), isoliquiritin apioside (ILA) and glycyrrhizic acid (GA) from licorice. A series of 1-alkyl-3-methylimidazolium ILs with different anions and alkyl chain lengths of cations were investigated and compared, and 1-butyl-3-methylimidazolium acetate ([C₄MIM]Ac) was finally selected as the extractant. The extraction parameters of the IL-UAE procedure were optimized, and the established method was validated in linearity, stability, precision, repeatability and recovery. The IL-UAE approach exhibited much higher extraction efficiency comparing with conventional UAE, and needed shorter extraction time and smaller solvent to solid ratio comparing with the pharmacopoeia method. In addition, the microstructures of licorice powders were observed before and after extraction with help of a scanning electron microscope (SEM) in order to explore the extraction mechanism. The results suggested that ILs as green solvents were effective for extraction of flavonoid glycosides and triterpenoid saponins from licorice.

An ionic liquids-ultrasound based method for efficient extraction of flavonoid glycosides and triterpenoid saponins from licorice was established.

The Chinese herbal formula Free and Easy Wanderer ameliorates oxidative stress through KEAP1-NRF2/HO-1 pathway

Posttraumatic stress disorder (PTSD) gains a lot of attention due to high prevalence and strong psychological upset, but the etiology remains undefined and effective treatment is quite limited. Growing studies demonstrated the involvement of oxidative stress in various psychiatry diseases, suggesting anti-oxidation therapy might be a strategy for PTSD treatment. Free and Easy Wanderer (FAEW) is a poly-herbal drug clinically used in China for hundreds of years in the treatment of psychiatric disorder. We hypothesized that FAEW exerts clinical effects through the activity against oxidative stress with fluoxetine as antidepressant control drug. Our results revealed that FAEW significantly reduced both endogenous and H₂O₂-induced exogenous ROS levels in the human glioblastoma T98G and neuroblastoma SH-SY5Y cell lines. Transcriptome-wide microarray analysis indicated NRF2/HO-1 as the common target of FAEW and fluoxetine. Western blotting assay proved that the two drugs promoted NRF2 release from KEAP1 in the cytoplasm and translocation to the nuclei in a KEAP1-dependent manner, the expression of the protein HO-1 increased accordingly, suggesting the participation of KEAP1-NRF2/HO-1 pathway. The chemical constituents of FAEW (i.e. paeoniflorin, baicalin) bound to KEAP1 in silico, which hence might be the effective substances of FAEW. In conclusion, FAEW counteracted H₂O₂-induced oxidative stress through KEAP1-NRF2/HO-1 pathway.

Identification of NF-κB as Determinant of Posttraumatic Stress Disorder and Its Inhibition by the Chinese Herbal Remedy Free and Easy Wanderer

Posttraumatic stress disorder (PTSD) is a mental disorder developing after exposure to traumatic events. Although psychotherapy reveals some therapeutic effectiveness, clinically sustainable cure is still uncertain. Some Chinese herbal formulae are reported to work well clinically against mental diseases in Asian countries, but the safety and their mode of action are still unclear. In this study, we investigated the mechanisms of Chinese remedy free and easy wanderer (FAEW) on PTSD. We used a reverse pharmacology approach combining clinical data to search for mechanisms of PTSD with subsequent in vitro verification and bioinformatics techniques as follows: (1) by analyzing microarray-based transcriptome-wide mRNA expression profiling of PTSD patients; (2) by investigating the effect of FAEW and the antidepressant control drug fluoxetine on the transcription factor NF-κB using reporter cell assays and western blotting; (3) by performing molecular docking and literature data mining based on phytochemical constituents of FAEW. The results suggest an involvement of inflammatory processes mediated through NF-κB in the progression of PTSD. FAEW was non-cytotoxic in vitro and inhibited NF-κB activity and p65 protein expression. FAEW's anti-inflammatory compounds, i.e., paeoniflorin, isoliquiritin, isoliquiritin apioside and ononin were evaluated for binding to IκK and p65-RelA in a molecular docking approach. Paeoniflorin, albiflorin, baicalin, isoliquiritin and liquiritin have been reported to relieve depression in vivo or in clinical trials, which might be the active ingredients for FAEW against PTSD.

Glycyrrhiza glabra

Liquorice foliage

Effect of apigenin-7-glucoside, genkwanin and naringenin on tyrosinase activity and melanin synthesis in B16F10 melanoma cells

AIMS

In this study, we have investigated the effects of apigenin-7-glucoside, genkwanin and naringenin, on mouse melanoma B16F10 cell proliferation. Influence of these natural products on percentage cell distribution in cycle phases and melanogenesis was also studied.

MAIN METHODS

Cell viability was determined at various periods using the MTT assay, whereas effects of tested compounds on progression through the cell cycle were analyzed by flow cytometry. In addition, amounts of melanin and tyrosinase were measured spectrophotometrically at 475 nm. Besides, the mechanism involved on the death route induced by the tested molecules was evaluated using the bis-benzimide trihydrochloride coloration method (Hoechst 33258).

KEY FINDINGS

Apigenin-7-glucoside, genkwanin and naringenin exhibited significant anti-proliferative activity against B16F10 melanoma cells after 24 and 48 h of incubation. Furthermore, apigenin-7-glucoside, genkwanin and naringenin provoked an increase of subG0/G1, S and G2/M phase cell proportion with a significant decrease of cell proportion in G0/G1 phases. The results evaluated using Hoechst 33,258, confirm that the percentage of B16F10 cells observed in the sub G0/G1 phase were undergoing apoptosis. Moreover, apigenin-7-glucoside and naringenin revealed an ability to enhance melanogenesis synthesis and tyrosinase activity of B16F10 melanoma cells. Whereas genkwanin induces a decrease of melanin synthesis by inhibiting tyrosinase activity.

SIGNIFICANCE

Our results promote the introduction of genkwanin in cosmetic preparations, as skin whitening agent, whereas apigenin-7-glucoside and naringenin should be introduced into cosmetic products as natural tanning agents.

Antigenotoxic and antioxidant potentials of newly derivatized compound naringenin-oxime relative to naringenin on human mononuclear cells

We investigated antigenotoxic and antioxidative effects of newly derivatized compound naringenin-oxime (NG-Ox) compared to its mother compound naringenin (NG) against oxidative damage induced by hydrogen peroxide (HP) in human peripheral blood mononuclear cells (PBMC). Antigenotoxic activity was assessed using alkaline single cell gel electrophoresis assay (comet assay). Oxidative status was evaluated by measurement of total antioxidant status, total oxidant status and lipid hydroperoxide levels in the cells. Oxidative stress index was also calculated. Both NG and NG-Ox show a protective effect against HP-induced oxidative damage on PBMC and are able to reduce oxidative stress. The percentage of antigenotoxic and antioxidant potential progressively increased in a dose-dependent manner. However, these activities were found to be more significant in NG-Ox-treated cells than in NG-treated cells. Taken together, these observations provide evidences indicating that both NG and NG-Ox are able to protect cells against oxidative damage and apparently NG-Ox is more effective than NG.

Two antigenotoxic chalcone glycosides from Mentha longifolia subsp. longifolia

CONTEXT

Mentha L. (Labiatae) species (mint) with their flavoring properties have been used in food industries for centuries. Besides they have a great importance in drug development and medicinal applications due to various bioactive compounds of several members of the genus.

OBJECTIVE

The aim of this study was to isolate bioactive compounds with antimutagenic potential by bio-guided fractionation and determine their structures by spectroscopic methods.

MATERIALS AND METHODS

The structural elucidation of the isolated compounds was done based on spectroscopic methods, including MALDI-MS, UV, IR, and 2D NMR experiments, and the bio-guided fractionation process was done by using the Ames/Salmonella test system. Henceforth, solely genotoxic and antigenotoxic potential of the new compounds were also confirmed up to 2 µM/plate by using the same test system.

RESULTS

Two new chalcone glycosides: (βR)-β,3,2',6'-tetrahydroxy-4-methoxy-4'-O-rutinosyldihydrochalcone and (βR)-β,4,2',6'-tetrahydroxy-4'-O-rutinosyldihydrochalcone, were isolated from Mentha longifolia (L.) Hudson subsp. longifolia, together with known six flavonoid glycosides and one phenolic acid: apigenin-7-O-glucoside, luteolin-7-O-glucoside, apigenin-7-O-rutinoside, luteolin-7-O-rutinoside, apigenin-7-O-glucuronide, luteolin-7-O-glucuronide, rosmarinic acid. According to the antimutagenicity results, both new test compounds significantly inhibited the mutagenic activity of 9-aminoacridine in a dose-dependent manner at the tested concentrations from 0.8 to 2 µM/plate. (βR)-β,4,2',6'-Tetrahydroxy-4'-O-rutinosyldihydrochalcone showed the maximum inhibition rate as 75.94% at 2 µM/plate concentration.

CONCLUSIONS

This is the first report that two new chalcone glycosides were isolated from Mentha longifolia subsp. longifolia and their antimutagenic potentials by using mutant bacterial tester strains. In conclusion, the two new chalcone glycosides showed a significant antigenotoxic effect on 9-aminoacridine-induced mutagenesis at tested concentrations.

Benzylidenetetralones, cyclic chalcone analogues, induce cell cycle arrest and apoptosis in HCT116 colorectal cancer cells

Colorectal cancer is the third most common cancer in the world, with 1.2 million new cancer cases annually. Chalcones are secondary metabolite precursors of flavonoids that exhibit diverse biological activities, including antioxidant and antitumor activities. The aim of this study was to investigate the antiproliferative effect of new synthetic chalcone derivatives on HCT116 cells. (E)-2-(2',4'-dimethoxybenzylidene)-1-tetralone (Q705) was found to be the most active (IC50 = 3.44 ± 0.25 μM). Based on these results, this compound was chosen for further analysis of its biochemical and molecular mechanisms. Our results showed that Q705 inhibited the growth and clonogenicity of HCT116 cells. The results of a flow cytometric analyses suggested that this compound caused a significant cell cycle arrest in G2/M phase and increased the proportion of cells in the subG0/G1 phase, marker of apoptosis. Q705-induced apoptosis was confirmed by TdT-mediated dUTP nick end labelling (TUNEL) assay. Treatment of HCT116 cells with this chalcone significantly increased the caspase-3,-7 activity and resulted in cleavage of poly-ADP-ribose polymerase (PARP). Changes in the nuclear morphology such as chromatin condensation were also observed. These effects were associated with a decreased expression of bcl-xL and increased overall ratio of bax/bcl-xL mRNA levels. Immunofluorescence and qRT-PCR analysis revealed that Q705 induced H2AX histone modifications characteristic of DNA damage, disruption of microtubule organization and downregulation of tubulins. In summary, these results suggest that the cyclic chalcone analogue Q705 has potential as a new compound for colorectal cancer therapy.

In vitro studies on protective effect of Glycyrrhiza glabra root extracts against cadmium-induced genetic and oxidative damage in human lymphocytes

Cadmium is a modern environmental contaminant that is toxic and carcinogenic. Glycyrrhiza glabra is a traditional medicinal herb which grows in the various parts of the World. Recent studies demonstrated that G. glabra has antifungal, antimicrobial, antioxidant, and powerful antiinflammatory features. The purpose of this study was to investigate the genetic safety of extracts from G. glabra and its effects on cadmium (as CdCl2) induced genotoxicity. Therefore we evaluated the capability of G. glabra extract to inhibit the rate of micronucleus (MN), sister chromatid exchange (SCE) formations induced by CdCl2. Moreover, to assess the effects of G. glabra on cell viability and oxidative status, we performed 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and total antioxidant capacity (TAC) assays. Our results showed that there were significant increases (P < 0.05) in both SCE and MN frequencies of cultures treated with CdCl2 (5 ppm) as compared to controls. However, co-application of G. glabra extract (5, 10 and 20 ppm) and CdCl2 resulted in decreases of MN and SCE rates as compared to the group treated with CdCl2 alone. Again, the results of MTT and TAC assays clearly indicated dose dependent ameliorative effects of G. glabra extracts against CdCl2 toxicity. In conclusion, this study demonstrated for the first time that G. glabra extracts provided increased resistance of DNA against CdCl2 induced genetic and oxidative damage in human lymphocytes. So, the risk on target tissues of CdCl2 could be reduced and ensured early recovery from its toxicity.

Liquorice, a unique "guide drug" of traditional Chinese medicine: a review of its role in drug interactions

ETHNOPHARMACOLOGICAL RELEVANCE

Liquorice is the root of Glycyrrhiza uralensis Fisch. or Glycyrrhiza glabra L., Leguminosae. It is a widely used herbal medicine native to southern Europe and parts of Asia and has beneficial applications in both the medicinal and the confectionery sectors. Unlike its usage in Europe, liquorice in traditional Chinese medicine is commonly combined with other herbs in a single prescription, as a unique "guide drug" to enhance the effectiveness of other ingredients, to reduce toxicity, and to improve flavor in almost half of Chinese herbal formulas. A review on phytochemical and pharmacological research to explain this unique "guide" effect is suggested for future investigations.

MATERIALS AND METHODS

The information was collected from scientific journals, books, and pharmacopeia. The studies about the traditional uses, randomized controlled trials, chemical, pharmacological and pharmacokinetic data related to liquorice-herb/drug interaction or combination were included in the review.

RESULTS

According to recent reports, the "guide" effect of liquorice is partially through components transformed in liquorice-drug interaction; altering enzyme activity of P450 isoforms, as evidenced by induction of model probe substrates; and modulation of drug transporter proteins such as intestinal P-glycoprotein.

CONCLUSION

The overview and comparison of traditional uses of liquorice with recent pharmacological studies and randomized controlled trials provide new insights into this ancient drug for future investigations and clinical use, especially in drug combination.

Glycyrrhiza and Uncaria Hook contribute to protective effect of traditional Japanese medicine yokukansan against amyloid β oligomer-induced neuronal death

ETHNOPHARMACOLOGICAL RELEVANCE

Yokukansan, a traditional Japanese (Kampo) medicine, composed of seven medicinal herbs has been traditionally used to treat neurosis, insomnia, and night crying and irritability in children. Recently, this medicine has been reported to improve the behavioral and psychological symptoms of dementia (BPSD) that often become problematic in patients with Alzheimer's disease (AD).

AIM OF THE STUDY

Amyloid β (Aβ) oligomers, which are extremely toxic to neurons, are involved in neurodegeneration in AD. In animals, yokukansan has been proven to improve memory impairments and BPSD-like behavior in transgenic mice overexpressing amyloid precursor protein and mice intracerebroventricularly injected with Aβ oligomers. These results suggest that yokukansan is potentially able to reduce the neurotoxicity of Aβ oligomers. Therefore, the present study aimed to explore the improving effects brought by yokukansan that consists of seven herbs for Aβ oligomer-induced neurotoxicity in vitro and to identify the candidate herbs in yokukansan's action.

MATERIALS AND METHODS

Primary cultured rat cortical neurons were used. Neurotoxicity induced by Aβ oligomers (3µM) and improving effects of yokukansan (300-1000 µg/mL) and its constituent herbs were evaluated in MTT assay, DNA fragmentation analysis, and electron microscopic analysis at 48h after treatment with Aβ oligomers and drugs. Moreover, changes in expression of genes related to endoplasmic reticulum (ER) stress and in caspase-3 activity that is the enzyme closely related to apoptosis were analyzed to investigate the underlying mechanisms.

RESULTS

Yokukansan ameliorated Aβ oligomer-induced neuronal damage in a dose-dependent manner in the MTT assay. This drug also suppressed DNA fragmentation caused by Aβ oligomers. Electron microscopic analysis suggested that yokukansan reduced karyopyknosis and the expansion of rough ER caused by Aβ oligomers. However, neither Aβ oligomers nor yokukansan affected the mRNA expression of any ER stress-related genes, including CHOP and GRP78. On the other hand, yokukansan dose-dependently suppressed Aβ oligomer-induced activation of caspase-3. Among the seven constituents of yokukansan, Glycyrrhiza and Uncaria Hook (60-200 µg/mL) suppressed Aβ oligomer-induced neuronal damage, DNA fragmentation, karyopyknosis, and caspase-3 activation to almost the same extent as yokukansan.

CONCLUSIONS

The present results suggest that yokukansan possesses an ameliorative effect against Aβ oligomer-induced neuronal apoptosis through the suppression of caspase-3 activation. Glycyrrhiza and Uncaria Hook may, at least in part, contribute to the neuroprotective effect of yokukansan. These mechanisms may underlie the improving effects of yokukansan on memory impairment and BPSD-like behaviors induced by Aβ oligomers.

An update on antitumor activity of naturally occurring chalcones

Chalcones, which have characteristic 1,3-diaryl-2-propen-1-one skeleton, are mainly produced in roots, rhizomes, heartwood, leaves, and seeds of genera Angelica, Sophora, Glycyrrhiza, Humulus, Scutellaria, Parartocarpus, Ficus, Dorstenia, Morus, Artocarpus, and so forth. They have become of interest in the research and development of natural antitumor agents over the past decades due to their broad range of mechanisms including anti-initiation, induction of apoptosis, antiproliferation, antimetastasis, antiangiogenesis, and so forth. This review summarizes the studies on the antitumor activity of naturally occurring chalcones and their underlying mechanisms in detail during the past decades.

Comparative analysis of the main bioactive components of San-ao decoction and its series of formulations

A high performance liquid chromatographic (HPLC) method with diode array detection (DAD) was established for simultaneous determination of seven main bioactive components in San-ao decoction and its series of formulae (San-ao decoction, Wu-ao decoction, Qi-ao decoction and Jia-wei San-ao decoction). Seven compounds were analyzed simultaneously with a XTerra C₁₈ column (4.6 mm × 250 mm, 5 µm) using a linear gradient elution of a mobile phase containing acetonitrile (A) and a buffer solution (0.02 mol/L potassium dihydrogen phosphate and adjusted to pH 3 using phosphoric acid) (B); the flow rate was 1.0 mL/min. The sample was detected with DAD at 210, 254 and 360 nm and the column was maintained at 30 °C. All the compounds showed good linearity (r² > 0.9984) in the tested concentration range. The precisions were evaluated by intra-day and inter-day tests, and relative standard deviation (R.S.D.) values within the range of 0.83%–2.53% and 0.64%–2.77% were reported, respectively. The recoveries of the quantified compounds were observed to cover a range from 95.34% and 104.82% with R.S.D. values less than 2.72%. The validated method was successfully applied for the simultaneous determination of seven main bioactive components including ephedrine (1), amygdalin (2), liquiritin (3), benzoic acid (4), isoliquiritin (5), formononetin (6) and glycyrrhizic acid (7) in San-ao decoction and its series of formulae. The results also showed a wide variation in the content of the identified active compounds in these samples, which could also be helpful to illustrate the drug interactions after some herbs combined in different formulations.

HPLC method determination of isoliquiritin apioside and isoliquiritin in rat plasma for application in pharmacokinetic study after an oral administration of zhigancao extract

A sensitive HPLC method was developed for the quantitative determination of isoliquiritin apioside (ILA) and isoliquiritin (IL) in rat plasma. After protein precipitation with acetonitrile, chloroform was used to separate lipid-soluble impurities from the plasma samples and remove acetonitrile. A chromatography was carried out on Diamonsil C18 (150 × 4.6 mm; 5 μm) analytical column, using a mobile phase consisting of water (containing phosphoric acid 0.1%, v/v); acetonitrile (72 : 28, v/v) at a flow rate of 1.0 mL/min. The wavelength-switching technology was performed to determine ILA and IL at 360 nm and wogonoside (internal standard, IS) at 276 nm. The calibration curves of ILA and IL were fairly linear over the concentration ranges of 0.060-3.84 μg/mL (r = 0.9954) and 0.075-4.80 μg/mL (r = 0.9968), respectively. The average extract recoveries of ILA, IL, and IS were all over 80%. The precision and accuracy for all concentrations of quality controls and standards were within 15%. The lower limit of quantification (LLOQ) was 0.060 μg/mL for ILA and 0.075 μg/mL for IL. The method was used in pharmacokinetic study after an oral administration of Zhigancao extract to rats.

Licocalchone-C extracted from Glycyrrhiza glabra inhibits lipopolysaccharide-interferon-γ inflammation by improving antioxidant conditions and regulating inducible nitric oxide synthase expression

The genus Glycyrrhiza consists of about 30 species, amoung these, G. glabra is the source of several phenolic compounds, known as flavonoids, such as licoagrodin, licoagrochalcones, licoagroaurone and licochalcone C, kanzonol Y, glyinflanin B and glycyrdione A, which have shown various pharmacological activities, including antitumor, antiparasitic, antileishmanial, anti-ulcer and antioxidative effects. Among these compounds, licochalcone C was isolated but its biology has not been fully examined. In our study we reproduced an inflammatory state by treating THP-1 (human myelomonocytic leukaemia) cells with pro-inflammatory stimuli, such as LPS and IFN-γ and we investigated the possible antioxidant activity of licochalcone C at a concentration of 50 μM. Our results show that treatment with licochalcone C attenuates the LPS-IFN-γ-induced inflammatory response by significantly decreasing the expression and activity of iNOS via NFκB (nuclear factor kappa-B), by influencing extracellular O₂⁻ production, and by modulating the antioxidant network activity of SOD (superoxide dismutase), CAT (catalase) and GPx (glutathione peroxidase) activity. Based on these results we hypothesize that Licochalcone C has antioxidant properties since it reduces the production of superoxide radicals and consequently reduces the activity of iNOS.

Antiobesity and lipid lowering effects of Glycyrrhiza chalcones: experimental and computational studies

Twelve flavonoids (1-12), isolated from Glycyrrhiza glabra roots were evaluated for their pancreatic lipase (PL) inhibitory activity in vitro. The structures of the isolated compounds were elucidated by spectroscopic methods. Amongst all the compounds 7, 8, 10 and 11 showed strong inhibition against PL with IC(50) values of 7.3 μM, 35.5 μM, 14.9 μM and 37.6 μM, respectively. Molecular docking studies on the most active compound 7 revealed that it binds with the key amino acid residues of the PL active site. In silico absorption, distribution, metabolism and excretion (ADME) parameters were also computed on the active compounds to determine their preliminary pharmacokinetic properties. Further, investigations were carried out to determine the antiobesity and lipid lowering effects of 7 and 10 in high fat diet (HFD) fed male SD rats. In the rats supplemented with compound 7 the body weight increase was only 23.2±3.6 g as compared to 64.2±0.5 g in the HFD control group while in the rats treated with compound 10 showed 23.2±3.6 g weight gain only. Compound 7 decreased the levels of plasma total cholesterol (TC) to 84.6±1.4 mg/dl and plasma total triglycerides (TG) to 128.8±6.0 mg/dl. Compound 10 also lowered the plasma TC and TG levels considerably. The results indicate the potential of the chalcone scaffold as a source of PL inhibitors for preventing obesity.

Cardioprotective effects of Glycyrrhiza uralensis extract against doxorubicin-induced toxicity

The purpose of the present study was to investigate the cardioprotective effects of Glycyrrhiza uralensis extract (GUE) against doxorubicin (DOX)-induced cardiotoxicity. Imprinting control region (ICR) mice were treated with saline, DOX (20 mg/kg intraperitoneal [ip] for once), GUE (100 mg/kg intragastric [ig] for 8 days), co-treatments with DOX and GUE (100 mg/kg ig for 8 days), and amifostine (100 mg/kg intravenous [iv] for once), respectively. Serum levels of lactate dehydrogenase (LDH) and creatine kinase isoenzyme (CK-MB), glutathione peroxidase (GSH-P(X)) activity, and glutathione (GSH) level in heart tissue were measured. Histopathologic analysis of heart tissue was also performed. Treatment with GUE significantly protected the mice from DOX-induced cardiotoxicity, indicated by decreased levels of serum LDH and CK-MB, improved heart morphology and increased GSH-P(X) activity and GSH level. Additionally, GUE did not compromise the tumor-inhibitory effect of DOX. In conclusion, our studies imply the potentially clinical application of GUE to overcome the cardiotoxicity of doxorubicin.

Dietary chalcones with chemopreventive and chemotherapeutic potential

Chalcones are absorbed in the daily diet and appear to be promising cancer chemopreventive agents. Chalcones represent an important group of the polyphenolic family, which includes a large number of naturally occurring molecules. This family possesses an interesting spectrum of biological activities, including antioxidative, antibacterial, anti-inflammatory, anticancer, cytotoxic, and immunosuppressive potential. Compounds of this family have been shown to interfere with each step of carcinogenesis, including initiation, promotion and progression. Moreover, numerous compounds from the family of dietary chalcones appear to show activity against cancer cells, suggesting that these molecules or their derivatives may be considered as potential anticancer drugs. This review will focus primarily on prominent members of the chalcone family with an 1,3-diphenyl-2-propenon core structure. Specifically, the inhibitory effects of these compounds on the different steps of carcinogenesis that reveal interesting chemopreventive and chemotherapeutic potential will be discussed.

Butein up-regulates the expression of the π class of glutathione S-transferase in rat primary hepatocytes through the ERK/AP-1 pathway

Induction of phase II enzymes is an important mechanism of chemoprevention. Here we compared the effects of chalcones on the expression of the π class of glutathione S-transferase (GSTP) in rat primary hepatocytes. Hepatocytes were treated with 10 or 25 μM of phloretin or butein for 24 h. Both butein and phloretin dose-dependently increased GSTP protein expression, and the induction potency of butein was stronger than that of phloretin. The increase in GSTP mRNA in cells treated with 25 μM of phloretin and butein was 107% and 211%, respectively (P < 0.05). Butein increased GST enzyme activity by 27% compared with that in the control cells (P < 0.05). In contrast, phloretin had no significant effect on GST enzyme activity. The pTA-luciferase reporter construct with the rat -2.7 kb GSTP promoter region was transiently transfected into Clone 9 liver cells, and the luciferase activity in butein-treated cells was 1.1-fold higher than that in control cells (P < 0.05). GSTP enhancer 1 (GPE1) deletion abolished the induction of reporter activity by butein. The phosphorylation of extracellular signal-regulated kinase (ERK), but not of c-Jun NH2-terminal kinase (JNK) and p38, was stimulated in the presence of butein. Pretreatment with PD98059, an ERK inhibitor, alleviated the increase in activator protein-1 (AP-1)-DNA binding activity and also the activation of GSTP protein expression by butein. Moreover, c-Jun is likely to bind to the GPE1. Silencing of ERK2 by siRNA gene knockdown reduced the butein-induced expression of GSTP. In conclusion, the increased GSTP expression by butein is likely related to the ERK-AP-1 pathway.

Leaf and root extracts of Moricandia arvensis protect against DNA damage in human lymphoblast cell K562 and enhance antioxidant activity

Four extracts were prepared from the roots and leaves of Moricandia arvensis: root chloroform extract (ChlR), leaf chloroform extract (ChlL), root ethyl acetate extract (EAR) and leaf ethyl acetate extract (EAL). The genotoxic and antigenotoxic properties of these extracts were investigated by assessing the induction and inhibition of the genotoxicity induced by the direct-acting mutagen, hydrogen peroxide (H(2)O(2)), using the "Comet assay." It appears that none of the different extracts produces a genotoxic effect, except the highest tested concentrations of the leaf extracts which were capable to eliciting DNA damage. Human lymphoblast cells K562 were pretreated with different concentrations of each extracts and then treated by H(2)O(2), for the antigenotoxic study. The results showed that all extracts inhibited the genotoxicity induced by H(2)O(2) and particularly ChlR (42.5μg/ml) and ChlL (65μg/ml) extracts. In addition, antioxidant potential study of root and leaf extracts using different antioxidant tests indicated that root extracts possess a potent antioxidant activity through namely their capacity to transfer electrons.