Transcriptional response of genes involved in cell defense system in human cells stressed by H2O2 and pre-treated with (Tunisian) Rhamnus alaternus extracts: Combination with polyphenolic compounds and classic in vitro assays

Antihyperglycemic Effect of Rhamnus alaternus L. Aqueous Extract in Streptozotocin-induced Diabetic Rats

BACKGROUND

Traditionally, the aerial parts of Rhamnus alaternus L. have been widely used in Mediterranean countries, including Morocco, to cure diabetes.

AIM

This study aimed to evaluate the antidiabetic effect of Rhamnus alaternus aqueous extract in streptozotocin(STZ)-induced diabetic rats.

OBJECTIVE

This work aimed to evaluate the antihyperglycemic effect of Rhamnus alaternus aqueous extract (RAAE) in normal and diabetic rats. Then the phytochemical composition, antioxidant capacity, and potential toxicity of RAAE were also assessed.

METHODS

The effects of acute (6 h) and subchronic (7 days) oral administration of RAAE (20 mg/kg) on blood glucose levels and lipid profiles were evaluated in normal and diabetic rats. Besides, a preliminary phytochemical screening, quantification of phenolic, flavonoid, and tannin contents as well as the antioxidant activity, using the DPPH method, were evaluated. Additionally, the toxicity of the aqueous extract (5 mg/kg) was also studied and the LD50 value was determined.

RESULTS

RAAE (20 mg/kg) over 7 days of oral administration significantly decreased the blood glucose levels both in normal and diabetic rats. In diabetic rats, this extract also improved oral glucose tolerance. In addition, RAAE possessed significant antioxidant activity. According to preliminary phytochemical research, RAAE contains several chemical compounds, including alkaloids, polyphenols, flavonoids, cyanidins, anthraquinones, and sterols. On the other hand, the quantitative phytochemical study of the aqueous extract revealed a considerable amount of total phenolic compounds (497.93 ± 3.38 mg GAE/1g of RAAE), flavonoids (100.42 ± 0.32 mg RE/ g of RAAE), and tannins (14.32 ± 0.37 mg CE/1g of RAAE).

CONCLUSION

We conclude that RAAE exerts a significant antihyperglycemic effect in STZ-induced diabetic rats at a low dose. Indeed, more research is still required to support the use of this plant in the Moroccan population's diabetes care.

Evaluation of Anticancer Potential of Flavones from Rhamnus alaternus against B16F10 Melanoma Cells

Melanoma has become an important health problem and new treatment have become an imperative medical need. Therefore, the finding and identification of natural product with less toxic effects, capable of promoting melanoma cell death have become an important goal of research in oncotherapy. In this study, we want to investigate the anticancer activity of an enriched total oligomers flavonoids (TOF) extract of R. alaternus in melanoma cells. First, TOF was exhibited to be rich in flavones. We revealed that this extract reduced proliferation and increased of sub-G1 and S phase cells built-up in B16-F10 cells in a dose-related manner. Moreover, In Vivo, TOF reduced tumor volume and weight with percentages of inhibition of 92.4% and 92.9%, respectively. R. alaternus was also found to be effective in reducing the level of pro-inflammatory cytokine IL-6 during metastasis. Level of TH1 cytokine, such as IL-2, was significantly enhanced by TOF treatment. Indeed, the histological examination of the tumor revealed the absence of mitoses and the presence of numerous melanin pigmented macrophage cells in the R. alaternus extract-treated group that could be explained by the induction of macrophage activation and by the arrest of the cell cycle in the Sub-G1 and S phases.

Assessment of Rhamnus alaternus Leaves Extract: Phytochemical Characterization and Antimelanoma Activity

Rhamnus alaternus (Rhamnaceae) has been used as a laxative, purgative, diuretic, antihypertensive, and depurative. However, few scientific research studies on its antimelanoma activity have been reported. This study aimed to investigate the in vitro antimelanoma effect of an enriched total oligomer flavonoid (TOF) extract, from R. alaternus, and to identify its phytochemical compounds. The chemical composition of TOF extract was assessed by HPLC-electrospray ionization tandem mass spectrometry (HPLC/ESI-MS²) analysis. Antimelanoma activity was determined on cultured tumor cell B16F10 by the crystal violet assay, the alkaline comet assay, acridine orange/ethidium bromide (AO/EB), annexin V-fluorescein isothiocyanate/ propidium iodide (V-FITC/PI) staining, the cell cycle distribution, and the wound healing assay. Regarding chemical composition, a mixture of quercetin diglucoside, quercetin-3-O-neohesperidoside, kaempferol-3-O-(2G-α-L-rhamnosyl)-rutinoside, rhamnetin hexoside, kaempferol-3-O-rutinoside, rhamnocitrin hexoside, pilosin hexoside, apigenin glucoside, and kaempferol-3-O-glucoside was identified as major phytochemical compounds of the extracts. TOF extract inhibits melanoma B16F10 cell proliferation in dose-dependent manner. The induction of apoptosis was confirmed by comet assay, AO/EB, and annexin V-FITC/PI test. TOF extract could also induce S phase cell cycle, inhibit, and delay the cell migration of B16F10 cells. The findings showed that TOF extract from R. alaternus could be a potentially good candidate for future use in alternative antimelanoma treatments.

Rhamnusalaternus Plant: Extraction of Bioactive Fractions and Evaluation of Their Pharmacological and Phytochemical Properties

Rhamnus alaternus, is a wild-growing shrub, belonging to the Rhamnaceae family. Widely distributed in the Mediterranean basin, R. alaternus is used in the usual medicine in numerous countries, mostly Tunisia, Algeria, Morocco, Spain, France, Italy, and Croatia. A large number of disorders-including dermatological complications, diabetes, hepatitis, and goiter problems-can be treated by the various parts of R. alaternus (i.e., roots, bark, berries, and leaves). Several bioactive compounds were isolated from R. alaternus, including flavonoids, anthocyanins, and anthraquinones, and showed several effects such as antioxidant, antihyperlipidemic, antigenotoxic, antimutagenic, antimicrobial, and antiproliferative. This review summarizes the updated information concerning the botanical description, distribution, extraction processes applied on R. alaternus, and its ethnopharmacology, toxicity, phytochemistry, and pharmacological effects.

Antigenotoxic and Antimutagenic Effects of Andrographis paniculata, a Traditional Medicinal Herb against Genotoxicity of Cyclophosphamide: An In Vitro Study on Human Peripheral Lymphocytes

Andrographis paniculata (family: Acanthaceae) is a medicinal herb—used in Indian system of medicine (Ayurveda, Siddha, and Unani), traditional and folk systems to treat various illnesses. This study examined the phytochemical constituents of ethanol extract from A. paniculata and its protective effect against genotoxicity caused by cyclophosphamide (CPA). Phytochemical screening and estimation of total phenolic content were analyzed using standard methods. The bioactive components from the ethanol extract of A. paniculata (EAP) were analyzed using gas chromatography-mass spectrometry. To investigate the protective effect of EAP against CPA-induced genotoxicity, human peripheral lymphocyte cultures were used. To test the antigenotoxic and antimutagenic effects of EAP, lymphocytes were treated with different concentrations of extract (50∼250 mg/mL) alone and co-treated along with CPA+EAP for 48 h. The cells were analyzed for structural chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs) in control, CPA treated, and CPA+ EAP co-treated lymphocytes. Results of the study revealed that the lymphocyte cultures which had 48 h continuous exposure to EAP (50∼250 mg/mL) did not show any significant changes in CAs and SCE frequencies. These results substanti-ate the antimutagenic nature of the extract. Furthermore, the lymphocytes co-treated with CPA along with extract showed a significant reduction in CAs (reduced from 26.50±2.50% to 11.00±1.00%) and SCEs (reduced from 9.92±0.63 per cell to 4.56±0.18 per cell). These results suggest that A. paniculata is protective against CPA induced genotoxicity and put forward its possible use as a supplement with chemotherapeutic drugs.

Isolation and identification of new anthraquinones from Rhamnus alaternus L and evaluation of their free radical scavenging activity

From the butanolic and the ethyl acetate extracts of Rhamnus alaternus L root bark and leaves, three new anthraquinone glycosides, alaternosides A-C (1,4,6,8 tetrahydroxy-3 methyl anthraquinone 1-O-ß-D-glucopyranosyl-4,6-di-O-α-L-rhamnopyranoside (1); 1,2,6,8 tetrahydroxy-3 methyl anthraquinone 8-O-ß-D-glucopyranoside (2) and 1, 6 dihydroxy-3 methyl 6 [2'-Me (heptoxy)] anthraquinone (3)) were isolated and elucidated together with the two known anthraquinone glycosides, Physcion-8-O-rutinoside (4) and emodin-6-O-α-L-rhamnoside (5) as well as with the known kaempferol-7-methylether (6), β-sitosterol (7) and β-sitosterol-3-O-glycoside (8). Their chemical structures were elucidated using spectroscopic methods (1D-, 2D-NMR and FAB-MS). Free radical scavenging activity of the isolated compounds was evaluated by their ability to scavenge DPPH^. free radicals. Compounds (3), (4) and (6) showed the highest activity with IC₅₀ values of 9.46, 27.68 and 2.35 μg/mL, respectively.

Toxic Effects of Rhamnus alaternus: A Rare Case Report

In Tunisia, there are about 478 species of plants commonly used in folk medicine. Medicinal plants and herbal remedies used are responsible for 2% of intoxications listed by Tunisian National Poison Center. Most cases are related to confusion between edible plants and toxic plants lookalikes or to an excessive consumption of therapeutic plants. We report the case of a 58-year-old man admitted to the Emergency Department of the Regional Hospital of Zaghouan (Tunisia), with renal failure and rhabdomyolysis. The patient reported having daily consumption of a homemade tea based on Mediterranean Buckthorn roots, during the last 6 months to treat type 2 diabetes. The aim of this work was to establish an association between the consumption of the herbal remedy and the occurrence of both renal failure and rhabdomyolysis. No similar cases have been reported in recent literature.

Flavonoid profile, antioxidant and cytotoxic activity of different extracts from Algerian Rhamnus alaternus L. bark

Background:

Rhamnus alaternus (Rhamnaceae) L. has been traditionally used for treatment of many diseases.

Objective:

In this study, we determined the antioxidant/free radical scavenger properties, the flavonoid profile and the cytotoxicity of aqueous and methanolic extracts obtained by maceration from Algerian R. alaternus bark, like also of aqueous extract prepared by decoction according to the traditional method. This to estimate the usefulness of the drug traditional preparation and compare it with those made in the laboratory.

Materials and Methods:

The antioxidant activity of the extracts was evaluated using five different redox-based assays, all involving one redox reaction with the oxidant. High-performance liquid chromatography/diode array detection/electrospray ionization mass spectrometry analysis was used to identify and quantify the flavonoids content. Cytotoxicity on human monocytic leukemia cells (U937) was also carried out.

Results:

All the extracts tested showed a good antioxidant/free radical scavenger activity and a similar flavonoid fingerprint. However, the methanolic one presented the best antioxidant activity that can be due to the highest flavonoid amount and significantly reduced the proliferation of leukemia cells. The results confirm that the extract prepared by decoction contains efficient antioxidant compounds and this justifies in part the therapeutic and preventive usefulness. Moreover, the methanolic extract exerted excellent cytotoxicity on U937 that could be attributed to kaempferol and rhamnocitrin glycosides.

Herbalists and wild medicinal plants in M'Sila (North Algeria): an ethnopharmacology survey

ETHNOPHARMACOLOGICAL RELEVANCE

The main aim of this study was to identify, catalogue and document the large number of wild medicinal plants used in the M'Sila region (northern Algeria) for the treatment of several human pathologies. Another more ambitious aim is to contribute to overcoming the limits of an orally transmitted pharmacopoeia, attempting to exploit the large ethnopharmacology patrimony of the region for further pharmacological purposes.

MATERIALS AND METHODS

Our field study was carried out over a period of three years (2008-2010). During this period, herbalists were interviewed using semi-structured questionnaires investigating the herbalist as a holder of information (gender, age and educational level) and about wild medicinal plants (local name, uses and part used). In addition, the relative importance value of the species was determined and informant consensus factor (ICF) was calculated for the medicinal plants included in the study.

RESULTS

A total of 83 herbalists were interviewed; men dominate the practice of traditional medicine in the region. About 41% of them are between 31 and 40 years, and about a third (34%) are illiterate. The traditional herbal knowledge is passed from generation to generation in the verbal form, a writing tradition being almost totally absent. The interviewed herbalists identified and recorded 58 plants species and 50 genera belonging to 27 plant families. Lamiaceae and Asteraceae were the most represented plant families. The aerial parts were the most commonly used plant part, while infusion and decoction were the most common method of traditional drug preparation.

CONCLUSIONS

The survey provides a veritable source of information on the herbalists and wild medicinal plants. Plants which are used in different parts of the world for the treatment of similar diseases may be deemed to be effective in pharmacological terms. These medicinal plants may be incorporated into the healthcare delivery system of the country.

The influence of organic solvents on estimates of genotoxicity and antigenotoxicity in the SOS chromotest

In this work, the toxicity and genotoxicity of organic solvents (acetone, carbon tetrachloride, dichloromethane, dimethylsulfoxide, ethanol, ether and methanol) were studied using the SOS chromotest. The influence of these solvents on the direct genotoxicity induced by the mutagens mitomycin C (MMC) and 4-nitroquinoline-1-oxide (4-NQO) were also investigated. None of the solvents were genotoxic in Escherichia coli PQ37. However, based on the inhibition of protein synthesis assessed by constitutive alkaline phosphatase activity, some solvents (carbon tetrachloride, dimethylsulfoxide, ethanol and ether) were toxic and incompatible with the SOS chromotest. Solvents that were neither toxic nor genotoxic to E. coli (acetone, dichloromethane and methanol) significantly reduced the genotoxicity of MMC and 4-NQO. When these solvents were used to dissolve vitamin E they increased the antigenotoxic activity of this compound, possibly through additive or synergistic effects. The relevance of these results is discussed in relation to antigenotoxic studies. These data indicate the need for careful selection of an appropriate diluent for the SOS chromotest since some solvents can modulate genotoxicity and antigenotoxicity.

Antimutagenic and free radical scavenger effects of leaf extracts from Accacia salicina

Background

Three extracts were prepared from the leaves of Accacia salicina; ethyl acetate (EA), chloroform (Chl) and petroleum ether (PE) extracts and was designed to examine antimutagenic, antioxidant potenty and oxidative DNA damage protecting activity.

Methods

Antioxidant activity of A. salicina extracts was determined by the ability of each extract to protect against plasmid DNA strand scission induced by hydroxyl radicals. An assay for the ability of these extracts to prevent mutations induced by various oxidants in Salmonella typhimurium TA102 and TA 104 strains was conducted. In addition, nonenzymatic methods were employed to evaluate anti-oxidative effects of tested extracts.

Results

These extracts from leaf parts of A. salicina showed no mutagenicity either with or without the metabolic enzyme preparation (S9). The highest protections against methylmethanesulfonate induced mutagenicity were observed with all extracts and especially chloroform extract. This extract exhibited the highest inhibitiory level of the Ames response induced by the indirect mutagen 2- aminoanthracene. All extracts exhibited the highest ability to protect plasmid DNA against hydroxyl radicals induced DNA damages. The ethyl acetate (EA) and chloroform (Chl) extracts showed with high TEAC values radical of 0.95 and 0.81 mM respectively, against the ABTS^.+.

Conclusion

The present study revealed the antimutagenic and antioxidant potenty of plant extract from Accacia salicina leaves.

Anthraquinone Profile, Antioxidant and Antimicrobial Properties of Bark Extracts of Rhamnus catharticus and R. orbiculatus

The anthraquinone profile, antioxidant and antimicrobial activities as well as the total phenol and total flavonoid contents were determined in methanol extracts of the barks of Rhamnus catharticus L. and R. orbiculatus Bornm. The most abundant anthraquinone derivatives in R. catharticus were physcion (67.8%) and emodin (26.2%), while R. orbiculatus contained mostly physcion (81.3%) and chrysophanol (14.6%). R. catharticus displayed better activity in the β-carotene–linoleic acid assay, as well as chelating activity, whereas its activity in the reducing power assay was significantly lower than that of R. orbiculatus. Both methanol extracts showed antimicrobial activity against all microbial species tested ( Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, Aspergillus niger, Microsporum gypseum) with MIC values either equal to or lower than 2.50 mg/mL. R. catharticus and R. orbiculatus contained several anthranoid aglycones and their bark extracts demonstrated notable antioxidant and antimicrobial properties. The results obtained indicate the medicinal potential of these two species.

Anti-inflammatory and antiulcerogenic activities of leaf extracts and sesquiterpene from Teucrium ramosissimum (Lamiaceae)

Teucrium ramosissimum (Lamiaceae) is a native and endemic medicinal plant from South of Tunisia traditionally used for the treatment of many diseases. The anti-inflammatory and antiulcerogenic activities of sesquiterpene (β-eudesmol), chloroform, and ethyl acetate leaf extracts from T. ramosissimum were assayed. Macrophage phagocytic activity and lymphocyte proliferation in the absence and presence of mitogens (lipopolysaccharide [LPS] or lectin) were investigated. Depending on the concentrations, the extracts affect macrophage functions by modulating their lysosomal enzyme activity and nitric oxide (NO) release. For lymphocyte proliferation assay, tested extracts enhance significantly cell proliferation either with or without mitogen stimulation. These results suggest that leaf extracts from T. ramosissimum contain potent components such as flavonoids that may be potentially useful for modulating immune cell functions in physiological and pathological conditions. Antiulcerogenic activity was examined on rat ethanol-induced ulcerogenic model. Compared with control (cimetidine), leaf extracts from T. ramosissimum exert different protective effects against ethanol-induced ulcerogenesis.

Evaluation of antioxidant and antigenotoxic activity of two flavonoids from Rhamnus alaternus L. (Rhamnaceae): kaempferol 3-O-β-isorhamninoside and rhamnocitrin 3-O-β-isorhamninoside

The antioxidant activity of kaempferol 3-O-β-isorhamninoside (K3O-ir) and rhamnocitrin 3-O-β-isorhamninoside (R3O-ir), isolated from the leaves of Rhamnus alaternus L., was determined by the ability of each compound to inhibit NBT photoreduction and to scavenge the free radical ABTS(+)(.). Genotoxic and antigenotoxic activities were assessed using the SOS chromotest. At a concentration of 150 μg/assay the two compounds showed the most potent inhibitory activity against superoxide anion by respectively 80.4% and 85.6%. K3O-ir was a very potent radical scavenger with an IC(50) value of 18.75 μg/ml. Moreover, these two compounds exhibit an inhibitory activity against genotoxicity induced by nitrofurantoine and aflatoxine B1 using the SOS chromotest bacterial assay system in the presence of Escherichia coli PQ37 strain. In this study, we have also evaluated correlation between antigenotoxic and antioxidant effects of K3O-ir and R3O-ir. The highest correlation was showed with R3O-ir (r=0.999).

Assessment of isorhamnetin 3-O-neohesperidoside from Acacia salicina: protective effects toward oxidation damage and genotoxicity induced by aflatoxin B1 and nifuroxazide

Antioxidant activity of isorhamnetin 3-O-neohesperidoside, isolated from the leaves of Acacia salicina, was determined by the ability of this compound to inhibit xanthine oxidase activity and to scavenge the free radical 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS(.-)) diammonium salt. Antigenotoxic activity was assessed using the SOS chromotest assay. This compound has the ability to scavenge the ABTS(.+) radical by a hydrogen donating mechanism. We also envisaged the study of the antioxidant effect of this compound by the enzymatic xanthine/xanthine oxidase (X/XOD) assay. Results indicated that isorhamnetin 3-O-neohesperidoside was a potent inhibitor of xanthine oxidase and superoxide anion scavengers. Moreover, this compound induced an inhibitory activity against nifuroxazide and aflatoxine B1 (AFB1) induced genotoxicity. Taken together, these observations provide evidence that isorhamnetin 3-O-neohesperidoside isolated from the leaves of A. salicina is able to protect cells against the consequences of oxidative stress.

Chemical investigation of different crude extracts from Teucrium ramosissimum leaves. Correlation with their antigenotoxic and antioxidant properties

The effect of extracts obtained from Teucrium ramosissimum leaves on genotoxicity and SOS response induced by aflatoxin B(1) (0.5 μg/assay) as well as nitrofurantoin (5 μg/assay) was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. The T. ramosissimum tested extracts exhibited no genotoxicity either with or without the external S9 activation mixture. However, all the extracts, particularly the total oligomers flavonoids (TOF) extract significantly decreased the genotoxicity induced by aflatoxin B(1) and nitrofurantoin. Antioxidant capacity of the tested extracts was evaluated using the enzymatic (xanthine/xanthine oxidase assay) (X/XOD) and the non-enzymatic (NBT/Riboflavine assay) systems. TOF extract was the most effective one in inhibiting both xanthine oxidase activity and NBT reduction. Our findings emphasize the potential of T. ramosissimum to prevent mutations and also its antioxidant effect.

Leaf extracts from Phlomis crinita Cav. subs. mauritanica Munby affect immune cell functions in vitro

Aqueous and methanolic leaf extracts from Phlomis crinita subs. mauritanica Munby were investigated for their potential immunomodulatory activity on mouse lymphocytes and macrophages in vitro. The phagocytic activity of macrophages and the proliferation of lymphocytes in the absence and presence of mitogens (lipopolysaccharide, LPS or lectin) were assayed. Depending on the concentrations, the extracts affect macrophage functions by modulating their lysosomal enzyme activity and nitric oxide release. For lymphocyte proliferation assay, both extracts enhance significantly cell proliferation either with or without mitogen stimulation. These results suggest that leaf extracts from P. crinita subs. mauritanica Munby contain potent components such as flavonoids that potentially may be useful for modulating immune cell functions in physiological and pathological conditions.

Mutagenic, antimutagenic and antioxidant potency of leaf extracts from Nitraria retusa

Four extracts were prepared from the leaves of Nitraria retusa; methanol, ethyl acetate, chloroform and hexane extracts. An assay for the ability of these extracts to prevent mutations induced by various oxidants in Salmonella typhimurium TA102 and TA 104 strains was conducted. These extracts from leaf parts of N. retusa showed no mutagenicity either with or without the metabolic enzyme preparation (microsome fraction). The highest protection against methylmethanesulfonate induced mutagenicity was observed with chloroform and methanol extracts with inhibition percentages of 44.93% (at 50 microg/plate in the presence of TA102 strain) and 38% (at 10 microg/plate in the presence of TA104 strain), respectively. Whereas Hexane and chloroform extracts reduced the mutagenicity induced by 2-aminoanthracene by 83.4% (using the S. typhimurium TA104 assay system) and 65.3% (using the S. typhimurium TA 102 assay system), respectively. Antioxidant activity of N. retusa extracts was determined by the ability of each extract to protect plasmid DNA against strand scission induced by hydroxyl radicals. Chloroform extract exhibited the highest ability to protect plasmid DNA against hydroxyl radical induced DNA damages and exhibited the highest antioxidant capacity, with 0.95mM trolox equivalent when tested by the ferric reducing/antioxidant method.

Antigenotoxic and antioxidant activities of isorhamnetin 3-O neohesperidoside from Acacia salicina

Antioxidant activity of isorhamnetin 3-O neohesperidoside (I3ON), isolated from the leaves of Acacia salicina, was determined by the ability of this compound to inhibit lipid peroxidation and to protect against hydroxyl radical-induced DNA damage in pKS plasmid DNA and Escherichia coli cultures. Antigenotoxic activity was assessed by using the comet assay. The IC(50) value of the inhibitory activity toward lipid peroxidation by I3ON is 0.6 mM. This compound was also able to protect against hydroxyl radical-induced DNA damage in pKS plasmid DNA. Moreover, this compound induced an inhibitory activity toward H2O2-induced genotoxicity. The protective effect exhibited by this molecule was also determined by analysis of gene expression as a response to an oxidative stress, using a cDNA microarray. Transcription of several genes related to the antioxidant system (HMOX2 and TXNL) and to the DNA repair pathway (XPC, POLD1, POLD2, PCNA, DDIT3, APEX, and LIG4) were upregulated after incubation with I3ON. Taken together, these observations provide evidence that the I3ON, isolated from the leaves of A. salicina, is able to protect cells against oxidative stress.

Changes in antioxidant endogenous enzymes (activity and gene expression levels) after repeated red wine intake

The antioxidant properties of wine have been largely related to the reactive oxygen species (ROS) scavenging ability of phenolic compounds. Polyphenolic compounds are hardly absorbed and quickly transformed into metabolites. Their antioxidant activities just as radical scavenging properties are therefore limited, but it is worth looking to other mechanisms. This study intended to test whether wine consumption affects antioxidant enzyme activity and gene expression. For this purpose, eight subjects drank 300 mL of red wine every day for a week and ate a low phenolic diet (LPD + W) specifically designed to avoid interferences from other polyphenols in the diet. The control period was a week with this diet, and volunteers refrained from drinking wine (LPD). Blood samples were taken at 0, 1, and 7 days. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities were determined in erythrocytes (SOD), plasma (CAT and GR), and blood (GPx). Gene expression was determined in macrophages. Oxidative stress caused by LPD reduced SOD, CAT, and GR activities. After wine consumption, these activities significantly increased (P < 0.05), and this overcame the effect of oxidative stress on enzyme activity. The modulation of CAT activity may be independent of changes in their gene expression, which significantly increased after LPD. However, SOD gene expression increased only during the LPD + W week. Enzyme activities are not all regulated in the same way. The results show that subacute moderate wine ingestion modulated antioxidant enzyme expression and activity, which is important for the prevention of ROS-associated diseases.

Cell protection induced by Acacia salicina extracts: inhibition of genotoxic damage and determination of its antioxidant capacity

Antioxidant activity of Acacia salicina extracts was determined by the ability of each extract to inhibit lipid peroxidation, to protect against DNA strand scission induced by hydroxyl radicals, and to scavenge the free radical, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(*+)). The IC(50) values of the inhibitory activity toward lipid peroxidation of total oligomer flavonoids (TOF), methanol, ethyl acetate, and aqueous extracts were respectively 28, 52, 472, and 480 microg/mL. All extracts have the ability to scavenge the ABTS(*+) radical by a hydrogen-donating mechanism and to protect pKS plasmid DNA against hydroxyl radicals- induced DNA damage. An assay for the ability of A. salicina extracts to prevent mutations induced by various mutagens in Salmonella typhimurium TA102 and TA104 cells was conducted. TOF, methanol, ethyl acetate, and aqueous extracts from leaf parts of A. salicina showed no mutagenicity either with or without the metabolic enzymes preparation (S9). Protection against methylmethanesulfonate-induced mutagenicity was observed for TOF, methanol, and ethyl acetate extracts. Likewise, all extracts exhibited a high inhibition level of the Ames response induced by the indirect mutagen, 2-aminoanthracene. The antigenotoxic activity could be ascribed, at least in part, to their antioxidant properties, but we cannot exclude additionally mechanisms. Thus, A. salicina may serve as an ideal candidate for a cost- effective, readily exploitable natural phytochemical compound.

Antioxidant activity and inhibition of aflatoxin B1-, nifuroxazide-, and sodium azide-induced mutagenicity by extracts from Rhamnus alaternus L

The effect of extracts obtained from Rhamnus alaternus L. leaves on genotoxicity and SOS response induced by aflatoxin B(1) (10 microg/assay) as well as nifuroxazide (20 microg/assay) was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. The evaluation of the mutagenic and antimutagenic actions of the same extracts against the sodium azide (1.5 microg/plate)-induced mutagenicity was assayed using the Salmonella typhimurium assay system. The R. alaternus tested extracts exhibited no genotoxicity either with or without the external S9 activation mixture. However, all the extracts, particularly aqueous extract (A) and its chloroformic fraction (A(2)) significantly decreased the genotoxicity induced by aflatoxin B(1) and nifuroxazide. Moreover, the different extracts showed no mutagenicity when tested with Salmonella typhimurium strains TA1535 and TA1538 either with or without the S9 mix. Aqueous extract as well as its A(2) fraction exhibited the highest level of protection towards the direct mutagen, sodium azide-induced response in TA1535 strain with mutagenicity inhibition percentages of 83.6% and 91.4%, respectively, at a dose of 250 microg/plate. The results obtained by the Ames test assay confirm those of SOS chromotest. These same active extracts exhibited high xanthine oxidase (XOD) inhibiting with respective IC(50) values of 208 and 137 microg/ml, and superoxide anion-scavenging effects (IC(50) values of 132 and 117 microg/ml) when tested in the XOD enzymatic assay system. Our findings emphasize the potential of R. alaternus to prevent mutations and also its antioxidant effect.

Antimutagenic, antigenotoxic and antioxidant activities of Acacia salicina extracts (ASE) and modulation of cell gene expression by H2O2 and ASE treatment

The total oligomers flavonoids (TOF), chloroform, petroleum ether and aqueous extracts from Acacia salicina, were investigated for the antioxidative, cytotoxic, antimutagenic and antigenotoxic activities. The viability of K562 cells were affected by all extracts after 48 h exposure. Our results showed that A. salicina extracts have antigenotoxic and/or antimutagenic activities. TOF and chloroform extracts exhibit antioxidant properties, expressed by the capacity of these extracts to inhibit xanthine oxidase activity. To further explore the mechanism of action of A. salicina extracts, we characterized expression profiles of genes involved in antioxidant protection and DNA repair in the human lymphoblastic cell line K562 exposed to H2O2. Transcription of several genes related to the thioredoxin antioxidant system and to the DNA base-excision repair pathway was up-regulated after incubation with chloroform, TOF and petroleum ether extracts. Moreover genes involved in the nucleotide-excision repair pathway and genes coding for catalase and Mn-superoxide-dismutase, two important antioxidant enzymes, were induced after incubation with the chloroform extract. Taken together, these observations provide evidence that the chloroform and TOF extracts of A. salicina leaves contain bioactive compounds that are able to protect cells against the consequences of an oxidative stress.