Elsevier

Food and Chemical Toxicology

Volume 50, Issue 9, September 2012, Pages 3352-3359
Food and Chemical Toxicology

Gentiana asclepiadea exerts antioxidant activity and enhances DNA repair of hydrogen peroxide- and silver nanoparticles-induced DNA damage

https://doi.org/10.1016/j.fct.2012.06.017Get rights and content

Abstract

Exposure to high levels of different environmental pollutants is known to be associated with induction of DNA damage in humans. Thus DNA repair is of great importance in preventing mutations and contributes crucially to the prevention of cancer. In our study we have focused on quantitative analysis of Gentiana asclepiadea aqueous or methanolic extracts obtained from flower and haulm, their antioxidant potency in ABTS post-column derivatisation, and their potential ability to enhance DNA repair in human lymphocytes after hydrogen peroxide (H2O2) treatment (250 μM, 5 min). We also studied DNA repair in human kidney HEK 293 cells after exposure to 20 nm silver nanoparticles (AgNPs) (100 μg/ml, 30 min) in the presence and absence of the plant extract. We have found that mangiferin along with unidentified polar compounds are the most pronounced antioxidants in the studied extracts. Extract from haulm exhibited slightly stronger antioxidant properties compared to flower extracts. However, all four extracts showed significant ability to enhance DNA repair in both cell types after H2O2 and AgNP treatments.

Highlights

► We performed a quantitative analysis of Gentiana asclepiadea aqueous and methanolic extracts. ► Mangiferin and an unidentified polar compound are the most pronounced antioxidants. ► Extract from haulm exhibited stronger antioxidant properties compared with flower extracts. ► Flower and haulm extracts enhanced repair of H2O2-induced DNA damage in human lymphocytes. ► Repair of DNA damage induced by nanosilver was stimulated by plant extracts in HEK 293 cells.

Introduction

The balance between antioxidation and oxidation is believed to be a critical factor in maintaining a healthy biological system (Dudonné et al., 2009). In recent years, many studies have indicated the important role of free radicals and reactive oxygen species (ROS) in the aetiology and progress of many human diseases (Heo et al., 2010; Skandrani et al., 2010a, Skandrani et al., 2010b). ROS such as superoxide radical (O2-), hydrogen peroxide (H2O2), hydroxyl radical (radical dotOH), and singlet oxygen (1O2), are of the greatest biological significance. ROS are produced continuously in all cells, as metabolic byproducts of a number of intracellular systems (Martínez-Cayuela, 1995).

In addition to endogenous sources of free radicals, there are many exogenous factors that cause ROS production in cells. For example some nanomaterials are considered to cause oxidative damage (Halamoda Kenzaoui et al., 2012). Among the 580 nanotechnology-based consumer products, silver nanoparticles (AgNPs) are the most common material (Woodrow Wilson International Center, 2007). Apart from applications in medicine, AgNPs are being widely used for water purification, food service and personal care products, and also in indoor air quality management (Cheng et al., 2004, Jain and Pradeep, 2005, Park et al., 2010, Zhang and Sun, 2007). There is evidence that AgNP exposure induces the generation of free oxygen radicals. This oxidative stress subsequently results in DNA damage and ultimately apoptosis (Ahamed et al., 2010, Hudecova et al., 2012d).

DNA is prone to oxidation by endogenous ROS as well as exogenous agents (including radiation and chemicals) and this can lead to different types of DNA damage (Sevcovicova and Hercegova, 2010). This damage can be either repaired or tolerated. Mis-repaired or unrepaired DNA lesions are likely to be mutagenic and thus can lead to carcinogenesis. The ability to repair DNA damage is associated with a decreased risk of cancer and possibly other human diseases. Protection of DNA from damage or modulation of DNA repair thus contribute to preventing mutations and maintaining genomic stability (Kovacs, 2002, Ramos et al., 2010). Mechanisms of oxidative DNA damage repair can differ significantly between organisms and cell types (Aherne et al., 2007, Baute and Depicker, 2008, Dianov and Parsons, 2007). The repair pathways include base excision repair (BER), nucleotide excision repair (NER) and mismatch repair (MMR) (Friedberg, 1985).

The comet assay is a simple and reliable method to detect DNA damage and can also be used for assessment of DNA repair (Azqueta et al., 2011). Both the in vitro DNA repair assay (Collins et al., 2012) as well as cellular DNA repair phenotype assays, called challenge assays (Decordier et al., 2010) have been successfully used to assess activity of different DNA repair pathways. Collins et al. (2012) reviewed evidence that DNA repair can be affected by phytochemicals and various components of diet.

There has been an increasing demand for antioxidants of plant origin in the food, beverage and cosmetic industries, and efforts have been made to identify new natural sources for active antioxidant phytochemicals (Dudonné et al., 2009, Skandrani et al., 2010a, Skandrani et al., 2010b). Plants synthesize antioxidant compounds as secondary products, mainly phenolics serving in plant defence mechanisms that counteract ROS and thus avoid oxidative damage. The antioxidant activities of phenolics are due to a number of different mechanisms, such as free-radical scavenging, hydrogen donation, singlet oxygen quenching, metal ion chelation, antioxidant enzyme activation, and acting as substrate for radicals such as superoxide or hydroxyl (Niciforovic et al., 2010).

Gentiana asclepiadea is a plant belonging to the family Gentianaceae. The dried roots and rhizomes have been traditionally used in folk medicine as remedies for poor appetite and digestive problems or even for hepatitis A virus infections (Mihailović et al., 2011, Saric, 1989). It is also used in small amounts as food and beverage flavouring, in antismoking products and even as a substitute for hops in making beer. It contains a variety of phytochemicals (mangiferin, swertiamarine, gentiopicroside, homoorientin/isoorientin, amaroswerine, sweroside and others) with some positive bioactivities. In our previous studies we have shown antioxidant, antigenotoxic and biomodulatory effects of G. asclepiadea extracts on various cells (including lymphocytes and HEK 293 cells) exposed to different agents (H2O2, zeocin, AgNPs) (Hudecova et al., 2010, Hudecova et al., 2012a, Hudecova et al., 2012b, Hudecova et al., 2012c, Hudecova et al., 2012d). Here we have studied the antioxidant activities of separated compounds by using the on-line method with 2,2´-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical cations (ABTS), post-column derivatisation. We have also used the cellular DNA repair ‘challenge’ assay with the alkaline comet assay to examine the effect of G. asclepiadea extracts on DNA repair in human peripheral blood mononuclear cells treated with H2O2 and HEK 293 cells treated with AgNPs. Both agents were previously shown to cause DNA oxidation resulting in strand breaks and oxidised DNA lesions (Ahamed et al., 2010, Piao et al., 2011, Hudecova et al., 2010, Hudecova et al., 2012a, Hudecova et al., 2012c, Hudecova et al., 2012d).

Section snippets

Preparation of extracts from G. asclepiadea

G. asclepiadea extracts were prepared as follows: plants were harvested from the Garden of Medicinal Plants, Faculty of Pharmacy, Comenius University, Bratislava (Slovakia) in August 2008. The separated plant material, weighing about 60 g, was air-dried to dryness at room temperature, cut into small pieces and then extracted with 150 ml of methanol or water at 65 °C. This procedure was repeated 5-times. The extract was then filtered and concentrated in vacuum and the rest of the water was removed

Composition of bioactive compounds in G. asclepiadea extracts

The most abundant bioactive components of family Gentianaceae are iridoids, xanthones, mangiferin, and C-glucoflavones (Jensen and Schripsema, 2002). On the basis of comparison of the retention times, peak orders, and spectral data with those of available standards three secoiridoids (swertiamarin, gentiopicroside, sweroside), two C-glucoflavones (isovitexin, homoorientin) and one xanthonoid (mangiferin) were identified in G. asclepiadea extracts. In the absence of other reference compounds,

Conflict of Interest

The authors declare that there are no conflicts of interest.

Acknowledgments

We would like to thank Fridrich Gregáň and Dagmar Vaculčíková (Department of Chemistry, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01, Banská Bystrica, Slovakia) for providing us the Gentiana asclepiadea extracts and Andrew R. Collins for reviewing manuscript. This work was supported by Polish-Norwegian Research Fund 115 [PRNF/122-A I-1/07], VEGA: 1/0025/11; 2/0072/09; APVT-20-00-2604 and NILU internal grant 106170. Granted governmental scholarships of Ministry of

References (45)

  • M.J. Piao et al.

    Silver nanoparticles induce oxidative cell damage in human liver cells through inhibition of reduced glutathione and induction of mitochondria-involved apoptosis

    Toxicol. Lett.

    (2011)
  • I. Skandrani et al.

    Assessment of phenolic content, free-radical-scavenging capacity genotoxic and anti-genotoxic effect of aqueous extract prepared from Moricandia arvensis leaves

    Food Chem. Toxicol.

    (2010)
  • M.L. Zeraik et al.

    Evaluation of the antioxidant activity of passion fruit (Passiflora edulis and Passiflora alata) extracts on stimulated neutrophils and myeloperoxidase activity assays

    Food Chem.

    (2011)
  • P. Zheng et al.

    Genetic diversity and gentiopicroside content of four Gentiana species in China revealed by ISSR and HPLC methods

    Biochem. Syst. Ecol.

    (2011)
  • D. Zielińska et al.

    Antioxidant activity of flavone C-glucosides determined by updated analytical strategies

    Food Chem.

    (2011)
  • S.A. Aherne et al.

    Effects of plant extracts on antioxidant status and oxidant-induced stress in Caco-2 cells

    Br. J. Nutr.

    (2007)
  • Azqueta A., Shaposhnikov, S., Collins, A.R., 2011. DNA Repair Measured by the comet assay, DNA Repair, Dr. Inna Kruman...
  • J. Baute et al.

    Base excision repair and its role in maintaining genome stability

    Crit. Rev. Biochem. Mol. Biol.

    (2008)
  • A.R. Collins et al.

    Effects of micronutrients on DNA repair

    Eur. J. Nutr.

    (2012)
  • D. Cheng et al.

    Antibacterial materials of silver nanoparticles application in medical appliances and appliances for daily use

    Chin. Med. Equip. J.

    (2004)
  • A. Dar et al.

    Analgesic and antioxidant activity of mangiferin and its derivatives: the structure activity relationship

    Biol. Pharm. Bull.

    (2005)
  • S. Dudonné et al.

    Comparative study of antioxidant properties and total phenolic content of 30 plant extracts of industrial interest using DPPH, ABTS, FRAP, SOD, and ORAC assays

    J. Agric. Food Chem.

    (2009)
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