In VivoGenotoxicity Evaluation of an Artichoke(Cynara scolymusL.)Aqueous Extract

Evaluation of the Protective and Regenerative Properties of Commercially Available Artichoke Leaf Powder Extract on Plasma and Liver Oxidative Stress Parameters

Hepatocellular damage by the harmful effects of xenobiotics, which increase the production of free radicals, is a widespread phenomenon. The extract from the leaves of Cynara scolymus L. available as an artichoke preparation (natural source) of antioxidants may serve as a potential hepatoprotective factor. This study aimed to evaluate the impact of the protective and regenerative properties of artichoke preparation on the liver in three extract doses: 0.5; 1.0; and 1.5 g/kg bw/day. The evaluation was conducted by measuring the levels of oxidative stress parameters, including glutathione (GSH), glutathione S-transferases (GST), nitric oxide (NO), superoxide dismutase (SOD), catalase (CAT), Trolox equivalent antioxidant capacity (TEAC), thiobarbituric acid reactive substances (TBARS), glutathione peroxidase (GPx), paraoxonase 1 (PON1), SH- group, nitrosylated protein (RSNO), as well as such liver enzymes as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in the plasma and liver homogenate of rats with liver damage induced by CCl4 (1 mL/kg bw). Measurements were taken in plasma and liver homogenate. The results have demonstrated that the artichoke preparation, owing to its high antioxidative potential, exhibits protective and regenerative effects on the liver. This is supported by the observation of higher GSH levels in the plasma of rats treated with artichoke extract for two weeks before CCl4 exposure. Furthermore, the artichoke extract has shown regenerative properties, as evidenced by lower ALT, AST, and SOD activity in the group treated with artichoke extract after CCl4 exposure. These findings suggest that the in vivo administration of artichoke preparation may be beneficial for the protection and regeneration of the liver.

Repeated oral dose toxicity and genotoxicity of a standardized Quisqualis indica extract

Quisqualis indica L. of Combretaceae family is a traditional medicine that is widely used for various gastrointestinal discomfort including stomach pain, constipation, and digestive problem. In this study, the potential repeated dose toxicity and genotoxicity of a standardized Quisqualis indica L. extract (HU033) were determined under good laboratory practice conditions. For the repeated dose toxicity test, HU033 was orally administered to Sprague-Dawley (SD) rats at doses of 500, 1000, and 2000 mg/kg/day for 13 consecutive weeks. The genotoxicity of HU033 was determined with a standard battery of genotoxicity test, including an in vitro bacterial reverse mutation test, an in vitro chromosomal aberration test, and an in vivo micronucleus test. After 13 weeks of repeated dose of HU033 by oral administration, there was no treatment related adverse clinical sign including food consumption, organ weights, and histopathological findings or significant decrement in bodyweight. The no-observed-adverse-effect level of HU033 was higher than 2000 mg/kg in both male and female SD rats. No target organs were identified. In addition, no evidence of HU033 genotoxicity was detected based on results from the bacterial reverse mutation test, chromosomal aberration test, and micronucleus test. Based on results of this study, HU033 could be safely used in food and medical products within the tested dose range.

Genotoxicity Comparison between Morinda citrifolia Fruit and Seed Substances

This study aimed to evaluate the genotoxic potential of the fruit and seed powder, fruit puree, and aqueous extracts of Morinda citrifolia (Rubiaceae, noni). The genotoxic potential of the noni substances was evaluated using in vitro Ames, in vitro chromosomal aberration, and in vivo micronucleus tests. All test procedures were conducted per Organization for Economic Cooperation and Development guidelines, and good laboratory practice. None of the noni fruit test substances showed genotoxic signs up to 5000 and 2000 μg/plate in the Ames and micronucleus tests, respectively. In the chromosomal aberration test, neither the fruit puree nor aqueous extract showed structural and numerical aberrations up to 5000 and 4650 μg/mL, respectively, irrespective of metabolic activation, in both 6 h and 24 h treatment groups. The safe ranges of noni fruit and seed powders were up to 2500 and 2100 μg/mL, respectively, in the 6 h treatment group and up to 1600–4100 and 370–450 μg/mL, respectively, in both 6 h and 24 h treatment groups in the presence of metabolic activation. Noni fruit and seeds were safe in terms of genotoxicity under our experimental conditions. Our data are the first to provide valuable genotoxic information on Morinda citrifolia.

In vivo and in vitro toxicological evaluations of aqueous extract from Cecropia pachystachya leaves

leaves are popularly used to treat asthma and diabetes. Despite the widespread consumption of this plant, there are few scientific studies regarding its toxicological potential. In order to conduct a thorough study concerning the potential adverse effects, the aim of this study was to assess acute and subacute toxicity tests of crude aqueous extract from C. pachystachya leaves (CAE-Cp) using in vivomodel, as well as in vitro cytotoxicity, genotoxicity and antioxidant activity. In addition, genotoxicity, and cytotoxicity of chlorogenic acid (CGA) and cytotoxicity of isoorientin (ISOO) were also evaluated. The antioxidant activity was verified by DPPH, cytotoxicity using sulforhodamine B (SRB) assay and genotoxicity by comet assay on V79 cells. The phytochemical analysis of CAE-Cp detected flavonoids and tannins, CGA and ISOO as the major compounds utilizing HPLC. The total flavonoid content (6.52 mg/g EQ) and antioxidant activity (EC₅₀ = 62.15 µg/ml) of CAE-Cp were determined. In vitro evaluations with CAE-Cp showed genotoxic effects at 0.31 to 2.5 mg/ml and an expressive cytotoxicity on HT-29 (IC₅₀ = 4.43 µg/ml) cells. CGA was genotoxic against V79 cells at 0.07 mg/ml and cytotoxic against to HT-29 (IC₅₀ = 71.70 µg/ml), OVCAR-3 (IC₅₀ = 80.07 µg/ml), MCF-7 (IC₅₀ = 45.58 µg/ml) and, NCI-H460 (IC₅₀ = 71.89 µg/ml) cancer cell lines. Wistar rats treated with a single dose (2,000 mg/kg) CAE-Cp decreased hemoglobin levels after 14 days, although no significant toxicity was observed in animals after 28 days. In view of the in vitro cytotoxicity and genotoxicity detected, further studies are necessary to establish the safe use of CAE-Cp.

Aqueous extract of Forsythia viridissima fruits: Acute oral toxicity and genotoxicity studies

ETHNOPHARMACOLOGICAL RELEVANCE

Forsythia viridissima fruit, one of Forsythiae Fructus (FF) is widely used in traditional medicine to treat diverse diseases-related clinical symptoms, including fever, pain, vomiting, nausea, and abscess. However, the safety of FF has not been fully assessed.

AIM OF THE STUDY

In this study, we evaluated the acute oral toxicity and genotoxic potential of an aqueous extract of Forsythia viridissima fruits (EFVF).

MATERIALS AND METHODS

For an acute oral toxicity test, male and female SD rats (n = 5) orally received a single dose of 5000 mg/kg EFVF. The genotoxic potential of EFVF was evaluated with a battery of tests, including an in vitro bacterial reverse mutation test using five mutant strains of Salmonella typhimurium (TA100, TA1535, TA98, TA1537) and Escherichia coli (WP2 uvrA), an in vitro chromosomal aberration test using Chinese hamster lung (CHL/IU) cells, and an in vivo micronucleus test using bone marrow cells in male ICR mice that were orally administered EFVF. All tests were completed in compliance with Organization for Economic Cooperation and Development guidelines and/or regional regulatory standards for toxicity tests.

RESULTS

In the acute oral toxicity test, the animals did not show any significant mortality and body weight changes for 14 days following a single dose of EFVF at 5000 mg/kg. There was no evidence of genotoxicity of EFVF based on the results of the in vitro bacterial reverse mutation test (up to 5000 μg/plate), the in vivo micronucleus test (up to 5000 mg/kg), and the in vitro chromosomal aberration test (1100-2500 μg/mL).

CONCLUSIONS

We found that EFVF is safe with regard to acute toxicity in rats as well as genotoxicity such as mutagenesis or clastogenesis under the present experimental conditions. These results might support the safety of EFVF as a potential therapeutic material for the traditional use or pharmaceutical development.

Genotoxicity evaluation of a Phragmitis rhizoma extract using a standard battery of in vitro and in vivo assays

ETHNOPHARMACOLOGICAL RELEVANCE

A rhizome of Phragmites communis Trinius has been used in traditional medicine to remove a heat, relieve vomiting and fever, nourish body fluids, and treat diseases like cancers. However, the safety of Phragmitis rhizoma has not yet been fully assessed.

AIM OF THE STUDY

The present study evaluated the genotoxicity of an aqueous extract of Phragmitis rhizoma (AEPR).

MATERIALS AND METHODS

The genotoxic potential of AEPR was evaluated using both in vitro and in vivo assay systems: a bacterial reverse mutation (AMES) test using auxotrophic mutant strains of Salmonella typhimurium (TA100, TA1535, TA98, TA1537) and Escherichia coli (WP2 uvrA), a chromosomal aberration test using Chinese hamster lung cells, and a micronucleus test using bone marrow cells from male ICR mice subjected to an oral administration of AEPR. All tests were completed in compliance with the OECD guidelines or regional regulatory standards for toxicity study, and Good Laboratory Practice.

RESULTS

When compared with the negative control, no genotoxic signs related to the AEPR treatment were observed in the AMES test up to 5000 μg/plate of AEPR and in the chromosomal aberration test up to 500 μg/ml of AEPR regardless of metabolic activation. Repeated oral administration of AEPR up to 5000 mg/kg/day for 2 days did not affect the body weight gains or mortalities of the experimental mice and did not induce any significant changes in the frequency of micronucleated polychromatic erythrocytes.

CONCLUSIONS

The present study demonstrated that aqueous extract of Phragmitis rhizoma is safe regarding genotoxicity in an experimental model at least under the conditions tested. Further toxicity assessment in a human clinical study should be done to support the safe use of Phragmitis rhizoma by patients and healthcare providers.

In vitro genotoxic and antigenotoxic effects of cynarin

ETHNOPHARMACOLOGICAL RELEVANCE

Cynarin is an artichoke phytochemical that possesses a variety of pharmacological features including free-radical scavenging and antioxidant activity. The origin of artichoke species appears to be Mediterranean region. Two of these species, globe artichoke (Cynara cardunculus var. scolymus L.) and cardoon (Cynara cardunculus var. altilis DC), are widely cultivated and consumed. This vegetable, as the basis of the mediterranean diet, has been used as herbal medicine for its therapeutic effects since ancient times. Therefore, this study was performed to determine genotoxic and antigenotoxic effects of cynarin against MMC (mitomycin C) and H₂O₂ (hydrogen peroxide) induced genomic instability using chromosome aberrations (CAs), sister chromatid exchanges (SCEs), micronucleus (MN), and comet assays in human lymphocytes.

MATERIALS AND METHODS

Lymphocytes obtained from two healthy volunteers (1 male and 1 female) were exposed to different concentrations of cynarin (12-194 μM) alone and the combination of cynarin and MMC (0.60 μM) or cynarin and H₂O₂ (100 μM, only for comet assay).

RESULTS

Cynarin alone did not induce significant genotoxic effect in the CA, SCE (except 194 μM), MN, and comet assays. The combination of some concentrations of cynarin and MMC decreased the frequency of CAs, SCEs and MN induced by MMC. Furthermore, the combination of cynarin and H₂O₂ reduced all comet parameters at all the concentrations compared to H₂O₂ alone. While the highest concentrations of cynarin significantly decreased mitotic index (MI), the combination of cynarin and MMC increased the reduction of MI induced by MMC alone.

CONCLUSION

All the results obtained in this study demonstrated that cynarin exhibited antigenotoxic effects rather than genotoxic effects. It is believed that cynarin can act as a potential chemo-preventive against genotoxic agents.

The role of artichoke leaf tincture (Cynara scolymus) in the suppression of DNA damage and atherosclerosis in rats fed an atherogenic diet

CONTEXT

Polyphenols and flavonoids in artichoke leaf tincture (ALT) protect cells against oxidative damage.

OBJECTIVES

We examined ALT effects on deoxyribonucleic acid (DNA) damage and lipid profiles in rat plasma and gene expression in rat aorta [haemeoxygenase-1 (HO1), haemeoxygenase-2 (HO2), NADPH oxidase 4 (NOX-4), monocyte chemoattractant protein-1 (MCP-1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2)].

MATERIALS AND METHODS

Eighteen male Wistar albino rats were divided into three groups (n = 6/group): The control group (CG) was fed with standard pellet chow for 11 weeks; the AD group was fed for a similar period of time with pellet chow supplemented with 2% cholesterol, 3% sunflower oil and 1% sodium cholate. The ADA group was fed with pellet chow (for 1 week), the atherogenic diet (see above) for the following 4 weeks and then with ALT (0.1 mL/kg body weight) and atherogenic diet for 6 weeks. According to HPLC analysis, the isolated main compounds in ALT were chlorogenic acid, caffeic acid, isoquercitrin and rutin.

RESULTS

Normalized HO-1 [0.11 (0.04-0.24)] and MCP-1 [0.29 (0.21-0.47)] mRNA levels and DNA scores [12.50 (4.50-36.50)] were significantly lower in the ADA group than in the AD group [0.84 (0.35-2.51)], p = 0.021 for HO-1 [0.85 (0.61-3.45)], p = 0.047 for MCP-1 and [176.5 (66.50-221.25)], p = 0.020 for DNA scores. HO-1 mRNA was lower in the ADA group than in the CG group [0.30 (0.21-0.71), p = 0.049].

CONCLUSIONS

Supplementation with ALT limited the effects of the atherogenic diet through reduced MCP-1 expression, thereby preventing oxidative damage.

Quantitative genotoxicity assays for analysis of medicinal plants: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants are known to contain numerous biologically active compounds, and although they have proven pharmacological properties, they can cause harm, including DNA damage.

AIM OF THE STUDY

Review the literature to evaluate the genotoxicity risk of medicinal plants, explore the genotoxicity assays most used and compare these to the current legal requirements.

MATERIAL AND METHODS

A quantitative systematic review of the literature, using the keywords "medicinal plants", "genotoxicity" and "mutagenicity", was undertakenQ to identify the types of assays most used to assess genotoxicity, and to evaluate the genotoxicity potential of medicinal plant extracts.

RESULTS

The database searches retrieved 2289 records, 458 of which met the inclusion criteria. Evaluation of the selected articles showed a total of 24 different assays used for an assessment of medicinal plant extract genotoxicity. More than a quarter of those studies (28.4%) reported positive results for genotoxicity.

CONCLUSIONS

This review demonstrates that a range of genotoxicity assay methods are used to evaluate the genotoxicity potential of medicinal plant extracts. The most used methods are those recommended by regulatory agencies. However, based on the current findings, in order to conduct a thorough study concerning the possible genotoxic effects of a medicinal plant, we indicate that it is important always to include bacterial and mammalian tests, with at least one in vivo assay. Also, these tests should be capable of detecting outcomes that include mutation induction, clastogenic and aneugenic effects, and structural chromosome abnormalities. In addition, the considerable rate of positive results detected in this analysis further supports the relevance of assessing the genotoxicity potential of medicinal plants.

Non-clinical toxicity studies on bioactive compounds within the framework of nutritional and health claims

The growing presence of products on the market with added value in terms of health makes essential their regulation and harmonization in critical aspects such as safety. The toxicology applied to the bioactive compounds should demonstrate the absence of toxic effects at doses advised for consumption, as well as evaluate the potential toxic effects in the assumption that the products are used in quantities superior to those recommended. The specific strategy should be defined case by case; therefore, prior to any toxicological development, it is essential to study all the information regarding the bioactive compounds (BACs) characterization, nutridynamics and nutrikinetics, that is available. In this guideline, a general strategy to be applied in the development of BACs is proposed. It includes a first in vitro phase to discard genotoxicity and endocrine effects and a second in vivo phase with different possibilities regarding the duration and the extension of the studies.

Protective activity of Cynara scolymus L. leaf extract against chemically induced complex genomic alterations in CHO cells

Cynara scolymus L., popularly known as artichoke, has been widely used in traditional medicine as an herbal medicament for therapeutic purposes. The study aimed at assessing the protective activity of Cynara scolymus leaf extract (LE) against DNA lesions induced by the alkylating agent ethylmethnesulphonate (EMS) in Chinese hamster ovary cells (CHO). The ability of C. scolymus L. LE to modulate the mutagenicity of EMS was examined using the cytokinesis block micronucleus (CBMN) cytome assay in three antigenotoxic protocols, pre- post- and simultaneous treatments. In the pre-treatment, C. scolymus L. LE reduced the frequencies of MNi and NBUDs induced by EMS in the lower concentration. In contrast, at the highest concentration (5 mg/ml) artichoke enhanced the frequency of MNi, potentiating EMS genotoxicity. In the simultaneous treatment only the induction of MNi was repressed by the exposure of cells to C. scolymus L. LE. No modification in genotoxicity was observed in LE post-treatment. The results obtained in this study suggest that lower concentrations of artichoke prevent chemically induced genomic damage in mammalian cells. In this context, the protective activity of C. scolymus L. could be associated to its constitutive antioxidants compounds.