Genotoxic and mutagenic effects of guarana (Paullinia cupana) in prokaryotic organisms

Mutagenic potential of medicinal plants evaluated by the Ames Salmonella/microsome assay: A systematic review

The Ames test has become one of the most commonly used tests to assess the mutagenic potential of medicinal plants since they have several biological activities and thus have been used in traditional medicine and in the pharmaceutical industry as a source of raw materials. Accordingly, this review aims to report previous use of the Ames test to evaluate the mutagenic potential of medicinal plants. A database was constructed by curating literature identified by a search on the electronic databases Medline (via Pubmed), Science Direct, Scopus, and Web of Science from 1975 to April 2020, using the following terms: "genotoxicity tests" OR "mutagenicity tests" OR "Ames test" AND "medicinal plants." From the research, 239 articles were selected, including studies of 478 species distributed across 111 botanical families, with Fabaceae, Asteraceae and Lamiaceae being the most frequent. It was identified that 388 species were non-mutagenic. Of these, 21% (83/388) showed antimutagenic potential, most notable in the Lamiaceae family. The results also indicate that 18% (90/478) of the species were mutagenic, of which 54% were mutagenic in the presence and absence of S9. Strains TA98 and TA100 showed a sensitivity of 93% in detecting plant extracts with mutagenic potential. However, the reliability of many reviewed studies regarding the botanical extracts may be questioned due to technical issues, such as testing being performed only in the presence or absence of S9, use of maximum doses below 5 mg/plate and lack of information on the cytotoxicity of tested doses. These methodological aspects additionally demonstrated that a discussion about the doses used in research on mixtures, such as the ones assessed with botanical extracts and the most sensitive strains employed to detect the mutagenic potential, should be included in a possible update of the guidelines designed by the regulatory agencies.

Guarana improves behavior and inflammatory alterations triggered by methylmercury exposure: an in vivo fruit fly and in vitro neural cells study

Methylmercury (MeHg) is a well-known environmental pollutant associated with neurological and developmental deficits in animals and humans. However, epidemiological data showed that people living in the Amazon region although exposed to MeHg do not present these effects probably due to the protective effect of certain foods. We hypothesized here if guarana, a highly caffeinated fruit and consumed on a daily basis by Amazon people, could have some protective effect against MeHg toxicity using two complementary approaches. To assess locomotor impairment and sleep disruption, we used fruit fly (Drosophila melanogaster) model, and to evaluate neuroinflammation, we used human SH-SY5Y neural cells by measuring inflammatory cytokines levels. Results showed that guarana had a protective effect on the locomotor activity of male fruit flies reducing the excessive sleepiness caused by MeHg and increasing daily activity. Also, guarana increased the viability of flies and attenuated neural cells mortality. In addition, guarana reduced all pro-inflammatory cytokines levels increased by MeHg, along with caspase-1, caspase -3, caspase-8, and 8-dOHG levels, whereas increased the anti-inflammatory (IL-10) cytokine levels, which was decreased by MeHg. Our study provides new insights on the protective effects of guarana on the viability, locomotor activity, sleep, and activity patterns in vivo and the in vitro neuronal anti-inflammatory effect against MeHg toxicity.

The mutagenic effect of psychostimulant modafinil in Wistar rats in vivo

The demands imposed by today's world require a fast and efficient society, then, significant section of the population looks for support from psychotropic medicine. Modafinil is a psychostimulant that promotes wakefulness, it being recommended for treatment of narcolepsy, obstructive sleep apnea, and shift-work sleep disorder, besides being a cognitive function potentiator. However, chemical components of drugs can alter genetic material. Thus, the present study evaluated the cytotoxic and clastogenic/mutagenic potential of 0.25, 0.50, and 0.75 mg of Modafinil/mL of corn oil/100g body weight in acute treatments and subacute treatments, 15 days, to Rattus norvegicus, treated via gavage in a single daily dose. The drug was not cytotoxic at any of the evaluated doses in either of the treatments. However, the medicine showed clastogenic/mutagenic activity in the acute treatment group at the standard dose and at double dose. Data from the present study indicates that there should be greater caution as to the use of this psychostimulant by human beings.

Antibacterial and antifungal activities of acetonic extract from Paullinia cupana Mart. seeds

The antibacterial and antifungal activities of the acetone extract from Paullinia cupana var. sorbilis Mart. (Sapindaceae) seeds, commonly called guarana, were assessed against selected bacterial and fungal strains. We tested the extract against both standard American Type Culture Collection (ATCC) and clinically isolated (CI) bacterial strains and three fungal strains. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values for bacteria and MIC and minimum fungicidal concentration for fungi were determined. The extract showed an activity against the nine bacterial strains tested, both CI and ATCC strains (MIC comprised between 32 and 128 μm/mL and MBC between 128 and 512 μm/mL), showing a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. Also, the tested fungi were sensitive to the extract (MIC between 125 and 250 μm/mL). The contemporaneous presence of different bioactivities in the extract from guarana suggests this plant as a source of bioactive substances.

Genotoxicity investigation of araticum(Annona crassiflora Mart., 1841, Annonaceae) using SOS-Inductest and Ames test

Although the use of medicinal plants or natural products has increased in recent decades all over the world, little information is available on their potential risk to health. Annona crassiflora Mart., a plant commonly known as araticum in Brazil, has been widely used in folk medicine for a long time since its seeds and leaves are often utilised in the treatment of cancer, snake bites, and venereal diseases, its fruits are consumed as tonic and astringent, and its bark powder has anti-fungal and anti-rheumatic properties. To evaluate the genotoxic and mutagenic properties induced by the ethanolic extract of araticum leaves, we performed the prophage λ induction (Inductest) and bacterial mutagenicity assays. We used Escherichia coli WP2s(λ) and RJF013 strains in the lysogenic induction test, whereas the mutagenic studies were carried out using Salmonella typhimurium histidine auxotroph strains TA97a, TA98, TA100, and TA102. Each experiment was performed three times in duplicate and included positive and negative controls. No statistically significant (p > 0.05) positive results were obtained for any of the strains tested, which suggests that the ethanolic extract of araticum leaves did not exhibit direct mechanisms of genotoxicity or mutagenicity that could be detected by the tests used in the present work.

Habitual intake of guaraná and metabolic morbidities: an epidemiological study of an elderly Amazonian population

The aim of the present study was to evaluate the associations of metabolic disorders and anthropometric and biochemical biomarkers of lipid, glucose and oxidative metabolism and the habitual ingestion of guaraná (Paullinia cupana, Mart. Var. sorbilis) by an elderly population residing in the Amazon Riverine region of the Maués municipality (Brazil). A case-controlled study was performed that included 637 elderly (≥60 years of age) patients classified as either those who habitually drank guaraná (GI, n = 421) or those who never drank guaraná (NG, n = 239) based upon their self-reported intake of guaraná. Indeed, the prevalence of various metabolic disorders was associated with guaraná ingestion. The prevalence of hypertension, obesity and metabolic syndrome in the GI group was lower than the prevalence found in the NG group. The NG group exhibited lower systolic and diastolic blood pressure values. The males in the GI group exhibited a lower waist circumference, on average, than the circumference found in the NG group, whereas the females in the GI group had lower cholesterol (total and LDL-c) levels than the control cohort. Additionally, a significant association was found between lower levels of advanced oxidative protein product (AOPP) and habitual guaraná consumption. The results constitute the first epidemiological study to suggest a potentially protective effect of habitual guaraná ingestion against metabolic disorders in elderly subjects.

Assessment of the mutagenic and antimutagenic activity of Synadenium umbellatum Pax latex by micronucleus test in mice

Synadenium umbellatum Pax, popularly known as "cola-nota", is a medicinal plant that grows in tropical regions. The latex of this plant is used against various diseases, such as diabetes mellitus, leprosy, tripanosomiasis, leukemia, and several malignant tumors. The mutagenic, antimutagenic, and cytotoxic effects of the latex of this plant were investigated by measuring the frequency of micronuclei in mice bone marrow cells. To evaluate mutagenicity, the animals were treated with four doses of latex (10, 30, 50, and 100 mg/kg body weight). To study the antimutagenic activity, the animals were simultaneously treated with latex and mitomycin C (4 mg/kg). The cytotoxicity was evaluated by polychromatic and normochromatic erythrocytes ratio. Our results showed a significant increase of frequency of micronucleated polychromatic erythrocytes (MNPCE) compared to the negative control group (p < 0.05). Concerning antimutagenicity, the doses of 10 and 30 mg/kg co-administered with mitomycin C showed significant decrease in MNPCE frequency compared to the positive control group (p < 0.05). However, no significant reduction in MNPCE frequency (p > 0.05) was detected at the doses of 50 and 100 mg/kg. Under our experimental conditions, the results obtained indicate strong mutagenic and cytotoxic activity of S. umbellatum latex except the dose of 10 mg/kg and moderate antimutagenic effect at lower doses.

Genotoxicity and mutagenicity of Echinodorus macrophyllus (chapéu-de-couro) extracts

Echinodorus macrophyllus, commonly known as chapéu-de-couro, is a medicinal plant used in folk medicine to treat inflammation and rheumatic diseases. In this work, we used short-term bacterial assays based on the induction of SOS functions to examine the genotoxicity and mutagenicity of an aqueous extract of E. macrophyllus leaves. Whole extract and an ethyl acetate fraction showed similar genotoxicity and caused an ~70-fold increase in lysogenic induction. The extract also gave a positive result in the SOS chromotest with an increase of 12-fold in β-Galactosidase enzymatic units. There was a strong trend towards base substitutions and frameshifts at purine sites in the mutations induced by the extract in Escherichia coli (CC103 and CC104 strains) and Salmonella typhimurium test strains (22-fold increase in histidine revertants in TA98 strain). Since reactive oxygen species may be implicated in aging process and in degenerative diseases, we used antioxidant compounds as catalase, thiourea and dipyridyl in the lysogenic induction test. All this compounds were able to reduce the induction factor observed in the treatment with chapéu-de-couro, thus suggesting that the genotoxicity and mutagenicity were attributable to the production of reactive oxygen species that targeted DNA purines.

Acute and subchronic toxicological evaluation of the semipurified extract of seeds of guaraná (Paullinia cupana) in rodents

We evaluated the toxicity of a semipurified extract (EPA fraction, containing caffeine and several flavan-3-ols and proanthocyanidins) of seeds of the native Amazon plant Paullinia cupana (guaraná) in rodents. Acute toxicity was tested in male Swiss mice, which received different doses orally (OR) and intraperitoneally (ip); control groups received water. These tests produced acute mortality, with LD(50) of 1.825 g/kg (OR) and 0.827 g/kg (ip), and a significant weight decrease in lungs of mice receiving a dose of 0.1g/kg. In the repeated-dose toxicity test, the EPA was administered OR daily to male and female Wistar rats at doses of 30, 150, and 300 mg/kg/day/90 days. Their behavior, mortality, weight changes, laboratory tests, and the weights and histopathology of organs were evaluated. No rats died during the tests. Males dosed at 150 or 300 mg/kg gained weight more slowly and lost kidney weight (absolute and relative weights, compared to the control group). Hematological and biochemical tests showed few changes, differing somewhat between males and females; the histopathological evaluation indicated no significant changes. These results indicate that the EPA fraction of guaraná caused no toxicity in rats at the smallest dose evaluated (30 mg/kg). No other species was evaluated.

Assessment of genotoxicity and cytotoxicity of "lixeira" (Curatella americanaL.) λ using the prophage induction test (SOS inductest)

Curatella americana L., commonly known as "lixeira" in Brazil, has been used in folk medicine to treat ulcers and inflammations. The purpose of the present work was to evaluate the cytotoxic and genotoxic potential of the ethanolic extract of C. americana stem bark using the prophage λ induction test (SOS inductest). To evaluate the cytotoxicity of this plant, after treatment with different concentrations of the extract, Escherichia coli WP2s(λ) cultures were diluted in M9 buffer, inoculated into LB plates, and incubated for 24 h at 37 °C. To assess genotoxicity, the lysogenic strain E. coli WP2s(λ) was treated with different concentrations of the extract. Then, the lysogenic strain was added to the indicator strain (RJF013), LB(1/2)(malt/amp), seeded into plates with the matches, and incubated for 24 h at 37 °C. After this period, the total number of colonies and the number of plaques were counted to evaluate C. americana cytotoxicity and genotoxicity, respectively. Our results showed that although the extract of "lixeira" did not modify the survival of bacteria (p > 0.05), it caused a significant increase in prophage λ induction, especially at the higher concentrations (p<0.05). Therefore, we conclude that the ethanolic extract of C. americana stem bark did not present cytotoxic effect, but some genotoxic potential was observed.

Assessment of the mutagenic, antimutagenic and cytotoxic activities of ethanolic extract of araticum (Annona crassiflora Mart. 1841) by micronucleus test in mice

A typical Brazilian plant, araticum (Annona crassiflora Mart.), is widely used in humans as therapeutic medicine to treat several diseases such as diarrhea, rheumatism and syphilis. It contains acetogenins which present cytotoxic, antitumogenic, and antiparasitic properties. In this study, mutagenic, antimutagenic and cytotoxic effects of araticum leaves ethanolic extract were evaluated by micronucleus test in mice. To evaluate the mutagenic activity, animals were treated with ethanolic extract of araticum (EEA) using 10, 20, 50, 100 and 160 mg.kg-1. For all doses, micronucleated polychromatic erythrocytes (MNPCE) frequency was evaluated at 24, 48 and 72 hours after treatment. To evaluate the antimutagenic activity, animals were treated with 10, 20, 50 and 100 mg.kg-1 of EEA and 4 mg.kg-1 of MMC simultaneously. The frequency of MNPCE was evaluated 36 hours after exposure. Cytotoxicity was evaluated by the polychromatic and normochromatic erythrocytes ratio (PCE/NCE). In the mutagenicity assessment, all doses of EEA resulted in no significant increase of MNPCE (P > 0.05), compared to solvent- control group. Regarding administration time, no significant difference among three evaluation periods was observed (P > 0.05). Such results indicate that EEA did not exert mutagenic activity. Cytotoxicity was evident in doses of 50, 100 and 160 mg.kg-1 at 24 and 48 hours after exposure. Concerning antimutagenicity, except the 10 mg.kg-1 co-administered with 4 mg/kg of MMC, all doses reduced significantly the frequency of MNPCE compared to the positive control group (P < 0.05). These results, therefore, indicate an antimutagenic activity of the EEA. Cytotoxicity was significantly increased (P < 0.01) at 100 mg.kg-1 EEA doses co-administered with 4 mg.kg-1 of MMC.

Effect of a commercial extract of Paullinia cupana (guarana) on the binding of 99mTc-DMSA on blood constituents: An in vivo study

We studied the influence of a commercial extract of Paullinia cupana (guarana) on the binding of technetium-99m-dimercaptosuccinic acid ((99m)Tc-DMSA) on blood constituents. Plasma (P) and blood cells (BC) from Wistar rats (control and treated) were separated. P and BC were precipitated with trichloroacetic acid (TCA) or ammonium sulphate (AS) and soluble (SF) and insoluble fractions (IF) isolated. The percentage of incorporated radioactivity (%ATI) in each fraction was determined. The treatment influenced the %ATI in IF-P and in IF-BC isolated by TCA precipitation.

Fluid bed drying of guarana (Paullinia cupana HBK) extract: effect of process factors on caffeine content

The aim of this study was to study the convective drying of the hydroalcoholic extracts obtained from powdered guarana seeds in a spouted bed dryer. The influence of process variables, such as the convective airflow rate, extract feed rate, and air inlet temperature, on the quality of the dry extract was determined using the caffeine and moisture content for the process evaluation. The caffeine content in the alcoholic and dried extracts was determined by capillary gas chromatography. The experiments were performed following a 3(3) factorial design and the data analyzed by response surface. The analysis of dry extract showed that the air and extract feed rates did not significantly affect (25% level) the caffeine content, but that drying temperature is a major factor to consider when the extract is submitted to fluid bed drying. Caffeine losses were significant (1% level) for drying temperatures above 120 degrees C, while moisture content was lower than 3% for temperatures above 120 degrees C. The data showed that there is an optimum temperature for the drying of guarana extracts in spouted beds, and under the conditions used in this study it was 120 degrees C.

Protective effects of guarana (Paullinia cupana Mart. var. Sorbilis) against DEN-induced DNA damage on mouse liver

Guarana (Paullinia cupana Mart. var. Sorbilis) is a plant originally from Brazil, which is rich in tannins. Some tannins are known to present protective effects against DNA damage. This study was performed to investigate the anti-genotoxic/cytotoxic properties of guarana in hepatocytes of mice injected with N-nitrosodiethylamine (DEN). The protective effect of guarana was evaluated both by comet assay and DNA smear fragmentation technique in two month-old female BALB/c mice. These were treated previously with 2.0 mg/g bw of guarana for 16 days and then injected with DEN (160 microg/g body weight) to induce DNA damage. The DEN-only treated group presented higher comet image length than the guarana plus DEN and untreated groups (116.06+/-5.0 microm, 104.09+/-3.3 microm and 93.28+/-14.4 microm, respectively; p<0.01). Guarana treatment presented a 52.54% reduction in comet image length when animals were exposed to DEN (p<0.05). DNA samples from the guarana plus DEN group clearly showed less EtBr fluorescence intensity when compared to the DEN-only group, reinforcing the comet assay data. These results show, for the first time, that guarana has a protective effect against DEN-induced DNA damage in mouse liver.

Antibacterial and antioxidant activities of ethanol extract from Paullinia cupana Mart

The antibacterial and antioxidant activity of the ethanol extract from Paullinia cupana var. sorbilis Mart. (Sapindaceae) seeds, commonly called guarana, was assessed towards selected bacteria as well as in different antioxidant models. The extract, at a concentration between 16 and 128 microg/ml, showed a significant antibacterial effect expressed as minimum inhibitory concentration (MIC) against both Gram-negative and Gram-positive bacteria. In particular, Pseudomonas aeruginosa (MIC=16 microg/ml), Proteus mirabilis (MIC=32 microg/ml), Proteus vulgaris (MIC=32 microg/ml) and Escherichia coli (MIC=32 microg/ml) were the most inhibited. The antioxidant activity was determined by the malonyldialdehyde (MDA) test, measuring the MDA concentration in 3T3-L1 cells after induced cellular damage using ferric ammonium citrate (FAC). The reduction of lipid peroxidation was 62.5% using a guarana extract with a concentration of 2 microg/ml. This effect was dose/dependent. The ethanol extract from Paullinia cupana seeds was analysed by spectrophotometry to determine the concentration of catechol substances after treatment of the extract with p-aminophenol. The total phenolics content in the ethanol extract was also determined spectrophotometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). The concentration of catechol equivalent was 6.06+/-0.13 mg/g (mean+/-S.D.), while the total phenolic content was 8.43+/-0.21 mg/g (mean+/-S.D.). The correlation index between antioxidant activity and catechol content was 0.96.

Effect of extract of medicinal plants on the labeling of blood elements with Technetium-99m and on the morphology of red blood cells: I--a study with Paullinia cupana

Drugs can alter the labeling and the morphology of red blood cells. As Paullinia cupana is used in popular medicine, we evaluated its influence on the labeling process using technetium-99m (Tc-99m). Blood was incubated with P. cupana, stannous chloride and Tc-99m. Samples were centrifuged and plasma (P) and blood cells (BC) were separated and precipitated with trichloroacetic acid. Soluble (SF) and insoluble fractions (IF) were isolated. The morphology of the blood cells was evaluated under an optical microscope. The results showed a significant (P = 0.05) decrease in the uptake of radioactivity for the RBC (97.93 +/- 0.74 to 36.90 +/- 4.71%), in IF-P and in IF-BC due to P. cupana extract. The study of the morphology of the RBC revealed alterations in the shape of these cells. We suggest that the P. cupana effect could be explained by an inhibition of the stannous and pertechnetate ions or oxidation of the stannous ion or by damages in the plasma membrane.

Guarana (Paullinia cupana): toxic behavioral effects in laboratory animals and antioxidants activity in vitro

The effects on toxic and behavioral levels of guarana (Paullinia cupana) were assessed in rats and mice subsequent to acute and chronic administrations and were compared to those produced by Ginseng (Panax ginseng). Experimental parameters included tests for antioxidant capacity in vitro and measured in vivo, toxicological screening, progress in weight, motor activity, death rate, and histopathological examination of the viscera. Guarana showed an antioxidant effect because, even at low concentrations (1.2 microg/ml), it inhibited the process of lipid peroxidation. In high doses of 1000-2000 mg/kg (i.p. and p.o.) it did not induce significant alterations in parameters for toxicological screening. No effects on motor activity were observed, neither did guarana alter the hypnotic effect of pentobarbital. Ginseng (250-1000 mg/kg i.p.), however, elicited reductions in motor activity, eyelid ptosis and bristling fur. Consumption of liquids containing guarana or ginseng and progress in weight of the animals remained at levels similar to the controls, even after prolonged administration. The percentage mortality was equivalent in control and in treated groups. The absence of toxicity of guarana was also demonstrated by histopathological examination, with no alteration being detected in heart, lungs, stomach, small and large intestine, liver, pancreas, kidneys, bladder and spleen.

Evaluation of the toxicity of guarana with in vitro bioassays

A natural stimulant, Paullinia cupana, commonly called guarana, was tested for its ability to induce in vitro toxicity in Chinese hamster ovary (CHO) cells and bacterial cells (Photobacterium phosphoreum). The cytotoxic effects of aqueous guarana extracts were evaluated by three endpoint systems: neutral red (NR) uptake assay, total protein content [kenacid blue (KB)] assay, and tetrazolium (MTT) assay. The Microtox test was also used. Results indicated that the lowest concentration of guarana tested was not toxic and that the IC50 values calculated with the NR, KB, and MTT assays were lower than the highest concentration tested (40 mg/ml). There was no significant difference in cytotoxicity between the three test systems. The EC50 values obtained with the Microtox assay were consistent with these data. The present in vitro analysis suggests that the concentration of guarana is of critical importance in its cytotoxic activity and high doses could be harmful to human health.