The micronucleus assay with mouse peripheral blood reticulocytes using acridine orange-coated slides

Phytochemical profile and determination of cytotoxicity, acute oral toxicity, genotoxicity, and mutagenicity of aqueous and ethanolic extracts of Pseudobombax marginatum (A. St.-Hil.) A. Robyns

Pseudobombax marginatum, popularly known as "embiratanha," is widely used by traditional communities as anti-inflammatory and analgesic agent. This study aimed to determine the phytochemical profile as well as cytotoxicity, acute oral toxicity, genotoxicity, and mutagenicity attributed to exposure to aqueous (AqEx) and ethanolic (EtEx) extracts of embiratanha bark. Phytochemical screening was conducted using thin-layer chromatography (TLC). Cell viability was analyzed using MTT assay with human mammary gland adenocarcinoma (MDA-MB-231) and macrophage (J774A.1) cell lines, exposed to concentrations of 12.5, 25, 50, or 100 µg/ml of either extract. For acute oral toxicity, comet assay and micronucleus (MN) tests, a single dose of 2,000 mg/kg of either extract was administered orally to Wistar rats. TLC analysis identified classes of metabolites in the extracts, including cinnamic acid derivatives, flavonoids, hydrolyzable tannins, condensed tannins, coumarins, and terpenes/steroids. In the cytotoxicity assay, the varying concentrations of extracts derived from embiratanha induced no significant alterations in the viability of MDA-MB-231 cells. The lowest concentration of EtEx significantly increased macrophage J774A.1 viability. However, the higher concentrations of AqEx markedly lowered macrophage J774A.1 viability. Animals exhibited no toxicity in the parameters analyzed in acute oral toxicity, comet assay, and MN tests. Further, EtEx promoted a significant reduction in DNA damage index and DNA damage frequency utilizing the comet assay, while the group treated with AqEx exhibited no marked differences. Thus, data demonstrated that AqEx or EtEx of embiratanha may be considered safe at a dose of 2,000 mg/kg orgally under our experimental conditions tested.

Cytotoxic, acute oral toxicity, genotoxic and mutagenic assessment of the essential oil from fresh leaves of Croton argyrophyllus (Kunth.)

ETHNOPHARMACOLOGICAL RELEVANCE

Croton argyrophyllus Kunth., commonly known as "marmeleiro" or "cassetinga," is widely distributed in the Brazilian Northeast region. Its leaves and flowers are used in traditional medicine as tranquilizers to treat flu and headaches.

AIM OF THE STUDY

This study was conducted to determine the chemical composition and toxicological safety of essential oil from C. argyrophyllus leaves using in vitro and in vivo models.

MATERIALS AND METHODS

The chemical composition of the essential oil was determined using a gas chromatograph coupled to a mass spectrometer. Cytotoxicity was tested in the HeLa, HT-29, and MCF-7 cell lines derived from human cells (Homo sapiens) and Vero cell lines derived from monkeys (Cercopithecus aethiops) using the MTT method. Acute toxicity, genotoxicity. Mutagenicity tests were performed in Swiss mice (Mus musculus), which were administered essential oil orally in a single dose of 2000 mg/kg by gavage.

RESULTS

The main components of the essential oil were p-mentha-2-en-1-ol, α-terpineol, β-caryophyllene, and β-elemene. The essential oil exhibited more than 90% cytotoxicity in all cell lines tested. No deaths or behavioral, hematological, or biochemical changes were observed in mice, revealing no acute toxicity. In genotoxic and mutagenic analyses, there was no increase in micronuclei in polychromatic erythrocytes or in the damage and index in the comet assay.

CONCLUSIONS

The essential oil was cytotoxic towards the tested cell lines but did not exert toxic effects or promote DNA damage when administered orally at a single dose of 2000 mg/kg in mice.

A comparative study on chromium-induced micronuclei assessment in the peripheral blood of Hsd:ICR mice

This study investigated the genotoxic effects of chromium (Cr) in Hsd:ICR mice, considering factors such as oxidative state, apoptosis, exposure pathway, duration, pregnancy, and transplacental exposure. Genotoxicity was assessed using the erythrocytes' micronucleus (MN) assay, while apoptosis was evaluated in nucleated blood cells. The results showed that Cr(III) (CrK(SO4 )2 and CrCl3 ) did not induce any marked genotoxic damage. However, Cr(VI) (CrO3 , K2 Cr2 O7 , Na2 Cr2 O7 , and K2 CrO4 ) produced varying degrees of genotoxicity, with CrO3 being the most potent. MN frequencies increased following 24-h exposure, with a greater effect in male mice. Administering 20 mg/kg of CrO3 via gavage did not lead to significant effects compared to intraperitoneal administration. Short-term oral treatment with a daily dose of 8.5 mg/kg for 49 days elevated MN levels only on day 14 after treatment. Pregnant female mice exposed to CrO3 on day 15 of pregnancy exhibited reduced genotoxic effects compared to nonpregnant animals. However, significant increases in MN levels were found in their fetuses starting 48 h after exposure. In summary, data indicate the potential genotoxic effects of Cr, with Cr(VI) forms inducing higher genotoxicity than Cr(III). These findings indicate that gender, exposure route, and pregnancy status might influence genotoxic responses to Cr.

Chemotherapeutic Mechanism of Action of the Synthetic Resorcinolic Methyl 3,5-dimethoxy-2-octanoylbenzoate

Resorcinolic lipids are described as potential examples of selective chemotherapeutic adjuvants that can enhance the effects of cyclophosphamide (CYC) while promoting cell death without causing DNA damage. Therefore, the current study attempted to describe how the resorcinolic lipid methyl 3,5-dimethoxy-2-octanoylbenzoate (AMS35BB) interacted with DNA (DNA docking) and how this compound affected genetic toxicology models and other biological characteristics when combined with CYC. We observed that AMS35BB, used alone (7.5 and 10 mg/kg), increases the frequency of genomic damage (comet assay) but not chromosomal damage (micronuclei assay), lowers phagocytosis, and promotes cell death in Swiss male mice. When used in association with CYC, AMS35BB can reduce the risk of genomic damage by up to 33.8% as well as chromosomal damage, splenic phagocytosis, cell death, and lymphocyte frequency. Molecular docking showed that AMS35BB had a higher affinity than the active metabolite of CYC for binding to the DNA double helix major groove. As a result, AMS35BB has the potential to be both an adjuvant when used in association with CYC and a therapeutic candidate for the development of a selective chemotherapeutic drug.

Carcinogenic risk of food additive AF-2 banned in Japan: a case study on reassessment of genotoxicity

BACKGROUND

Carcinogenic risk assessment studies have been repeatedly improved and are still being debated to find a goal. Evaluation might be changed if new approaches would be applied to some chemicals which means that new approaches may change the final assessment. In this paper, the risk assessment of a chemical, in particular the proper carcinogenicity, is examined using the long-banned food additive, 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide, AF-2, as a case study.

RESULTS

First, Ames tests were carried out using strains TA1535, TA100, TA1538, and TA98 and their nitroreductase-deficient strains YG7127, YG7128, YG7129, and YG7130. The results showed that mutagenic activity was reduced by about 50% in the nitroreductase-deficient strains, indicating that part of the mutagenic activity shown in Ames test was due to bacterial metabolism. Second, in vivo genotoxicity tests were conducted, including the one that had not been developed in 1970's. Both a micronucleus test and a gene mutation assay using transgenic mice were negative. Third, assuming it is a genotoxic carcinogen, the virtual safety dose of 550 μg/day was calculated from the TD50 in rats with a probability of 10-5.

CONCLUSION

AF-2 has been shown to be carcinogenic to rodents and has previously been indicated to be genotoxic in vitro. However, the present in vivo genotoxicity study, it was negative in the forestomach, a target organ for cancer, particularly in the gene mutation assay in transgenic mice. Considering the daily intake of AF-2 in the 1970s and its virtually safety dose, the carcinogenic risk of AF-2 could be considered acceptable.

Absence of maternal-fetal adverse effects of Alternanthera littoralis P. Beauv. following treatment during pregnancy in mice

Alternanthera littoralis P. Beauv is a plant native to Brazil that exhibits various beneficial activities including antioxidant, antibacterial, antifungal, antiprotozoal, anti-hyperalgesic, and anti-inflammatory properties. The aim of this study was to assess the impact of the ethanol extract of Alternanthera littoralis (EEAl) on reproductive outcomes, embryofetal development, and DNA integrity of pregnant female mice. Pregnant Swiss female mice were randomly assigned to three experimental groups (n = 10): controls were administered either 1% Tween 80 (vehicle), EEAl 100 mg/kg or EEAl 1000 mg/kg. Treatment was administered through gavage during the gestational period until day 18. On gestational days 16, 17, and 18, a peripheral blood sample from the tail vein was obtained for DNA integrity analysis (micronucleus test). After the last collection, animals were euthanized by cervical dislocation. Maternal organs and fetuses were collected, weighed, and subsequently analyzed. Reproductive outcome parameters were assessed by measurement of number of implants, live fetuses, and resorptions. Embryonic development was determined by adequacy of weight for gestational age as well as determination of external, visceral, and skeletal malformations. Data demonstrated that EEAl did not produce maternal toxicity at either dose associated with no marked alterations in any of the reproductive outcome parameters including implantation sites, live/dead fetuses ratio, fetal viability, post-implantation losses, resorptions, and resorption rate. However, EEAl 1000 group reduced embryofetal development by lowering placental weight. In addition, there was an increase in the frequency of external and skeletal malformations in the EEAl 1000 group, which could not be attributed to extract exposure as these values were within control levels. Based upon our findings, evidence indicates that the EEAl at the concentrations employed in our study may be considered safe for use during pregnancy and extracts of this plant show potential for development of phytomedicines to be used in pregnancy.

The ethanolic extract of Salvia lachnostachys Benth is not maternotoxic, does not alter reproductive performance, but has teratogenic potential

Salvia lachnostachys Benth is native to Brazil and has anti-inflammatory, anti-arthritic, cytotoxic, antitumor, and antihyperalgesic activities. The population, including pregnant women, consume this plant to treat pain, inflammation, flu, spasms, insomnia, and depression, mainly. There are no safety reports on the use of this plant during pregnancy. The present study aimed to evaluate the effects of S. lachnostachys ethanolic extract (EESl) on reproductive performance, embryofetal development, and DNA integrity of pregnant female mice. Pregnant females were randomly divided into three experimental groups (n = 10): The Control group was treated with a vehicle, and treatment groups were administered with EESl at 100 and 1000 mg/kg, respectively. Treatment occurred by gavage throughout the gestational period until day 18. Afterward, reproductive performance, embryofetal development, and DNA integrity parameters were evaluated. The results indicated that EESl did not alter any reproductive performance parameters. However, it changed embryofetal outcome through reduced placental weight (EESl 100 mg/kg), decreased fetal weight (EESl 100 and 1000 mg/kg), and increased frequency of small for gestational age fetuses (EESl 1000 mg/kg). In addition, EES1 increased the frequency of external, visceral, and skeletal malformations. Because of the above, it is considered that EESl is not maternotoxic, does not alter reproductive performance, but does alter embryofetal development. Its use in the gestational period is not indicated due to its teratogenic potential.

Cytotoxicity, oral toxicity, genotoxicity, and mutagenicity evaluation of essential oil from Psidium glaziovianum Kiaersk leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Members of the Psidium genus have been suggested in ethnobotanical research for the treatment of various human diseases, and some studies have already proven their popular uses through research, such as Psidium glaziovianum, which is found in Brazil's northeast and southeast regions and has antinociceptive and anti-inflammatory properties; however, the safety of use has not yet been evaluated.

AIM OF THE STUDY

This study investigated the safety of using essential oil obtained from P. glaziovianum leaves (PgEO) in vitro and in vivo models.

MATERIALS AND METHODS

Cytotoxicity was evaluated in murine erythrocytes, while acute toxicity, genotoxicity (comet assay) and mutagenicity (micronucleus test) studies were performed using Swiss albino mice.

RESULTS

In the cytotoxicity assay, the hemolysis rate indicated a low capacity of PgEO to cause cell lysis (0.33-1.78%). In the acute oral toxicity study, animals treated with up to up to 5000 mg/kg body weight did not observe mortality or physiological changes. Neither dosage caused behavioral problems or death in mice over 14 days. The control and 2,000 mg/kg groups had higher feed intake and body weight than the 5,000 mg/kg PgEO group. Erythrocyte count, hemoglobin level, mean corpuscular volume, and MCV decreased, but serum alanine and aspartate aminotransferases increased. In the genotoxic evaluation, 5000 mg/kg PgEO enhanced nucleated blood cell DI and DF.

CONCLUSIONS

The present study describes that PgEO can be considered well tolerated in acute exposure at doses up to 2000 mg/kg, however the dose of 5000 mg/kg of PgEO should be used with caution.

[Antigenotoxicity of the soy isoflavone genistein in mice exposed to carcinogenic hexavalent chromium compounds]

Introduction

Introduction: the consumption of antioxidant-rich foods such as soy isoflavones may be an alternative in the protection and modulation against metal-induced genotoxicity with carcinogenic potential associated with oxidative stress. Objective: to evaluate the antigenotoxic effects of soy isoflavone genistein in mice exposed to carcinogenic compounds of hexavalent chromium (Cr[VI]). Material and method: twenty-five male Hsd:ICR mice were divided into five groups treated as follows: a) vehicle 1 (sterile distilled water, intraperitoneally); b) vehicle 2 (corn oil for fat-soluble compounds, orally); c) 15 mg/kg of genistein, orally; d) 20 mg/kg of CrO3, intraperitoneally; and e) 15 mg/kg of genistein four hours before the application of 20 mg/kg of CrO3. Evaluations of micronuclei (MN), apoptosis, ratio of polychromatic/normochromatic erythrocytes (EPC/ENC) and cell viability in peripheral blood obtained at 0, 24, 48 and 72 hours were performed. Results: the treatment with genistein reduced MN when administered prior to treatment with CrO3, the effect being greater at 48 hours (reduction of 84 %). Cell viability was reduced with genistein and CrO3 treatments alone, the effect being greater in the latter. Conclusions: genistein effectively blocked the genotoxic action of CrO3. The fact that MN and apoptosis were reduced in the group treated with genistein and CrO3 suggests that genistein could have inhibited the oxidative damage of Cr(VI) since, as there were no cells with damage, the apoptotic pathways were not activated.

3-Heptylidene-4,6-Dimethoxy-3H-Isobenzofuran-1-One Is Genotoxic, Increases the Frequency of Cell Death, and Potentiates the Effects of Cyclophosphamide and Cisplatin

3-heptylidene-4,6-dimethoxy-3H-isobenzofuran-1-one (Phthalide 1) is the precursor of three resorcinol lipids that have been described as potential chemotherapeutic agents and capable of potentiating the effects of cyclophosphamide. In this study, we evaluated the genotoxic potential, cell-killing potential, and interactions with cyclophosphamide and cisplatin of phthalide 1. Twelve groups were created from 120 mice: Negative Control, cyclophosphamide (100 mg/kg), cisplatin (6 mg/kg), Phthalide 1 (5, 10 and 20 mg/kg), and associations of 1 with cyclophosphamide and 1 with cisplatin. The results demonstrate that 1 increases (p < 0.05) the frequency of chromosomal damage, liver and kidney cell death, and splenic phagocytosis. The association of 1 with cyclophosphamide and cisplatin demonstrated a chemopreventive effect and, therefore, a reduction (p < 0.05) in the frequency of chromosomal damage. However, cell death and splenic phagocytosis did not suffer significant variations. As a result of the above, 1 has potential chemotherapeutic application and may be a candidate for developing a new generation of chemotherapeutics. In addition, it has characteristics to be used as a chemotherapy adjuvant in association with cyclophosphamide and cisplatin since it increases the frequency of cell death induced by chemotherapy. We also reported that the chemopreventive effect of 1, in association with cyclophosphamide and cisplatin, can prevent adverse effects (induction of DNA damage in non-tumor cells) without interfering with the mode of action of chemotherapy drugs and, therefore, without reducing the induction of cell death.

ZIM, a Norbornene Derived from 4-Aminoantipyrine, Induces DNA Damage and Cell Death but in Association Reduces the Effect of Commercial Chemotherapeutics

Cancer incidence is increasing, and the drugs are not very selective. These drugs cause adverse effects, and the cells become resistant. Therefore, new drugs are needed. Here, we evaluated the effects of ZIM, a candidate for chemotherapy, and 4-AA alone and in association with commercial chemotherapeutic agents. Subsequently, the results of ZIM and 4-AA were compared. Male Swiss mice were treated with doses of 12, 24, or 48 mg/kg ZIM or 4-AA alone or in association with cisplatin (6 mg/kg), doxorubicin (16 mg/kg), and cyclophosphamide (100 mg/kg). Biometric parameters, DNA damage (comet and micronuclei), cell death, and splenic phagocytosis were evaluated. DNA docking was also performed to confirm the possible interactions of ZIM and 4-AA with DNA. 4-AA has been shown to have low genotoxic potential, increase the frequency of cell death, and activate phagocytosis. ZIM causes genomic and chromosomal damage in addition to causing cell death and activating phagocytosis. In association with chemotherapeutical agents, both 4-AA and ZIM have a chemopreventive effect and, therefore, reduce the frequency of DNA damage, cell death, and splenic phagocytosis. The association of 4-AA and ZIM with commercial chemotherapeutic agents increased the frequency of lymphocytes compared to chemotherapeutic agents alone. Molecular docking demonstrated that ZIM has more affinity for DNA than 4-AA and its precursors (1 and 2). This was confirmed by the lower interaction energy of the complex (-119.83 kcal/mol). ZIM can break the DNA molecule and, therefore, its chemotherapeutic effect can be related to DNA damage. It is considered that ZIM has chemotherapeutic potential. However, it should not be used in combination with cisplatin, doxorubicin, and cyclophosphamide as it reduces the effects of these drugs.

The Ethanolic Extract of Gomphrena celosioides Mart. Does Not Alter Reproductive Performance or Embryo-Fetal Development, nor Does It Cause Chromosomal Damage

Gomphrena celosioides is a native Brazilian plant found in the State of Mato Grosso do Sul. It is used in folk medicine to treat kidney diseases, skin diseases, infections, rheumatism, gastrointestinal diseases, and respiratory diseases. It is also used as an abortifacient. To evaluate the effects of the ethanolic extract of Gomphrena celosioides (EEGc) on reproductive performance, embryo development, and chromosome stability, Swiss mice were randomly divided into experimental groups (n = 10). The animals in the control group received the vehicle Tween 80–1% in the proportion of 0.1 mL/10 g of body weight orally, from the first to the 18th gestational day. The animals in the treatment groups received the EEGc (100, 1000, and 2000 mg/kg) from the first to the 18th gestational day. The animals underwent evaluations of their reproductive performance and embryofetal development. The results showed that the EEGc did not change the animals’ final weight, weight gain, uterine weight, or net weight gain. The evaluation showed that the absolute and relative organs’ weights did not vary between the different experimental groups. In addition, the EEGc did not change the numbers of implants, live fetuses, dead fetuses, or fetal resorptions. There were no differences in post-operative loss rates, implantations, or resorptions, nor were there differences in fetal viability or sex ratio. The use of the EEGc did not result in different frequencies of malformations. In addition, the EEGc did not alter the frequency of chromosomal damage or frequency of micronuclei. Based on our findings, we considered the extract of Gomphrena celosioides to be safe for use during pregnancy, although some parameters indicated caution in its use.

The effect of low doses of chlorpyrifos on blood and bone marrow cells in Wistar rats

The aim of this study was to investigate the genotoxic potential of low doses of chlorpyrifos (CPF) on blood and bone marrow cells in adult male Wistar rats. CPF was administered by oral gavage at daily doses of 0.010, 0.015, and 0.160 mg/kg of body weight (bw) for 28 consecutive days. Positive control (PC) was administered 300 mg/kg bw/day of ethyl methane sulphonate (EMS) for the final three days of the experiment. Toxic outcomes of exposure were determined with the in vivo micronucleus (MN) assay and alkaline comet assay. The 28-day exposure to the 0.015 mg/kg CPF dose, which was three times higher than the current value of acute reference dose (ARfD), reduced body weight gain in rats the most. The in vivo MN assay showed significant differences in number of reticulocytes per 1000 erythrocytes between PC and negative control (NC) and between all control groups and the groups exposed to 0.015 and 0.160 mg/kg bw/day of CPF. The number of micronucleated polychromatic erythrocytes per 2000 erythrocytes was significantly higher in the PC than the NC group or group exposed to 0.015 mg/kg bw/day of CPF. CPF treatment did not significantly increase primary DNA damage in bone marrow cells compared to the NC group. However, the damage in bone marrow cells of CPF-exposed rats was much higher than the one recorded in leukocytes, established in the previous research. Both assays proved to be successful for the assessment of CPFinduced genome instability in Wistar rats. However, the exact mechanisms of damage have to be further investigated and confirmed by other, more sensitive methods.

Protective Effect of Resveratrol against Hexavalent Chromium-Induced Genotoxic Damage in Hsd:ICR Male Mice

The aim of this study is to examine the ability of resveratrol to counteract hexavalent chromium [Cr(VI)]-induced genetic damage, as well as the possible pathways associated with this protection. Hsd:ICR male mice are divided into groups of the following five individuals each: (a) control 1, distilled water; (b) control 2, ethanol 30%; (c) resveratrol, 50 mg/kg by gavage; (d) CrO₃, 20 mg/kg intraperitoneally; (e) resveratrol + CrO₃, resveratrol administered 4 h prior to CrO₃. The assessment is performed on peripheral blood. Micronuclei (MN) kinetics are measured from 0 to 72 h, while 8-hydroxydeoxyguanosine (8-OHdG) adduct repair levels, endogenous antioxidant system biomarkers, and apoptosis frequency were quantified after 48 h. Resveratrol reduces the frequency of Cr(VI)-induced MN and shows significant effects on the 8-OHdG adduct levels, suggesting that cell repair could be enhanced by this polyphenol. Concomitant administration of resveratrol and Cr(VI) results in a return of the activities of glutathione peroxidase and catalase to control levels, accompanied by modifications of superoxide dismutase activity and glutathione levels. Thus, antioxidant properties might play an important role in resveratrol-mediated inhibition of Cr(VI)-induced oxidant genotoxicity. The increase in apoptotic cells and the decrease in necrosis further confirmed that resveratrol effectively blocks the actions of Cr(VI).

In vivo assessment of antioxidant, antigenotoxic, and antimutagenic effects of bark ethanolic extract from Spondias purpurea L

Medicinal plants have always been used for therapeutic purposes; however, some plants may contain toxic and mutagenic substances. The aim of this study was to assess the cytotoxic, genotoxic, mutagenic, antioxidant, antigenotoxic, and antimutagenic effects of the bark ethanolic extract of Spondias purpurea L. using male and female Swiss albino mice. To determine the protective effects of the extract, benzo[a]pyrene (B[a]P) and cyclophosphamide (CP) were selected as cell damage inducers. The extract was examined at doses of 500, 1000, or 1500 mg/kg body weight (BW)via gavage alone or concomitant with B[a]P or CP. Oxidative stress was measured by quantification of blood catalase activity (CAT), reduced glutathione (GSH) levels in total blood, liver, and kidney, and concentrations of malondiadehyde (MDA) in liver and kidney. Genotoxicity and antigenotoxicity were evaluated by the comet assay using peripheral blood. Cytotoxicity, mutagenicity, and antimutagenicity were determined utilizing the micronucleus test in bone marrow and peripheral blood. The S. purpurea L extract increased CAT activity and GSH levels accompanied by a decrease in MDA levels after treatment with B[a]P and CP. No genotoxic, cytotoxic, or mutagenic effects were found in mice exposed only to the extract. These results indicate that the extract of S. purpurea exhibited protective effects against oxidative and DNA damage induced by B[a]P and CP.

Evaluation of the safety of ethanolic extract from Piper amalago L. (Piperaceae) leaves in vivo: Subacute toxicity and genotoxicity studies

Piper amalago L. (Piperaceae) is traditionally used due to its anti-inflammatory, analgesic, diuretic, and antiparasitic properties. However, few studies have focused on its adverse effects, compromising its safe use. This study evaluated the toxicological safety of ethanolic extract from Piper amalago leaves (EEPA), through subacute toxicity and genotoxicity assays in rodents. In subacute toxicity, 100, 200 or 300 mg/kg of EEPA were tested in female Wistar rats, by gavage, for 28 days. For genotoxicity test, female Swiss mice were orally treated with 17.5, 175 or 1750 mg/kg of EEPA and the comet, micronucleus, and splenic phagocytic assays were evaluated. In subacute toxicity, the extract induced an increase in the food and water intakes, as well as in the liver absolute weight, and in the heart and kidney relative weights. EEPA also provoked alterations in histopathological analysis of liver and in hemato-biochemical parameters, evidenced by a decrease in hematocrit levels and albumin levels, and an increase in the number of platelets and in alkaline phosphatase and cholesterol levels. However, EEPA did not presented genotoxic nor mutagenic properties. EEPA showed hemato-biochemical toxicity profile in rats and should be used with caution, especially when for prolonged period.

Genotoxicity and 28-day repeated dose oral toxicity study of ovatodiolide in rats

Ovatodiolide is a bioactive cembrane-type diterpenoid isolated from Anisomeles indica (L.) Kuntze. It has been proven that ovatodiolide is anti-inflammatory, anti-tumorigenic, anti-melanogenic and attenuates asthma by regulating signaling pathways. The aim of this study was to evaluate the safety of ovatodiolide by conducting genotoxicity tests and 28-day oral toxicity tests in rats. Genotoxicity assays were conducted by using a bacterial reverse mutation test and mammalian chromosomal aberration test to assess whether ovatodiolide causes reverse mutations and mutagenicity with or without metabolism activation. For the in vivo mammalian erythrocyte micronucleus test, mice were administered a single dose of 0, 250, 500 or 1000 mg/kg b.w. ovatodiolide by single gavage. In the acute oral toxicity test, rats were given a single dose of ovatodiolide 1000 mg/kg b.w. by single gavage. In the 28-day oral toxicity test, groups were divided into a control, ovatodiolide 10, 25 and 50 mg/kg b.w. The results showed that there was no mutagenicity in the bacterial reverse mutation test or the mammalian chromosomal aberration test with or without S9 fraction. Ovatodiolide did not produce an increase in micronucleated reticulocytes in the micronucleus test. The results revealed that the acute oral toxicity of ovatodiolide is over 1000 mg/kg b.w. in rats. Moreover, 10, 25 and 50 mg/kg b.w. of ovatodiolide did not cause a significant effect in rats. According to the results of the genotoxicity and oral toxicity studies in rats, ovatodiolide did not produce any adverse effects, and the tested doses can serve as clinical references.

The Use of Natural Fiber-Rich Food Product Is Safe and Reduces Aberrant Crypt Foci in a Pre-Clinical Model

BACKGROUND

Colorectal cancer is a highly prevalent disease, requiring effective strategies for prevention and treatment. The present research aimed to formulate a natural fiber-rich food product (NFRFP) and to evaluate its safety, toxicogenetics, and effects on aberrant crypt foci induced by 1,2-dimethyl-hydrazine in a preclinical model.

METHODS

A total of 78 male Wistar rats were distributed in six experimental groups: negative control, positive control (1,2-Dimethylhydrazine-40 mg/Kg), and four groups fed with 10% NFRFP: NFRFP, pre-treatment protocol, simultaneous treatment, and post-treatment protocol.

RESULTS

The NFRFP was shown to be a good source of fibers and did not change biometric, biochemical, hematological, and inflammatory parameters, and did not induce signs of toxicity and genotoxicity/carcinogenicity. NFRFP exhibited a chemopreventive effect, in all protocols, with damage reduction (% DR) of 75% in the comet test. NFRFP reduced the incidence of aberrant crypt outbreaks by 49.36% in the post-treatment protocol.

CONCLUSIONS

The results suggest the applicability of NFRFP in the human diet due to potential production at an industrial scale and easy technological application in different products, since it could be incorporated in food without altering or causing small changes in final product sensory characteristics.

Antioxidant and Antigenotoxic Actions of Gum Arabic on the Intestinal Mucosa, Liver and Bone Marrow of Swiss Mice Submitted to Colorectal Carcinogenesis

Colorectal carcinogenesis is characterized by oxidative stress and the formation of aberrant crypts in its initial stages. Gum arabic (GA) is a natural product with antioxidant properties, and, therefore, supposed antitumor action. The aim of this study was to evaluate the effects of GA on the formation of aberrant crypts, as well as the local, hepatic, and systemic genotoxicity and oxidative stress. We induced colorectal carcinogenesis in Swiss male mice, afterwards treated them with water, 2.5% GA or 5% GA via gavage for twelve weeks and then performed surgery in order to obtain samples to analysis (proximal and distal colon, liver, blood, and bone marrow). The number of aberrant crypts in the GA-treated animals was lower than in the control groups. Likewise, there was a decline of colonic, hepatic, and systemic genotoxicity and oxidative stress. These results reflect the antioxidant role of GA and may lead to the development of treatments that inhibit colorectal carcinogenesis.

Biological safety of Syagrus coronata (Mart.) Becc. Fixed oil: Cytotoxicity, acute oral toxicity, and genotoxicity studies

ETHNOPHARMACOLOGICAL RELEVANCE

Syagrus coronata, popularly known as licuri, is a palm native to caatingas. The fixed oil extract of licuri nuts is used by the population of Northeast Brazil for therapeutic purposes, including as an antifungal, anti-inflammatory, and a cicatrizant agent. However, there is no scientific information on the possible harmful health effects of the oil and hence its medicinal usability is unknown.

AIM OF THE STUDY

We aimed to analyze the biological safety and possible antioxidant activity of fixed S. Coronata oil.

MATERIALS AND METHODS

Chemical analysis of the oil was performed using gas chromatography with flame ionization detection (CG-FID). The cytotoxicity of varying concentrations of the oil (12.5, 25, 50, 100, and 200 μg/mL) was evaluated using the tetrazolium reduction assay in three cell lines: HEK-293 kidney embryonic cells, J774.A1 macrophages, and the tumor line Sarcoma-180 (S-180). Oral toxicity, genotoxicity, and mutagenicity tests were performed in mice which were administered a single dose of 2000 mg/kg of fixed licuri oil, by gavage. For acute toxicity tests, changes in blood and biochemical parameters, behavior, and weight were analyzed; histomorphometric analyses of the liver, kidney, and spleen were also performed. The comet assay and micronucleus (MN) test were performed to analyze genotoxicity. The antioxidant potential was assessed by the total antioxidant capacity (AAT) and DPPH elimination activity.

RESULTS

Licuri oil consists predominantly of saturated fatty acids, and lauric acid is the major compound. The highest concentrations of the oil showed low levels of cytotoxicity; however, LC50 was not reached in any of the tests. The acute toxicity study did not reveal any evidence of adverse effects in animals treated with oil; biochemical investigation of blood showed a decrease in blood concentration of total proteins and uric acid. The kidneys, spleen, and liver showed no morphological changes indicative of a pathological process. Genotoxic or mutagenic activity was not detected through both the comet assay and MN test. In addition, the oil showed low antioxidant activity in both methods.

CONCLUSION

Licuri oil from the stem of S. coronata did not present significant toxic effects as well as absence of genetic damage when administered orally. Future studies are needed to investigate its pharmacological potential.

Antigenotoxic effects of (-)-epigallocatechin-3-gallate (EGCG) and its relationship with the endogenous antioxidant system, 8-hydroxydeoxyguanosine adduct repair (8-OHdG), and apoptosis in mice exposed to chromium(VI)

This study aimed to investigate the relationship between endogenous antioxidant system, 8-hydroxydeoxyguanosine adduct (8-OHdG) repair, and apoptosis in mice treated with chromium(VI) alone and in the presence of the antigenotoxic compound (-)-epigallocatechin-3-gallate (EGCG). Groups of 5 Hsd:ICR male mice were divided and treated as follows: (1) control, vehicle only; (2) EGCG, 8.5 mg/kg by gavage alone; (3) CrO₃, 20 mg/kg intraperitoneally alone; and (4) EGCG combined with CrO₃, EGCG was administered 4 hr prior to CrO₃. Peripheral blood parameters were analyzed before treatment administration (time 0), and 48 hr after exposure. The administration of EGCG increased 8-OHdG levels and superoxide dismutase (SOD) activity. Treatment with CrO₃ increased number of micronucleus (MN) presence, elevated apoptotic/necrotic cells frequencies, decreased 8-OHdG levels, diminished total antioxidant capacity (TAC), increased glutathione (GSH) total levels, and lowered SOD activity. Administration of EGCG prior to treatment with CrO₃ resulted in lower concentrations of MN, reduced apoptotic and necrotic cell number, and restored TAC and SOD activity to control levels. It is conceivable that the dose of EGCG plays an important role in the genotoxic damage protection pathways. Thus, this study confirms the action of EGCG as an antigenotoxic agent against chromium(VI)-induced oxidative insults and demonstrates potential protective pathways for EGCG actions to counteract genotoxic damage induced by this metal.

Micronucleated erythrocytes in peripheral blood from neonate rats fed by nursing mothers exposed to X-rays

Most women with breast cancer can become pregnant and give birth while undergoing radiation therapy and breastfeeding is generally not contraindicated. The induction of long-lived reactive species in proteins, such as casein by X-ray radiation and DNA damage to unexposed organisms, has been shown when ingesting irradiated cheese. To determine whether exposing lactating rats to X-rays increases the number of micronucleated erythrocytes (MNEs) in peripheral blood of their unexposed or breastfeeding rat pups, 15 female Wistar rats were divided into three groups: Negative control; Experimental group exposed to X-rays, and group exposed to X-rays plus vitamin C. The mothers of groups 2 and 3 were irradiated for three consecutive days after giving birth, returning them to their respective cages each time to continue lactation. A blood sample was taken from the mothers and pups at 0, 24, and 48 hr. Blood smears were stained with acridine orange to analyze MNEs. In mother rats, the frequency of micronucleated polychromatic erythrocytes (MNPCEs) increased significantly at 24 and 48 hr in both study groups exposed to radiation. Likewise, in rat pups the MNPCE and MNE frequencies increased in both groups with radiation and radiation plus vitamin C at 24 and 48 hr, and a protection from vitamin C was observed. In conclusion, the genotoxic damage produced in rat pups that were lactated by mothers irradiated with X-rays is possibly due to the effect of long-lived reactive species that were formed in the breast milk of female Wistar rats during the irradiation process.

Effect of sampling time on somatic and germ cell mutations induced by acrylamide in gpt delta mice

Background

Acrylamide (AA) is a rodent carcinogen and classified by the IARC into Group 2A (probable human carcinogen). AA has been reported to induce mutations in transgenic rodent gene mutation assays (TGR assays), the extent of which is presumed to depend on exposure length and the duration of expression after exposure. In particular, it is not clear in germ cells. To investigate mutagenicity with AA in somatic and germ cells at different sampling times, we conducted TGR assays using gpt delta transgenic mice.

Results

The male gpt delta mice at 8 weeks of age were treated with AA at 7.5, 15 and 30 mg/kg/day by gavage for 28 days. Peripheral blood was sampled on the last day of the treatment for micronucleus tests and tissues were sampled for gene mutation assays at day 31 and day 77, those being 3 and 49 days after the final treatment (28 + 3d and 28 + 49d), respectively. Another group of mice was treated with N-Ethyl-N-nitrosourea (ENU) at 50 mg/kg/day by intraperitoneal administration for 5 consecutive days and tissues were sampled at the day 31 and day 77 (5 + 26d and 5 + 72d). Frequencies of micronucleated erythrocytes in the peripheral blood significantly increased at AA doses of 15 and 30 mg/kg/day. Two- to three-fold increases in gpt mutation frequencies (MFs) compared to vehicle control were observed in the testes and lung treated with 30 mg/kg/day of AA at both sampling time. In the sperm, the gpt MFs and G:C to T:A transversions were significantly increased at 28 + 3d, but not at 28 + 49d. ENU induced gpt mutations in these tissues were examined at both 5 + 26d and 5 + 72d. A higher mutant frequency in the ENU-treated sperm was observed at 5 + 72d than that at 5 + 26d.

Conclusions

The gpt MFs in the testes, sperm and lung of the AA-treated mice were determined and compared between different sampling times (3 days or 49 days following 28 day-treatment). These results suggest that spermatogonial stem cells are less sensitive to AA mutagenicity under the experimental condition. Prolonged expression time after exposure to AA to detect mutagenicity may be effective in somatic cells but not in germ cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41021-021-00175-5.

Aqueous extract from leaves of Doliocarpus dentatus (Aubl.) Standl. relieves pain without genotoxicity activity

ETHNOPHARMACOLOGICAL RELEVANCE

In the State of Mato Grosso do Sul, the watery sap of Doliocarpus dentatus is used to alleviate thirst, and the leaves of this species are used to relieve pain and swelling associated with inflammatory processes.

AIM OF THE STUDY

This study aimed to analyze the compounds of the leaves from the aqueous extract of D. dentatus (EADd) and evaluate its toxicogenetic and pain relief effects in animal models.

MATERIALS AND METHODS

Compounds were identified in EADd by UHPLC-HRMS (Ultra high-performance liquid chromatography coupled to high resolution mass spectrometry). The oral dose of 17 mg/kg EADd, calculated according to ethnopharmacological uses, and doses between 30 and 300 mg/kg were used to test Swiss mice in formalin- and acetic acid-induced models of pain and behavior. EADd (100-2000 mg/kg) was assayed in mice by comet, micronucleus, and phagocytosis tests and by peripheral leukocyte counts.

RESULTS

Phenolic compounds and flavonoids as well as trigonelline and isoquercetin were identified in EADd. All oral doses of EADd exhibited antinociceptive activity, as indicated by a decrease in pain in both phases, a decrease in cold hypersensitivity induced by formalin, and a decrease in abdominal contortions induced by acetic acid. EADd did not alter the exploratory, motor or motivational activities of the animals. The comet and micronucleus tests indicated that EADd was not genotoxic and did not change the phagocytic activity or peripheral leukocyte count.

CONCLUSIONS

These results demonstrate that EADd could act as an antinociceptive agent that does not present genotoxicity. This study should contribute to justifying, in part, the popular use of D. dentatus in pain management, ensuring its safe use.

Pyriproxyfen does not cause microcephaly or malformations in a preclinical mammalian model

Pyriproxyfen is used in Brazil to combat epidemics of Dengue Fever, Chikungunya Fever, and Zika virus. This study assessed the effects of pyriproxyfen on reproductive performance, embryo-fetal development, head measurements, and DNA integrity in a preclinical model. Thirty pregnant mice were divided into three groups (n = 10): control (drinking water-0.1 ml/10 g (body weight-b.w., gavage) and treated with pyriproxyfen 0.0002 mg/kg and 0.0021 mg/kg (b.w., gavage) during the gestational period. Analysis of biometric, reproductive performance and embryo-fetal development parameters related to control presented no significant differences, suggesting no maternal or embryo-fetal toxicity. Head measurements showed no differences except an increase in anterior/posterior measurement and glabella/external occipital protuberance. Analysis of DNA integrity showed an increase in micronucleus only at 72 h for the lowest dose group. Thus, we infer that pyriproxyfen is not related to the occurrence of microcephaly, nor does it alter reproductive performance, embryo-fetal development or DNA integrity.

4-Hydroxyhalcone effects on cisplatin-induced genotoxicity model

BACKGROUND

The genotoxicity of cisplatin (CP) as a platinum-based antineoplastic agent due to its oxidative stress induction was well known. In this research, we examined 4-hydroxychalcone (4-HCH) as a natural food that presents flavonoid effects on reactive oxygen species (ROS) production and CP-induced in vivo genotoxicity.

METHOD AND MATERIALS

Cytotoxicity of CP and 4-HCH was measured on human embryonic kidney 293 cells with MTT assay. Then, intracellular ROS content at IC50 concentration of CP was measured with 2',7'-dichlorofluorescein diacetate (DCFDA) dye. Finally, 4-HCH was administered intraperitoneally at 10 and 40 mg/kg/BW doses as a pre and post-treatment schedule in a mice model of CP genotoxicity (7 mg/kg). Acridine-orange-stained bone marrow cells were quantified for micronucleus presence examination.

RESULTS

The calculated IC50 of CP and 4-HCH were reported around 19.4 and 133.6 μM, respectively, on HEK293 cells. Also, it was observed that 4-HCH at 0.2, 2 and 10 μM concentrations did not show obvious cytotoxicity. The fluorimetry confirmed that pre-treatment with 10 μM and co-treatment with 2 μM of 4-HCH could attenuate the CP-induced ROS production (P < 0.05 and P < 0.01, respectively). Also, the lowest micronucleated cells were seen in 10 mg/kg 4-HCH-treated group after CP exposure (39 ± 7.9, P < 0.0001).

DISCUSSION

Our results demonstrated the antigenotoxic action of 4-HCH in CP-treated mice bone marrow cells for the first time in both concentrations of 10 and 40 mg/kg especially in the form of co-treatment. Further studies required clinical application of this compound in a combination of CP to attenuate the normal cells' genotoxicity side effects.

Toxicity assessment of saline extract and lectin-rich fraction from Microgramma vacciniifolia rhizome

Microgramma vacciniifolia is broadly used in folk medicine but safety information is unavailable. Therefore, we evaluated the toxicity of a saline extract and a lectin-rich fraction of M. vacciniifolia rhizome. The extract showed hemolytic activity on mice erythrocytes at 1000 μg/mL, whereas the fraction promoted hemolysis (8.57-26.15%) at all tested concentrations (10-1000 μg/mL). Acute toxicity test in mice indicated an LD₅₀ of >5000 mg/kg. Hematological alterations and increased serum alkaline phosphatase level were observed in the treated animals. Transaminases and urea levels increased in the groups treated with the extract or fraction at 5000 mg/kg. Leukocyte infiltration was observed in the liver of extract-treated animals and in the liver and lungs of mice treated with the fraction. The kidneys of animals treated with the fraction at 5000 mg/kg presented hydropic degeneration. The extract and fraction did not induce oxidative stress in the liver and did not show genotoxicity, as examined by micronucleus and comet assays. In conclusion, the preparations were not lethal to mice but caused some signs of toxicity, mainly the fraction. The results indicated the need to evaluate the toxicity of M. vacciniifolia rhizome in other models and in chronic assays.

Characterization and assessment of the genotoxicity and biocompatibility of poly (hydroxybutyrate) and norbixin membranes

Purpose

To synthesize and characterize poly(hydroxybutyrate) (PHB) and norbixin membranes to evaluate them for genotoxicity in rats and wound healing in mice by histological staining.

Methods

For the evaluation of genotoxicity, male rats ( Rattus novegicus ) were divided into three groups (n= 5): 5% PHB/Norbixin membrane introduced into the peritoneum by laparotomy; B – negative control; C – positive control (intraperitoneal dose of cyclophosphamide 50 mg/kg). For the evaluation of biocompatibilty, a cutaneous wound was induced on the back of males mice ( Mus musculus ) divided into two experimental treatment groups: control and membrane that underwent euthanasia after 7 and 14 days treatment. Statistical analysis ware made by One Way Anova post hoc Tukey Test (p<0.05).

Results

Regarding the incidence of polychromatic erythrocytes, there was no difference between negative control and 5% PHB/Norbixin membrane; however, when compared to the positive control represented by cyclophosphamide, there was a significant difference (p <0.001). As for DNA damage, the changes induced in the first 4h were repaired in 24h. In addition, the membrane was effective in abbreviating the inflammatory process and served as a scaffold due to the stimulus to reepithelialization mainly on the 7 days of treatment.

Conclusion

The non-genotoxic PHB/Norbixin 5% membrane presented promising results that suggest its effectiveness as a guide for tissue regeneration given its biocompatibility.

Tityus stigmurus venom causes genetic damage in blood and testicular cells and affects the number and morphology of gametogenic lineage cells in mice

Scorpion envenomation represents an important health problem in many parts of the world, due to the high number and severity of accidents. Recent studies demonstrated that some species can produce venoms with genetic damage potential. Here, we evaluated whether Tityus stigmurus venom causes genetic damage in blood and testicular cells of Swiss mice. We also analyzed the effect of the venom on the number of spermatogenic lineage cells. Five groups of mice received 0.387 mg/kg of the venom, intraperitoneally; one group received saline solution (control group). Blood and testicular cells were collected for comet assay and histological analysis at different times after treatment (1, 2, 6, 12, and 48 h). Blood was also collected 48 h after treatment for the micronucleus test in erythrocytes. Histological analysis was performed by counting cells of the spermatogenic lineages; the nuclear area of elongated spermatocytes was also evaluated. Treatment with the venom induced DNA damage that endured from 1 h to 48 h, as confirmed by the comet assay. The micronucleus test demonstrated that the venom induced mutations in erythrocytes. The number of spermatogonia and rounded spermatids decreased in some groups; the number of elongated spermatids increased, and their nuclear size decreased 1 h after treatment. Genetic damage can be caused directly by the venom, but we suggested that reactive oxygen species that result from inflammatory process caused by the envenomation may have an important role in the DNA damage. Genetic damage and apoptosis may explain the changes in the number of spermatogenic cells. Furthermore, the decrease in nuclear area may result from chromatin loss. Genetic damage in testicular cells, associated with alterations in the number and morphology of spermatogenic cells, can result in reproduction disorders in animals, or humans, stung by T. stigmurus.

Synthesis and evaluation of resveratrol derivatives as fetal hemoglobin inducers

Resveratrol (RVT) derivatives (10a-i) were designed, synthesized, and evaluated for their potential as gamma-globin inducers in treating Sickle Cell Disease (SCD) symptoms. All compounds were able to release NO at different levels ranging from 0 to 26.3%, while RVT did not demonstrate this effect. In vivo, the antinociceptive effect was characterized using an acetic acid-induced abdominal contortion model. All compounds exhibited different levels of protection, ranging from 5.9 to 37.3%; the compound 10a was the most potent among the series. At concentrations between 3.13 and 12.5 µM, the derivative 10a resulted in a reduction of 41.1-64.3% in the TNF-α levels in the supernatants of macrophages that were previously LPS-stimulated. This inhibitory effect was higher than that of RVT used as the control. In addition, the compound 10a and RVT induced double the production of the gamma-globin chains (γG + γA), compared to the vehicle, using CD34+ cells. Compound 10a also did not induce membrane perturbation and it was not mutagenic in the in vivo assay. Thus, compound 10a emerged as a new prototype of the gamma-globin-inducer group with additional analgesic and anti-inflammatory activities and proving to be a useful alternative to treat SCD symptoms.

Evaluation of the cytotoxicity, oral toxicity, genotoxicity, and mutagenicity of the latex extracted from Himatanthus drasticus (Mart.) Plumel (Apocynaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Himatanthus drasticus is a tree popularly known as janaguba. Endemic to Brazil, it is found in the Cerrado and Caatinga biomes, rock fields, and rainforests. Janaguba latex has been used in folk medicine for its antineoplastic, anti-inflammatory, analgesic, and antiallergic activities. However, studies investigating the safety of its use for medicinal purposes are limited.

AIM OF THE STUDY

This study aimed to evaluate the toxicity of the latex extracted from H. drasticus.

MATERIALS AND METHODS

The latex was extracted from H. drasticus specimens by removing a small area of bark (5 × 30 cm) and then dissolving the exudate in water and lyophilizing it. Phytochemical screening was performed by TLC and GC-MS, protein, and carbohydrate levels. Cell viability was performed by the MTT method. Acute oral toxicity, genotoxicity, and mutagenicity assays were performed in mice.

RESULTS

TLC showed the presence of saponins and reducing sugars, as well as steroids and terpenes. The GC-MS analysis of the nonpolar fraction identified lupeol acetate, betulin, and α/β-amyrin derivatives as the major compounds. The latex was toxic to S-180 cells at 50 and 100 μg/mL. No signals of toxicity or mutagenicity was found in mice treated with 2000 mg/kg of the latex, but genotoxicity was observed in the Comet assay.

CONCLUSIONS

H. drasticus latex showed toxicity signals at high doses (2000 mg/kg). Although the latex was not mutagenic to mice, it was genotoxic in the Comet assay in our experimental conditions. Even testing a limit dose of 2000 mg/kg, which is between 10 to 35-fold the amount used in folk medicine, caution must be taken since there is no safe level for genotoxic compounds exposure. Further studies on the toxicological aspects of H. drasticus latex are necessary to elucidate its possible mechanisms of genotoxicity.

Evaluation of Anti-Cytotoxic and Anti-Genotoxic Effects of Nigella sativa through a Micronucleus Test in BALB/c Mice

Nigella sativa (N. sativa) is a medicinal plant used for its therapeutic pharmacological effects such as anti-inflammatory, antioxidant, anticancer, antidiabetic, and immunomodulation. This study explored the anti-cytotoxic and anti-genotoxic effect of N. sativa through a micronucleus test (MNT) of BALB/c mice peripheral blood. Using 6-to-8-week-old healthy male BALB/c mice, four groups were formed: (1) Control (sterile water), single-dose 2 mg/kg/intraperitoneal (i.p); (2) N. sativa oil, 500 mg/kg/24 h/7 days/i.p; (3) Cisplatin (CP), single-dose 2 mg/kg/subcutaneous (s.c); (4) N. sativa + CP with their respective dosage. When evaluating polychromatic erythrocytes (PCE), a biomarker of cytotoxicity, the group treated with N. sativa + CP experienced an increase in the frequency of PCE, which demonstrated the recovery of bone marrow and modulation of cell proliferation. The analysis of micronucleated polychromatic erythrocytes (MNPCE), an acute genotoxicity biomarker, showed similar frequency of MNPCE within the groups except in CP, but, in the N. sativa + CP group, the frequency of MNPCE decreased and then regulated. Finally, the frequency of micronucleated erythrocytes (MNE), a biomarker of genotoxicity, the supplementation of N. sativa oil did not induce genotoxic damage in this model. Thus, we conclude that N. sativa has both cytoprotective, genoprotective effects and modulates cell proliferation in BALB/c mice.

Gold-Coated Superparamagnetic Iron Oxide Nanoparticles Attenuate Collagen-Induced Arthritis after Magnetic Targeting

The aim of the study was to evaluate if gold-coated superparamagnetic iron oxide nanoparticles (AuSPION) magnetic-targeted to the arthritic articulation of collagen induced arthritis (CIA) rats are able to ameliorate rheumatoid arthritis without producing significant biological adverse effects in comparison to colloidal Au nanoparticles (AuC) and metotrexate (MTX). Male Wistar rats were divided into control; arthritic; AuSPION (150 μg kg^-1); AuC (150 μg kg^-1) and MTX (2.5 μg kg^-1). Treatments were administered thrice every other day by the intraperitoneal route 15 min after all groups had a neodymium magnet coupled to the right ankle joint (kept for 1 h). Paw edema and body weight were measured weekly. Joint sections were evaluated by Haematoxylin & Eosin and immunohistochemistry (TNF-α, IL-1β). Biomarkers of oxidative stress were used to evaluate toxicity. Among the evaluated treatments, AuSPION led to significant clinical improvements (decreased edema and infiltration by leukocytes as well as less positively immunostained cells for both TNF-α and IL-1β in synovium) accompanied by a lack of toxicity as indicated by redox state and genotoxicity assays. Our results clearly indicate that the magnetic targeting of AuSPION suppresses joint edema and inflammation, cytokine expression as well as the redox imbalance, thereby contributing to an amelioration of arthritis severity in CIA rats. The results demonstrate for the first time the potentiality of AuSPION administration under a magnetic field as an attractive alternative for future treatments of rheumatic diseases.

Assessment of Pig-a, Micronucleus, and Comet Assay Endpoints in Tg.RasH2 Mice Carcinogenicity Study of Aristolochic Acid I

A newly developed in vivo Pig-a gene mutation assay displays great potential for integration into genotoxicity tests. To obtain more evidence for application of the Pig-a assay, we integrated this assay, micronucleus test in peripheral blood (MN-pb test) and bone marrow (MN-bm test), as well as a Comet assay into a transgenic RasH2 mice carcinogenicity study. Fourteen male RasH2 mice and five wild-type (WT) mice were treated with a strong mutagen aristolochic acid I at a dose of 5 mg/kg/day for 4 consecutive weeks. Mice recovered in 5 weeks. Peripheral bloods were collected for Pig-a assay, MN-pb test, and Comet assay at several time points, while bone marrow and target organs were harvested for the MN-bm test and pathological diagnosis after mice were euthanized. Finally, 13 of the 14 RasH2 mice developed squamous cell carcinomas in the forestomach, while there were no carcinomas in the WT mice. Pig-a mutant frequencies (MFs) consecutively increased throughout the study to a maximum value of approximately 63-fold more than background. These frequencies were relative to the incidence, size, and malignant degree of tumors. Micronucleated reticulocytes increased from Day 1 to Day 49, before returning to background levels. No positive responses were observed in either the MN-bm test or the Comet assay. Results suggested that, when compared with the other two tests, the Pig-a assay persistently contributed to sustaining MFs, enhanced detection sensitivity due to the accumulation of Pig-a mutations, and demonstrated better predictability for tumorigenicity. Environ. Mol. Mutagen. 61:266-275, 2020. © 2019 Wiley Periodicals, Inc.

Phytochemical study, molecular docking, genotoxicity and therapeutic efficacy of the aqueous extract of the stem bark of Ximenia americana L. in the treatment of experimental COPD in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ximenia americana L. is popularly known as yellow plum, brave plum or tallow wood. All the parts of this plant are used in popular medicine. Its reddish and smooth bark are used to treat skin infections, inflammation of the mucous membranes and in the wound healing process.

OBJECTIVE

Verification of phytochemical profile, the molecular interaction between flavonoid, (-) epi-catechin and 5-LOX enzyme, by means of in silico study, the genotoxic effect and to investigate the pharmacological action of the aqueous extract of the stem bark of X. americana in pulmonary alterations caused by experimental COPD in Rattus norvegicus.

MATERIALS AND METHODS

The identification of secondary metabolites was carried out by TLC and HPLC chromatographic methods, molecular anchoring tests were applied to analyze the interaction of flavonoid present in the extract with the enzyme involved in pulmonary inflammation process and the genotoxic effect was assessed by comet assay and micronucleus test. For induction of COPD, male rats were distributed in seven groups. The control group was exposed only to ambient air and six were subjected to passive smoke inhalations for 20 min/day for 60 days. One of the groups exposed to cigarette smoke did not receive treatment. The others were treated by inhalation with beclomethasone dipropionate (400 mcg/kg) and aqueous and lyophilized extracts of X. americana (500 mg/kg) separately or in combination for a period of 15 days. The structural and inflammatory pulmonary alterations were evaluated by histological examination. Additional morphometric analyses were performed, including the alveolar diameter and the thickness of the right ventricle wall.

RESULTS

The results showed that the aqueous extract of the bark of X. americana possesses (-) epi -catechin, in silico studies with 5-LOX indicate that the EpiC ligand showed better affinity parameters than the AracA ligand, which is in accordance with the results obtained in vivo studies. Genotoxity was not observed at the dose tested and the extract was able to stagnate the alveolar enlargement caused by the destruction of the interalveolar septa, attenuation of mucus production and decrease the presence of collagen fibers in the bronchi of animals submitted to cigarette smoke.

CONCLUSION

Altogether, the results proved that the aqueous extract of X. americana presents itself as a new option of therapeutic approach in the treatment of COPD.

Protective effects of bark ethanolic extract from Spondias dulcis Forst F. against DNA damage induced by benzo[a]pyrene and cyclophosphamide

This study evaluated the genotoxicity, mutagenicity, antigenotoxicity, and antimutagenicity effects on biochemical parameters of oxidative stress of the Spondias dulcis bark ethanolic extract on mice. The extract was evaluated in the doses of 500, 1000, and 1500 mg/kg bw via gavage. To evaluate the protective effects of the extract, benzo[a]pyrene (B[a]P) and cyclophosphamide (CP) were chosen as DNA damage inducers. Genotoxicity and antigenotoxicity were evaluated by the comet assay. Cytotoxicity, mutagenicity, and antimutagenicity were evaluated by the micronucleus test in bone marrow and peripheral blood. The biochemical parameters of oxidative stress were evaluated by the quantification of catalase activity (CAT) and reduced glutathione (GSH) in total blood, liver and kidney, and malondialdehyde (MDA), in liver and kidney. No genotoxic, cytotoxic, or mutagenic effect was found on mice exposed to the extract. The extract depleted the number of damaged nucleoids in total blood and the number of micronucleus (MN) in both cell types. The extract was able to increase CAT activity and GSH levels and decrease MDA levels after treatment with B[a]P and CP. The results indicate that the S. dulcis extract has potential to be used as preventive compound against DNA damage caused by CP and B[a]P.

2,4-Decadienal does not induce genotoxic effects in in vivo micronucleus studies

2,4-Decadienal (E,E-) occurs naturally in foods and is also used as a flavoring ingredient. In vivo micronucleus studies were used to evaluate the potential for 2,4-decadienal to cause genotoxic effects. Male Han Wistar rats were dosed either by intraperitoneal injection or by gavage in two independent studies. The animals (12/group) received 25, 50, or 100 mg/kg bw of 2,4-decadienal via intraperitoneal injection, or 350, 700, or 1400 mg/kg bw via gavage. Dose-dependent decreases in the percentages of peripheral blood reticulocytes were observed in both studies, indicating that the target tissue was exposed to toxic levels of 2,4-decadienal. No induction of micronuclei in the bone marrow polychromatic erythrocytes or the peripheral blood reticulocytes was observed in either study. These results, coupled with previous mutagenicity studies, support the overall conclusion that 2,4-decadienal does not present a concern for genotoxicity.

The effect of lycopene supplementation on radiation-induced micronuclei in mice reticulocytes in vivo

Lycopene (LYC) is a natural pigment present in tomatoes and other red fruits and vegetables including red carrots, red peppers, watermelons, pink grapefruits, apricots, pink guavas, and papaya. There is some evidence that LYC may provide protection against mutations induced by ionizing radiation. The study aimed to investigate whether the genetic material of reticulocytes (RET) could be protected from radiation-induced damage by LYC. Mice were treated with LYC [0.15 mg/kg bodyweight (bw), 0.30 mg/kg bw], acute and fractionated irradiation (0.5 Gy, 1 Gy applied daily), or with both agents (0.5 Gy + 0.15 mg/kg bw LYC, 0.5 Gy + 0.30 mg/kg bw LYC, 1 Gy + 0.15 mg/kg bw LYC, 1 Gy + 0.30 mg/kg LYC). LYC supplementation was started at 24 h or 1 week after the first irradiation. Irradiation significantly enhanced the frequency of micronuclei (MN) in RET. LYC treatment at a dose of 0.15 mg/kg bw 24 h after starting fractionated radiation at 1 Gy significantly decreased (41-68%, p < 0.0125) the level of MN in peripheral blood and bone marrow RET. LYC supplementation at 0.30 mg/kg bw did not significantly alter the frequency of MN in peripheral blood, but significantly increased the frequency of bone marrow RET MN. LYC treatment on day 8 following the first radiation exposure showed results similar (92-117%, p > 0.24) to those obtained with irradiation alone. Lycopene may act as a radiomitigator but must be administered at low doses and as soon as possible after irradiation. Contrary, combined exposure with high doses of irradiation and LYC may enhance the mutagenic effect of irradiation.

Assessment of the toxicogenic effects and cell death potential of the ester (Z)-methyl 4-((1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino)-4-oxobut-2-anoate in combination with cisplatin, cyclophosphamide and doxorubicin

Despite rapid advances in both the early detection and treatment of cancer, the mortality from this disease remains high, which justifies the development of new products that are more selective and effective and have fewer side effects. Accordingly, a novel ester was synthesized that contains two pharmacophores with important biological activities: (I) 4-aminoantipyrine, which has anti-inflammatory and antioxidant effects, and (II) the pharmacophore 1,4-dioxo-butenyl, which has cytotoxic activity. When administered alone, this compound is non-genotoxic, and it does not cause an increasing in splenic phagocytosis. Nevertheless, it can induce cell death. When administered in combination with commercial chemotherapeutic agents, such as doxorubicin, cisplatin, and cyclophosphamide, the ester shows antigenotoxic activity and decreases phagocytosis and reduces the potential to cause cell death. These results indicate that the compound should not be used in combination with chemotherapeutic agents that exert their effect through DNA damage, an important feature of antitumor drugs.

Conus striatus venom exhibits non-hepatotoxic and non-nephrotoxic potent analgesic activity in mice

Constant research into the pharmaceutical properties of marine natural products has led to the discovery of many potentially active agents considered worthy of medical applications. Genus Conus, which approximately comprises 700 species, is currently under every researcher's interest because of the conopeptides in their crude venom. Conopeptides have a wide range of pharmacological classes and properties. This research focused on the crude venom of Conus striatus to assess its analgesic activity, mutagenicity, nephrotoxicity, and hepatotoxicity in mice. The crude venom was extracted from the conus snails and the protein concentration was determined using Bradford's method. The analgesic activity of the venom was determined using the hot-plate method and standard IFCC method was used to determine the alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Evaluation of mutagenicity was done using micronucleus assay and the nephrotoxicity of the venom was determined using Kidney Coefficient and serum creatinine concentration. The maximum tolerable dose (MTD) of the crude venom was found to be 75 ppm. The venom exhibited potent analgesic activity even higher than the positive control (Ibuprofen). Most of the analgesic drugs can usually impact damage in the liver and kidneys. However, AST and ALT results revealed that the venom has no adverse effects on the liver. Although the venom increased the incidence of micronucleated polychromatic erythrocytes, making it mutagenic, with MTD concentration's mutagenicity comparable to the positive control methyl methanesulfonate (MMS). The kidney coefficients, on the other hand, showed no significant difference between the treated groups and that of the untreated group. The serum creatinine also showed a concentration-dependent increase; with MTD treated mice got the highest creatinine concentration. However, MTD/2 and MTD/4 showed no significant difference in creatinine levels with respect to the untreated groups. Hence, the nephrotoxicity of the venom was only evident when used at higher concentration. The venom exhibited potent analgesic activity indicated that the C. striatus crude venom extract could have a potential therapeutic component as analgesic drugs that displayed no hepatic damage. This study also suggests that for this venom to be utilized for future medical applications, their usage must be regulated and properly monitored to avoid nephrotoxic effect.

Toxicity study of Bidens pilosa in animals

Bidens pilosa (BP) is an edible Asteraceae plant found worldwide that has traditionally been used as food without noticeable side effects. BP has also been used as an herbal medicine to treat over 41 categories of disease in humans and animals. However, to date no long-term toxicity study of BP has been conducted in animals. In this study, 24-week oral toxicity of BP at doses of 0%, 0.5%, 2.5%, 5% and 10% of food was investigated in mice. Mortality, body weight, organ weight, food intake, water consumption, hematology, serum biochemistry, urinalysis, genotoxicity and organ histopathology of animals of both sexes were analyzed. No significant difference in the above parameters was observed between control and BP-fed mice except that body weight and food intake in those fed with 10% BP were significantly less than controls. In addition, similar results were seen in chickens fed with BP for 28 days. Collectively, the data demonstrate that BP has no adverse effects in mice and chickens at dose of 5% or less of food.

In Vivo Evaluation of the Genotoxic Effects of Poly (Butylene adipate-co-terephthalate)/Polypyrrole with Nanohydroxyapatite Scaffolds for Bone Regeneration

Here, butylene adipate-co-terephthalate/polypyrrole with nanohydroxyapatite (PBAT/PPy/nHAp) scaffolds were fabricated and characterized. The electrospinning process was carried out using 12 kV, a needle of 23 G, an infusion pump set at 0.3 mL/h, and 10 cm of distance. Afterwards, nHAp was directly electrodeposited onto PBAT/PPy scaffolds using a classical three-electrode apparatus. For in vivo assays (comet assay, acute and chronic micronucleus), 60 male albino Wistar rats with 4 groups were used in each test (n = 5): PBAT/PPy; PBAT/PPy/nHAp; positive control (cyclophosphamide); and the negative control (distilled water). Peripheral blood samples were collected from the animals to perform the comet test after 4 h (for damage) and 24 h (for repair). In the comet test, it was shown that the scaffolds did not induce damage to the % DNA tail and neither for tail length. After the end of 48 h (for acute micronucleus) and 72 h (for chronic micronucleus), bone marrow was collected from each rat to perform the micronucleus test. All of the produced scaffolds did not present genotoxic effects, providing strong evidence for the biological application of PBAT/PPy/nHAp scaffolds.

Dosage time affects alkylating agents induced micronuclei in mouse peripheral blood reticulocytes through the function of erythropoietin

Previously, we reported that the frequency of micronucleated reticulocytes (MNRETs) in the peripheral blood of male C3H/He mice intraperitoneally administered ethylnitrosourea (ENU) (25 mg/kg body weight) in the dark period (zeitgeber time, ZT15) was higher than in the light period (ZT3). In this study, to clarify the mechanism underlying this phenomenon, we investigated the differences in micronucleus (MN) induction observed between ZT3 and ZT15 using five chemicals, methylnitrosourea (MNU), ethylmethane sulfonate (EMS), mitomycin C, cyclophosphamide and vincristin. MNU and EMS, monofunctional alkylating agents, showed higher frequencies of MNRETs in the ZT15 than the ZT3 treatment similar to ENU. However, no differences were observed for the other chemicals. In the comet assay, more DNA damage was induced by ENU in the ZT15 than the ZT3 treatment. Furthermore, the plasma erythropoietin (EPO) level, a known effector of MN induction with anti-apoptotic activity mediated by Bcl-xL expression, was higher in the dark than in the light period. EPO did not increase the frequency of MNRETs. However, in the ENU treatment group at ZT3 following EPO injection a significant increase of MNRETs was observed similar to the ZT15 treatment. Higher expression of apoptosis-related genes such as Bcl-xL was induced in bone marrow cells from mice treated with ENU at ZT15 compared with ZT3. From these results, it was speculated that the differences in MN induction in the peripheral blood of mice exposed to monofunctional alkylating agents such as ENU depend on apoptotic or anti-apoptotic conditions related to the circadian rhythms of EPO in bone marrow.

Gum arabic and red propolis protecteting colorectal preneoplastic lesions in a rat model of azoxymethane1

Purpose

To evaluate red propolis, gum arabic and L-lysine activity on colorectal preneoplastic lesions induced by azoxymethane (AOM).

Methods

The study featured 4 control groups (I-IV) and 4 experimental groups (V-VIII), totaling 48 rats. Once a week for 2 weeks, animals on control groups received saline, while animals in experimental groups received azoxymethane (15 mg/kg i.p.). The follow up along 16 weeks included daily oral gavage to administer water (I and V), L-lysine (150 mg/kg)(II and VI), própolis (100mg/5ml/kg)(III and VII), or gum arabic (5ml/kg)(IV and VIII). Was performed surgery on the animals in the end of this time in order to collect blood for biological assays (TBARS, GSH), followed by their sacrifice to tissue extract.

Results

Oxidative stress (TBARS) and the number of aberrant crypt foci (ACF) in distal colon were lower using própolis (p<0.01 for both parameters). Gum arabic reduced preneoplastic lesions (ACF ≤ 4 crypts) on distal colon and on the entire colon (p<0.05).

Conclusions

Red propolis reduced AOM-induced oxidative stress (TBARS) and total number of ACF in the distal colon. L-lysine neither protected against nor enhanced AOM-induced ACF. Gum arabic reduced the number of ACF.

Effects of hydroxyurea on CNV induction in the mouse germline

Copy number variants (CNVs) are important in genome variation and genetic disease, with new mutations arising frequently in the germline and somatic cells. Replication stress caused by aphidicolin and hydroxyurea (HU) is a potent inducer of de novo CNVs in cultured mammalian cells. HU is used extensively for long-term management of sickle cell disease. Here, we examined the effects of HU treatment on germline CNVs in vivo in male mice to explore whether replication stress can act as a CNV mutagen in germline mitotic divisions as in cultured cells and whether this would support a concern for increased CNV mutations in offspring of men treated with HU. Several trials of HU administration were performed by oral gavage and subcutaneous pump, with CNVs characterized in C57BL/6 x C3H/HeJ hybrid mouse offspring by microarray and mate-pair sequencing. HU had a short half-life of ~14 min and a narrow dose window over which studies could be performed while maintaining fertility. Tissue histopathology and reticulocyte micronucleus assays verified that doses had a substantial tissue and genetic toxicity. CNVs were readily detected in offspring that originated in both paternal and maternal mouse strains, as de novo and inherited events. However, HU did not increase CNV formation above baseline levels. These results reveal a high rate of CNV mutagenesis in the mouse germline but do not support the hypothesis that HU would increase CNV formation during mammalian spermatogenesis, perhaps due to highly toxic effects on sperm development or experimental variables related to HU pharmacology in mice. Environ. Mol. Mutagen. 59:698-714, 2018. © 2018 Wiley Periodicals, Inc.

Resorcinolic lipid 3-heptyl-3,4,6-trimethoxy-3H-isobenzofuran-1-one is a strategy for melanoma treatment

AIMS

Previous studies performed by our research group indicated that cytosporone analogues are capable of prevent or repair DNA damages. This work presents the evaluation of the activity of AMS35AA for metastatic murine melanoma cells (B16F10) in experimental model in vitro and, in pre-clinic assay of metastatic melanoma in vivo, using mice lineage C57BL/6.

MAIN METHODS

In vitro assays were performed: MTT and comet assay, flow cytometry evaluation, gene expression assay by RT-PCR, qualitative evaluation of cell death using B16F10 cells. In vivo assays: micronucleus and comet assay, splenic phagocytosis, melanoma murine model and histopathological analysis, using mice lineage C57BL/6 (n = 20).

KEY FINDINGS

In vitro results performed by MTT assay showed that AMS35AA is cytotoxic for B16F10 cells (p < 0.05). Based on comet assay the genotoxicity of the IC₅₀ was determined (95.83 μg/mL) (p < 0.05). These data were corroborated by flow cytometry analysis after the treatment with AMS35AA, which indicates the cellular death by apoptosis (p < 0.05) and increasing of ATR, p53, p21 and GADD45 gene expressions verified using RT-PCR. With respect to in vivo results, it was observed that AMS35AA did not show genotoxic activity. Data of tumor volume ex vivo indicate reduction of tumor for the treated animals with AMS35AA up to 15.84×, which is superior to Dacarbazina (50 mg/Kg, p.c.; i.p.).

SIGNIFICANCE

In summary, the study showed that AMS35AA reveals relevant results regarding to cytotoxicity of B16F10 murine melanoma cells, inducing death by apoptosis via mitochondrial and/or mediated by DNA damages.