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

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.

Protective effect of exogenous melatonin in rats and their offspring on the genotoxic response induced by the chronic consumption of alcohol during pregnancy

Maternal alcoholism can induce serious injuries in embryonic and fetal development. The metabolism of alcohol increases the production of free radicals and acetaldehyde, molecules capable of reacting with DNA, impairing organogenesis. Melatonin is a powerful antioxidant that can act as a protective agent against DNA damage caused by genotoxic agents, such as ethanol. This study evaluated the protective effect of exogenous melatonin in rats and their offspring on the genotoxic response induced by chronic alcohol consumption during pregnancy. Twenty-five pregnant rats were divided into the following groups: NC - Negative control; ET - Rats receiving ethanol (3 g/kg/day); ET+10 M - Rats receiving ethanol (3 g/kg/day) and melatonin (10 mg/kg/day); ET+15 M - Rats receiving ethanol (3 g/kg/day) and melatonin (15 mg/kg/day); PC - Positive control (40 mg/kg cyclophosphamide). The dams and 10 pups (five males and five females) from each group were anesthetized to collect blood and liver from the dams and blood, liver and brain of neonates to evaluate the frequency of DNA damage by the comet assay. Blood was also used for the micronucleus test. The results demonstrated a significant increase in DNA damage in the blood and liver cells of dams receiving ethanol and their offspring as well as in the brain of these neonates. Treatments with melatonin (10 and 15 mg/kg/day) significantly reduced the genotoxicity caused by ethanol in the blood of dams and neonates (males and females), liver of dams and male offsprings, and in the brain of female offsprings. It was shown that only the female offspring exposed to maternal alcohol consumption showed a higher frequency of micronuclei in polychromatic erythrocytes. Consequently, exogenous melatonin may be a promising therapeutic agent against genotoxic damage induced by alcohol; however, further studies are needed to confirm these benefits.

Evaluation of the effects of the larvicides temephos on reproductive performance, embryofetal development and DNA integrity of Swiss mice

Temephos is considered the gold standard by the Ministry of Health for controlling the larvae of the mosquito Aedes aegypti. The present study evaluated the effects of Temephos larvicide on the reproductive performance, embryo-fetal development and DNA integrity of Swiss mice. This study used 30 pregnant female mice: 10 were controls treated with drinking water at a dosage of 0.1 mL/10 g (body weight - b.w., administered orally - a.o.), and 20 were treated with Temephos at doses of 0.0043 mg/kg and 0.043 mg/kg (b.w., a.o.) during the gestational period. Statistical analysis showed that Temephos did not alter the biometric or reproductive parameters. Comparing the weight of the fetus to the stage of pregnancy demonstrated that the 0.0043 mg/kg dosage increased the size of the fetuses. No external malformations were detected. However, the 0.043 mg/kg dosage induced changes in the sternum, with the main change being the center of the sternum, xiphoid processes and absence of the manubrium. The other skeletal and visceral alterations did not differ from the control group and are considered variants of normality. The analysis of head measurements showed an increase in the anterior/posterior measurements of the glabella, the external occipital protuberance and the biauricular plane. The circumference and area of the head did not present significant differences. The micronucleus test showed only a 0.043 mg/kg increase in 48 h. Thus, it is considered that Temephos has a low teratogenic and genotoxic risk.

The OECD's micronucleus test guideline for single exposure to an agent and the genotox-kinetic alternative

The 'Organization for Economic Co-operation and Development (OECD) guidelines for the Testing of Chemicals' aims to identify whether a chemical is a genotoxic hazard, and these guidelines 'are periodically reviewed in the light of scientific progress, changing regulatory needs and animal welfare considerations'. OECD published a mammalian erythrocyte micronucleus test guideline for testing chemicals (1) that proposes: 'Animals are treated with the test chemical once…Samples of peripheral blood are taken at least twice (from the same group of animals), starting not earlier than 36 h after treatment, with appropriate intervals following the first sample, but not extending beyond 72 h'. This guidelines are base on the report by the Collaborative Study Group for the Micronucleus Test (CSGMT), which was based on the sampling of mice peripheral blood every 24 h We investigated the kinetics of micronucleus induction by taking samples prior to administration and every 8 or 10 h after single treatment. The comparisons suggest that 24-h sampling could cause not only an underestimation of the responses to various agents but also a misestimation of the time of maximal induction. We proposed that samples of peripheral blood must be collected at two different times during an optimal 25-h sampling range (from 25 to 50 h). Besides, we hypothesize that the time of maximal EPC-MN induction depends on the time required for the mechanisms involved in micronucleus production; and we suggest that a kinetic analysis of MN-PCE induction by several agents with well-known mechanisms of micronuclei induction would allow derivation of a specific relationship between the kinetics of MN-PCE induction and some process of DNA breaks and/or micronuclei induction.

The safe use of Doliocarpus dentatus in the gestational period: Absence of changes in maternal reproductive performance, embryo-fetal development and DNA integrity

ETHNOPHARMACOLOGICAL RELEVANCE

Doliocarpus dentatus (Dilleniaceae) is commonly used in Brazil for the treatment of inflammatory process pain and urinary retention. Previous studies of our group have demonstrated the anti-inflammatory and antimycobacterial action of the ethanolic extract of Doliocarpus dentatus (EEDd) as well as the safety of its use.

AIM OF THE STUDY

we investigated the effects of EEDd on reproductive performance, fetal development and DNA integrity in pregnant female Swiss mice.

MATERIAL AND METHODS

thirty female Swiss mice were divided into three experimental groups (n = 10): control group treated with 1% tween-80 and EEDd1 and EEDd2 groups treated with EEDd at doses of 100 and 1000 mg/kg, respectively. The treatment occurred by oral gavage throughout the gestational period. At the end of pregnancy, parameters related to reproductive performance, embryofoetal development and DNA integrity was evaluated.

RESULTS

both doses of the extract tested did not alter the reproductive parameters, did not present significant differences in the embryofetal development when compared to the control group and also did not induce the formation of micronuclei.

CONCLUSION

the EEDd do not alter the reproductive parameters, embryofetal development and DNA integrity, ensuring its safe use during pregnancy.

Flow cytometric method for scoring rat liver micronuclei with simultaneous assessments of hepatocyte proliferation

The current report describes a newly devised method for automatically scoring the incidence of rat hepatocyte micronuclei (MNHEP) via flow cytometry, with concurrent assessments of hepatocyte proliferation-frequency of Ki-67-positive nuclei, and the proportion of polyploid nuclei. Proof-of-concept data are provided from experiments performed with 6-week old male Crl:CD(SD) rats exposed to diethylnitrosamine (DEN) or quinoline (QUIN) for 3 or 14 consecutive days. Non-perfused liver tissue was collected 4 days after cessation of treatment in the case of 3-day studies, or 1 day after last administration in the case of 14-day studies for processing and flow cytometric analysis. In addition to livers, blood samples were collected one day after final treatment for micronucleated reticulocyte (MN-RET) measurements. Dose-dependent increases in MNHEP, Ki-67-positive nuclei, and polyploidy were observed in 3- and 14-day DEN studies. Both treatment schedules resulted in elevated %MNHEP for QUIN-exposed rats, and while cell proliferation effects were subtle, appreciable increases to normalized liver weights were observed. Whereas DEN caused markedly higher %MNHEP when exposure was extended to two weeks, QUIN-induced MNHEP were slightly increased with protracted dosing. Parallel microscopy-based MNHEP frequencies were highly correlated with flow cytometry-based measurements (four study/aggregate R²  = 0.80). No increases in MN-RET were seen in any of the four studies. Collectively, these results suggest liver micronuclei are amenable to an automated scoring technique that provides objective analyses and higher information content relative to conventional microscopy. Additional work is needed to expand the number and types of chemicals tested, identify the most advantageous treatment schedules, and test the transferability of the method. Environ. Mol. Mutagen. 59:176-187, 2018. © 2018 Wiley Periodicals, Inc.

The mixture of cashew nut shell liquid and castor oil results in an efficient larvicide against Aedes aegypti that does not alter embryo-fetal development, reproductive performance or DNA integrity

Dengue fever, chikungunya fever and Zika virus are epidemics in Brazil that are transmitted by mosquitoes, such as Aedes aegypti or Aedes albopictus. The liquid from shells of cashew nuts is attractive for its important biological and therapeutic activities, which include toxicity to mosquitoes of the genus Aedes. The present study evaluated the effects of a mixture of surfactants from natural cashew nutshell liquid and castor oil (named TaLCC-20) on the mortality of larvae and on the reproductive performance, embryonic and fetal development and genetic stability of Swiss mice. A total of 400 Ae. aegypti larvae (third larval stage) were treated with TaLCC-20 concentrations of 0.05 mg/L, 0.5 mg/L, or 5 mg/L (ppm). Twenty pregnant female mice were also orally administered TaLCC-20 at doses of 5 mg/kg and 50 mg/kg body weight (b.w.), and 10 animals were given only drinking water at 0.1 mL/10 g b.w. (orally). The results of a larvicide test demonstrated that 5 mg/mL TaLCC-20 killed 100% of larvae within three hours, which is comparable to the gold standard indicated by the Ministry of Health. Overall, these results show that TaLCC-20 is an efficient larvicide that does not induce genetic damage. In addition, changes in reproductive performance and embryo-fetal development appear positive, and the formulation is cost effective. Therefore, TaLCC-20 is an important product in the exploration of natural larvicides and can assist in fighting mosquitos as vectors for dengue fever, chikungunya fever and Zika virus, which are emerging/re-emerging and require proper management to ensure minimal harm to the human population. Therefore, TaLCC-20 can be considered a key alternative to commercial products, which are effective yet toxigenic.

Integration of liver and blood micronucleus and Pig-a gene mutation endpoints into rat 28-day repeat-treatment studies: Proof-of-principle with diethylnitrosamine

Regulatory guidance documents stress the value of assessing multiple tissues and the most appropriate endpoints when evaluating chemicals for in vivo genotoxic potential. However, conducting several independent studies to consider multiple endpoints and/or tissue compartments is resource intensive. Furthermore, conventional approaches for scoring genotoxicity endpoints are slow, tedious, and less objective than what would be considered ideal. In an effort to address these issues with current practices, we attempted to i) employ flow cytometry-based methods to score liver micronuclei, blood micronuclei, and blood Pig-a gene mutation, and ii) integrate the endpoints into a common general toxicology study design-the rat 28-day repeat dose study. A proof-of-principle experiment was performed with 6-week old male Crl:CD(SD) rats exposed to diethylnitrosamine (DEN) for 28 consecutive days. One day later blood was collected for micronucleated reticulocyte (MN-RET) and Pig-a mutation assays, and liver tissue was obtained for micronucleated hepatocyte (MNHEP) scoring. MN-RET frequencies were not affected by DEN exposure, and mean Pig-a mutant cell frequencies were only slightly elevated. On the other hand, % MNHEP showed marked, dose-related increases (2.2, 7.2, and 9.1 mean fold-increase for 5, 10, 15 mg DEN/kg/day, respectively). Concurrent with MNHEP analyses, assessments of Ki-67-positive events and the proportion of 8n nuclei provided evidence for treatment-related changes to hepatocyte proliferation. Collectively, these results reinforce the importance of evaluating chemicals' genotoxic potential in liver in addition to hematopoietic cells, and suggest that several automated measurements can be successfully integrated into repeat-dose studies for higher efficiencies and better utilization of fewer animals.

Assessment of genetic integrity, splenic phagocytosis and cell death potential of (Z)-4-((1,5-dimethyl-3-oxo-2-phenyl-2,3dihydro-1H-pyrazol-4-yl) amino)-4-oxobut-2-enoic acid and its effect when combined with commercial chemotherapeutics

The increased incidence of cancer and its high treatment costs have encouraged the search for new compounds to be used in adjuvant therapies for this disease. This study discloses the synthesis of (Z)-4-((1,5-dimethyl-3-oxo-2-phenyl-2,3dihydro-1H-pyrazol-4-yl) amino)-4-oxobut-2-enoic acid (IR-01) and evaluates not only the action of this compound on genetic integrity, increase in splenic phagocytosis and induction of cell death but also its effects in combination with the commercial chemotherapeutic agents doxorubicin, cisplatin and cyclophosphamide. IR-01 was designed and synthesized based on two multifunctionalyzed structural fragments: 4-aminoantipyrine, an active dipyrone metabolite, described as an antioxidant and anti-inflammatory agent; and the pharmacophore fragment 1,4-dioxo-2-butenyl, a cytotoxic agent. The results indicated that IR-01 is an effective chemoprotector because it can prevent clastogenic and/or aneugenic damage, has good potential to prevent genomic damage, can increase splenic phagocytosis and lymphocyte frequency and induces cell death. However, its use as an adjuvant in combination with chemotherapy is discouraged since IR-01 interferes in the effectiveness of the tested chemotherapeutic agents. This is a pioneer study as it demonstrates the chemopreventive effects of IR-01, which may be associated with the higher antioxidant activity of the precursor structure of 4-aminoantipyrine over the effects of the 1,4-dioxo-2-butenyl fragment.

Genetic toxicological assessment and anti-arthritic effects of an ethanolic extract obtained from Salvia lachnostachys Benth leaves in mice

In the present study, mice were subjected to prolonged treatment with ethanolic extract of Salvia lachnostachys Benth leaves (SLEE), and the inflammatory and arthritic parameters were evaluated using the Complete Freund's Adjuvant (CFA) model. The genotoxicity of SLEE were also assayed using genetic toxicological tests. For the CFA model, 28 male C57BL/6 mice were distributed randomly into four groups (control, 50 mg/kg of SLEE, 100 mg/kg of SLEE and dexamethasone) for the evaluation of hyperalgesia and paw edema for 21 days after injection of CFA into the paw. To conduct the toxicogenetic assessments (comet assay and micronuclei assay), apoptosis and splenic phagocytosis were evaluated in male Swiss mice after the administration of saline (control group), cyclophosphamide (positive control group) and SLEE (10, 100 and 1000 mg/kg). SLEE significantly reduced the mechanical hyperalgesia and edema caused by CFA injection. The results of the toxicogenetic assessment revealed no toxicogenetic potential in the mice, and the evaluation of apoptosis showed an increase in apoptotic cells in the spleen after 72 h of treatment with SLEE (1000 mg/kg). SLEE exhibited anti-arthritic activity with no toxicogenetic damage. These toxicogenic results support the safety of SLEE.

Effects of indirubin and isatin on cell viability, mutagenicity, genotoxicity and BAX/ERCC1 gene expression

CONTEXT

Indigofera suffruticosa Miller (Fabaceae) and I. truxillensis Kunth produce compounds, such as isatin (ISA) and indirubin (IRN), which possess antitumour properties. Their effects in mammalian cells are still not very well understood.

OBJECTIVE

We evaluated the activities of ISA and/or IRN on cell viability and apoptosis in vitro, their genotoxic potentials in vitro and in vivo, and the IRN- and ISA-induced expression of ERCC1 or BAX genes.

MATERIALS AND METHODS

HeLa and/or CHO-K1 cell lines were tested (3 or 24 h) in the MTT, Trypan blue exclusion, acridine orange/ethidium bromide, cytokinesis-blocked micronucleus (CBMN) and comet (36, 24 and 72 h) tests after treatment with IRN (0.1 to 200 μM) or ISA (0.5 to 50 μM). Gene expression was measured by RT-qPCR in HeLa cells. Swiss albino mice received IRN (3, 4 or 24 h) by gavage (50, 100 and 150 mg/kg determined from the LD₅₀ - 1 g/kg b.w.) and submitted to comet assay in vivo.

RESULTS

IRN reduced the viability of CHO-K1 (24 h; 5 to 200 μM) and HeLa cells (10 to 200 μM), and was antiproliferative in the CBMN test (CHO-K1: 0.5 to 10 μM; HeLa: 5 and 10 μM). The drug did not induce apoptosis, micronucleus neither altered gene expression. IRN and ISA were genotoxic for HeLa cells (3 and 24 h) at all doses tested. IRN (100 and 150 mg/kg) also induced genotoxicity in vivo (4 h).

CONCLUSION

IRN and ISA have properties that make them candidates as chemotherapeutics for further pharmacological investigations.

Raw data of the effects of Chlorogenic acid in 3-Nitropropionic acid induced toxicity and genotoxicity

The raw data showed in this article comes from the published research article entitled "Protective effects of Chlorogenic acid in 3-Nitropropionic acid induced toxicity and genotoxicity" Food Chem Toxicol. 2017 May 3. pii: S0278-6915(17)30226-0. DOI:10.1016/j.fct.2017.04.048. [1]. Data illustrates antitoxic and antigenotoxic effects of Chlorogenic acid (CGA) on toxicity and genotoxicity produced by the in vivo treatment with mitochondria toxin 3-Nitropropionic acid (3-NP) in mice. Toxicity and genotoxicity was evaluated in erythrocytes of peripheral blood through the micronuclei assay. Data was share at the Elsevier repository under the reference number FCT9033.

In vivo chemotherapeutic insight of a novel isocoumarin (3-hexyl-5,7-dimethoxy-isochromen-1-one): Genotoxicity, cell death induction, leukometry and phagocytic evaluation

Chemotherapy is one of the major approaches for the treatment of cancer. Therefore, the development of new chemotherapy drugs is an important aspect of medicinal chemistry. Chemotherapeutic agents include isocoumarins, which are privileged structures with potential antitumoral activity. Herein, a new 3-substituted isocoumarin was synthesized from 2-iodo-3,5-dimethoxy-benzoic acid and oct-1-yne in a cross-coupling Sonogashira reaction followed by a copper iodide-catalyzed intramolecular cyclization as key step using MeOH/Et₃N as the solvent system. The present study also evaluated the leukometry, phagocytic activity, genotoxic potential and cell death induction of three different doses (5 mg/kg, 10 mg/kg and 20 mg/kg) of this newly synthesized isocoumarin, alone and in combination with the commercial chemotherapeutic agents cyclophosphamide (100 mg/kg) and cisplatin (6 mg/kg) in male Swiss mice. The results suggest that the isocoumarin has genotoxicity and causes cell death. Noteworthy, this new compound can increase splenic phagocytosis and lymphocyte frequency, which are related to immunomodulatory activity. When combined with either cyclophosphamide or cisplatin, chemopreventive activity led to a reduction in the effects of both chemotherapeutic drugs. Thus, the new isocoumarin is not a candidate for chemotherapeutic adjuvant in treatments using cyclophosphamide or cisplatin. Nevertheless, the compound itself is an important prototype for the development of new antitumor drugs.

Anti-inflammatory, antimycobacterial and genotoxic evaluation of Doliocarpus dentatus

ETHNOPHARMACOLOGICAL RELEVANCE

Doliocarpus dentatus is a medicinal plant widely used in Mato Grosso do Sul State for removing the swelling pain caused by the inflammation process and for treating urine retention.

AIM OF THE STUDY

The genotoxic aspects and the anti-inflammatory and antimycobacterial activity of the ethanolic extract obtained from the leaves of D. dentatus (EEDd) were investigated.

MATERIALS AND METHODS

The EEDd was evaluated against Mycobacterium tuberculosis, and the compound composition was evaluated and identified by nuclear magnetic resonance (NMR). The mice received oral administration of EEDd (30-300mg/kg) in carrageenan models of inflammation, and EEDd (10-1000mg/kg) was assayed by the comet, micronucleus, and phagocytosis tests and by the peripheral leukocyte count.

RESULTS

Phenols (204.04mg/g), flavonoids (89.17mg/g), and tannins (12.05mg/g) as well as sitosterol-3-O-β-D-glucopyranoside, kaempferol 3-O-α-L-rhamnopyranoside, betulinic acid and betulin were present in the EEDd. The value of minimal inhibitory concentration (MIC) of EEDd was 62.5µg/mL. The EEDd induced a significant decrease in the edema, mechanical hypersensitivity and leukocyte migration induced by carrageenan. The comet and micronucleus tests indicated that the EEDd was not genotoxic. The EEDd also did not change the phagocytic activity or the leukocyte perLipheral count.

CONCLUSIONS

The EEDd does not display genotoxicity, phagocytosis and could act as an antimycobacterial and anti-inflammatory agent. This study should contribute to ensuring the safe use of EEDd.

Mitigation of whole-body gamma radiation-induced damages by Clerodendron infortunatum in mammalian organisms

Several phytoceuticals and extracts of medicinal plants are reported to mitigate deleterious effects of ionizing radiation. The potential of hydro-alcoholic extract of Clerodendron infortunatum (CIE) for providing protection to mice exposed to gamma radiation was investigated. Oral administration of CIE bestowed a survival advantage to mice exposed to lethal doses of gamma radiation. Radiation-induced depletion of the total blood count and bone marrow cellularity were prevented by treatment with CIE. Damage to the cellular DNA (as was evident from the comet assay and the micronucleus index) was also found to be decreased upon CIE administration. Radiation-induced damages to intestinal crypt cells was also reduced by CIE. Studies on gene expression in intestinal cells revealed that there was a marked increase in the Bax/Bcl-2 ratio in mice exposed to whole-body 4 Gy gamma radiation, and that administration of CIE resulted in significant lowering of this ratio, suggestive of reduction of radiation-induced apoptosis. Also, in the intestinal tissue of irradiated animals, following CIE treatment, levels of expression of the DNA repair gene Atm were found to be elevated, and there was reduction in the expression of the inflammatory Cox-2 gene. Thus, our results suggest a beneficial use of Clerodendron infortunatum for mitigating radiation toxicity.

Effects of dichloromethane and butanol fractions of Gochnatia polymorpha floccosa in maternal reproductive outcome, embryo-fetal development and DNA integrity in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Gochnatia polymorpha ssp. floccosa (Asteraceae) also known as ''Cambará'' is used as medicinal plant in Brazil to treat infections and inflammation. Previous studies showed that its ethanolic extract could be bioprospecting of a new anti-inflammatory phytotherapy for use during pregnancy. This work aimed to evaluate dichloromethane (DCM) and butanolic (BT) fractions from G. polymorpha on embryo-fetal development and DNA integrity in mice.

MATERIALS AND METHODS

Female mice were treated with 50 and 20mg/kg of the DCM and BT fractions, respectively, during organogenesis and gestational period.

RESULTS AND CONCLUSION

The present study shows that DCM and BT fractions from G. polymorpha possess mutagenic activity but are not teratogenic. Based on the fact that the reproductive indices are similar in control and treated animals, we may infer that the mutagenic effect was in somatic cell, at least in part, because the reabsorption number and reabsorption rates did not change in DCM and BT exposed groups.

Reference control data obtained from an in vivo comet-micronucleus combination assay using Sprague Dawley rats

According to the International Conference on Harmonization Guidance on Genotoxicity Testing and Data Interpretation for Pharmaceuticals Intended for Human Use (ICH S2(R1)), a positive response in any in vitro assay necessitates additional in vivo test(s) (other tissue/endpoint) in addition to the erythrocyte micronucleus test when Option 1 of the test battery is selected. When Option 2 of the test battery is selected, a bacterial gene mutation test and two in vivo tests with different tissues/endpoint are required. The in vivo alkaline comet assay is recommended as the second in vivo test because it can detect a broad spectrum of DNA damage in any tissue and can be combined with the erythrocyte micronucleus test. Considering animal welfare, a combination assay is preferable to an individual assay. Thus, we validated the protocol for the in vivo comet-micronucleus combination assay in rats with three daily administrations and determined the dose of the positive control (ethyl methanesulfonate; EMS, 200mg/kg/day). We also collected the negative control (vehicle) and positive control (EMS) data from the comet (liver, stomach, and kidney) and micronucleus (bone marrow) combination assay using male Sprague Dawley (SD) rats. The negative control data were comparable to our historical control data obtained from stand-alone assays. The positive control data showed clear and consistent positive responses in both endpoints.

Antimutagenic Effects of Polymethoxy Flavonoids of Citrus unshiu

Citrus fruits have been used as edible fruit and traditional medicine for various diseases such as cancer. In the courses of our study to find antimutagens, we have found that the ethanolic extract of the peel of Citrus unshiu Marc showed antimutagenic effects against several mutagens in the Ames test using Salmonella typhimurium TA98 strain. Three polymethoxy flavonoids, nobiletin, 3,5,6,7,8,3′,4′-heptamethoxyflavone, and tangeretin, were identified in the extract as major constituents. These three polymethoxy flavonoids showed antimutagenic effects in the Ames test in vitro and in the micronucleus test in vivo.

Evaluation of acute toxicity, genotoxicity and inhibitory effect on acute inflammation of an ethanol extract of Morus alba L. (Moraceae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Morus alba L. (white mulberry) is used in traditional medicine worldwide, including Brazil. The leaves of this plant are used to treat inflammatory disorders. Universal interest in this plant necessitates studies on the toxicological safety and scientific substantiation of the medicinal properties of M. alba. In previous work, we investigated the acute toxicity of orally administered M. alba ethanol extract in mice.

AIM OF THE STUDY

This work was designed to investigate the ethanol extract obtained from M. alba leaves for acute toxicity when intraperitoneally administered, in vivo genotoxicity, and potential to reduce acute inflammation. In order to further investigate the constituents of the extract, we also obtained the high-performance liquid chromatography (HPLC) fingerprint of the extract.

MATERIALS AND METHODS

Phytochemical analysis by thin layer chromatography (TLC) was performed and the results were used to obtain the HPLC fingerprint. Acute toxicity of 300 and 2000mg/kg b.w. i.p. doses administered to mice for 14 days was evaluated. Genotoxicity was evaluated by counting the number of micronucleated polychromatic erythrocytes in the blood of mice that either received or did not receive the extract at 75, 150 and 300mg/kg b.w. per os. The anti-inflammatory effect of the same doses administered per os was investigated using the carrageenan air pouch model.

RESULTS

The TLC analysis of the extract revealed the presence of a remarkable amount of flavonoids and cinnamic acids. The HPLC fingerprint showed the presence of one major peak corresponding to chlorogenic acid and two smaller peaks corresponding to flavonoids. In the toxicity assays, there were no deaths or deviations in behavior of treated mice as compared to the control at any dose. However, biochemical, hematological, and histological analyses showed that intraperitoneal injection caused several forms of damage to the mice, which were not observed in case of oral administration, studied in our previous work. Oral administration of the extract did not result in genotoxicity and considerably reduced (58.6-65.6% inhibition) leukocyte migration in all doses evaluated, in comparison with the negative control.

CONCLUSIONS

The ethanol extract from M. alba leaves administered intraperitoneally possesses a greater degree of toxicity in mice when compared to per os administration. The extract was not genotoxic when ingested by mice and exhibited a highly inhibitory effect against acute inflammation, which is probably linked to the presence of chlorogenic acid and flavonoids in the composition. This work contributes to the determination of safety of the medicinal use of M. alba leaves.

Antimutagenic Effects of Selenium-Enriched Polysaccharides from Pyracantha fortuneana through Suppression of Cytochrome P450 1A Subfamily in the Mouse Liver

Both selenium (Se) and polysaccharides from Pyracantha fortuneana (Maxim.) Li (PFPs) (P. fortuneana) have been reported to possess antioxidative and immuno-protective activities. Whether or not Se-containing polysaccharides (Se-PFPs) have synergistic effect of Se and polysaccharides on enhancing the antioxidant and immune activities remains to be determined. We previously reported that polysaccharides isolated from Se-enriched P. fortuneana (Se-PFPs) possessed hepatoprotective effects. However, it is not clear whether or not they have anti-mutagenic effects. In the present study, we compared and evaluated anti-mutagenic effects of Se-PFPs at three concentrations (1.35, 2.7 and 5.4 g/kg body weight) with those of PFPs, Se alone or Se + PFPs in mice using micronucleus assay in bone marrow and peripheral blood as well as mitomycin C-induced chromosomal aberrations in mouse testicular cells. We also elucidated the underlying mechanism. Our results demonstrated that Se-PFPs inhibited cyclophosphamide (CP)-induced micronucleus formation in both bone marrow and peripheral blood, enhanced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in mouse liver, and reduced the activity and expression of cytochrome P450 1A (CYP4501A) in mouse liver in a dose-dependent manner. In addition, we found that the anti-mutagenic potential of Se-PFPs was higher than those of PFPs, Se alone or Se + PFPs at the same level. These results suggest that the anti-mutagenic potential of Se-PFPs may be mediated through the inhibition of the activity and expression of CYP4501A. This study indicates that application of Se-PFPs may provide an alternative strategy for cancer therapy by targeting CYP1A family.

Evaluation of the toxicokinetics and apoptotic potential of ethanol extract from Echinodorus macrophyllus leaves in vivo

This study evaluates the toxicological, genotoxic, mutagenic and apoptotic potential of an in vivo assay from Echinodorus macrophyllus extract (EEM). The acute toxicity test used 02 groups (n = 5) of female Wistar rats: negative control group (saline) and experimental group (2000 mg/kg b.w. EEM), both orally administered (gavage) at single doses and monitored for 14 days. To assess the genotoxic, mutagenic and apoptotic potential, 50 male Swiss mice were divided into 5 groups (n = 10): Group I: negative control (saline solution 0.1 ml/10 g b.w.); Group II: positive control (cyclophosphamide 100 mg/kg b.w.) intraperitoneally administered; groups III-V received EEM at 500, 1000 and 2000 mg/kg b.w., respectively. Groups I, III-V received oral administrations (gavage). The results showed that there was no acute lethality or any signs of acute toxicity, indicating that LD₅₀ is greater than 2000 mg/kg b.w. The groups treated with EEM showed no genotoxic or mutagenic activity and did not induce apoptosis in the liver and kidney. Therefore, EEM showed no acute toxicity and at doses of 500, 1000 and 2000 mg/kg b.w. absence of genotoxicity, mutagenicity and no apoptotic events were observed.

Mesenchymal stem cell therapy promotes the improvement and recovery of renal function in a preclinical model

Acute renal failure (ARF) is an extremely important public health issue in need of novel therapies. The present study aimed to evaluate the capacity of mesenchymal stem cell (MSC) therapy to promote the improvement and recovery of renal function in a preclinical model. Wistar rats were used as the experimental model, and our results show that cisplatin (5mg/kg) can efficiently induce ARF, as measured by changes in biochemical (urea and creatinine) and histological parameters. MSC therapy performed 24h after the administration of chemotherapy resulted in normalized plasma urea and creatinine levels 30 and 45d after the onset of kidney disease. Furthermore, MSC therapy significantly reduced histological changes (intratubular cast formation in protein overload nephropathy and tubular hydropic degeneration) in this ARF model. Thus, considering that current therapies for ARF are merely palliative and that MSC therapy can promote the improvement and recovery of renal function in this model system, we suggest that innovative/alternative therapies involving MSCs should be considered for clinical studies in humans to treat ARF.

The Osmanthus fragrans flower phenylethanoid glycoside-rich extract: Acute and subchronic toxicity studies

ETHNOPHARMACOLOGICAL RELEVANCE

Osmanthus fragrans var. thunbergii (O. fragrans) flower has been consumed as folk medicine for thousands of years. O. fragrans flower extract is a well-characterized phenylethanoid glycoside-rich extract, which has been used as a natural anti-oxidant. The aim of this study was to evaluate the safety of O. fragrans flower phenylethanoid glycoside-rich extract (OFFE).

MATERIALS AND METHODS

The OFFE was extracted by 80% (v/v) aqueous ethanol with 0.01% sodium isoascorbate (w/v) from the O. fragrans flower and purified on HPD300 resins. The total phenylethanoid glycosides content and individual phenylethanoid glycosides was determined by photocolorimetric method and reversed phase UPLC respectively. An acute oral toxicity study, reverse mutation test, bone marrow cell micronucleus test, and sperm abnormality test as well as a 90-day oral toxicity study were performed on experimental animals.

RESULTS

The total content of phenylethanoid glycosides in OFFE was 73.4g acteoside equivalent per 100g of extract, include acteoside (52.5g per 100g of extract), salidroside (13.8g per 100g of extract), and isoacteoside (2.6g per 100g of extract) and so on. No acute lethal effect at the maximal tested OFFE dose of 10g/kg body weight (bw) in either rats or mice was observed, suggesting that OFFE can be considered nontoxic. No evidence for mutagenicity was detected in any of the three mutagenic tests. Administration at levels of 0.50, 1.00, and 2.00g/kg bw to rats for 90 days failed to induce any significant hematological, clinical, chemical, or histopathological changes. The no-observed adverse-effect-level for OFFE was >2.00g/kg bw for the study on subchronic toxicity.

CONCLUSION

The results showed that consuming OFFE has no adverse effects and poses no health risk in the acute oral toxicity study, subchronic oral toxicity study, and in the micronucleus test, which may provide supportive evidence for the safety of OFFE powder that has been used in medicine as well as in functional foods, and dietary supplements.

In Vivo Effects of Vanadium Pentoxide and Antioxidants (Ascorbic Acid and Alpha-Tocopherol) on Apoptotic, Cytotoxic, and Genotoxic Damage in Peripheral Blood of Mice

This study was conducted to investigate the effects of vanadium pentoxide (V2O5), ascorbic acid (AA), and alpha-tocopherol (α-TOH) on apoptotic, cytotoxic, and genotoxic activity. Groups of five Hsd:ICR mice were treated with the following: (a) vehicle, distilled water; (b) vehicle, corn oil; (c) AA, 100 mg/kg intraperitoneally (ip); (d) α-TOH, 20 mg/kg by gavage; (e) V2O5, 40 mg/kg by ip injection; (f) AA + V2O5; and (g) α-TOH + V2O5. Genotoxic damage was evaluated by examining micronucleated polychromatic erythrocytes (MN-PCE) obtained from the caudal vein at 0, 24, 48, and 72 h after treatments. Induction of apoptosis and cell viability were assessed at 48 h after treatment in nucleated cells of peripheral blood. Treatment with AA alone reduced basal MN-PCE, while V2O5 treatment marginally increased MN-PCE at all times after injection. Antioxidants treatments prior to V2O5 administration decreased MN-PCE compared to the V2O5 group, with the most significant effect in the AA + V2O5 group. The apoptotic cells increased with all treatments, suggesting that this process may contribute to the elimination of the cells with V2O5-induced DNA damage (MN-PCE). The necrotic cells only increased in the V2O5 group. Therefore, antioxidants such as AA and α-TOH can be used effectively to protect or reduce the genotoxic effects induced by vanadium compounds like V2O5.

Cardanol: toxicogenetic assessment and its effects when combined with cyclophosphamide

Cardanol is an effective antioxidant and is a compound with antimutagenic and antitumoral activity. Here, we evaluated the genotoxic and mutagenic potential of saturated side chain cardanol and its effects in combination with cyclophosphamide in preventing DNA damage, apoptosis, and immunomodulation. Swiss mice were treated with cardanol (2.5, 5 and 10 mg/kg) alone or in combination with cyclophosphamide (100 mg/kg). The results showed that cardanol is an effective chemopreventive compound, with damage reduction percentages that ranged from 18.9 to 31.76% in the comet assay and from 45 to 97% in the micronucleus assay. Moreover, cardanol has the ability to reduce the frequency of apoptosis induced by cyclophosphamide. The compound did not show immunomodulatory activity. A final interpretation of the data showed that, despite its chemoprotective capacity, cardanol has a tendency to induce DNA damage. Hence, caution is needed if this compound is used as a chemopreventive agent. Also, this compound is likely not suitable as an adjuvant in chemotherapy treatments that use cyclophosphamide.

Systematic tracking of altered haematopoiesis during sporozoite-mediated malaria development reveals multiple response points

Haematopoiesis is the complex developmental process that maintains the turnover of all blood cell lineages. It critically depends on the correct functioning of rare, quiescent haematopoietic stem cells (HSCs) and more numerous, HSC-derived, highly proliferative and differentiating haematopoietic progenitor cells (HPCs). Infection is known to affect HSCs, with severe and chronic inflammatory stimuli leading to stem cell pool depletion, while acute, non-lethal infections exert transient and even potentiating effects. Both whether this paradigm applies to all infections and whether the HSC response is the dominant driver of the changes observed during stressed haematopoiesis remain open questions. We use a mouse model of malaria, based on natural, sporozoite-driven Plasmodium berghei infection, as an experimental platform to gain a global view of haematopoietic perturbations during infection progression. We observe coordinated responses by the most primitive HSCs and multiple HPCs, some starting before blood parasitaemia is detected. We show that, despite highly variable inter-host responses, primitive HSCs become highly proliferative, but mathematical modelling suggests that this alone is not sufficient to significantly impact the whole haematopoietic cascade. We observe that the dramatic expansion of Sca-1(+) progenitors results from combined proliferation of direct HSC progeny and phenotypic changes in downstream populations. We observe that the simultaneous perturbation of HSC/HPC population dynamics is coupled with early signs of anaemia onset. Our data uncover a complex relationship between Plasmodium and its host's haematopoiesis and raise the question whether the variable responses observed may affect the outcome of the infection itself and its long-term consequences on the host.

Carvedilol protects the kidneys of tumor-bearing mice without impairing the biodistribution or the genotoxicity of cisplatin

Cisplatin (Cisp) is an effective antitumor drug; however, it causes severe nephrotoxicity. Minimization of renal toxicity is essential, but the interference of nephroprotective agents, particularly antioxidants, with the antitumor activity of cisplatin is a general concern. We have recently demonstrated that the anti-hypertensive and antioxidant drug carvedilol (CV) protects against the renal damage and increases the survival of tumor-bearing mice without impairing the tumor reduction by cisplatin. So far, reports on the antioxidant mechanism of CV are controversial and there are no data on the impact of CV on the antitumor mechanisms of cisplatin. Therefore, this study addresses the effect of CV on mechanisms underlying the tumor control by cisplatin. CV did not interfere with the biodistribution or the genotoxicity of cisplatin. We also addressed the antioxidant mechanisms of CV and demonstrated that it does not neutralize free radicals, but is an efficient chelator of ferrous ions that are relevant catalyzers in cisplatin nephrotoxicity. The present data suggest that oxidative damage and genotoxicity play different roles in the toxicity of cisplatin on kidneys and tumors and therefore, some antioxidants might be safe as chemoprotectors. Altogether, our studies provide consistent evidence of the beneficial effect of CV on animals treated with cisplatin and might encourage clinical trials.

Modulation of hexavalent chromium-induced genotoxic damage in peripheral blood of mice by epigallocatechin-3-gallate (EGCG) and its relationship to the apoptotic activity

This study was conducted to investigate the relationship between modulation of genotoxic damage and apoptotic activity in Hsd:ICR male mice treated with (-)-epigallocatechin-3-gallate (EGCG) and hexavalent chromium [Cr(VI)]. Four groups of 5 mice each were treated with (i) control vehicle only, (ii) EGCG (10 mg/kg) by gavage, (iii) Cr(VI) (20 mg/kg of CrO3) intraperitoneally (ip), and (iv) EGCG in addition to CrO3 (EGCG-CrO3). Genotoxic damage was evaluated by examining presence of micronucleated polychromatic erythrocytes (MN-PCE) obtained from peripheral blood of the caudal vein at 0, 24, 48, and 72 h after treatment. Induction of apoptosis and cell viability were assessed by differential acridine orange/ethidium bromide (AO/EB) staining. EGCG treatment produced no significant changes in frequency of MN-PCE. However, CrO3 treatment significantly increased number of MN-PCE at 24 and 48 h post injection. Treatment with EGCG prior to CrO3 injection decreased number of MN-PCE compared to CrO3 alone. The MN-PCE reduction was greater than when EGCG was administered ip. The frequency of early apoptotic cells was elevated at 48 h following EGCG, CrO3, or EGCG-CrO3 exposure, with highest levels observed in the combined treatment group, while the frequencies of late apoptotic cells and necrotic cells were increased only in EGCG-CrO3 exposure. Our findings support the view that EGCG is protective against genotoxic damage induced by Cr(VI) and that apoptosis may contribute to elimination of DNA-damaged cells (MN-PCE) when EGCG was administered prior to CrO3. Further, it was found that the route of administration of EGCG plays an important role in protection against CrO3-induced genotoxic damage.

Toxicological analysis and anti-inflammatory effects of essential oil from Piper vicosanum leaves

This study assessed the anti-inflammatory effects of the essential oil from Piper vicosanum leaves (OPV) and evaluated the toxicological potential of this oil through acute toxicity, genotoxicity and mutagenicity tests. The acute toxicity of OPV was evaluated following oral administration to female rats at a single dose of 2 g/kg b.w. To evaluate the genotoxic and mutagenic potential, male mice were divided into five groups: I: negative control; II: positive control; III: 500 mg/kg of OPV; IV: 1000 mg/kg of OPV; V: 2000 mg/kg of OPV. The anti-inflammatory activity of OPV was evaluated in carrageenan-induced pleurisy and paw edema models in rats. No signs of acute toxicity were observed, indicating that the LD50 of this oil is greater than 2000 mg/kg. In the comet assay, OPV did not increase the frequency or rate of DNA damage in groups treated with any of the doses assessed compared to that in the negative control group. In the micronucleus test, the animals treated did not exhibit any cytotoxic or genotoxic changes in peripheral blood erythrocytes. OPV (100 and 300 mg/kg) significantly reduced edema formation and inhibited leukocyte migration analyzed in the carrageenan-induced edema and pleurisy models. These results show that OPV has anti-inflammatory potential without causing acute toxicity or genotoxicity.

Diaryl sulfide analogs of combretastatin A-4: Toxicogenetic, immunomodulatory and apoptotic evaluations and prospects for use as a new chemotherapeutic drug

Combretastatin A-4 exhibits efficient anti-cancer potential in human tumors, including multidrug-resistant tumors. We evaluated the mutagenic, apoptotic and immunomodulatory potential of two diaryl sulfide analogs of combretastatin A-4, 1,2,3-trimethoxy-5-([4-methoxy-3-nitrophenyl]thio)benzene (analog 1) and 1,2,3-trimethoxy-5-([3-amino-4-methoxyphenyl]thio)benzene (analog 2), as well as their association with the anti-tumor agent cyclophosphamide, in Swiss mice. Such evaluation was achieved using the comet assay, peripheral blood micronucleus test, splenic phagocytosis assay, and apoptosis assay. Both analogs were found to be genotoxic, mutagenic and to induce apoptosis. They also increased splenic phagocytosis, although this increase was more pronounced for analog 2. When combined with cyclophosphamide, analog 1 enhanced the mutagenic and apoptotic effects of this anti-tumor agent. In contrast, analog 2 did not enhance the effects of cyclophosphamide and prevented apoptosis at lower doses. These data suggest that analog 1 could be an adjuvant chemotherapeutic agent and possibly improve the anti-neoplastic effect of cyclophosphamide. Additionally, this compound could be a candidate chemotherapeutic agent and/or an adjuvant for use in combined anti-cancer therapy.

A novel cytosporone 3-Heptyl-4,6-dihydroxy-3H-isobenzofuran-1-one: synthesis; toxicological, apoptotic and immunomodulatory properties; and potentiation of mutagenic damage

BACKGROUND

A large number of studies are attempting to identify alternative products from natural sources or synthesized compounds that effectively interact with cancer cells without causing adverse effects on healthy cells. Resorcinolic lipids are a class of bioactive compounds that possess anticancer activity and are able to interact with the lipid bilayer. Therefore, the objective of this study was to synthesize a novel resorcinolic lipid and test its biological proprieties.

METHODS

We aimed to synthesize a novel resorcinolic lipid belonging to the class of cytosporones, AMS049 (3-Heptyl-4,6-dihydroxy-3H-isobenzofuran-1-one) and to evaluate the toxicity of two concentrations of this lipid (7.5 and 10 mg/kg) by determining its genotoxic, mutagenic, immunomodulatory, and apoptotic effects, as well as any biochemical and histopathological alterations in mice treated with cyclophosphamide. The results were analyzed by ANOVA followed by the Tukey test A . level of significance of p < 0.05 was adopted.

RESULTS

The new cytosporone AMS049 was synthesized in only three steps and in satisfactory yields. The results indicate that the compound is neither genotoxic nor mutagenic and does not alter biochemical parameters. The histological alterations observed in the liver and kidneys did not compromise the function of these organs. Histology of the spleen suggested immunomodulation, although no changes were observed in splenic phagocytosis or differential blood cell count. The results also show that AMS049 potentiates the mutagenic effect of the chemotherapy drug cyclophosphamide and that the combination induces apoptosis.

CONCLUSION

These facts indicate a potential therapeutic application of this novel cytosporone as an important chemotherapeutic adjuvant.

Analysis of the anti-inflammatory and chemopreventive potential and description of the antimutagenic mode of action of the Annona crassiflora methanolic extract

CONTEXT

Annona crassiflora Mart. (Annonaceae) is a medicinal plant that is widely used in folk medicine, which leads to its investigation as a potential source of new pharmacological principles.

OBJECTIVE

This study describes the anti-inflammatory, antiallodynic, and antimutagenic/chemopreventive activities of the leaves A. crassiflora methanolic extract. Its antimutagenic mode of action was analyzed in a plant or animal experimental model.

MATERIALS AND METHODS

Total flavonoids were quantified by spectrophotometry at 415 nm and its composition was analyzed by (1)H NMR spectra. Animals received orally, 30, 100, and 300 mg/kg of extract in both tests, carrageenan-induced paw edema and myeloperoxidase activity. Animals were treated with 100 and 300 mg/kg, in all the analyzed tests, pleural cell migration and protein exudation, carrageenan-induced cell migration into the pouch, induction of joint inflammation and carrageenan-induced allodynia response in the mouse paw. To evaluate the antimutagenic/chemopreventive activity through the Allium cepa test, we used 5, 10, and 15 mg/L of extract, and for the micronucleus test in the peripheral blood, we used the dose of 15 mg/kg.

RESULTS

The fractionation of the ethyl acetate (EA) fraction, resulting from the partition of the methanol extract of the A. crassiflora, afforded through chromatographic methods resulted in the isolation of kaempferol 3-O-β-glucoside and kaempferol 3-O-β-diglucoside. Oral treatment with 100 and 300 mg/kg of extract significantly inhibited the carrageenan-induced edema formation, with inhibitions of 53 ± 7% and 47 ± 10%; in MPO activity, the observed inhibitions were 60 ± 7% for 100 mg/kg treatment and 63 ± 7% for 300 mg/kg. The ACME reduced significantly the total leukocytes (an inhibition of 78 ± 9% with 100 mg/kg and 90 ± 7% with 300 mg/kg) and protein levels (approximately 100% inhibition with both doses) in the pleurisy model. In carrageenan-induced leukocyte migration into the pouch, the extract inhibited leukocyte migration only when administered 300 mg/kg per dose (the reduction was 43 ± 5%). Pretreatment with extract failed to reduce the zymosan-induced edema formation and did not inhibit the carrageenan-induced mechanical allodynia. Damage reduction in Allium cepa tested with different concentrations (5, 10, and 15 mg/L) was 66.17, 75.75, and 69.19% for the pre-treatment; 72.72, 33.33, and 22.22% for the simple simultaneous treatment; 100.50, 93.93, and 102.52% for the simultaneous treatment with pre-incubation; 89.39, 79.79, and 84.34%; for the post-treatment, and 86.36, 81.31, and 93.43% for the continuous treatment. The antimutagenic evaluation in the micronucleous test showed a damage reduction of 75.00 and 64.58% for the pre-treatment and simultaneous protocols, respectively. The post-treatment protocol increased the cyclophosphamide effects in 45.83%.

CONCLUSION

These results suggest that this medicinal plant has chemopreventive and anti-inflammatory therapeutic potential.

Genotoxicity-suppressing effect of aqueous extract of Connarus ruber cortex on cigarette smoke-induced micronuclei in mouse peripheral erythrocytes

Introduction

According to published information, it has not been determined whether the inhalation of cigarette smoke can induce chromosome aberrations and/or point mutations in mice, though cigarette smoke is clearly carcinogenic to mice. We tested clastogenicity of inhaled cigarette smoke in mouse by a micronucleus test using peripheral erythrocytes. Since it is important to determine the in vivo anti-genotoxic effect against inhaled cigarette smoke to reduce the risk of tobacco carcinogenesis, we also tested in vivo anti-gnotoxic effect against inhaled cigarette smoke of a Connarus extract whose in vitro anti-genotoxic effect was shown.

Results

Male ICR mice were exposed for 1 min to a 6-fold dilution of the smoke once a day for up to 14 consecutive days. Although the frequencies of reticulocytes with micronucleus (MNRETs) and erythrocytes with micronuclei (MN erythrocytes) did not increase within 72 h after a single inhalation of cigarette smoke, the frequency of MN erythrocytes increased significantly upon inhalation for 7 and 14 days. When the Connarus extract was fed to mice at >23.7 ppm during the inhalation period of 14 days, frequency of MN erythrocytes was significantly lower than that at 0 ppm. In vitro antioxidant activity of Connarus extract was almost same to that of vitamin C. The antioxidant activity of the Connarus extract might play an important role in its anti-genotoxic effect against cigarette smoke in vivo, like vitamins C.

Conclusions

Consecutive inhalation of cigarette smoke is clastogenic to mouse bone marrow as shown by the increased frequency of MN erythrocytes. Also, it was shown the possibility that the Connarus extract reduces the risk of tobacco carcinogenesis.

Flavonoid detection in hydroethanolic extract of Pouteria torta (Sapotaceae) leaves by HPLC-DAD and the determination of its mutagenic activity

It is well known that phytotherapy has grown in popularity in recent years. Because a drug cannot be administered without ensuring its effectiveness and safety, the standardization and regulation of phytotherapeutic drugs are required by the global market and governmental authorities. This article describes a simple and reliable high-performance liquid chromatography-diode array detection analysis method for the simultaneous detection of myricetin-3-O-β-D-galactopyranoside, myricetin-3-O-α-L-arabinopyranoside, and myricetin-3-O-α-L-rhaminopyranoside present in the hydroethanolic extract (ethanol/H2O, 7:3, v/v) of Pouteria torta. The mutagenic activity of the extract was evaluated on Salmonella typhimurium and by an in vivo micronucleus test on the peripheral blood cells of Swiss mice. The linearity, sensitivity, selectivity, repeatability, accuracy, and precision of the assay were evaluated. The analytical curves were linear and exhibited good repeatability (with a deviation of less than 5%) and demonstrated good recovery (within the 83-107% range). The results demonstrate that the hydroethanolic extract exhibited a mutagenic activity in both assays, suggesting caution in the use of this plant in folk medicine.

Evaluation of cytotoxicity, genotoxicity and hematotoxicity of the recombinant spore-crystal complexes Cry1Ia, Cry10Aa and Cry1Ba6 from Bacillus thuringiensis in Swiss mice

The insecticidal properties of Cry-endotoxins from Bacillus thuringiensis (Bt) have long been used as spore-crystals in commercial spray formulations for insect control. Recently, some Bt-endotoxin genes have been cloned in many different plants. Toxicological evaluations of three spore-crystal endotoxins, BtCry1Ia, BtCry10Aa and BtCry1Ba6 from B. thuringiensis, were carried out on mice to understand their adverse effects on hematological systems and on genetic material. These three spore-crystals have shown toxic activity to the boll weevil, which is one of the most aggressive pests of the cotton crop. Cry1Ia, Cry10Aa and Cry1Ba6 did not increase the micronucleus frequency in the peripheral erythrocytes of mice and did not cause changes in the frequency of polychromatic erythrocytes. However, some hematologic disburbances were observed, specifically related to Cry1Ia and Cry1Ba6, respectively, for the erythroid and lymphoid lineage. Thus, although the profile of such adverse side effects can be related to their high level of exposure, which is not commonly found in the environment, results showed that these Bt spore-crystals were not harmless to mice, indicating that each spore-crystal endotoxin presents a characteristic profile of toxicity and might be investigated individually.

Hepatoprotective effects of Met-enkephalin on acetaminophen-induced liver lesions in male CBA mice

Recent histopathological investigations in patients with hepatitis suggested possible involvement of Met-enkephalin and its receptors in the pathophysiology of hepatitis. Consequently, we evaluated the potential hepatoprotective effects of this endogenous opioid pentapeptide in the experimental model of acetaminophen induced hepatotoxicity in male CBA mice. Met-enkephalin exhibited strong hepatoprotective effects in a dose of 7.5 mg/kg, which corresponds to the protective dose reported for several different animal disease models. In this group plasma alanine aminotransferase and aspartate aminotransferase enzyme activities, as well as liver necrosis score were significantly reduced in comparison to control animals treated with physiological saline (p>0.01). The specificity of the peptide hepatoprotection was investigated from the standpoint of the receptor and peptide blockade. It was concluded that Met-enkephalin effects on the liver were mediated via δ and ζ opioid receptors. Genotoxic testing of Met-enkephalin confirmed the safety of the peptide.