Micronucleus Test In Bone Marrow Cells Research Articles

Assessment of acute, subacute genetic toxicities and immunomodulatory activity of palm (Trachycarpus fortunei) buds

Ethnopharmacology relevancePalm buds are a natural green resource of the forest, which are not only rich in nutrients but contain a large number of phenolic acids and flavonoids, among other components. It has a variety of biological activities such as antioxidant and uterine smooth muscle stimulation.Aim of the study: To evaluate the safety of palm buds for use as a nutraceutical product and food by evaluating the toxicity, subacute toxicity and genotoxicity of the young palm buds. Also studied for its immune-enhancing activity. Materials and methodsAcute toxicity tests were performed in mice using the maximum tolerance method, and the manifestations of toxicity and deaths were recorded after administration of 10,000 mg/mL for 14 consecutive d (days) of observations. To assess subacute toxicity, mice were treated with palm buds (750, 1500, or 3000 mg/mL) daily for 28 days. The teratogenicity of palm buds was assessed by the Ames test, the mouse bone marrow cell micronucleus test, and the mouse spermatozoa malformation test. In addition, we evaluated the immune-enhancing ability of palm buds by the mouse carbon profile test, delayed-type metamorphosis reaction, and serum hemolysin assay. ResultsIn the acute toxicity study, the Median Lethal Dose (LD50) was greater than 10,000 mg/kg bw in both male and female rats. There were also no deaths or serious toxicities in the subacute study. The no-observed-adverse-effect level (NOAEL) was 3000 mg/kg bw. However, the mice's food intake decreased after one week. The medium and high dose groups had a reducing effect on body weight in mice of both sexes. In addition, the changes in organ coefficients of the liver, kidney and stomach in male mice were significantly higher in the high-dose group (3.23 ± 0.35, 0.75 ± 0.05, 0.57 ± 0.05 g) than in the control group (2.94 ± 0.18, 0.58 ± 0.05, 0.50 ± 0.02 g). Hematological analyses showed that all the indices of the rats in each palm sprout dose group were within the normal range. The results of blood biochemical indicators showed that there was a significant reduction in TP in the blood of male mice in the high-dose group (44.6 ± 7.8 g/L) compared to the control group (58.3 ± 15.1 g/L). In histopathological analysis, none of the significant histopathological changes were observed. The results of the immunological experiment in mice showed that the liver coefficient and thymus coefficient of the high-dose group (8400 mg/kg) were significantly lower than the control group. There was no remarkable difference in auricle swelling between each dose palm bud group (1400, 2800, or 8400 mg/kg) and the control group. The anti-volume number of the high-dose group was significantly increased. ConclusionPalm buds have non-toxic effects in vivo and have little effect on non-specific and cellular immunity in the test mice within the dose range of this experiment. The immunoenhancement in mice is mainly achieved through humoral immunity. In conclusion, our results suggest that palm buds are safe for use as healthcare products and food.

Acute, chronic, and genotoxic studies on the protopine total alkaloids of the Macleaya cordata (willd.) R. Br. in rodents.

The protopine alkaloids are widely distributed within the opium poppy family and have a wide range of pharmacological effects. MPTA is a product of the protopine total alkaloids extracted from the Macleaya cordata (Willd.) R. Br. Previously, we reported good anti-inflammatory activity of MPTA as well as oral acute and sub-chronic toxicity studies in rats. In order to perform a systematic toxicological safety assessment of MPTA, oral acute toxicity, genotoxicity (bone marrow cell chromosome aberration test, sperm abnormality test, bone marrow cell micronucleus test, and rat teratogenicity test), and chronic toxicity in mice were performed in this study. In the oral acute toxicity test, the LD50 in ICR mice was 481.99 mg/kg, with 95% confidence limits ranging from 404.27 to 574.70 mg/kg. All three mutagenicity tests tested negative in the range of 60.25–241.00 mg/kg. The results of the teratogenicity test in rats showed no reproductive or embryonic developmental toxicity at only 7.53 mg/kg, which can be considered as a no observed effect level (NOEL) for the teratogenicity test. Therefore, MPTA is safe for use at the doses tested, but attention should be paid to the potential risk to pregnant animals and the safety evaluation and toxicity mechanisms in target animals should be further investigated.

Toxicology evaluation of selenium protein powder

The experiment was conducted to evaluate the safety of selenium protein powder, a novel organic selenium nutritional supplement, and reported corresponding data and results based on a series of toxicological tests. It was examined to evaluate oral acute toxicity by median lethal dose test and mutagenic potential by bone marrow cell micronucleus test and sperm abnormality test using Kun-Ming mice. The results showed that the oral LD 50 of selenium protein powder exceeded 31.25 g/kg body weight in mice. No mutagenicity was found by mouse bone marrow cell micronucleus test and mouse sperm abnormality test. The results suggested greater safety of selenium protein powder as a nutritional selenium supplement, and selenium protein powder has the potential for development and application in food systems or functional foods.

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

Ethnopharmacological relevanceOsmanthus 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 methodsThe 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. ResultsThe 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. ConclusionThe 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.

Drinking water toxicity study of the environmental contaminant––Bromate

Bromate is a byproduct of water disinfection that is produced when waters contain bromide treated with ozone. To investigate the level of the toxicity of bromate and find the most sensitive indicators in a short time, a series of toxicological assessments were conducted including the acute toxicity, cumulative toxicity, genetic toxicity and subacute toxicity of bromate (using Potassium Bromate to represent bromate). The LD50 of orally administered Potassium Bromate was 215 mg/kg in Wistar rats and 464 mg/kg in ICR mice. The cumulative toxicity of Potassium Bromate was not obvious. The Ames test, mouse bone marrow cell micronucleus test and mouse sperm abnormality test did not indicate mutagenicity. The results of the subacute study did not exhibit significant differences in most of the parameters, except the white blood cell count, which was significantly decreased in male rats. In addition, Potassium Bromate influenced the albumin, creatinine, total cholesterol, triglycerides and glucose levels in male rats to various extents. A thorough analysis of the above tests clearly demonstrates that bromate has toxicity, not obvious cumulative toxicity and the white blood cell count can be used as an indicator to reflect the toxicity of bromate and investigate bromate's toxic mechanism.

Toxicological evaluation of lactase derived from recombinant Pichia pastoris.

A recombinant lactase was expressed in Pichia pastoris, resulting in enzymatic activity of 3600 U/mL in a 5 L fermenter. The lactase product was subjected to a series of toxicological tests to determine its safety for use as an enzyme preparation in the dairy industry. This recombinant lactase had the highest activity of all recombinant strains reported thus far. Acute oral toxicity, mutagenicity, genotoxic, and subchronic toxicity tests performed in rats and mice showed no death in any groups. The lethal dose 50% (LD50) based on the acute oral toxicity study is greater than 30 mL/kg body weight, which is in accordance with the 1500 L milk consumption of a 50 kg human daily. The lactase showed no mutagenic activity in the Ames test or a mouse sperm abnormality test at levels of up to 5 mg/plate and 1250 mg/kg body weight, respectively. It also showed no genetic toxicology in a bone marrow cell micronucleus test at levels of up to 1250 mg/kg body weight. A 90-day subchronic repeated toxicity study via the diet with lactase levels up to 1646 mg/kg (1000-fold greater than the mean human exposure) did not show any treatment-related significant toxicological effects on body weight, food consumption, organ weights, hematological and clinical chemistry, or histopathology compared to the control groups. This toxicological evaluation system is comprehensive and can be used in the safety evaluation of other enzyme preparations. The lactase showed no acute, mutagenic, genetic, or subchronic toxicity under our evaluation system.

Comparative study of genotoxicity and tissue distribution of nano and micron sized iron oxide in rats after acute oral treatment

Though nanomaterials (NMs) are being utilized worldwide, increasing use of NMs have raised concerns over their safety to human health and environment. Iron oxide (Fe2O3) NMs have important applications. The aim of this study was to assess the genotoxicity of Fe2O3-30nm and Fe2O3-bulk in female Wistar rats. Fe2O3-30nm was characterized by using transmission electron microscopy, dynamic light scattering, laser Doppler velocimetry and surface area analysis. The rats were treated orally with the single doses of 500, 1000, 2000mg/kg bw of Fe2O3-30nm and Fe2O3 –bulk. The genotoxicity was evaluated at 6, 24, 48 and 72h by the comet assay in leucocytes, 48 and 72h by micronucleus test (MNT) in peripheral blood cells, 18 and 24h by chromosomal aberration (CA) assay and 24 and 48h by MNT in bone marrow cells. The biodistribution of iron (Fe) was carried out at 6, 24, 48 and 72h after treatment in liver, spleen, kidney, heart, brain, bone marrow, urine and feces by using atomic absorption spectrophotometry.The % tail DNA, frequencies of micronuclei and CAs were statistically insignificant (p>0.05) at all doses. These results suggest that Fe2O3-30nm and Fe2O3-bulk was not genotoxic at the doses tested.Bioavailability of Fe was size and dose dependent in all the tissues from the groups exposed to Fe2O3-30nm. Fe2O3 NMs were able to enter in the organs and the rats are biocompatible with much higher concentration of Fe. However, the accumulated Fe did not cause significant genotoxicity. This study provides additional knowledge about the toxicology of Fe2O3 NMs.

Multiple toxicity studies of trehalose in mice by intragastric administration

In the present study, aberration, body weight, food consumption, haematology, organ coefficients, and both gross and microscopic appearance of some histiocytes were compared between the test and control groups. A sperm abnormality test, bone marrow cell micronucleus test, and a haematology study were conducted at levels of 1.25g/kg, 2.5g/kg, and 5g/kg of trehalose. In both the sperm abnormality test and bone marrow cell micronucleus test, statistically significant differences were observed between the positive control and treatment groups (P<0.05), while no statistical difference was observed among the negative control, high dose, moderate dose and low dose groups (P>0.05). In the haematology study, there was no significant difference found from the controls at P>0.05. The results obtained in the present study could support the conclusion that consumption of trehalose has no adverse effects for humans.

Mutagenicity and Safety Evaluation of the Water Extract of Camellia oleifera Abel

The purpose of this study was to evaluate the mutagenicity and safety of water extract of the fruit hull of Camellia oleifera Abel (WECO), which was prepared using hot-reflux method. The oral maximum tolerated dose (MTD) of WECO was above 20 g/kg body weight both in rats and in mice, which can be regarded as virtually nontoxic. No mutagenicity was found in Ames test, mouse bone marrow cell micronucleus test and mouse sperm abnormality test. In the subacute study, the SD rats were administered orally at 0.5, 1, or 2 g/kg/BW for 30 d. There were no treatment-related toxic effects from WECO. No significant differences were found in parameters of body weight, hematology value, clinical chemistry value, and organ/body weight ratio. The level of no observed adverse effect level (NOAEL) for WECO was 2 g/kg/BW for subacute toxicity study. With the gradual increase in tea oil production, it was in urgent need of dealing with Camellia fruit hull, which was always discarded because of low economic benefits. Camellia fruit hull has been shown to have significant antioxidant effects including DPPH radical-scavenging ability and ferric-reducing antioxidant power (Zhang and others 2010). Toxicological evaluation of WECO provided a safety assurance of WECO for developing dietary supplements and functional foods.

Safety assessment of Cordyceps guangdongensis

Cordyceps guangdongensis as a kind of fungus, has been discovered and cultivated successfully in recent years. However, its safety assessments have not been studied. In this report, a serial of tests for toxicological safety assessments were depicted in details. These tests included bacterial reverse mutation (Ames) study, bone marrow cell micronucleus test in mice, sperm aberration test in mice, teratogenicaction test in rats, acute toxicity test and 13-week oral toxicity study in rats. After a profound analysis of these tests, it clearly demonstrated that C. guangdongensis did not have any mutagenic, clastogenic nor genotoxic effects; the oral LD50 of the biomass in rats was greater than 15 g/kg body weight; the no-observed adverse-effect-levels (NOAEL) was 5.33 g/kg body weight according to the 13-week oral toxicity analysis. Therefore, a conclusion can be drawn that C. guangdongensis is considered safe for long term consumption.

Mutagenicity and Safety Evaluation of Ethanolic Extract of Prunus mume

The ethanolic extract of Prunus mume (EPM) is a novel polyphenol preparation derived from branches (with leaves) of Prunus mume, which could be used as a functional ingredient for antioxidant and antiobesity therapy. The purpose of this study was to evaluate the safety of EPM. An EPM was prepared and evaluated for oral acute and subacute toxicity in Sprague-Dawley rats, while its mutagenic potential was assessed by a reverse mutation test using Salmonella typhimurium, by a bone marrow cell micronucleus test using ICR mice, and by a sperm abnormality test using ICR mice. The results showed no acute lethal effects at the maximal tested EPM dose of 20 g/kg bw in either rats or mice, suggesting that EPM can be regarded as virtually nontoxic. Administration at levels of 0.84, 1.67, and 3.33 g/kg bw to rats for 30 d did not induce any significant hematological, clinical, chemical, or histopathological changes. No mutagenicity evidence was detected in any of the 3 mutagenic tests. The level of "no observed adverse effect" (NOAEL) for EPM was above 3.33 g/kg bw for the subacute toxicity study.

Hydroquinone: An Evaluation of the Human Risks from its Carcinogenic and Mutagenic Properties

The toxicology of hydroquinone has been reviewed on a number of previous occasions. This review targets its potential for carcinogenicity and possible modes of carcinogenic action. The evaluation made by IARC (1999) of its carcinogenic risk to humans was that hydroquinone is not classifiable as to its carcinogenicity to humans (Group 3). This evaluation was based on inadequate evidence in humans and limited evidence in experimental animals. The epidemiological information comes from four cohort studies involving occupational exposures. A cohort of lithographers, some of whom had worked with hydroquinone, had an excess of malignant melanoma based on five cases, but only two of the cases had reported exposure to hydroquinone. In a study of photographic processors the number of exposed individuals was uncertain and the numbers of cases of individual cancer sites were small. In view of the statistical power limitations of these studies for individual diagnostic categories of cancers, they are not considered to be informative with regard to the carcinogenicity of hydroquinone. A cohort of workers with definite and lengthy exposure to hydroquinone, during either its manufacture or its use, had low cancer rates compared with two comparison populations; the reason for the lower than expected rates is unclear. In a motion picture film processing cohort there were significant excess malignancies of the respiratory system among workers engaged in developing, where there was exposure to hydroquinone as well as other chemicals. There was no information on tobacco smoking habits and no dose-response relationship. Hydroquinone has been shown reproducibly to induce benign neoplasms in the kidneys of male F344 rats dosed orally either by gavage (25 and 50 mg/kg body weight) or diet (0.8%). The gavage study has been evaluated in considerable detail. This evaluation showed that all renal tubule adenomas and all cases of renal tubule atypical hyperplasia occurred in areas of severe or end-stage chronic progressive nephropathy and that the neoplasms were not otherwise confined to any particular part of the kidney. It is likely that the mode of carcinogenic action of hydroquinone is exacerbation of this natural disease process. Hydroquinone is mutagenic in vitro and in vivo, having caused genotoxicity or chromosomal aberrations in rodent bone-marrow cells. At least a portion, if not all, of the chromosomal effects are caused by interference by hydroquinone or its metabolites with chromosomal segregation, probably due to interaction with mitotic spindle proteins. However, the dose routes used to demonstrate these effects in almost all of the studies in vivo were intraperitoneal or subcutaneous injection, which were considered inappropriate. There were five studies by the oral route. These included a mouse bone-marrow cell micronucleus test in which a weak, marginally positive response was obtained following a single oral dose of 80 mg/kg body weight. The remaining oral route studies all showed no significant effect. They included a mouse bone-marrow cell micronucleus test in which there was no genotoxic activity after exposure to a diet containing 0.8% hydroquinone for 6 days; two 32P-post-labeling assays, one with targets of Zymbal gland, liver, and spleen in Sprague-Dawley rats, the other with the kidney as target in F344 rats; and the last oral assay was for 8-hydroxydeoxyguanosine adducts in F344 rat kidney DNA. Thus, the evidence (and the database) for any genotoxic effect in vivo is sparse and none has been observed in kidney. While glutathione conjugates could be responsible for the tumor induction, careful histology seems to show that the most actively toxic of several glutathione compounds tested, 2,3,5-triglutathion-S-yl hydroquinone, targets a very specific region of the kidney, the outer stripe of the outer medulla (OSOM), whereas hydroquinone-associated adenomas are more randomly distributed and occur in the cortex as well as the medulla. A nongenotoxic mode of action that involves exacerbation of a spontaneously occurring rodent renal disease, chronic progressive nephropathy (CPN), is proposed and evaluated. This disease is particularly prominent in male rats and the evidence is consistent with an absence of any human counterpart; therefore, the increased incidence of renal tubule adenomas in hydroquinone-dosed male rats is without human consequence.

Safety evaluation of short-term exposure to chitooligomers from enzymic preparation

Chitooligomers have significant application to the development of functional foods. This paper evaluated systematically the safety of chitooligomers, which were prepared by enzymatic depolymerization of chitosan. The oral maximum tolerated dose of this chitooligomes was more than 10 g/kg body weight in mice. It had no mutagenicity judged by negative experimental results of Ames test, mouse bone marrow cell micronucleus test and mouse sperm abnormality test. A 30-day feeding study shows that no abnormal symptoms and clinical signs or deaths were found in rats during the test. There were no significant difference in body weight, food consumption and food availability of rats in each test group. No significant differences were found in each hematology value, clinical chemistry value and organ/body weight ratio, either. No abnormality of any organ was found during histopathological examination. It is concluded that short-term ingestion of chitooligomers is of non-toxicity.

Toxicology and safety of anti-oxidant of bamboo leaves. Part 1: Acute and subchronic toxicity studies on anti-oxidant of bamboo leaves

The anti-oxidant of bamboo leaves (AOB) has recently been certificated as a novel kind of natural anti-oxidant by the Ministry of Health of the People’s Republic of China, and has been used in various food systems. Here, AOB was subjected to a series of acute and subchronic toxicological tests to evaluate its safety. It was examined to evaluate acute oral toxicity by using Kun-Ming mice and Sprague-Dawley rats, and its mutagenic potential assessed by reverse mutation test using Salmonella typhimurium, bone marrow cell micronucleus test using Kun-Ming mice, and sperm abnormality test using Kun-Ming mice. In addition, a 90-day oral toxicity study using Sprague-Dawley rats was conducted to evaluate subchronic toxicology. The results showed that the maximum tolerated dose (MTD) of AOB was >10 g/kg body weight in both rats and in mice, which can be regarded as virtually non-toxic. No mutagenicity evidence was detected in any of the three mutagenic tests. Administration at levels of 1.43, 2.87 and 4.30 g/kg per day to the rats for 90 days did not induce significant hematological, clinic, chemical and histopathological changes, and suggested a no-observed-adverse-effect level (NOAEL) of 4.30 g/kg per day. These results indicate that AOB can be generally regarded as safe for use as a food additive.

Safety evaluation of a triterpenoid-rich extract from bamboo shavings

Triterpenoids, which may have significant application to the development of natural medicines and functional foods as biological active components, are widely distributed throughout the plant kingdom. This paper evaluated the safety of a triterpenoid-rich extract of bamboo shavings (EBS) systematically. (i) Acute toxicity test: The oral maximum tolerated dose of EBS was more than 10 g/kg body weight both in rats and in mice, due to the absence of toxicity according to the criteria of acute toxic classifications. (ii) Mutagenicity test: It had no mutagenicity judged by negative experimental results of Ames test, mouse bone marrow cell micronucleus test and mouse sperm abnormality test. (iii) 30 days feeding study: No abnormal symptoms and clinical signs or deaths had been found in rats in each group during the test. No significant difference had been found in body weight, food consumption and food availability of rats in each test group ( P > 0.05). In addition, no significant differences were found in each hematology value, clinical chemistry value and organ/body weight ratio, either ( P > 0.05). No abnormality of any organ was found during histopathological examination. It can be concluded that the extract of bamboo shavings is of low toxicity and support the use of EBS for various foods.

Relationship between experimental results in mammals and man: II. Cytogenetic analysis of bone-marrow cells after treatment of cytembena and cyclophosphamide-cytembena combination

Cytogenetic analysis and the micronucleus test of bone-marrow cells was used to study the possible extrapolation of results from experimental animals to man. Cytembena was given i.p. in doses of 5, 10, 20, 40 and 80 mg/kg body wt. to Wistar rats in doses of 20, 40 and 80 mg/kg body wt. to ICR mice an dto Chinese hamsters. Five patients with various types of malignancy, so far medically untreated, received 20 mg Cytembena/kg body wt i.v. A combination of Cytembena and cylophosphamide was applied i.p. in single equal doses 1 : 1 of 5, 10, 20, and 40 mg/kg body wt to ICR mice, Chinese hamsters and Wistar rats. Patients were given i.v. 20 mg Cytembena and 20 mg cyclophosphamide/kg body wt. Bone-marrow cells were examined 24 h after the administration. The frequency of abnormal metaphases and chromosomal breaks after Cytembena treatment was low; nonetheless, the indicated dose-effect relationship was found in all the rodents used. The frequency of chromosomal breaks was 2–3 times higher in rodents in comparison with man, after treatment with a dose of 20 mg Cytembena/kg body wt. Highest frequencies of induced aberrations were found in mice. The rodents appeared to be 3–4 times more sensitive to the induction of chromosomal breaks and abnormal metaphases than man, after a dose of 20 mg Cytembena and 20 mg cyclophosphamide/kg body wt.