Buccal Micronucleus Cytome Assay Research Articles

Assessment of effects of mouthwash by Buccal Micronucleus Cytome Assay: a Preliminary Study

ABSTRACT: Mouthwashes are the most common antiseptic used for buccal hygiene. However, some studies have shown that these compounds containing alcohol can induce genotoxic and carcinogenic effects. The human buccal micronucleus cytome assay (BMCyt) has been used widely to investigate biomarkers for DNA damage, cell death, cytockinesis defects and basal cell frequency in buccal cells. Thus, the aim of this study was to assess whether the mouthwashes could induce genetic damage in exfoliated cells of the buccal epithelium by BMCyt. Sixty individuals participated of this study, divided in two groups: one, exposed to mouthwashes (n = 30), and another, not exposed (control group; n = 30). Nuclear damage (micronucleus and nuclear buds), incomplete cytokinesis (binucleated cells), cell death (condensed chromatin, karyorrhectic, pyknotic and karyolytic cells) and basal cells were evaluated in epithelium cells using image analysis at x1,000 magnification. The results showed a significant increase of nuclear buds, pyknotic and basal cells in exposed group. We observed that the composition of alcoholic products can be related to the micronucleus and nuclear bud cells frequencies, according to the following order: Listerine® > Colgate® > Oral B®. However, studies with a larger numbers of individuals are need to support the preliminary findings presented here. RESUMO: Os enxaguatorios bucais sao os antissepticos mais utilizados para a higiene bucal. No entanto, alguns estudos demonstraram que estes compostos que contem alcool podem induzir efeitos genotoxicos e carcinogenicos. O ensaio de micronucleos em celulas da mucosa bucal (BMCyt assay) de humanos tem sido amplamente utilizado para investigar biomarcadores para avaliacao de danos no DNA, morte celular, defeitos na citocinese e frequencia de celulas basais em celulas bucais. Assim, o objetivo deste estudo foi avaliar se os enxaguatorios poderiam induzir danos geneticos em celulas esfoliadas do epitelio bucal pelo ensaio BMCyt. Participaram do estudo 60 individuos, divididos em dois grupos: um grupo exposto aos enxaguatorios (n = 30) e outro nao exposto (grupo controle, n = 30). Os danos nucleares (micronucleos e brotos nucleares), citocineses incompletas (celulas binucleadas), morte celular (celulas com cromatina condensada, cariorrexis, picnoticas e carioliticas) e celulas basais foram avaliados em celulas de epitelio usando analise de imagem com aumento de 1.000x. Os resultados mostraram um aumento significativo de celulas com brotos nucleares, picnoticas e basais no grupo exposto. Observamos que a composicao de enxaguantes contendo alcool pode estar relacionada as frequencias de micronucleos e de celulas com brotos nucleares, de acordo com a seguinte ordem: Listerine®> Colgate®> Oral B®. No entanto, estudos com um maior numero de individuos sao necessarios para sustentar os resultados preliminares aqui apresentados.

Characterization of the particulate matter and relationship between buccal micronucleus and urinary 1-hydroxypyrene levels among cashew nut roasting workers

The present study is the first assessment of occupational risk associated with artisanal cashew nut roasting using exposure and effect biomarkers, as well as a characterization and dispersion analysis of the released particulate matter (PM). A real-time particle monitor was used to quantify PM1.0, PM2.5 and PM10. Furthermore, the PM was sampled using a Handi-vol sampler, and the physicochemical characteristics were determined by SEM-EDS analysis. Trajectories, dispersion and deposition of the emitted material were calculated using the NOAA-HYSPLIT model. Urinary 1-hydroxypyrene (1-OHP) levels were analyzed by HPLC. DNA damage, chromosomal instability and cell death were measured by a buccal micronucleus cytome assay (BMCyt). The PM concentrations for all measurements in the exposed area were higher than in the non-exposed area. SEM-EDS analyses exhibited a wide variety of particles, and K, Cl, S and Ca biomass burning tracers were the major inorganic compounds. In addition, atmospheric modeling analysis suggested that these particles can reach regions farther away than 40 kilometers. Occupational polycyclic aromatic hydrocarbon exposure was confirmed by increases in 1-OHP levels in cashew nut workers. Frequencies of BMCyt biomarkers of genotoxicity (micronuclei and nuclear bud) and cytotoxicity (pyknosis, karyolysis, karyorrhexis and condensed chromatin) were higher in the exposed group compared with the controls. The influence of factors, such as age, on the micronuclei frequencies was demonstrated, and a correlation between 1-OHP and micronuclei was observed. To the best of our knowledge, no other study has demonstrated a correlation between these types of biomarkers. The use of exposure (1-OHP) and effect (BMCyt) biomarkers were therefore efficient in assessing the occupational risk associated with artisanal cashew nut roasting, and the high rates of PM2.5 are considered to be a potential contributor to this effect.

Cytogenetic analysis of micronuclei and cell death parameters in epithelial cells of pesticide exposed tea garden workers

Buccal micronucleus cytome assay was carried out in 47 exposed (sprayers and leaf harvesters), 47 non-exposed (controls) to determine the extent of damage working in the tea plantations of Terai region of West Bengal, India. As the pesticide exposed male workers were found to consume alcohol and smoked cigarettes/bidis, 35 smokers and 30 alcoholics were also included for comparison. Results showed a significant difference in micronuclei (9.91 ± 2.74, p ≤ .001), nuclear bud (4.98 ± 1.31, p ≤ .001), binucleate (6.26 ± 2.84, p ≤ .001), karyorrhectic (8.36 ± 2.28, p ≤ .001), pyknotic (5.62 ± 1.78, p ≤ .05) as well as karyolytic (6.81 ± 3.00, p ≤ .001) nuclei compared with control. Comparison also revealed a higher frequency of micronuclei (6.11 ± 2.55, p ≤ .01), nuclear bud (4.06 ± 1.97, p ≤ .05), binucleate (4.34 ± 1.85, p ≤ .001), karyorrhectic (6.83 ± 2.12, p ≤ .001), and karyolytic (6.20 ± 2.54, p ≤ .001) nuclei except pyknotic cell in the smoker than control. Frequency of binucleate (3.80 ± 1.73, p ≤ .05), karyorrhectic (5.57 ± 2.34, p ≤ .05), pyknotic (5.50 ± 1.36, p ≤ .05), and karyolytic (6.30 ± 2.71, p ≤ .001) nuclei was higher in the alcoholics than control (non-alcoholics), whereas the micronuclei and nuclear bud were found to be non-significant compared with the control. Our analyses also revealed a higher proportion of the micronucleus and the cell death parameters in the pesticide exposed males than females, which indicated that pesticide, smoking, and alcohol may act synergistically to cause more damage to the buccal epithelial cells. However, age and the exposure duration have no influence on the micronucleus and other cell death parameters.

Mutagenic potential assessment associated with human exposure to natural radioactivity

Lucrécia city, known to harbor a high cancer rate, is located in a semiarid region characterized by the presence of mineral reservoirs, facing a high exposure to metal and natural radioactivity. The present study aimed to assess the environmental scenario at a semiarid region located in Northeastern Brazil. Metal concentration, alpha and beta radiation, and cyanobacteria content in tap water along with indoor radon and gamma emitters (U, K and Th) concentrations were measured. In addition, mutagenic and nuclear instability effects were assessed using buccal micronucleus cytome assay. The study included five samplings corresponding to a period between 2007 and 2009. Drinking water from Lucrécia city presented levels of Mn, Ni and Cr along with cyanobacteria in concentrations one to four times higher than regulatory guidelines considered. Furthermore, high levels of all the tested radionuclides were found. A high percentage of the houses included in this study presented indoor radon concentrations over 100 Bq m−3. The mean annual effective dose from Lucrécia houses was six times higher than observed in a control region. The levels of exposure in most of the Lucrécia houses were classified as middle to high. A significant mutagenic effect, represented as an increase of micronuclei (MN) frequency and nuclear abnormalities as nuclear buds (NB), binucleated cells (BN), and pyknotic cells (PYC) were found. The results obtained highlight the role of high background radioactivity on the observed mutagenic effect and could help to explain the exacerbated cancer rate reported in this locality.

Inter-laboratory consistency and variability in the buccal micronucleus cytome assay depends on biomarker scored and laboratory experience: results from the HUMNxl international inter-laboratory scoring exercise.

The buccal micronucleus cytome (BMNcyt) assay in uncultured exfoliated epithelial cells from oral mucosa is widely applied in biomonitoring human exposures to genotoxic agents and is also proposed as a suitable test for prescreening and follow-up of precancerous oral lesions. The main limitation of the assay is the large variability observed in the baseline values of micronuclei (MNi) and other nuclear anomalies mainly related to different scoring criteria. The aim of this international collaborative study, involving laboratories with different level of experience, was to evaluate the inter- and intra-laboratory variations in the BMNcyt parameters, using recently implemented guidelines, in scoring cells from the same pooled samples obtained from healthy subjects (control group) and from cancer patients undergoing radiotherapy (treated group). The results indicate that all laboratories correctly discriminated samples from the two groups by a significant increase of micronucleus (MN) and nuclear bud (NBUD) frequencies and differentiated binucleated (BN) cells, associated with the exposure to ionizing radiation. The experience of the laboratories was shown to play an important role in the identification of the different cell types and nuclear anomalies. MN frequency in differentiated mononucleated (MONO) and BN cells showed the greatest consistency among the laboratories and low variability was also detected in the frequencies of MONO and BN cells. A larger variability was observed in classifying the different cell types, indicating the subjectivity in the interpretation of some of the scoring criteria while reproducibility of the results between scoring sessions was very good. An inter-laboratory calibration exercise is strongly recommended before starting studies with BMNcyt assay involving multiple research centers.

Occupational exposure to anesthetics leads to genomic instability, cytotoxicity and proliferative changes

Data on the genotoxic and mutagenic effects of occupational exposure to the most frequently used volatile anesthetics are limited and controversial. The current study is the first to evaluate genomic instability, cell death and proliferative index in exfoliated buccal cells (EBC) from anesthesiologists. We also evaluated DNA damage and determined the concentrations of the anesthetic gases most commonly used in operating rooms. This study was conducted on physicians who were allocated into two groups: the exposed group, which consisted of anesthesiologists who had been exposed to waste anesthetic gases (isoflurane, sevoflurane, desflurane and nitrous oxide − N2O) for at least two years; and the control group, which consisted of non-exposed physicians matched for age, sex and lifestyle with the exposed group. Venous blood and EBC samples were collected from all participants. Basal DNA damage was evaluated in lymphocytes by the comet assay, whereas the buccal micronucleus (MN) cytome (BMCyt) assay was applied to evaluate genotoxic and cytotoxic effects. The concentrations of N2O and anesthetics were measured via a portable infrared spectrophotometer. The average concentration of waste gases was greater than 5 parts per million (ppm) for all of the halogenated anesthetics and was more than 170ppm for N2O, expressed as a time-weighted average. There was no significant difference between the groups in relation to lymphocyte DNA damage. The exposed group had higher frequencies of MN, karyorrhexis and pyknosis, and a lower frequency of basal cells compared with the control group. In conclusion, exposure to modern waste anesthetic gases did not induce systemic DNA damage, but it did result in genomic instability, cytotoxicity and proliferative changes, which were detected in the EBC of anesthesiologists. Thus, these professionals can be considered at risk for developing genetic alterations resulting from occupational exposure to these gases, suggesting the need to minimize this exposure.

Air pollution biological effects in children living in Lecce (Italy) by Buccal micronucleus cytome assay (the MAPEC_LIFE study)

The aim of the MAPEC_LIFE (Monitoring Air Pollution Effects on Children for Supporting Public Health Policy) study is to evaluate the associations between the concentrations of air pollutants and early biological effects in children living in five Italian towns (Brescia, Torino, Lecce, Perugia and Pisa) characterised by varying levels of air pollution. This paper presents the results of micronucleus cytome assays performed on the oral mucosa cells of subjects living in Lecce (Puglia, Italy) and their relationship to factors associated with indoor/outdoor exposure and lifestyles. The study was conducted on 6-8-year-old schoolchildren living in Lecce. The micronucleus cytome assay was performed on exfoliated buccal cells collected from the oral mucosa of children using a soft-bristled toothbrush. Micronuclei were evaluated only in normal differentiated cells. Overall, 43.0% of the samples tested were positive, with an average frequency of 0.28 MN/1000 differentiated cells. Data analysis shows positive associations between the frequency of MN in the children’s buccal mucosa cells and obesity, heavy traffic and smoking mothers, while outdoor sports seem to have the opposite effect. These data will be integrated with data from the other cities involved in the MAPEC_LIFE study and could be used

Genotoxic effects of X-rays in buccal mucosal cells in children subjected to dental radiographs.

Objectives/Aims:Bitewing and digital dental panoramic radiographs have become important adjuvants for successful dental practice in pediatric dentistry. Both methods lead to genetic changes in the oral buccal epithelium that have not yet been satisfactorily explored. The aim of the present study was to evaluate the genotoxic effects induced by X-ray radiation from bitewing and panoramic dental radiography in exfoliated buccal epithelial cells of children, using the Buccal Micronucleus Cytome assay.Materials and Methods:Children (n=40) who met the inclusion criteria and provided signed informed consent were included in the study. Children were selected for undergoing bitewing radiographs (group 1; n=20) or digital dental panoramic radiographs (group 2; n=20). Exfoliated buccal mucosal cells were obtained by scraping the right/left buccal mucosa with a wooden spatula immediately before the X-ray exposure and 10±2 days after exposure.Results:The frequency of micronuclei increases significantly post exposure to both bitewing and digital dental panoramic radiography in children, but the frequency was higher in bitewing radiographs.Conclusion:It was concluded that the frequency of micronuclei increases post exposure to both bitewing and digital panoramic radiographs. Increased radiation exposure results in an increase in micronuclei frequency.

DNA damage and cytotoxicity in pathology laboratory technicians exposed to organic solvents.

The aim of this study was to evaluate potential DNA damage and cytotoxicity in pathology laboratory technicians exposed to organic solvents, mainly xylene. Peripheral blood and buccal cells samples were collected from 18 technicians occupationally exposed to organic solvents and 11 non-exposed individuals. The technicians were sampled at two moments: Monday and Friday. DNA damage and cytotoxicity were evaluated using the Comet Assay and the Buccal Micronucleus Cytome assay. Fifteen subjects (83.5%) of the exposed group to solvents complained about some symptom probably related to contact with vapours of organic solvents. DNA damage in the exposed group to solvents was nearly 2-fold higher on Friday than on Monday, and in both moments the individuals of this group showed higher levels of DNA damage in relation to controls. No statistical difference was detected in buccal cell micronucleus frequency between the laboratory technicians and the control group. However, in the analysis performed on Friday, technicians presented higher frequency (about 3-fold) of karyolytic and apoptotic-like cells (karyorrhectic and pyknotic) in relation to control group. Considering the damage frequency and the working time, a positive correlation was found in the exposed group to solvents (r=0.468; p=0.05). The results suggest that pathology laboratory workers inappropriately exposed to organic solvents have increased levels of DNA damage.

Buccal Micronucleus Cytome Assay in Sickle Cell Disease.

Sickle Cell Anaemia (SCA) is a commonly inherited blood disorder preceded by episodes of pain, chronic haemolytic anaemia and severe infections. The underlying phenomenon which causes this disease is the point mutation in the haemoglobin beta gene (Hbβ) found on chromosome 11 p. Increased oxidative stress leads to DNA damage. DNA damage occurring in such conditions can be studied by the buccal micronucleus cytome assay, which is a minimally invasive method for studying chromosomal instability, cell death and regenerative potential of human buccal tissue. To evaluate genomic instability in patients with sickle cell disease by buccal micronucleus cytome assay. The study included 40 sickle cell anemia patients (Group A) and 40 age and sex matched controls (Group B). Buccal swabs were collected and stained with Papanicolaou (PAP). Number of cells with micronucleus, binuclei, nuclear bud, pyknosis and karyolysis were counted in two groups as parameters for the evaluation of genome stability. All the analysis was done using t-test. A p-value of <0.001 was considered statistically significant. There was a statistically significant increase in micronuclei number in SCA patients when compared with controls. Karyolytic (un-nucleated) cell number in Group A was more than to those of the controls. The results might suggest that patients with sickle cell anaemia have genome instability which is represented by the presence of micronuclei in the somatic cells. Presence of apoptotic cells might only indicate the bodily damage to the tissue as a result of the disease.

PAH exposure and relationship between buccal micronucleus cytome assay and urinary 1-hydroxypyrene levels among cashew nut roasting workers

The present study conducted the first assessment of the occupational risk associated to artisanal cashew nut roasting by the use of exposure and effect biomarkers, as well as the characterization a ...

Buccal Micronuclei Assay as a Tool For Biomonitoring DNA Damage in Oral Lichen Planus.

The malignant transformation rate of Oral Lichen Planus (OLP) is between 0% and 5.8%. Oral lesions of lichen planus clinically presents itself multifocally, simulating the process of field cancerization in high risk malignancies. The Buccal MicroNucleus Cytome Assay (BMN Assay) provides a platform to identify the high risk individuals by evaluating the markers of nuclear damage at an earliest micro invasive phase. To evaluate DNA damage in exfoliated buccal mucosal cells in individuals with oral lichen planus lesions and thereby to delineate the high risk group. Buccal smears from 22 OLP and 10 control samples were stained in modified Feulgen-Rossenback reaction for micronuclei assay. Cytological evaluation of number of MicroNucleated cells (CMN), Total Number of Micronuclei (TMN) in micronucleated cells was done in both groups. Frequency of micronucleated cells (CMN) when compared among the study and control group, a mean value of 4.27 ± 1.80 and 0.90 ± 0.88 were obtained respectively. On comparing the total number of micronuclei in the micronucleated cells (TMN) between the study and control groups, a mean value of 5.38 ± 2.42 and 1.5 ± 0.88 were obtained respectively. There was a significant increase in the frequency of micronuclei and the micronucleated cells in the oral lichen planus as compared to normal individuals.

DNA damage and cellular abnormalities in tuberculosis, lung cancer and chronic obstructive pulmonary disease

Background: Tuberculosis (TB), Lung Cancer (LC) and Chronic Obstructive Pulmonary Diseases (COPD) affect millions of individuals worldwide. Monitoring of DNA damage in pathological situations has been investigated because it can add a new dimension to clinical expression and may represent a potential target for therapeutic intervention. The aim of this study was to evaluate DNA damage and the frequency of cellular abnormalities in TB, LC and COPD patients by comparing them to healthy subjects.&#x0D; Methods: The detection of DNA damage by a buccal micronucleus cytome assay was investigated in patients with COPD (n = 28), LC (n = 18) and TB (n = 22) and compared to control individuals (n = 17).&#x0D; Results: The COPD group had a higher frequency of apoptotic cells compared to TB and LC group. The TB group showed a higher frequency of DNA damage, defect in cytokinesis, apoptotic and necrotic cells. Patients with LC had low frequency of chromosomal aberrations than TB and COPD patients.&#x0D; Conclusion: COPD patients showed cellular abnormalities that corresponded to cell death by apoptosis and necrosis, while patients with TB presented defects in cytokinesis and dysfunctions in DNA repair that resulted in the formation of micronucleus (MN) besides apoptotic and necrotic cells. Patients with COPD, TB and LC had a low frequency of permanent DNA damage.

DNA damage and cellular abnormalities in tuberculosis, lung cancer and chronic obstructive pulmonary disease.

BackgroundTuberculosis (TB), Lung Cancer (LC) and Chronic Obstructive Pulmonary Diseases (COPD) affect millions of individuals worldwide. Monitoring of DNA damage in pathological situations has been investigated because it can add a new dimension to clinical expression and may represent a potential target for therapeutic intervention. The aim of this study was to evaluate DNA damage and the frequency of cellular abnormalities in TB, LC and COPD patients by comparing them to healthy subjects.MethodsThe detection of DNA damage by a buccal micronucleus cytome assay was investigated in patients with COPD (n = 28), LC (n = 18) and TB (n = 22) and compared to control individuals (n = 17).ResultsThe COPD group had a higher frequency of apoptotic cells compared to TB and LC group. The TB group showed a higher frequency of DNA damage, defect in cytokinesis, apoptotic and necrotic cells. Patients with LC had low frequency of chromosomal aberrations than TB and COPD patients.ConclusionCOPD patients showed cellular abnormalities that corresponded to cell death by apoptosis and necrosis, while patients with TB presented defects in cytokinesis and dysfunctions in DNA repair that resulted in the formation of micronucleus (MN) besides apoptotic and necrotic cells. Patients with COPD, TB and LC had a low frequency of permanent DNA damage.

Multi-Parameter Approach for Evaluation of Genomic Instability in the Polycystic Ovary Syndrome.

The polycystic ovary syndrome (PCOS), characterized by hyperandrogenism and chronic anovulation, is a common endocrine disorder in women. PCOS, which is associated with polycystic ovaries, hirsutism, obesity and insulin resistance, is a leading cause of female infertility. In this condition there is an imbalance in female sex hormones. All the sequelae symptoms of PCOS gradually lead to cancer in the course of time. It is heterogeneous disorder of unknown etiology so it is essential to find the exact cause. In this study both invasive and non-invasive techniques were employed to establish the etiology. Diagnosis was based on Rotterdam criteria (hyperandrogenism, ovulatory dysfunction, PCOM) and multiparameters using buccal samples and dermatoglypic analysis and cytogenetic study for 10 cases and four age and sex matched controls. In clinical analysis we have observed the mean value of total testosterone level was 23.6nmol/L, total hirsutism score was from 12-24, facial acne was found in in 70% patients with 7-12 subcapsular follicular cysts, each measuring 2-8 mm in diameter. In dermatoglypic analysis we observed increases in mean value (45.9°) of ATD angle when compared with control group and also found increased frequency (38%) of Ulnar loops on both fingers (UU), (18%) whorls on the right finger and Ulnar loop on left finger (WU) and (16%) arches on right and left fingers (AA) were observed in PCOS patients when compared with control subjects. Features which could be applied as markers for PCOS patients are the presence of Ulnar loops in middle and little fingers of right and left hand. The buccal micronucleus cytome assay in exfoliated buccal cells, we found decrease in frequency of micronuclei and significant increases in frequency of karyolysed nuclei in polycystic ovarian syndrome patients. Chromosome aberration analysis revealed a significant increase in frequency of chromosome aberrations (CAs) in PCOS patients when compared with controls. From this present work it can be concluded that non-invasive technique like dermatoglypics analysis and buccal micronucleus cytome assays with exfoliated buccal cell can also be effective biomarkers for PCOS, along with increased CAs in lymphocytes as a sign of genetic instability. There is a hypothesis that micronuclei and chromosomal aberrations could have a predictive value for cancer. From this present work it can be concluded to some extent that non-invasive technique like dermatoglypics and buccal cell analysis can also be effective for diagnosis.

Evaluation of air pollution genotoxic effects in children by the buccal micronucleus cytome assay

Background Epidemiological studies have found a consistent association between exposure to air pollution, especially to particulate matter (PM), and the incidence and mortality for several chronic diseases such as lung cancer, cardiovascular diseases and diabetes. Among the mechanisms responsible for these adverse effects, genotoxic damage is of particular concern. Children are a high risk group with respect to the short- and long-term effects …

The buccal micronucleus cytome assay as a tool for the evaluation of air pollution early biological effects in children: Current status of the MAPEC (Monitoring Air Pollution Effects on Children for supporting public health policy) study

The buccal micronucleus cytome assay as a tool for the evaluation of air pollution early biological effects in children: Current status of the MAPEC (Monitoring Air Pollution Effects on Children for supporting public health policy) study

In vivo evaluation of the genotoxic effects of Hyrax auxiliary orthodontic appliances containing silver-soldered joints

Auxiliary appliances consisting of silver-soldered joints may be present in the patient’s oral cavity for a long time. The aim of this study was to investigate, in vivo, the potential genotoxic effects of Hyrax-type maxillary expanders containing silver-soldered joints on the cells of the buccal mucosa. Buccal cells were collected from 20 patients and processed to perform the buccal comet assay (BCA) and the buccal micronucleus cytome (BMCyt) assay, to investigate DNA and chromosomal damage, respectively. For the BCA, patients were evaluated before and 14 days after the appliances were installed. For the BMCyt assay, the patients were evaluated longitudinally; before the insertion of the appliance and after one, six, and twelve months. The BCA showed significant increases in damage frequency and damage index in exfoliated buccal cells, following insertion of the appliance. For the BMCyt assay, the endpoints related to cell proliferation, cell death, and chromosomal damage (micronuclei and nuclear buds) resulted in no significant differences over the 12-month study period. In conclusion, the use of orthodontic appliances containing silver-soldered joints can significantly increase DNA damage as measured by the BCA.

Buccal Cytome Biomarkers and Their Association with Plasma Folate, Vitamin B12 and Homocysteine in Alzheimer's Disease

Background/Aims: Alzheimer's disease (AD) is an irreversible neurodegenerative disorder and is the commonest form of dementia. One aim of this study was to determine whether AD individuals have altered plasma folate, vitamin B₁₂ and homocysteine (Hcy) levels compared to controls. The other aim was to investigate correlations between B vitamins and buccal biomarkers to test whether they are influenced by B vitamin status. Methods: Folate, vitamin B₁₂ and Hcy were measured using ARCHITECT® and AxSYM® assays. Genomic stability was measured using the buccal micronucleus cytome assay. Results: The area under the receiver operating characteristic curve for AD basal cells was 0.96 (p < 0.0001), for karyorrhectic cells 0.88 (p < 0.0001) and for basal and karyorrhectic cells 0.91 (p < 0.0001). Hcy was significantly increased (p = 0.0003) compared to controls. Plasma vitamin B₁₂ in controls showed a positive correlation with pyknosis (r = 0.5365, p = 0.004), karyolysis (r = 0.5447, p = 0.004) and condensed chromatin (r = 0.5238, p = 0.006). Plasma vitamin B₁₂ in AD cases showed a positive correlation with micronuclei (r = 0.3552, p = 0.04) and basal cells (r = 0.3448, p = 0.04), whilst plasma Hcy showed a negative correlation with karyorrhectic cells (r = -0.4107, p = 0.01). Conclusions: Hcy was significantly increased in AD cases relative to controls. The lower frequency of basal cells and karyorrhectic cells observed in AD cases may be explained by lower vitamin B₁₂ and higher Hcy levels, respectively.

Buccal Micronucleus Cytome Assay- A Biomarker of Genotoxicity

The buccal micronucleus cytome assay in exfoliated buccal cells is utilized as biomarkers for DNA damage, cell death and basal cell frequency. It offers great opportunity to evaluate genotoxicity by the way of quantifying mean frequencies of micronuclei, binucleated cell, broken egg, karyolysis, karyorrhexis, pycknosis and condensed chromatin. This assay is sensitive, minimally invasive, simple, cheap, easy and fast. It has precision and statistical power obtained from scoring large number of cells. Micronucleus assay has been extensively used to assess genetic damage due to lifestyle characteristics, occupational exposure, diseases and environmental risk. It also has applications in human biomonitoring, ecotoxicology, cancer risk assessment, pharmaceutical drug testing and the impacts of dietary micronutrients and micronutrient combinations on DNA damage. Fluorescence in situ hybridization is a valuable addition to micronucleus assay as combination of both enables us to characterize the genetic contents of the micronuclei. The present article reviews and updates on usefulness of buccal micronucleus cytome assay as a biomarker. It gives a detailed description of the methodology of buccal micronucleus test and analysis of the results. We also discussed the criteria for identification and classification of nuclear anomalies. We have also proposed the future directions namely high-throughput automation for further enhancing the reliability of micronucleus assay to be applicable on large scale experimental and epidemiological studies. It would help in overcoming many of the problems caused by inter-observer variability in evaluation of slides.