Displaying publications 1 - 20 of 53 in total

  1. Othman, M., Ahmad, K.
    ASM Science Journal, 2007;1(2):181-182.
    Comet 17P/Holmes was discovered by Edwin Holmes on 6 November 1892 while he was conducting regular observations of the Andromeda Galaxy (M31). Calculations using observation of its orbits established the perihelion date as 13 June and the orbital period as 6.9 years. The 1899 and 1906 appearances were observed, but the comet was only seen again in 1964. The comet has since been
    observed on every subsequent return.
    Matched MeSH terms: Comet Assay
  2. Razinah Sharif, Ahmad Rohi Ghazali, Nor Fadilah Rajab
    DNA damaging effect of the salted and fermented food products (salted fishes, dried shrimps and shrimp pastes) collected from three different locations in Malacca namely Pantai Puteri, Batang Tiga and Kelemak on the DNA of the Chang liver cells were evaluated via Alkaline Comet Assay. Treatment at 62.5 mg/ml following 24 hours of incubation was used based on the preliminary cytotoxicity data. Percentage of damage to the DNA was calculated using software for scoring based on the tail moment and tail intensity (severity of the DNA damage). Hydrogen peroxide was used as positive control at 0.1 mM following 30 minutes of incubation in 4 C. The results showed that the methanol extracts of shrimp pastes and salted fish from Pantai Puteri, exhibited a higher DNA damage (shrimp pastes - TM - 8.33 ± 2.19; TI - 31.67 ± 5.84, salted fishes - TM - 2.25 ± 0.86; TI - 9.25 ± 1.55) and were expressed as (shrimp pastes) 56.66 ± 8.74% of DNA damage and methanol salted fish extracts from the same location showed 13.00 ± 2.84% of the DNA damage on Chang liver cells compared to the other extracts. Values for methanol extract of shrimp pastes from Pantai Puteri were comparable to the positive control - Hydrogen peroxide (TM- 9.50 ± 1.50; TI - 30.50 ± 2.50). On the other hand, aqueous salted fishes extract from Pantai Puteri (TM - 1.33 ± 0.42; TI - 8.67 ± 2.42) and shrimp pastes extracts from Kelemak (methanol extract - TM -1.75 ± 0.15; TI -7.50 ± 0.50, aqueous extract - TM - 1.00 ± 0.00; TI - 5.00 ± 0.00) showed slightly high value for tail moment and tail intensity as compared to negative control (TM - 0.29 ± 0.05; TI - 2.50 ± 0.29). Values for methanol extracts of shrimp pastes from Pantai Puteri were comparable to the positive control (TM- 9.50 ± 1.50; TI - 30.50 ± 2.50). In conclusion, our results demonstrate genotoxic damage induced by few salted and fermented food extracts in Chang liver cell.
    Matched MeSH terms: Comet Assay
  3. Siti Robayah Mohd Zakri, Kannan, Thirumulu Ponnuraj, Nora Aziz, Siti Fadilah Abdullah, Dasmawati Mohamad, Ismail Ab Rahman, et al.
    The aim of this study was to determine the genotoxicity of a locally produced nanocomposite by Universiti Sains Malaysia, Malaysia using Comet assay. Stem cells from human exfoliated deciduous teeth (SHED) were treated with the nanocomposite at five different concentrations (0.006, 0.0125, 0.025, 0.05, and 0.1 mg/ml) along with concurrent negative (medium alone) and positive control (zinc sulfate heptahydrate) and incubated at 37°C for 24 hours in an incubator at 5% CO2. The tail moment was used to assess the extent of DNA damage. The tail moment for the group of SHED treated with nanocomposite (for all the five different concentrations) was not statistically significant as compared to the negative control, suggesting that the locally produced dental nanocomposite did not induce any DNA damage. Hence, it can be concluded that the locally produced nanocomposite is non-genotoxic on stem cells from human exfoliated deciduous teeth.
    Matched MeSH terms: Comet Assay
  4. Muhammad H, Omar MH, Rasid ENI, Suhaimi SN, Mohkiar FH, Siu LM, et al.
    Plants (Basel), 2021 Feb 11;10(2).
    PMID: 33670296 DOI: 10.3390/plants10020343
    The present study was carried out to assess the genotoxicity potential of Ficus deltoidea var. kunstleri aqueous extract (FDAE) using standard in vitro assays. The DNA damage of V79B cells was measured using the alkaline comet assay treated at 0.1 mg/mL (IC10) and 0.3 mg/mL (IC25) of FDAE together with positive and negative controls. For in vitro micronucleus assay, the V79B cells were treated with FDAE at five different concentrations (5, 2.5, 1.25, 0.625, and 0.3125 mg/mL) with and without S9 mixture. The bacteria reverse mutation assay of FDAE was performed on Salmonella typhimurium strains TA98, 100, 1535, 1537, and Escherichia coli strain WP2uvrA using pre-incubation method in the presence or in the absence of an extrinsic metabolic system (S9 mixture). FDAE at 0.1 and 0.3 mg/mL significantly increased DNA damage in both comet tail and tail moment (p < 0.05). No significant changes were detected in the number of micronucleated cell when compared to control. Tested at the doses up to 5000 µg/plate, the FDAE did not increase the number of revertant colonies for all strains. In conclusion, further investigation needs to be conducted in animal model to confirm the non-genotoxicity activities of FDAE.
    Matched MeSH terms: Comet Assay
  5. Chye SM, Hseu YC, Liang SH, Chen CH, Chen SC
    Bull Environ Contam Toxicol, 2008 Jan;80(1):58-62.
    PMID: 18058049
    Para-Phenylenediamine (PPD), the main aromatic amines used in the hair dye formation, and its four derivatives (2-chloro-p-phenylenediamine, 4-chloro-o-phenylenediamine, 2-nitro-p-phenylenediamine, and 4-nitro-o-phenylenediamine) were examined for their potential to produce single strand DNA breaks in human lymphocytes using the alkaline comet assay. Results revealed that all the tested chemicals within the range of doses from 100 microM to 500 microM showed the genotoxicity in a dose-dependent manner after the incubation of lymphocytes with these chemicals for 2 h. In this study, we first reported that PPD and its four derivatives can elicit the type of single strand breaks in human lymphocytes.
    Matched MeSH terms: Comet Assay/methods*
  6. Musa M, Ponnuraj KT, Mohamad D, Rahman IA
    Nanotechnology, 2013 Jan 11;24(1):015105.
    PMID: 23221152 DOI: 10.1088/0957-4484/24/1/015105
    Nanocomposite is used as a dental filling to restore the affected tooth, especially in dental caries. The dental nanocomposite (KelFil) for tooth restoration used in this study was produced by the School of Dental Sciences, Universiti Sains Malaysia, Malaysia and is incorporated with monodispersed, spherical nanosilica fillers. The aim of the study was to determine the genotoxic effect of KelFil using in vitro genotoxicity tests. The cytotoxicity and genotoxicity of KelFil was evaluated using MTT assay, comet assay and chromosome aberration tests with or without the addition of a metabolic activation system (S9 mix), using the human lung fibroblast cell line (MRC-5). Concurrent negative and positive controls were included. In the comet assay, no comet formation was found in the KelFil groups. There was a significant difference in tail moment between KelFil groups and positive control (p < 0.05). Similarly, no significant aberrations in chromosomes were noticed in KelFil groups. The mitotic indices of treatment groups and negative control were significantly different from positive controls. Hence, it can be concluded that the locally produced dental restoration nanocomposite (KelFil) is non-genotoxic under the present test conditions.
    Matched MeSH terms: Comet Assay/methods*
  7. Saberbaghi T, Abbasian F, Mohd Yusof YA, Makpol S
    PMID: 23573154 DOI: 10.1155/2013/780504
    In this study, the effects of Chlorella vulgaris (CV) on replicative senescence of human diploid fibroblasts (HDFs) were investigated. Hot water extract of CV was used to treat HDFs at passages 6, 15, and 30 which represent young, presenescence, and senescence ages, respectively. The level of DNA damage was determined by comet assay while apoptosis and cell cycle profile were determined using FACSCalibur flow cytometer. Our results showed direct correlation between increased levels of damaged DNA and apoptosis with senescence in untreated HDFs (P < 0.05). Cell cycle profile showed increased population of untreated senescent cells that enter G0/G1 phase while the cell population in S phase decreased significantly (P < 0.05). Treatment with CV however caused a significant reduction in the level of damaged DNA and apoptosis in all age groups of HDFs (P < 0.05). Cell cycle analysis showed that treatment with CV increased significantly the percentage of senescent HDFs in S phase and G2/M phases but decreased the population of cells in G0/G1 phase (P < 0.05). In conclusion, hot water extract of Chlorella vulgaris effectively decreased the biomarkers of ageing, indicating its potential as an antiageing compound.
    Matched MeSH terms: Comet Assay
  8. Vadivelu RK, Yeap SK, Ali AM, Hamid M, Alitheen NB
    PMID: 23056140 DOI: 10.1155/2012/251362
    Betulinic acid is a widely available plant-derived triterpene which is reported to possess selective cytotoxic activity against cancer cells of neuroectodermal origin and leukemia. However, the potential of betulinic acid as an antiproliferative and cytotoxic agent on vascular smooth muscle (VSMC) is still unclear. This study was carried out to demonstrate the antiproliferative and cytotoxic effect of betulinic acid on VSMCs using 3-[4,5-dimethylthizol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry cell cycle assay, BrdU proliferation assay, acridine orange/propidium iodide staining, and comet assay. Result from MTT and BrdU assays indicated that betulinic acid was able to inhibit the growth and proliferation of VSMCs in a dose-dependent manner with IC(50) of 3.8 μg/mL significantly (P < 0.05). Nevertheless, betulinic acid exhibited G(1) cell cycle arrest in flow cytometry cell cycle profiling and low level of DNA damage against VSMC in acridine orange/propidium iodide and comet assay after 24 h of treatment. In conclusion, betulinic acid induced G(1) cell cycle arrest and dose-dependent DNA damage on VSMC.
    Matched MeSH terms: Comet Assay
  9. Yadav K, Lakra WS, Sharma J, Goswami M, Singh A
    Fish Physiol Biochem, 2012 Aug;38(4):1035-1045.
    PMID: 22203177 DOI: 10.1007/s10695-011-9588-7
    Tor tor is an important game and food fish of India with a distribution throughout Asia from the trans-Himalayan region to the Mekong River basin to Malaysia, Pakistan, Bangladesh and Indonesia. A new cell line named TTCF was developed from the caudal fin of T. tor for the first time. The cell line was optimally maintained at 28°C in Leibovitz-15 (L-15) medium supplemented with 20% fetal bovine serum (FBS). The propagation of TTCF cells showed a high plating efficiency of 63.00%. The cytogenetic analysis revealed a diploid count of 100 chromosomes at passage 15, 30, 45 and 60 passages. The viability of the TTCF cell line was found to be 72% after 6 months of cryopreservation in liquid nitrogen (-196°C). The origin of the cell lines was confirmed by the amplification of 578- and 655-bp sequences of 16S rRNA and cytochrome oxidase subunit I (COI) genes of mitochondrial DNA (mtDNA) respectively. TTCF cells were successfully transfected with green fluorescent protein (GFP) reporter plasmids. Further, immunocytochemistry studies confirm its fibroblastic morphology of cells. Genotoxicity assessment of H₂O₂ in TTCF cell line revealed the utility of TTCF cell line as in vitro model for aquatic toxicological studies.
    Matched MeSH terms: Comet Assay
  10. Al-Zubairi A, Ismail P, Pei Pei C, Rahmat A
    Environ Toxicol Pharmacol, 2008 May;25(3):298-303.
    PMID: 21783866 DOI: 10.1016/j.etap.2007.10.032
    The aim of this study was to evaluate the genotoxic effects of a crude extract of khat (Catha edulis, Forsk) leaves in rats. Two groups were fed khat crude extract, 1000 and 2000mg/kg body weight, for 90 days and were compared with a control group. The alkaline (pH>13) version of comet assay was used in this study. However, no previous published work has been undertaken and showed the effect of khat on DNA migration in the comet assay. To compare the comet assay results with another genetic endpoint, blood samples were analyzed for chromosomal aberrations. These results showed no DNA damage detected using comet assay in both the khat treated groups, while the results of chromosomal aberrations assay showed a significant increase (P<0.05) in the 2000mg/kg body weight treated group compared to the control group.
    Matched MeSH terms: Comet Assay
  11. Kusrini E, Hashim F, Azmi WN, Amin NM, Estuningtyas A
    PMID: 26474244 DOI: 10.1016/j.saa.2015.09.021
    The terbium trinitrate.trihydrate.18-crown ether-6, Tb(NO3)3(OH2)3.(18C6) complex has been characterized by elemental analysis, photoluminescence and single X-ray diffraction. The IC50 values were determined based on MTT assay while light and fluorescence microscopy imaging were employed to evaluate the cellular morphological changes. Alkaline comet assay was performed to analyze the DNA damage. The photoluminescence spectrum of the Tb complex excited at 325 nm displayed seven luminescence peaks corresponding to the (5)D4→(7)F(0, 1, 2, 3, 4, 5, 6) transitions. The cytotoxicity and genotoxicity studies indicated that the Tb(NO3)3(OH2)3.(18C6) complex and its salt form as well as the 18C6 molecule have excellent anti-amoebic activity with very low IC50 values are 7, 2.6 and 1.2 μg/mL, respectively, with significant decrease (p<0.05) in Acanthamoeba viability when the concentration was increased from 0 to 30 μg/mL. The mode of cell death in Acanthamoeba cells following treatment with the Tb complex was apoptosis. This is in contrast to the Tb(NO3)3.6H2O salt- and 18C6 molecule-treated Acanthamoeba, which exhibited necrotic type cells. The percentage of DNA damage following treatment with all the compounds at the IC25 values showed high percentage of type 1 with the % nuclei damage are 14.15±2.4; 46.00±4.2; 36.36±2.4; 45.16±0.6%, respectively for untreated, treated with Tb complex, Tb salt and 18C6 molecule. The work features promising potential of Tb(NO3)3(OH2)3.(18C6) complex as anti-amoebic agent, representing a therapeutic option for Acanthamoeba keratitis infection.
    Matched MeSH terms: Comet Assay
  12. Siti Balkis Budin, Norfadilah Rejab, Abdul Gapor Mohd Top, Wan Nazaimoon Wan Mohamud, Mokhtar Abu Bakar, Khairul Osman, et al.
    This study was conducted to evaluate the oxidative damage in diabetic mellitus induced rats. The evaluation of DNA damage was carried out by the Alkaline Comet Assay using peripheral lymphocyte cells taken from streptozotocin-induced diabetic rats (50 mg/kg) and control rats. The levels of malondealdehyde (MDA), 4-hydroxynonenal (4-HNE), fasting blood glucose (FBG) and HbA1c were also measured. All the induced diabetic rats were hyperglycemic until the end of the study with significantly higher levels of FBG and HbA1c as compared to the control rats. The results showed the percentage of tail DNA and tail moment values were also significantly higher in the diabetic induced rats. The same observations were made on the levels of plasma MDA and 4-HNE. In conclusion, this study indicated that hyperglycemic condition in diabetic induced rats could generate oxidative DNA damage.
    Matched MeSH terms: Comet Assay
  13. Salman, M.O., Al-Wasiti, E.A., Thamir, K.A., Al-Ani, I.M., Al-Salihi, A.R.
    Introduction: We aim to investigate the effect of vasectomy on the histology of the testis as well as to evaluate DNA fragmentation in testicular tissue of male mice. Methods: Bilateral vasectomy was performed on 20 mature male mice; 10 control mice underwent sham-operation. After 6 weeks, the testes were evaluated for histological changes and DNA fragmentation by single cell gel electrophoresis (comet assay). Results: Marked alterations were observed in the testes of vasectomized mice, including degeneration of spermatids, thickened basement membrane, dilatation of the seminiferous tubules, exfoliation of germ cells, reduction in the seminiferous cell population, vacuolated appearance of the epithelium in the tubules and marked interstitial fibrosis. Single cell gel electrophoresis showed a highly significant (P
    Matched MeSH terms: Comet Assay
  14. Tew LS, Cai MT, Lo LW, Khung YL, Chen NT
    Materials (Basel), 2018 Jul 09;11(7).
    PMID: 29987236 DOI: 10.3390/ma11071170
    Photodynamic therapy (PDT) is a cancer treatment that employs the production of cytotoxic reactive oxygen species (ROS), subsequently triggering tumor apoptosis and tumor size reduction. However, this approach suffers from insufficient light penetration depth. In order to mitigate this issue, pollen-structured gold clusters (PSGCs) were designed for mediating X-ray-induced PDT for radiotherapy enhancement. The structure of PSGCs provides a large surface area that is able to generate ROS upon X-ray irradiation. The synthesized PSGCs were exposed to different X-ray doses and the generated ROS was then quantified by dihydroethidium (DHE) assay. Furthermore, at the cellular level, the PDT efficacy of PSGCs was evaluated via immunofluorescence staining with γ-H2AX and comet assay. The results demonstrated that PSGCs possess a significantly high ROS-generating capacity and a remarkable PDT efficacy in the treatment of breast cancer cells, thus showing potential clinical uses in deep-tissue cancer treatment.
    Matched MeSH terms: Comet Assay
  15. Eshkoor S, Ismail P, Rahman S, Moin S, Adon M
    Balkan J. Med. Genet., 2013 Dec;16(2):45-52.
    PMID: 24778563 DOI: 10.2478/bjmg-2013-0031
    The ageing process is influenced by many internal and external factors. The toxic substances in the environment can cause genomic damages to cells, which increase the risk of early ageing. Furthermore, the cytochrome P450 1A2 (CYP1A2) gene polymorphism is a susceptibility factor and may enhance the risk of DNA damage in cells. The current study was carried out to show whether occupational exposure could cause genotoxicity in cells carrying the CYP1A2 gene polymorphism, thus enhancing the likelihood of early ageing. This study was conducted on mechanical workshop workers and a control group by collecting buccal cells from their mouths. Restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) was used to identify the CYP1A2 gene polymorphism in the cells. In addition, three extra methods including micronuclei (MN) test, comet assay and real-time PCR (RT-PCR) were applied to determine the effects of gene polymorphisms on DNA damage and ageing from occupational exposure. The results showed that DNA damage in the cells carrying the mutated genotype was higher than the wild genotype. In addition, the difference in MN frequency (p = 0.001) and relative telomere length (p = 0.002) between workers and controls was significant (p <0.05) in the mutated genotype. The findings indicated a possible protective effect of gene polymorphism against early ageing, which was characterized by lack of a significant influence of CYP1A2 gene polymorphism on genetic material in the subjects (p >0.05). It was concluded that the CYP1A2 gene could be a contributing factor to prevent early ageing from occupational exposure.
    Matched MeSH terms: Comet Assay
  16. Ping KY, Darah I, Chen Y, Sasidharan S
    Asian Pac J Trop Biomed, 2013 Sep;3(9):692-6.
    PMID: 23998008 DOI: 10.1016/S2221-1691(13)60140-9
    To evaluate the cytotoxicity and genotoxicity activity of Euphorbia hirta (E. hirta) in MCF-7 cell line model using comet assay.
    Matched MeSH terms: Comet Assay
  17. Wesam RK, Ghanya AN, Mizaton HH, Ilham M, Aishah A
    Asian Pac J Trop Med, 2013 Oct;6(10):811-6.
    PMID: 23870471 DOI: 10.1016/S1995-7645(13)60143-1
    OBJECTIVE: To investigate the cytotoxicity and the genotoxicity of standardized aqueous of dry leaves of Erythroxylum cuneatum (E. cuneatum) in human HepG2 and WRL68 cells.

    METHODS: The cytotoxicity of E. cuneatum extract was evaluated by both MTS and LDH assays. Genotoxicity study on E. cuneatum extract was assessed by the single cell gel electrophoresis (comet assay). The protective effect of E. cuneatum against menadione-induced cytotoxicity was also investigated.

    RESULTS: Results from this study showed that E. cuneatum extract exhibited cytotoxic activities towards the cells with IC50 value of (125±12) and (125±14) μg/mL for HepG2 and WRL68 cells respectively, after 72 h incubation period as determined by MTS assay. LDH leakage was detected at (251±19) and (199.5±12.0) μg/mL for HepG2 and WRL68 respectively. Genotoxicity study results showed that treatment with E. cuneatum up to 1 mg/mL did not cause obvious DNA damage in WRL68 and HepG2 cells. Addition of E. cunaetum did not show significant protection towards menadione in WRL68 and HepG2 Cells.

    CONCLUSIONS: E. cuneatum standardized aqueous extract might be developed in order to establish new pharmacological possibilities for its application.

    Matched MeSH terms: Comet Assay
  18. Eshkoor SA, Marashi SJ, Ismail P, Rahman SA, Mirinargesi M, Adon MY, et al.
    Genet. Mol. Res., 2012;11(2):1486-96.
    PMID: 22653598 DOI: 10.4238/2012.May.21.5
    We evaluated the possible influence of glutathione S-transferase mu (GSTM1) and glutathione S-transferase theta (GSTT1) genes on genetic damage due to occupational exposure, which contributes to accelerate ageing. This study was conducted on 120 car auto repair workshop workers exposed to occupational hazards and 120 controls without this kind of exposure. The null and non-null genotypes of GSTM1 and GSTT1 genes were determined by multiplex PCR. Micronucleus frequency, Comet tail length and relative telomere length differences between the null and non-null genotypes of the GSTM1 gene were significantly greater in the exposed group. Lack of GSTT1 did not affect the damage biomarkers significantly (P > 0.05), while lack of GSTM1 was associated with greater susceptibility to genomic damage due to occupational exposure. It was concluded that early ageing is under the influence of these genes and the environmental and socio-demographic factors. Duration of working time was significantly associated with micronucleus frequency, Comet tail length and relative telomere length.
    Matched MeSH terms: Comet Assay
  19. Jayakumar R, Kanthimathi MS
    Food Chem, 2012 Oct 01;134(3):1580-4.
    PMID: 25005983 DOI: 10.1016/j.foodchem.2012.03.101
    Spices are rich sources of antioxidants due to the presence of phenols and flavonoids. In this study, the DNA protecting activity and inhibition of nicotine-induced cancer cell migration of 9 spices were analysed. Murine fibroblasts (3T3-L1) and human breast cancer (MCF-7) cells were pre-treated with spice extracts and then exposed to H₂O₂ and nicotine. The comet assay was used to analyse the DNA damage. Among the 9 spices, ginger, at 50 μg/ml protected against 68% of DNA damage in 3T3-L1 cells. Caraway, cumin and fennel showed statistically significant (p<0.05) DNA protecting activity. Treatment of MCF-7 cells with nicotine induced cell migration, whereas pre-treatment with spices reduced this migration. Pepper, long pepper and ginger exhibited a high rate of inhibition of cell migration. The results of this study prove that spices protect DNA and inhibit cancer cell migration.
    Matched MeSH terms: Comet Assay
  20. Al-Shami SA, Rawi CS, Ahmad AH, Nor SA
    Toxicol Ind Health, 2012 Sep;28(8):734-9.
    PMID: 22025505 DOI: 10.1177/0748233711422729
    The genotoxic effects of increasing concentrations (below lethal concentration [LC₅₀]) of cadmium ([Cd] 0.1, 1 and 10 mg/L), copper ([Cu] 0.2, 2 and 20 mg/L) and zinc ([Zn] 0.5, 5 and 50 mg/L) on Chironomus kiiensis were evaluated using alkaline comet assay after exposure for 24 h. Both the tail moment and the olive tail moment showed significant differences between the control and different concentrations of Cd, Cu and Zn (Kruskal-Wallis, p < 0.05). The highest concentration of Cd was associated with higher DNA damage to C. kiiensis larvae compared with Cu and Zn. The potential genotoxicity of these metals to C. kiiensis was Cd > Cu > Zn.
    Matched MeSH terms: Comet Assay
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