DNA damage in BALB/c mice infected with Lacazia loboi and its relation to nutritional status

Background: Jorge Lobo’s disease, also known as lacaziosis, is a cutaneous-subcutaneous mycosis with chronic evolution. It is caused by the fungus Lacazia loboi. Herein we report a study that relates the genotoxicity caused by L. loboi in isogenic mice with nutritional status, through a normal or restricted diet. Methods: DNA damage was assessed in the peripheral blood by the comet assay (tail intensity).Results: The results for leukocytes showed increases in the mean tail intensity in mice under dietary restriction, in infected mice under dietary restriction and in infected mice ingesting a normal diet. Conclusion: These results indicate that dietary restriction and L. loboi infection may increase DNA damage levels in mice, as detected by the comet assay

Phytochemical investigation and radical scavenging activities of Melia azedarach and its DNA protective effect in cultured lymphocytes.

CONTEXT: Melia azedarach Linn (Meliaceae) is an Ayurvedic medicinal plant which is native to India. It is traditionally used for the treatment of leprosy, inflammation, scrofula, anthelmintic, antilithic, diuretic, deobstruent and cardiac disorders. OBJECTIVE: To evaluate the phytochemical constituents and antioxidant activities of the ethanol leaf extract of Melia azedarach (MA) and its protective effect against H2O2-induced cellular damage in cultured lymphocytes. MATERIALS AND METHODS: The dose-dependent study of MA (20, 40, 60, 80, 100 µg/ml) was used to study in vitro radical scavenging assays. The effective dose of MA (60 µg/ml) was further used to study the H2O2-induced DNA damage (comet assay and DNA fragmentation assay) in cultured lymphocytes. RESULTS: The ethanol extract of MA (20, 40, 60, 80, 100 µg/ml) exhibited a significant dose-dependent inhibition of in vitro radical scavenging assays and their corresponding IC50 values as follows: hydroxyl radical (26.50 ± 0.26 µg/ml), superoxide anion (30.00 ± 0.32 µg/ml), nitric oxide radical (48.00 ± 0.48 µg/ml), DPPH radical (30.55 ± 0.32 µg/ml) and reducing power (22.00 ± 0.22 µg/ml). The increase in the severity of DNA damage and TBARS was increased significantly (p<0.05) at 500 µM H2O2-treated cultured lymphocytes and RBC cellular membranes. The phytochemical screening studies identified 13 chemical constituents present in the leaf extract of MA. DISCUSSION AND CONCLUSION: The results of this study demonstrate that MA offers protection against H2O2-induced cellular damage and it can be developed as an effective antioxidant during oxidative stress.

Food borne yeasts as DNA-bioprotective agents against model genotoxins.

Yeasts isolated from Italian beverages and foods (wine and cheeses) were identified as Saccharomyces cerevisiae and Debaryomyces hansenii by sequencing the D1/D2 domain of the 26S rRNA gene and differentiated, at strain level, by microsatellite PCR fingerprinting and RAPD-PCR. All the strains showed antioxidant activity, as demonstrated by their ability to scavenge the free radical diphenyl-1-picrylhydrazyl (DPPH). Furthermore, tested strains revealed high in vitro inhibitory activity against two model genotoxins, 4-nitroquinoline-1-oxide (4-NQO) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), as showed by short-term methods with different target cells: SOS-Chromotest with Escherichia coli PQ37 and Comet assay with HT-29 enterocytes. High inhibitory activity towards 4-NQO was associated with cell viability, while heat-inactivated cells showed a reduced antigenotoxic capability. Surprisingly, high inhibition of MNNG genotoxicity was observed even with heat-treated cells. Moreover, the strains able to inhibit the genotoxins induced some changes in the spectroscopic properties of the original compound. This result perfectly agrees with the information obtained by the two bioassays. Interestingly, strains characterized for antioxidant and antigenotoxic properties, also presented acid-bile tolerance, indicating that food autochthonous yeasts could be expected to reach gut in viable form and thus prevent genotoxin DNA damage in situ.

Chromosomal aberration, micronucleus and Comet assays on peripheral blood lymphocytes of leprosy patients undergoing multidrug treatment. (Mutagenesis, 17, 309-312, 2002)

To evaluate the genetic damage in leprosy patients, we carried out the alkaline Comet assay and chromosomal aberration (CA) and micronucleus (MN) tests in peripheral blood lymphocytes of 50 leprosy patients receiving multidrug treatment (MDT) and 50 healthy individuals. The Comet assay showed statistically higher mean values for length to width ratios of DNA mass (P < 0.01) and for mean frequencies of tailed cells (P < 0.001) in cells of leprosy patients than in those of controls. Similarly, the mean frequencies of micronucleated cells (per 1000 cytochalasin B-induced binucleated cells) were significantly greater (P < 0.001) in leprosy patients (19.92 +/- 2.564) than in controls (1.6 +/- 0.231). A statistically significant 10-fold increase in the frequency of CAs (11.16 +/- 0.411) was observed in leprosy patients compared with controls (1.28 +/- 0.242). In multiple regression analyses, when patients and controls were considered together, disease factor alone significantly influenced the genotoxicity markers. In the control group, age and alcohol consumption significantly influenced MN and length to width ratios and CA frequency, respectively. However, in MDT-treated leprosy patients none of the other confounding factors (sex, age, smoking and alcohol drinking) significantly affected the extent of genetic damage.

Chromosomal aberration, micronucleus and Comet assays on peripheral blood lymphocytes of leprosy patients undergoing multidrug treatment.

To evaluate the genetic damage in leprosy patients, we carried out the alkaline Comet assay and chromosomal aberration (CA) and micronucleus (MN) tests in peripheral blood lymphocytes of 50 leprosy patients receiving multidrug treatment (MDT) and 50 healthy individuals. The Comet assay showed statistically higher mean values for length to width ratios of DNA mass (P < 0.01) and for mean frequencies of tailed cells (P < 0.001) in cells of leprosy patients than in those of controls. Similarly, the mean frequencies of micronucleated cells (per 1000 cytochalasin B-induced binucleated cells) were significantly greater (P < 0.001) in leprosy patients (19.92 +/- 2.564) than in controls (1.6 +/- 0.231). A statistically significant 10-fold increase in the frequency of CAs (11.16 +/- 0.411) was observed in leprosy patients compared with controls (1.28 +/- 0.242). In multiple regression analyses, when patients and controls were considered together, disease factor alone significantly influenced the genotoxicity markers. In the control group, age and alcohol consumption significantly influenced MN and length to width ratios and CA frequency, respectively. However, in MDT-treated leprosy patients none of the other confounding factors (sex, age, smoking and alcohol drinking) significantly affected the extent of genetic damage.

Chromosomal aberration, micronucleus and Comet assays on peripheral blood lymphocytes of leprosy patients undergoing multidrug treatment

To evaluate the genetic damage in leprosy patients, we carried out the alkaline Comet assay and chromosomal aberration (CA) and micronucleus (MN) tests in peripheral blood lymphocytes of 50 leprosy patients receiving multidrug treatment (MDT) and 50 healthy individuals. The Comet assay showed statistically higher mean values for length to width ratios of DNA mass (P < 0.01) and for mean frequencies of tailed cells (P < 0.001) in cells of leprosy patients than in those of controls. Similarly, the mean frequencies of micronucleated cells (per 1000 cytochalasin B-induced binucleated cells) were significantly greater (P < 0.001) in leprosy patients (19.92 +/- 2.564) than in controls (1.6 +/- 0.231). A statistically significant 10-fold increase in the frequency of CAs (11.16 +/- 0.411) was observed in leprosy patients compared with controls (1.28 +/- 0.242). In multiple regression analyses, when patients and controls were considered together, disease factor alone significantly influenced the genotoxicity markers. In the control group, age and alcohol consumption significantly influenced MN and length to width ratios and CA frequency, respectively. However, in MDT-treated leprosy patients none of the other confounding factors (sex, age, smoking and alcohol drinking) significantly affected the extent of genetic damage.