A stable dark variant separated from photobacterium phosphoreum (A2) was fixed in agar-gel membrane and immobilized onto an exposed end of a fiber-optic linked with bioluminometer. The variant could emit a luminescent signal in the presence of genotoxic agents, such as Mitomycin C (MC). The performance of this whole-cell optical fiber sensor system was examined as a function of several parameters, including gel probe thickness, bacterial cell density, and diameter of the fiber-optic core and working temperature. An optimal response to a model genotoxicant, Mitomycin C, was achieved with agar-bacterial gel membrane: the thickness of gel membrane was about 5 mm; the cell density of bacteria in gel membrane was about 2.0 x 10(7)/ml; the diameter of fiber-optic core was 5.0 mm; the working temperature was 25 degrees C. Under these optimized conditions, the response time was less than 10 h to Mitomycin C, with a lower detection threshold of 0.1 mg/L.
Biosensing Techniques ; Chemiluminescent Measurements ; Fiber Optics ; Luminescent Proteins/*genetics ; Mitomycin/*pharmacology ; Mitomycin/toxicity ; Photobacterium/*genetics ; Transcription, Genetic/drug effects ; Variation (Genetics)

OBJECTIVETo observe the influence of 1.8 GHz microwave (MW) specific absorption rate (SAR, 3 W/kg) on human lymphocytes DNA damage induced by 4 chemical mutagens [mitomycin C (MMC), bleomycin (BLM), methyl methanesulfonate (MMS), and 4-nitroquinoline 1-oxide (4NQO)].

METHODSComet assay in vitro was used to detect human lymphocyte DNA damage induced by 1.8 GHz MW, 4 chemical mutagens, and MW plus 4 chemicals 0 h and 21 h respectively after exposure. The time exposed to MW or mutagens was 2 h or 3 h respectively. The results were showed by tail length (TL) and tail moment (TM).

RESULTSThe difference of DNA damage between MW group and control group was not statistically significant (P > 0.05). DNA damages in MW plus MMC groups and MW plus 4NQO groups were significantly greater than those in the corresponding concentrations of MMC groups and 4NQO groups (P < 0.01 or P < 0.05). However, MW did not enhance DNA damage induced by MMS and BLM (P > 0.05).

CONCLUSIONExposure to 1.8 GHz (SAR, 3 W/kg) microwave may not induce human lymphocyte DNA damage, but could enhance DNA damage induced by MMC and 4NQO.

4-Nitroquinoline-1-oxide ; toxicity ; Adult ; Bleomycin ; toxicity ; Cells, Cultured ; Comet Assay ; DNA ; drug effects ; DNA Damage ; Humans ; Lymphocytes ; drug effects ; radiation effects ; Male ; Methyl Methanesulfonate ; toxicity ; Microwaves ; adverse effects ; Mitomycin ; toxicity ; Mutagens ; toxicity

OBJECTIVETo study the modulatory effect of distillate of Ocimum sanctum (traditionally known as Tulsi) leaf extract (DTLE) on genotoxicants.

METHODSIn the present investigation, we studied the antigenotoxic and anticlastogenic effect of distillate of Tulsi leaf extract on (i) human polymorphonuclear leukocytes by evaluating the DNA strand break without metabolic activation against mitomycin C (MMC) and hexavalent chromium (Cr+6) and (ii) human peripheral lymphocytes (in vitro) with or without metabolic activation against mitomycin C (MMC), hexavalent chromium (Cr+6) and B[a]P by evaluating chromosomal aberration (CA) and micronucleus assay (MN). Three different doses of DTLE, 50 microL/mL, 100 microL/mL, and 200 microL/mL were selected on the basis of cytotoxicity assay and used for studying DNA strand break, chromosomal aberration and micronucleus emergence. The following positive controls were used for inducing genotoxicity and clastogenicity: MMC (0.29 micromol/L) for DNA strand break, chromosomal aberration and 0.51 micromol/L for micronucleus assay; Potassium dichromate (Cr+6) 600 micromol/L for DNA strand break and 5 micromol/L for chromosomal aberration and micronucleus assay; Benzo[a]pyrene (30 micromol/L) for chromosomal aberration and 40 micromol/L for micronucleus assay. The active ingredients present in the distillate of Tulsi leaf extract were identified by HPLC and LC-MS.

RESULTSMitomycin C (MMC) and hexavalent chromium (Cr+6) induced statistically significant DNA strand break of respectively 69% and 71% (P<0.001) as revealed by fluorometric analysis of DNA unwinding. Furthermore, the damage could be protected with DTLE (50 microL/mL, 100 microL/mL, and 200 microL/mL) on simultaneous treatment. Chromosomal aberration and micronucleus formation induced by MMC, Cr+6 and B[a]P were significantly protected (P<0.001) by DTLE with and without metabolic activation.

CONCLUSIONDistillate of Tulsi leaf extract possesses antioxidants contributed mainly by eugenol, luteolin and apigenin as identified by LC-MS. These active ingredients may have the protective effect against genotoxicants.

Adult ; Benzopyrenes ; toxicity ; Cell Survival ; drug effects ; Chromium ; toxicity ; Chromosome Aberrations ; drug effects ; DNA ; metabolism ; DNA Damage ; drug effects ; Humans ; Lymphocytes ; drug effects ; Mass Spectrometry ; Mitomycin ; toxicity ; Mutagens ; toxicity ; Ocimum ; chemistry ; Plant Extracts ; pharmacology ; Plant Leaves ; chemistry

OBJECTIVETo study that low-intensity microwave whether or not enhances the genotoxic effects of mitomycin C(MMC) on human lymphocytes.

METHODSSingle strand DNA breaks and chromosomal aberrations were measured by comet assay and cytokinesis-blocked micronucleus(CBMN) test in vitro when human lymphocytes were exposed to 2,450-MHz microwave (5.0 mW/cm2) alone and in combination with mitomycin C.

RESULTSIn the comet assay, the average comet lengths of microwave group[(29.1 +/- 8.1) micron in male and (25.9 +/- 7.5) micron in female] were not significantly different from those of control groups [(26.3 +/- 6.6) and (24.1 +/- 4.3) micron respectively] (P > 0.05). The average comet lengths of MMC group(0.0125, 0.0250, 0.0500, 0.1000 microgram/ml) were significantly longer than those of control groups (P < 0.01) and were increased with the dose of MMC. The average comet lengths of microwave combined with MMC (MW + MMC) also were increased with the doses of MMC and were significantly longer than those of control groups (P < 0.01). When MMC was > or = 0.0250 microgram/ml, microwave and MMC synergistically increased the single strand DNA breaks. In the micronucleus test, the average micronucleus rates of microwave groups were not higher than those of control groups (P > 0.05). The average micronucleus rates of MMC groups and MW + MMC groups were significantly higher than those of control groups (P < 0.01) when MMC was > or = 0.0500 microgram/ml. The average micronucleus rates of MW + MMC groups seemed higher than those of corresponding MMC groups, however the difference was not significant (P > 0.05).

CONCLUSIONLow-intensity(2,450-MHz) microwave did not induce DNA and chromosome damages on human lymphocytes, but enhanced the effects of DNA breaks induced by MMC.

Chromosome Aberrations ; Comet Assay ; DNA Breaks, Single-Stranded ; Female ; Humans ; Lymphocytes ; drug effects ; radiation effects ; ultrastructure ; Male ; Micronuclei, Chromosome-Defective ; Microwaves ; adverse effects ; Mitomycin ; toxicity

A stable dark variant separated from photobacterium phosphoreum (A2) was fixed in agar-gel membrane and immobilized onto an exposed end of a fiber-optic linked with bioluminometer. The variant could emit a luminescent signal in the presence of genotoxic agents, such as Mitomycin C (MC). The performance of this whole-cell optical fiber sensor system was examined as a function of several parameters, including gel probe thickness, bacterial cell density, and diameter of the fiber-optic core and working temperature. An optimal response to a model genotoxicant, Mitomycin C, was achieved with agar-bacterial gel membrane: the thickness of gel membrane was about 5 mm; the cell density of bacteria in gel membrane was about 2.0 x 10(7)/ml; the diameter of fiber-optic core was 5.0 mm; the working temperature was 25 degrees C. Under these optimized conditions, the response time was less than 10 h to Mitomycin C, with a lower detection threshold of 0.1 mg/L.
Biosensing Techniques ; Fiber Optic Technology ; Genetic Variation ; Luminescent Measurements ; Luminescent Proteins ; genetics ; Mitomycin ; pharmacology ; toxicity ; Optical Fibers ; Photobacterium ; genetics ; Transcription, Genetic ; drug effects