Screening the partial coding region of metallothionein isoform-2 gene in Zebu cattle

Metallothionein [MT] is important because it binds tightly to heavy metals to decrease their toxicity. DNA was isolated from 30 toxic metal exposed and 30 toxic metal unexposed Zebu cows. The amplified metallothionein isoform-2 [MT-2] PCR product [489 bp] was further used for PCR-RFLP and DNA sequencing. MT-2 TaqI PCR-RFLP revealed homozygous genotype [AA] except for the E23 animal [AB]. The genotype frequency of AA and AB [E23] genotypes in the exposed groups was 0.967 and 0.033 respectively. DNA sequencing was carried out for the toxic metal exposed sample [E23] and the control group sample [C13]. Blast comparisons of the sequences were then aligned against a nucleotide database which revealed 150 nucleotide substitutions consisting of 70 transitions and around 80 transversions. DNA sequencing followed by PCR-RFLP for MT-2 revealed a higher number of nucleotide substitutions [150] for the AB genotype of E23 as compared to the AA genotype [38] of E21. The proportions of transversion mutations in the AB genotype were higher as compared to the MT-2 AA genotype. DNA sequencing was carried out based on random sampling for E21 and C13. Alignment analysis of the E21 and C13 sample revealed 38 nucleotide substitutions consisting of equal numbers of transition and transversion. BLAST analysis of the identified partial sequence revealed 89% identity with Bos taurus, 85% identity with sheep, 98% identity with buffalos and 100% identity with goat MT-2 sequences. Overall findings of the present study revealed DNA sequence variation in the coding region of the MT-2 gene of Zebu cattle which can be utilised to characterize and explore markers for heavy metal homeostasis in Zebu cattle

Modulatory effect of distillate of Ocimum sanctum leaf extract (Tulsi) on human lymphocytes against genotoxicants / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the modulatory effect of distillate of Ocimum sanctum (traditionally known as Tulsi) leaf extract (DTLE) on genotoxicants.</p><p><b>METHODS</b>In 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.</p><p><b>RESULTS</b>Mitomycin 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.</p><p><b>CONCLUSION</b>Distillate 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.</p>

Anticlastogenic effect of redistilled cow's urine distillate in human peripheral lymphocytes challenged with manganese dioxide and hexavalent chromium / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the anticlastogenic effect of redistilled cow's urine distillate (RCUD) in human peripheral lymphocytes (HLC) challenged with manganese dioxide and hexavalent chromium.</p><p><b>METHODS</b>The anticlastogenic activity of redistilled cow's urine distillate was studied in human polymorphonuclear leukocytes (HPNLs) and human peripheral lymphocytes in vitro challenged with manganese dioxide and hexavalent chromium as established genotoxicants and clastogens which could cause induction of DNA strand break, chromosomal aberration and micronucleus. Three different levels of RCUD: 1 microL/mL, 50 microL/mL and 100 microL/mL, were used in the study.</p><p><b>RESULTS</b>Manganese dioxide and hexavalent chromium caused statistically significant DNA strand break, chromosomal aberration and micronucleus formation, which could be protected by redistilled cow's urine distillate.</p><p><b>CONCLUSION</b>The redistilled cow's urine distillate posseses strong antigenotoxic and anticlastogenic properties against HPNLs and HLC treated with Cr+6 and MnO2. This property is mainly due to the antioxidants present in RCUD.</p>