The toxic effects of benzo[α]pyrene （B[α]P） at different concentrations （0.1, 0.5, 1, 2.5 and 7.5 μgL^-1） on scallop （Chlamys farreri） immune system were studied. The results showed that B[α]P had significan...The toxic effects of benzo[α]pyrene （B[α]P） at different concentrations （0.1, 0.5, 1, 2.5 and 7.5 μgL^-1） on scallop （Chlamys farreri） immune system were studied. The results showed that B[α]P had significant toxic effects on the haemocyte counts, neutral red uptake, phagocytosis, bacteriolytic and antibacterial activity （P〈0.05）, while the seawater control and acetone control had no significant differences. The haemocyte counts, neutral red uptake, phagocytosis and bacteriolytic activity in all B[α]P treatment groups as well as antibacterial activity in groups of 0.5, 1, 2.5 and 7.5 μgL^-1·B[α]P decreased significantly （P〈0.05）. Some of these indices tended to be stable on the sixth day and others on the ninth day, and the indices showed clear time- and concentration-response to B[α]E Bactenolytic activity in 0.1 μgL^-1 B[α]P treatment group and antibacterial activity in 0.1 ggLl and 0.5 μgL^-1 B[α]P treatment groups increased at the beginning of exposure and reached their peaks on day 1 and day 6, respectively. Following that, both activities decreased gradually and became stable after day 9. When all the indices reached stability, they were significantly lower than those in control group （P〈0.05）, except for antibacterial activity in 0.1 μgLl B[α]P treatment group （P〉0.05）. Thus, B[α]P has evident toxic effects on scallop immune system, which supports the view that a relationship exists between pollution and lmmunomodulation in aquatic organisms.展开更多
Objective To study the benzo(a)pyrene(B[a]P)-induced mRNA expression of aromatic hydrocarbon receptor(AHR)and cytochrome P4501A1(CYP1A1)genes in rat liver.Methods Rats were injected intraperitoneally with 5,10 and 15m...Objective To study the benzo(a)pyrene(B[a]P)-induced mRNA expression of aromatic hydrocarbon receptor(AHR)and cytochrome P4501A1(CYP1A1)genes in rat liver.Methods Rats were injected intraperitoneally with 5,10 and 15mg/kg of B[a]P.The total RNAs were extracted from rat livers by RNA purification kit,and the mRNA expression of AHR and CYP1A1 genes was determined by reverse transcription polymerase chain reaction(RT-PCR).β-actin was used as the internal control.The mRNA expression of both AHR and CYP1A1 genes was measured at indicated time points(24,48 and 72h)after B[a]P treatment at three different concentrations(5,10 and 15mg/kg).Results The mRNA expression of AHR gene increased in a time-dependent manner at the concentration of 10mg/kg but not at 5 and 15mg/kg of B[a]P.The mRNA expression of CYP1A1 gene differed significantly at 48h and 24h in rat livers treated with 10 and 15mg/kg dosage of B[a]P.The mRNA expression of AHR and CYP1A1 genes increased with B[a]P treatment in a concentration-dependent manner.The time-dependent increase in mRNA expression was shown by AHR but not by CYP1A1 gene with B[a]P(10mg/kg)treatment.Conclusion This study demonstrates that toxic B[a]P increases the mRNA expression of both AHR and CYP1A1 genes in vivo,suggesting that B[a]P may play a role in cancer genesis by this way.展开更多
Objective To study the modulatory effect of distillate of Ocimum sanctum （traditionally known as Tulsi） leaf extract （DTLE） on genotoxicants. Methods In the present investigation, we studied the antigenotoxic and ...Objective To study the modulatory effect of distillate of Ocimum sanctum （traditionally known as Tulsi） leaf extract （DTLE） on genotoxicants. Methods 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 μL/mL, 100 μL/mL, and 200 μL/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 μmol/L） for DNA strand break, chromosomal aberration and 0.51 μmol/L for micronucleus assay; Potassium dichromate （Cr^＋6） 600 μmol/L for DNA strand break and 5 μmol/L for chromosomal aberration and micronucleus assay; Benzo[a]pyrene （30 μmol/L） for chromosomal aberration and 40 μmol/L for micronucleus assay. The active ingredients present in the distillate of Tulsi leaf extract were identified by HPLC and LC-MS. Results 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 μL/mL, 100 μL/mL, and 200 μL/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. Conclusion 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.展开更多
基金supported by Science and Technology Development Project of Qingdao,China (06-2-2-21-jch)
文摘The toxic effects of benzo[α]pyrene （B[α]P） at different concentrations （0.1, 0.5, 1, 2.5 and 7.5 μgL^-1） on scallop （Chlamys farreri） immune system were studied. The results showed that B[α]P had significant toxic effects on the haemocyte counts, neutral red uptake, phagocytosis, bacteriolytic and antibacterial activity （P〈0.05）, while the seawater control and acetone control had no significant differences. The haemocyte counts, neutral red uptake, phagocytosis and bacteriolytic activity in all B[α]P treatment groups as well as antibacterial activity in groups of 0.5, 1, 2.5 and 7.5 μgL^-1·B[α]P decreased significantly （P〈0.05）. Some of these indices tended to be stable on the sixth day and others on the ninth day, and the indices showed clear time- and concentration-response to B[α]E Bactenolytic activity in 0.1 μgL^-1 B[α]P treatment group and antibacterial activity in 0.1 ggLl and 0.5 μgL^-1 B[α]P treatment groups increased at the beginning of exposure and reached their peaks on day 1 and day 6, respectively. Following that, both activities decreased gradually and became stable after day 9. When all the indices reached stability, they were significantly lower than those in control group （P〈0.05）, except for antibacterial activity in 0.1 μgLl B[α]P treatment group （P〉0.05）. Thus, B[α]P has evident toxic effects on scallop immune system, which supports the view that a relationship exists between pollution and lmmunomodulation in aquatic organisms.
基金supported by the National Natural Science Foundation of China(No.30660214)the Natural Science Foundation of Inner Mongolia Autonomous Region(No.200607010907)Doctor Initializing Fund Application of Inner Mongolia Medical College(No.2005BQ001)
文摘Objective To study the benzo(a)pyrene(B[a]P)-induced mRNA expression of aromatic hydrocarbon receptor(AHR)and cytochrome P4501A1(CYP1A1)genes in rat liver.Methods Rats were injected intraperitoneally with 5,10 and 15mg/kg of B[a]P.The total RNAs were extracted from rat livers by RNA purification kit,and the mRNA expression of AHR and CYP1A1 genes was determined by reverse transcription polymerase chain reaction(RT-PCR).β-actin was used as the internal control.The mRNA expression of both AHR and CYP1A1 genes was measured at indicated time points(24,48 and 72h)after B[a]P treatment at three different concentrations(5,10 and 15mg/kg).Results The mRNA expression of AHR gene increased in a time-dependent manner at the concentration of 10mg/kg but not at 5 and 15mg/kg of B[a]P.The mRNA expression of CYP1A1 gene differed significantly at 48h and 24h in rat livers treated with 10 and 15mg/kg dosage of B[a]P.The mRNA expression of AHR and CYP1A1 genes increased with B[a]P treatment in a concentration-dependent manner.The time-dependent increase in mRNA expression was shown by AHR but not by CYP1A1 gene with B[a]P(10mg/kg)treatment.Conclusion This study demonstrates that toxic B[a]P increases the mRNA expression of both AHR and CYP1A1 genes in vivo,suggesting that B[a]P may play a role in cancer genesis by this way.
文摘Objective To study the modulatory effect of distillate of Ocimum sanctum （traditionally known as Tulsi） leaf extract （DTLE） on genotoxicants. Methods 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 μL/mL, 100 μL/mL, and 200 μL/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 μmol/L） for DNA strand break, chromosomal aberration and 0.51 μmol/L for micronucleus assay; Potassium dichromate （Cr^＋6） 600 μmol/L for DNA strand break and 5 μmol/L for chromosomal aberration and micronucleus assay; Benzo[a]pyrene （30 μmol/L） for chromosomal aberration and 40 μmol/L for micronucleus assay. The active ingredients present in the distillate of Tulsi leaf extract were identified by HPLC and LC-MS. Results 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 μL/mL, 100 μL/mL, and 200 μL/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. Conclusion 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.
