Genetic susceptibility of DNA damage induced by vinyl chloride monomer exposure / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the association between DNA damage induced by vinyl chloride monomer (VCM) and polymorphisms of DNA repair genes and xenobiotic metabolism genes of VCM.</p><p><b>METHODS</b>Comet assay was employed to detect DNA damage. Based on the status of DNA damage, the VCM exposure workers were divided into two groups: DNA damage group (75) and control group (75). Case-control design was used to investigate the association between the genetic polymorphisms and DNA damage induced by VCM. Genotypes of XRCC1 (Arg194Trp, Arg280His and Arg399Gln), XPD (Ile199Met, Asp312Asn and Lys751Gln) and CYP2E1 were identified by the PCR-RFLP. PCR assay was used to detect positive and null genotype of GSTT1 and GSTM1.</p><p><b>RESULTS</b>Univariate analysis showed that the CYP2E1 c1c2/c2c2 and XPD751 Lys/Gln and Gln/Gln genotypes were significantly associated with the increased levels of DNA damage, XRCCI 339 Arg/Gln and Gln/Gln genotypes were significantly associated with the decreased levels of DNA damage (P < 0.01, P < 0.05, respectively). Logistic regression analysis showed that there was significant association between the genotypes of XRCC1 194, XRCC1 399, XPD 751, CYP2E1 and DNA damages. A prominent risk decreasing of DNA damage was observed for those individuals possessing XRCC1 399Arg/Gln + Gln/Gln genotypes (OR: 0.35, 95%CI: 0.12 approximately 1.01, respectively); The results also showed that there were significant associations between CYP2E1 c1c2/c2c2 and DNA damage both in high and low VCM-exposed groups (OR: 2.57, 95%CI: 1.01 approximately 6.59 and OR: 2.57, 95%CI: 0.99 approximately 6.87).</p><p><b>CONCLUSION</b>Cumulative exposure dose and genotypes of XRCC1 194, XRCC1 399, XPD 751 and CYP2E1 may modulate the DNA damage induced by VCM exposure.</p>

Progress in research on anthocyanidin components in Chinese traditional medicine against neoplasm / 中国中药杂志

Anthocyanidin is a type of the plant pigments distributed very extensively, in traditional Chinese herbal products as well. In this review was introduced the recently progress in the anti-cancer trials of anthocyanidins, including the anti-oxidation, the prevention of DNA strand scission, stimulation of cell differentiation, induction of cell apoptosis, interference of regulation of cell proliferation, anti-angiogenic property etc, and the research of anti-cancer mechanisms of anthocyanidin and its structure-activity relationship, pointed the foreground of research and development of anti-cancer medicine.

DNA damages of liver cells and expressions of DNA damage repair genes in rats exposed to vinyl chloride monomer / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study DNA damages of liver cells in rats exposed to vinyl chloride monomer (VCM), and the expressions of DNA damage repair enzymes including O(6)-methyl guanine-DNA methyl transferase (MGMT), X-ray repair cross-complementing group 1 (XRCC1) and X-ray repair cross-complementing group 3 (XRCC3); and to explore the repair mechanism of DNA damage induced by VCM.</p><p><b>METHODS</b>Rats were exposed to VCM by intraperitoneal injection. DNA damages were detected by single cell gel electrophoresis (comet assay). The expressions of DNA damage repair enzymes were measured by immunohistochemical methods.</p><p><b>RESULTS</b>The percentages of comet cells in low, moderate, and high dose groups (11.75%, 12.38%, and 17.63%, respectively) were greater than that of control (5.67%). The latter two groups were significantly different from that of control (P < 0.05, P < 0.01). The expressions of MGMT and XRCC1 decreased, and XRCC3 increased with the dose of VCM increased. DNA damage was correlated with the expression of XRCC3 (r = 0.438, P = 0.067).</p><p><b>CONCLUSION</b>VCM can cause DNA damage of liver cells with dose-response relationship. DNA damage repair enzymes take part in the repairing of DNA damage induced by VCM.</p>

STUDY ON THE ASTAXAN TH IN-PRODUCING YEAST PHAFFIA RHODOZYMA MUTATED BY NTG / 微生物学通报

astaxanthin is an effective antioxidant and natural pigment which has wide application. Phaffia rhodozyma is a good source of astaxantin, but wild strain has limited use in industry because of low production level of astaxanthin. Several mutants of Phaffia rhodozyma were obtained by exerting mutagen N-methyl-N-nitro-N -nitrosoguanidine. The growth curve suggested that pigments were mainly produced in the middle and latter periods of log phase. The pigments were extracted from Phaffia rhodozyma and analysed by esterification, thin layer chromatography and absorption spectrometry. It was proved that astaxanthin, astaxanthin diester and ?-carotene were the major components of the pigments produced by Phaffia rhodozyma. We also studied the pigments producing phase of Phaffia rhodozyma. and founded that astaxanthin was stable to light under butylated hydroxytoluene coexistance.