• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.287-290
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• 2014

Objective: Genetic variation is considered to strongly impact on detoxification of carcinogens and therefore is related to cancer risk. However, findings for the null genotypes of GSTT1 and GSTM1 have not always been consistent. Therefore the present meta-analysis was conducted. Methods: We accessed the reported study at different research areas and used various databases, including PubMed and Wanfang Med Onlion from 1990 to May 1st 2013. We calculated the odds ratio (OR), 95% confidence interval (CI) and P value for oral cancer by using Review Manager 5.1 and STATE 12. Results: We found that there was no increased oral cancer risk among subjects carrying GSTM1 and GSTT1 null genotype (OR=1.35, 95%CI=0.68-2.68, P=0.39) and (OR=1.41, 95%CI=0.72-2.77, P=0.31) in the Chinese population. In contrast, in studies in India a significant correlation between GSTM1 null genotype and oral cancer was observed (OR=1.59, 95%CI=1.20-2.11, P=0.001), but not in GSTT1 (OR=1.21, 95% CI=0.84-1.74, P=0.31). Conclusion: We discovered that GSTM1 deletion polymorphism had a significant effect on the susceptibility of oral cancer in the Indian population.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7215-7219
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• 2013

Background: Variation in metabolic genes is regarded as an important factor in processes leading to cancer. However, the effect of GSTT1 null genotype is divergent in the form of lung cancer. Methods: Studies were conducted at different research databases from 1990 to 2013 and the total odds ratio (OR) and 95% confidence interval (CI) were calculated for lung cancer. Review Manager 5.2 and STATE 12 are employed. Results: Total OR value is calculated from 17 articles with 2,118 cases and 2,915 controls. We discovered no significant increase in lung cancer risk among subjects carrying GSTT1 null genotype [OR = 1.15; 95% CI 0.97-1.36] in this meta-analysis. Conclusion: The GSTT1 deletion polymorphism does not have a significant effect on the susceptibility to lung cancer overall in China.

• Journal of Ginseng Research
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• v.17 no.2
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• pp.123-126
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• 1993

Effects of chronic administration of ginseng extracts (30 or 150 mg/kg/day for 52 days, p.o.) to mice on the activities of DT-diaphorase and glutathione S-transferase (GST) in the liver and the brain were studied. The DT-diaphorase activity in the liver was increased over 2-fold at the dose of both 30 and 150 mg/kg/day, while there was no change in the activity of the enzyme in the brain. The GST activity in the liver was increased in a dose-dependent fashion up to 142% of the control value at the dose of 150 mg/kg/day. while there was no change in the activity of the enzyme in the brain. The ginseng-induced increase in the activities of these hepatic phase II drug-metabolizing enzymes which are involved in the detoxification of carcinogens, is suggested to underlie, at least in part, the anticarcinogenic activity of Panax ginseng.

• Mycobiology
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• v.30 no.4
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• pp.213-218
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• 2002

The induction of NAD(P)H: quinone oxidoreductase(QR), glutathione S-transferase(GST), and glutathione(GSH) levels in hepa1c1c7 cells(murine hepatoma) by waxy brown rice cultured with Phellinus igniarius to induce anticarcinogenic enzymes were measured. In addition, the inhibition of polyamines metabolism was tested with the growth of Acanthamoeba castellanii. The result shows that QR, GST activities, and GSH levels of experimental animals were increased much more by feeding the methanol extract of waxy brown rice cultured with Phellinus igniarius than those of the rats received the ethanol of uncultured brown rice. The growth of A. castellanii was inhibited mostly at 40 mg/3 ml concentration of methanol extract of waxy brown rice cultured with P. gniarius. The results suggested that waxy brown rice cultured with P. igniarius possess chemopreventive activity by inducing anticarcinogenic enzymes and inhibiting polyamine metabolism.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1697-1701
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• 2013

Background: Studies of associations between genetic polymorphism of glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) with risk of nasopharyngeal cancer (NPC) have generated conflicting results. Thus, a meta-analysis was performed to clarify the effects of GSTM1 and GSTT1 polymorphisms on the risk of developing NPC. Materials and Methods: A literature search in two electronic databases namely PubMed and EMBASE up to December 2012 was conducted and eligible papers were finally selected based on the inclusion and exclusion criteria. The pooled odds ratio (OR) and presence of heterogeneity and publication bias in those studies were evaluated. Results: A total of 9 studies concerning nasopharyngeal cancer were evaluated. Analyses of all relevant studies showed increased NPC risk to be significantly associated with the null genotypes of GSTMI (OR=1.43, 95%CI 1.24-1.66) and GSTT1 (OR=1.28, 95%CI=1.09-1.51). In addition, evidence of publication bias was detected among the studies on GSTM1 polymorphism. Conclusions: This meta-analysis demonstrated the GSTM1 and GSTT1 null genotypes are associated with an increased risk of NPC.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1364-1368
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• 1999

This study was carried out to investigate the inhibiton effects of Coprinus comatus ethanol extract of edible mushroom on liver damage in benzo(a)pyrene (B(a)P) treated mice. The activities of serum aminotransferase, cytochrome P 450 and hepatic content of lipid peroxide after B(a)P treatment were increased than those of control, but those levels were significantly decreased by the treatment of Coprinus comatus ethanol extract. Whereas, the hepatic glutathione content and glutathione S transferase activity were decreased by B(a)P treatment than those of control, but those were increased by the treatment of Coprinus comatus ethanol extract. Also the activities of superoxide dismutase, catalase and glutathione peroxidase after B(a)P treatment were markedly increased than those of control, but those levels were decreased by the treatment of Coprinus comatus ethanol extract. These results suggest that Coprinus comatus ethanol extract have a protective effect on liver damage by benzo(a)pyrene through the mechanisms of decreasing lipid peroxide and activities of free radical generating enzymes.

• BMB Reports
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• v.38 no.5
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• pp.563-570
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• 2005

Tamoxifen citrate (TAM), is widely used for treatment of breast cancer. It showed a degree of hepatic carcinogenesis. The purpose of this study was to elucidate the antioxidant capacity of green tea (Camellia sinensis) extract (GTE) against TAM-induced liver injury. A model of liver injury in female rats was done by intraperitoneal injection of TAM in a dose of $45\;mg\;Kg^{-1}\;day^{-1}$, i.p. for 7 successive days. GTE in the concentration of 1.5%, was orally administered 4 days prior and 14 days after TAM-intoxication as a sole source of drinking water. The antioxidant flavonoid; epicatechin (a component of green tea) was not detectable in liver and blood of rats in either normal control or TAM-intoxicated group, however, TAM intoxication resulted in a significant decrease of its level in liver homogenate of tamoxifen-intoxicated rats. The model of TAM-intoxication elicited significant declines in the antioxidant enzymes (glutathione-S-transferase,glutathione peroxidase, superoxide dismutase and catalase) and reduced glutathione concomitant with significant elevations transaminase) levels. The oral administration of 1.5% GTE to TAM-intoxicated rats, produced significant increments in the antioxidant enzymes and reduced glutathione concomitant with significant decrements in TBARS and liver transaminases levels. The data obtained from this study speculated that 1.5% GTE has the capacity to scavenge free radical and can protect against oxidative stress induced by TAM intoxication. Supplementation of GTE could be useful in alleviating tamoxifen-induced liver injury in rats.

• BMB Reports
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• v.35 no.6
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• pp.615-622
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• 2002

The purpose of this study was to determine the effects of dietary garlic powder on diethylnitrosamine (DEN)-induced hepatocarcinogenesis and cytochrome P450 (CYP) enzymes in weaning male Sprague-Dawley rats by using the medium-term bioassay system of Ito et al. The rats were fed diets that contained 0, 0.5, 2.0 or 5.0% garlic powder for 8 weeks, beginning the diets with the intraperitoneal (i.p.) injection of DEN. The areas of placental glutathione S-transferase (GST-P) positive foci, an effective marker for DEN-initiated lesions, were significantly decreased in the rats that were fed garlic-powder diets; the numbers were significantly decreased only in the 2.0 and 5.0% garlic-powder diets. The p-nitrophenol hydroxylase (PNPH) activities and protein levels of CYP 2E1 in the hepatic microsomes of the rats that were fed the 2.0 and 5.0% garlic powder diet were much lower than those of the basal-diet groups. Pentoxyresorufin O-dealkylase (PROD) activity and CYP 2B1 protein level were not influenced by the garlic-powder diets and carcinogen treatment. Therefore, the suppression of CYP 2E1 by garlic in the diet might influence the formation of preneoplastic foci during hepatocarcinogenesis in rats that are initiated with DEN.

• Korean Journal of Pharmacognosy
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• v.34 no.4 s.135
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• pp.297-302
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• 2003

Cnidii Rhizoma water extract (CRW) was tested for liver cancer chemopreventive potential by measuring the inhibition of phase I enzyme and benzo[a]pyrene-DNA adduct formation and induction of phase II detoxification enzymes. There was 17.0% inhibition in the activity of cytochrome P450 1A1 enzyme with the treatment of 150 mg/ml CRW. At concentration of 30 mg/ml CRW, the binding of $[^3H]B[a]P$ metablites to DNA of NCTC-clone 1469 cell was inhibited by 33.3%. CRW was potent inducer of quinone reductase (QR) and glutathione S-transferase (GST) activities in cultured murine hepatoma Hepalc1c7 cells. However, hepatic glutathione (GSH) level was not influenced by CRW. These findings suggest that CRW has chemopreventive potential of liver cancer by inhibiting cytochrome P450 1A1 activity and benzo[a]pyrene-DNA adduct formation and inducing QR and GST activities.

• YAKHAK HOEJI
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• v.37 no.5
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• pp.538-543
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• 1993

Effects of betaine, a major component of Lycii Fructus, on carbon tetrachloride intoxicated rats were evaluated. Histological studies showed that betaine had improved the typical necrosis around centrilobular area in liver tissue due to the carbon tetrachloride intoxication. Betaine, whether it was administrated simultaneously or prior to carbon tetrachloride, prevented or retarded the elevation of liver-weight/body-weight ratio due to the carbon tetrachloride intoxication. Betaine also significantly elevated the reduced activities of some enzymes, cytochrome P-450, 7-ethoxycoumarin-0-deethylase and glutathione-S-transferase, involved in xenobiotic metabolism due to carbon tetrachloride intoxication. These results demonstrate a possible hepato-protective role of betaine against fatty liver that could be easily induced by carbon tetrachloride in rat.