ABSTRACT
@#Objectives. Polymorphisms in metabolic genes which alter rates of bioactivation and detoxification have been shown to modulate susceptibility to colorectal cancer. This study sought to evaluate the colorectal cancer risk from environmental factors and to do polymorphism studies on genes that code for Phase I and II xenobiotic metabolic enzymes among Filipino colorectal cancer patients and matched controls. Methods. A total of 224 colorectal cancer cases and 276 controls from the Filipino population were genotyped for selected polymorphisms in GSTM1, GSTP1, GSTT1, NAT1 and NAT2. Medical and diet histories, occupational exposure and demographic data were also collected for all subject participants.Results. Univariate logistic regression of non-genetic factors identified exposure to UV (sunlight) (OR 1.99, 95% CI: 1.16-3.39) and wood dust (OR 2.66, 95% CI: 1.21-5.83) and moldy food exposure (OR 1.61, 95% CI:1.11-2.35) as risk factors; while the NAT2*6B allele (recessive model OR 1.51, 95% CI :1.06-2.16; dominant model OR 1.87, 95% CI: 1.05-3.33) and homozygous genotype (OR 2.19, 95% CI: 1.19-4.03) were found to be significant among the genetic factors. After multivariate logistic regression of both environmental and genetic factors, only UV radiation exposure (OR 2.08, 95% CI: 1.21-3.58) and wood dust exposure (OR 2.08, 95% CI: 0.95-5.30) remained to be significantly associated with increasing colorectal cancer risk in the study population.Conclusion. This study demonstrated that UV sunlight and wood dust exposure play a greater role in influencing colorectal cancer susceptibility than genotype status from genetic polymorphisms of the GST and the NAT` genes.
Subject(s)
Colorectal Neoplasms , Polymorphism, GeneticABSTRACT
ABSTRACT In this work, the potential chemopreventive activities of Elaeagnus umbellata fruit aqueous (EUFA) and leaf aqueous (EULA) extracts focusing on the modulatory influence of xenobiotic metabolizing enzymes (XMEs), antioxidant enzymes, glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), lactate dehydrogenase (LDH) activity, lipid peroxidation (LP), sulfhydryl groups were investigated in the hepatic and extrahepatic organs of Swiss albino mice (50 and 100 mg/kg body wt given orally for 14 days) and compared with BHA (0.75 % in diet). The modulatory and chemopreventive properties of two different doses EUFA and EULA were observed for cytochrome P450, cytochrome b5, sulfhydryl groups, NADPH-cytochrome P450 reductase, NADH-cytochrome b5 reductase, 7-ethoxyresorufin-deethylase and N,N-dimethylaniline N-oxidase activities in the liver and compared with BHA as a standard. The activities of glutathione S-transferase (GST) and DT-diaphorase (DTD) showed a significant increase in the kidney, forestomach, heart and brain at both doses of EUFA and EULA. The results of EULA-treated groups were found a notable increase in LDH, G6PD, 6PGD, GST and DTD activities. Superoxide dismutase level in liver, kidney and heart exhibited a significant increase at both doses of EULA. Glutathione reductase activity was a remarkable level at high dose of EUFA in liver, kidney and EULA in kidney. Both doses of EUFA were effective in inducing glutathione peroxidase activitiy in heart. The levels of LP at low and high doses of EULA-treated and EUFA-treated were effective in liver and kidney, respectively. The present results demonstrate that significant effects in the level of XMEs and antioxidant enzymes of EUFA and EULA are remarkable for modulating roles and natural chemoprevention properties and therefore is considered for a valuable natural source.