Silymarin prevents benzo(a)pyrene-induced toxicity in Wistar rats by modulating xenobiotic-metabolizing enzymes.

Unlabelled: Benzo(a)pyrene (B(a)P), which is commonly used as an indicator species for polycyclic aromatic hydrocarbon (PAH) contamination, has a large number of hazardous consequences on human health. In the presence of the enzyme cytochrome-P-450 1A1 (CYP1A1), it undergoes metabolic activation to form reactive intermediates that are capable of inducing mutagenic, cytotoxic, teratogenic and carcinogenic effects in various species and tissues. Research within the last few years has shown that flavonoids exhibit chemopreventive effect against these toxins.

CYP1A1 gene polymorphisms: lack of association with breast cancer susceptibility in the southern region (Madurai) of India.

The cytochrome P 450 1A1 gene encoding a phase I metabolic enzyme appears to be a candidate for breast cancer risk. It is involved in the phase I detoxification of polycyclic aromatic hydrocarbons (PAHs) and 2-hydroxylation of estrogens and mammary carcinogens into 2-hydroxy catechol metabolites. Several studies have investigated polymorphisms in CYP1A1 and breast cancer risk with inconsistent results.

Silymarin prevents the toxicity induced by benzo(a)pyrene in human erythrocytes by preserving its membrane integrity: an in vitro study.

Silymarin, the purified extract from milk thistle Silybum marianum (L.) Gaertn, consists mainly of four isomeric flavonolignans: silibinin, isosilibinin, silidianin, and silichristin. The present study was carried out to evaluate the protective potential of silymarin in human erythrocytes against in vitro exposure to the carcinogen benzo(a)pyrene (B(a)P).

Hydroxytyrosol, the phenolic compound of olive oil protects human PBMC against oxidative stress and DNA damage mediated by 2,3,7,8-TCDD.

The protective effect of hydroxytyrosol (HT), a strong antioxidant compound from extra virgin olive oil, against TCDD induced toxicity was investigated in human peripheral blood mononuclear cells (PBMC). PBMC (1 × 10(6)cellsmL(-1)) were divided into four groups and were incubated in a CO(2) incubator (5% CO(2)) for 12h with vehicle, TCDD (10 nM), TCDD+HT (10 nM+100 μM) and HT alone (100 μM) respectively. To clarify the role of HT against TCDD induced cytotoxicity, oxidative stress and the levels of antioxidant enzymes were assessed.

Silymarin protects PBMC against B(a)P induced toxicity by replenishing redox status and modulating glutathione metabolizing enzymes--an in vitro study.

PAHs are a ubiquitous class of environmental contaminants that have a large number of hazardous consequences on human health. An important prototype of PAHs, B(a)P, is notable for being the first chemical carcinogen to be discovered and the one classified by EPA as a probable human carcinogen. It undergoes metabolic activation to QD, which generate ROS by redox cycling system in the body and oxidatively damage the macromolecules.