OBJECTIVETo investigate the effect of tBHQ and sulforaphane on the protein expression in Nrf2-ARE signaling pathway of Caco2 cells.

METHODSHuman colorectal carcinoma Caco2 cells were treated with 20 micromol/L tBHQ and 5 micromol/L sulforaphane (SFN) respectively. Real time PCR, Western blotting and immunoflourescence staining (IF) were performed to measure the target gene expression.

RESULTSNrf2, AKR1C1 and NQO1 protein expressions were increased time-dependently in Caco2 cells after treatment with tBHQ and SFN. Time-course experiments showed that tBHQ and SFN increased the accumulation of Nrf2, and concomitantly increased the protein levels of AKR1C1 and NQO1. Real-time PCR and Western blotting showed that tBHQ and SFN significantly increased the expression of Nrf2 at 8h after the treatment, and AKR1C1 and NQO1 at 16 h. Confocal microscopy technique showed that Nrf2 accumulated in the nucleus at 6-8 h after treatment with tBHQ. After 1 h treatment with tBHQ the nuclear Nrf2 maintained at elevated level for at least 4 h with tBHQ withdrawn.

CONCLUSIONtBHQ and SFN induced nuclear accumulation of Nrf2 and activated Nrf2-dependent regulation of ARE-mediated gene expression in Caco2 cells. In addition, the results provide experimental evidence for choosing the dose and frequency of the inducer in cancer chemoprevention study and in developing inhibitors of Nrf2-ARE signaling pathway.

Anticarcinogenic Agents ; pharmacology ; Antioxidants ; metabolism ; pharmacology ; Caco-2 Cells ; Calcium-Transporting ATPases ; antagonists & inhibitors ; Humans ; Hydroquinones ; pharmacology ; Isothiocyanates ; NF-E2-Related Factor 2 ; genetics ; metabolism ; physiology ; Oxidative Stress ; genetics ; physiology ; Response Elements ; physiology ; Signal Transduction ; drug effects ; Thiocyanates ; pharmacology

AIMTo determine the effect of two different extracts of red maca in male rats.

METHODSProstatic hyperplasia was induced in male rats with testosterone enanthate (TE). The study comprised six groups: one control group (group 1), one group treated with TE (group 2), two groups treated with TE and aqueous extract of red maca (groups 3 and 4), one group treated with hydroalcoholic extract of red maca (group 5) and one group treated with finasteride (0.1 mg, group 6). Differences in the aqueous extract dependent on the length of time of boiling, whether for 2 or 3 hours, for groups 3 and 4 was assessed. Extracts of red maca contained 0.1 mg of benzylglucosinolate. Thereafter, a dose-response effect of different doses of benzylglucosinolates (0.02-0.08 mg) in red maca extracts was assessed.

RESULTSProstate weight was similar in rats treated with freeze-dried aqueous extract of red maca prepared after 2 and 3 hours of boiling. Freeze-dried aqueous extract of red maca, hydroalcoholic extract of red maca and finasteride reduced prostate weight in rats with prostatic hyperplasia. No difference was observed between the data obtained from aqueous extract or hydroalcoholic extract of red maca. A dose dependent reduction of prostate weight was observed with the increase of the dose of benzylglucosinolates in red maca extracts.

CONCLUSIONThe present study showed that hydroalcoholic or aqueous extract of red maca containing 0.1 mg of benzylglucosinolate can reduce prostate size in male rats in which prostatic hyperplasia had been induced by TE.

Alcohols ; Animals ; Finasteride ; therapeutic use ; Lepidium ; Male ; Organ Size ; drug effects ; Plant Extracts ; therapeutic use ; Prostate ; drug effects ; pathology ; Prostatic Hyperplasia ; chemically induced ; drug therapy ; pathology ; Rats ; Testosterone ; analogs & derivatives ; Thiocyanates ; analysis ; pharmacology ; Thioglucosides ; analysis ; pharmacology ; Water

Sulforaphane (SFN) is a naturally occurring compound which is known to induce the phase II antioxidant genes via Nrf2 activation, although the underlying mechanism has not been fully elucidated. In this study, we investigated Nrf2 induction in response to SFN in human bronchial epithelial BEAS-2B cells and determined the signaling pathways involved in this process. SFN treatment reduced cell viability. Prior to cell death, intracellular reactive oxygen species (ROS) were generated at a high rate within a minute of commencing SFN treatment. Pretreatment with antioxidant N-acetylcysteine (NAC) blocked SFN-induced decrease in cell growth. Erk1/2 was activated within 30 min of SFN addition, whereas Akt phosphorylation did not significantly change until the first 8 hr after SFN treatment but then became substantially low until 48 hr. Inhibition of Erk1/2 phosphorylation attenuated SFN-induced loss of cell viability. Nrf2 protein levels in both nuclear and whole cell lysates were increased by SFN treatment, which was dependent on ROS production. Knockdown of Nrf2 with siRNA attenuated SFN-induced heme oxygenase-1 (HO-1) up-regulation. Induction of the Nrf2/HO-1 after SFN treatment was potently suppressed by pretreatment with NAC. Overall, our results indicate that SFN mediates antioxidative and antiproliferative responses by generating ROS in BEAS-2B cells.
Acetylcysteine/pharmacology ; Anticarcinogenic Agents/pharmacology ; Antioxidants/*pharmacology ; Bronchi/cytology/*drug effects/metabolism ; Cell Line ; Cell Proliferation/*drug effects ; Epithelial Cells/drug effects/metabolism ; Extracellular Signal-Regulated MAP Kinases/metabolism ; Free Radical Scavengers/pharmacology ; Heme Oxygenase-1/biosynthesis ; Humans ; NF-E2-Related Factor 2/biosynthesis/genetics ; Oxidative Stress/drug effects ; Proto-Oncogene Proteins c-akt/metabolism ; RNA Interference ; RNA, Small Interfering ; Reactive Oxygen Species/*metabolism ; Respiratory Mucosa/cytology/*drug effects/metabolism ; Signal Transduction/drug effects ; Thiocyanates/*pharmacology