Limits...
Induction of epoxide hydrolase, glucuronosyl transferase, and sulfotransferase by phenethyl isothiocyanate in male Wistar albino rats.

Abdull Razis AF, Mohd Noor N, Konsue N - Biomed Res Int (2014)

Bottom Line: Phenethyl isothiocyanate (PEITC) is an isothiocyanate found in watercress as the glucosinolate (gluconasturtiin).At the Medium dose, only SULT level was increased, whereas at the High dose marked increase in EH level was observed.It is concluded that PEITC modulates carcinogen-metabolising enzyme systems at doses reflecting human intake thus elucidating the mechanism of its chemoprevention.

View Article: PubMed Central - PubMed

Affiliation: Food Safety Research Centre (FOSREC), Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia.

ABSTRACT
Phenethyl isothiocyanate (PEITC) is an isothiocyanate found in watercress as the glucosinolate (gluconasturtiin). The isothiocyanate is converted from the glucosinolate by intestinal microflora or when contacted with myrosinase during the chopping and mastication of the vegetable. PEITC manifested protection against chemically-induced cancers in various tissues. A potential mechanism of chemoprevention is by modulating the metabolism of carcinogens so as to promote deactivation. The principal objective of this study was to investigate in rats the effect of PEITC on carcinogen-metabolising enzyme systems such as sulfotransferase (SULT), N-acetyltransferase (NAT), glucuronosyl transferase (UDP), and epoxide hydrolase (EH) following exposure to low doses that simulate human dietary intake. Rats were fed for 2 weeks diets supplemented with PEITC at 0.06 µmol/g (low dose, i.e., dietary intake), 0.6 µmol/g (medium dose), and 6.0 µmol/g (high dose), and the enzymes were monitored in rat liver. At the Low dose, no induction of the SULT, NAT, and EH was noted, whereas UDP level was elevated. At the Medium dose, only SULT level was increased, whereas at the High dose marked increase in EH level was observed. It is concluded that PEITC modulates carcinogen-metabolising enzyme systems at doses reflecting human intake thus elucidating the mechanism of its chemoprevention.

Show MeSH

Related in: MedlinePlus

Effect of PEITC on glucuronosyl transferase activity in rat liver. Groups of five rats were exposed to diets supplemented with PEITC at 0.06 (low dose), 0.6 (medium dose), and 6.0 (high dose) μmol/g diet for 14 days, whereas another group served as control. At the end of the treatment period, hepatic S9 was prepared from which microsomes were isolated and used to determine glucuronosyl transferase activity. Results are presented as mean ± SD for five rats. *P < 0.05.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3921933&req=5

fig1: Effect of PEITC on glucuronosyl transferase activity in rat liver. Groups of five rats were exposed to diets supplemented with PEITC at 0.06 (low dose), 0.6 (medium dose), and 6.0 (high dose) μmol/g diet for 14 days, whereas another group served as control. At the end of the treatment period, hepatic S9 was prepared from which microsomes were isolated and used to determine glucuronosyl transferase activity. Results are presented as mean ± SD for five rats. *P < 0.05.

Mentions: Even though the effects of isothiocyanates on quinone reductase and glutathione S-transferases have been well reported both in vitro and in vivo, their capability to modulate other phase II enzyme systems involved in carcinogen metabolism has received little attention. Glucuronosyl transferases are a very essential phase II detoxifying enzyme system involved in the metabolism of chemical carcinogens including aromatic amines and polycyclic aromatic hydrocarbons [38]. The current studies found that PEITC at the low dose has the potential to upregulate glucuronosyl transferase (Figure 1), which commensurate previous findings where cruciferous vegetable consumption led to increased glucuronidation of the heterocyclic amine PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine) in human volunteers, even though other components in the vegetables are likely to have also contributed to the upregulation of this enzyme [39]. Similarly, the consumption of diets supplemented with cruciferous vegetables reduced serum bilirubin levels, the glucuronidation that was catalysed by glucuronosyl transferase 1A1 (UGT1A1) [40]. In addition, PEITC isolated from watercress enhanced the metabolism of nicotine due to increased glucuronidation among smokers [41], while in rat liver slices, PEITC led to increase in the glucuronidation of 1-naphthol [26].


Induction of epoxide hydrolase, glucuronosyl transferase, and sulfotransferase by phenethyl isothiocyanate in male Wistar albino rats.

Abdull Razis AF, Mohd Noor N, Konsue N - Biomed Res Int (2014)

Effect of PEITC on glucuronosyl transferase activity in rat liver. Groups of five rats were exposed to diets supplemented with PEITC at 0.06 (low dose), 0.6 (medium dose), and 6.0 (high dose) μmol/g diet for 14 days, whereas another group served as control. At the end of the treatment period, hepatic S9 was prepared from which microsomes were isolated and used to determine glucuronosyl transferase activity. Results are presented as mean ± SD for five rats. *P < 0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3921933&req=5

fig1: Effect of PEITC on glucuronosyl transferase activity in rat liver. Groups of five rats were exposed to diets supplemented with PEITC at 0.06 (low dose), 0.6 (medium dose), and 6.0 (high dose) μmol/g diet for 14 days, whereas another group served as control. At the end of the treatment period, hepatic S9 was prepared from which microsomes were isolated and used to determine glucuronosyl transferase activity. Results are presented as mean ± SD for five rats. *P < 0.05.
Mentions: Even though the effects of isothiocyanates on quinone reductase and glutathione S-transferases have been well reported both in vitro and in vivo, their capability to modulate other phase II enzyme systems involved in carcinogen metabolism has received little attention. Glucuronosyl transferases are a very essential phase II detoxifying enzyme system involved in the metabolism of chemical carcinogens including aromatic amines and polycyclic aromatic hydrocarbons [38]. The current studies found that PEITC at the low dose has the potential to upregulate glucuronosyl transferase (Figure 1), which commensurate previous findings where cruciferous vegetable consumption led to increased glucuronidation of the heterocyclic amine PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine) in human volunteers, even though other components in the vegetables are likely to have also contributed to the upregulation of this enzyme [39]. Similarly, the consumption of diets supplemented with cruciferous vegetables reduced serum bilirubin levels, the glucuronidation that was catalysed by glucuronosyl transferase 1A1 (UGT1A1) [40]. In addition, PEITC isolated from watercress enhanced the metabolism of nicotine due to increased glucuronidation among smokers [41], while in rat liver slices, PEITC led to increase in the glucuronidation of 1-naphthol [26].

Bottom Line: Phenethyl isothiocyanate (PEITC) is an isothiocyanate found in watercress as the glucosinolate (gluconasturtiin).At the Medium dose, only SULT level was increased, whereas at the High dose marked increase in EH level was observed.It is concluded that PEITC modulates carcinogen-metabolising enzyme systems at doses reflecting human intake thus elucidating the mechanism of its chemoprevention.

View Article: PubMed Central - PubMed

Affiliation: Food Safety Research Centre (FOSREC), Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia.

ABSTRACT
Phenethyl isothiocyanate (PEITC) is an isothiocyanate found in watercress as the glucosinolate (gluconasturtiin). The isothiocyanate is converted from the glucosinolate by intestinal microflora or when contacted with myrosinase during the chopping and mastication of the vegetable. PEITC manifested protection against chemically-induced cancers in various tissues. A potential mechanism of chemoprevention is by modulating the metabolism of carcinogens so as to promote deactivation. The principal objective of this study was to investigate in rats the effect of PEITC on carcinogen-metabolising enzyme systems such as sulfotransferase (SULT), N-acetyltransferase (NAT), glucuronosyl transferase (UDP), and epoxide hydrolase (EH) following exposure to low doses that simulate human dietary intake. Rats were fed for 2 weeks diets supplemented with PEITC at 0.06 µmol/g (low dose, i.e., dietary intake), 0.6 µmol/g (medium dose), and 6.0 µmol/g (high dose), and the enzymes were monitored in rat liver. At the Low dose, no induction of the SULT, NAT, and EH was noted, whereas UDP level was elevated. At the Medium dose, only SULT level was increased, whereas at the High dose marked increase in EH level was observed. It is concluded that PEITC modulates carcinogen-metabolising enzyme systems at doses reflecting human intake thus elucidating the mechanism of its chemoprevention.

Show MeSH
Related in: MedlinePlus