Comparison of Isothiocyanate Metabolite Levels and Histone Deacetylase Activity in Human Subjects Consuming Broccoli Sprouts or Broccoli Supplement

Abstract

Increased consumption of cruciferous vegetables such as broccoli may reduce the risk of various cancers. Myrosinase is required to convert dietary glucosinolates from broccoli into bioactive isothiocyanates. We evaluated isothiocyanate excretion profiles in healthy subjects who consumed broccoli sprouts or broccoli supplement (no myrosinase) with equivalent glucosinolate content. Urinary metabolites of two major isothiocyanates, sulforaphane and erucin, were measured by liquid chromatography coupled with tandem mass spectrometry. Peak excretion of sulforaphane and erucin was higher and occurred sooner in subjects who consumed broccoli sprouts compared to subjects who consumed the supplement. A subject-dependent shift in the ratio of urinary sulforaphane to erucin metabolites was observed in both groups indicating conversion of sulforaphane to erucin. Lower histone deacetylase activity was observed in the peripheral blood mononuclear cells only in subjects consuming sprouts. In conclusion, fresh broccoli sprouts differ from broccoli supplements in regards to excretion of isothiocyanates and bioactivity in human subjects.

A Glance at… Broccoli, glucoraphanin, and sulforaphane

“…In humans, the bioavailability of supplemental free sulforaphane is about fourfold greater than the bioavailability of sulforaphane originating as part of glucoraphanin [17]. Others have observed 7-to 12-fold increases in sulforaphane absorption when broccoli products or glucoraphanin are ingested in the presence of myrosinase activity [18][19][20][21][22]. All of these data confirm the importance of myrosinase activity for human absorption of sulforaphane from broccoli and broccoli products [6,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”

Protective effects of Brassica oleracea sprouts extract toward renal damage in high-salt-fed SHRSP

“…Brassica oleracea juice was administered to rats based on animal weight (340 ml/120 mg), as calculated on the basis of amounts of broccoli sprouts administered to humans in the previous studies [18,19]. GW6471 was first solved in dimethyl sulfoxide and then further diluted in 0.9% NaCl solution to reach the final concentration.…”

Sensitization of HER2 Positive Breast Cancer Cells to Lapatinib Using Plants-Derived Isothiocyanates

“…Anticancer effects of SFN has been proven in numerous cancer cell lines and in vivo experiments (18). Mechanisms of SFN action are complex and include inhibition of phase I xenobiotic metabolizing enzymes, induction of phase II detoxification enzymes, inhibition of histone deacetylases, induction of oxidative stress, genotoxic stress, inhibition of microtubule dynamics, and modulation of numerous signaling pathways leading to cell cycle arrest and apoptosis of cancer cells (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Recently, it has been shown that SFN inhibits Akt-mTOR-S6K prosurvival pathway, which results in global protein synthesis inhibition and decreased survival of phenotypically different breast cancer cells (31).…”