Robert K. Heaney

Improved method for the determination of the total glucosinolate content of rapeseed by determination of enzymically released glucose

A method is described for the determination of the total glucosinolate content of rapeseed. The method is an improvement of a previously described procedure and avoids the necessity for a defatting step. The new and old methods are compared with each other and with a high-performance liquid chromatographic method.

Induction of the anti-carcinogenic enzyme quinone reductase by food extracts using murine hepatoma cells

&NA; Over 145 extracts of vegetables, fruits, herbs, spices and beverages which are consumed regularly in the European diet have been surveyed for potential anti‐carcinogenic activity using an assay which measures the induction of NAD(P)H: (quinone acceptor) menadione oxidoreductase (quinone reductase, QR) activity in murine cells challenged with solutions of potential inducers. Where appropriate the study has included extracts prepared from cooked and autolysed material. The results indicate that extracts of some brassicas, legumes (peas), lettuces, red pepper, grapefruit and some herbs including basil, tarragon and rosemary are inducers of QR activity. Inducing activity is strongly dependent on processing and on variety.

Induction of glutathione S-transferase activity in hepG2 cells by extracts from fruits and vegetables

Abstract The human hepatoma cell line, hepG2, retains many of the xenobiotic metabolising enzymes found in normal hepatocytes, including an inducible glutathione S -transferase (GST). The isoform of GST that is induced by xenobiotics in this cell line is GSTA1-1. As a first step to determining the effect of diet on induction of GST in humans, we have examined the ability of extracts from a wide variety of fruits and vegetables to induce GST activity in hepG2 cells. Extracts from cruciferous vegetables (broccoli, Brussels sprouts, cabbage) were the most potent inducers, but this was dependent on the variety. Most of the extracts from fruits, with the exception of grapefruit, were poor inducers. Similarities and differences between the induction of GST and of quinone reductase in mouse hepalclc7 cells are discussed. The results show that extracts from cruciferous vegetables are effective inducers of human GST, in agreement with previous studies on GST in animals and cell lines derived from animals.