The modulation of
garlic oil (GO) and three
allyl compounds,
diallyl sulfide (
DAS),
diallyl disulfide (DADS) and
diallyl trisulfide (DATS), on the antioxidation system in rat livers and red blood cells was examined. Rats were orally administered GO (200 mg/kg
body weight),
DAS (20, 80 mg/kg
body weight), DADS (80 mg/kg
body weight) or DATS (70 mg/kg
body weight) three times a week for 6 weeks. Control rats received
corn oil (2 ml/kg
body weight) alone. GO, DADS and DATS treatment significantly increased the
glutathione (GSH) content (48-84%) in red blood cells (P < 0.05). DATS displayed a greater enhancement than GO and DADS (P < 0.05).
Hemolysis induced by
tert-butyl hydroperoxide was not suppressed by GO or allyl compound treatment although higher GSH content was evident. Hepatic GSH was not influenced by garlic components. In rat livers, DADS and DATS significantly increased the activity of GSH
reductase (46 and 54%, respectively) and of GSH S-
transferase (GST) (63 and 103%, respectively), but decreased the GSH
peroxidase activity (27 and 28%, respectively). In contrast, GSH
reductase and GST activities in the
DAS group, either 20 or 80 mg/kg
body weight, were similar to the control group. A decrease of GSH
peroxidase activity was observed in rats dosed with 80 mg/kg
body weight (P < 0.05). An increase in GST activity and a decrease in GSH
peroxidase activities were also noted in GO-treated rats (P < 0.05). In red blood cells, three GSH-related
antioxidant enzyme activities were not affected by
garlic oil and its organosulfur components. Immunoblot assay showed that, accompanying the increase in hepatic GST activity, GO, DADS,
DAS (80 mg/kg
body weight) and DATS increased the expression of GST Ya, Yb1 and Yc
proteins. Results indicate that GO and three
allyl compounds play a differential role in modulation of the GSH-related
antioxidant system in rat livers and red blood cells.