Effects of Garlic Oil and Its Organosulfur Compounds on the Activities of Hepatic Drug-Metabolizing and Antioxidant Enzymes in Rats Fed High- and Low-Fat Diets

Abstract

We examined the effects of garlic oil (GO) and two of its organosulfur compounds, diallyl sulfide (DAS) and diallyl disulfide (DADS), on the drug-metabolizing and antioxidant systems in rats and sought to determine whether these effects are associated with dietary fat. Rats were fed a high-fat diet and received GO or DADS (200 mg/kg body wt) or DAS (100 mg/kg) orally three times a week for seven weeks. Control animals received corn oil alone. Another group of rats was fed a low-fat diet, with or without GO. GO and DADS significantly reduced the body weight gain of rats (p < 0.05). GO, however, dramatically increased the spleen weight and spleen weight-to-body weight ratio (p < 0.05). DAS increased glutathione S-transferase (GST) and 7-pentoxyresorufin O-dealkylase activities, whereas DADS increased only GST activity (p < 0.05). Immunoblot assay showed GO-, DAS-, and DADS-enhanced expression of the placental form of GST and cytochrome P-450 IIBI but suppressed cytochrome P-450 IIEI expression. Hepatic antioxidant enzyme activities were also modulated by these garlic components. GO and DADS inhibited glutathione peroxidase activity (p < 0.05), and DADS and DAS enhanced glutathione reductase activity (p < 0.05). Only GO enhanced the superoxide dismutase activity (p < 0.05). All these garlic components increased glutathione levels in red blood cells (p < 0.05) but did not influence hepatic glutathione levels. Although the amount of fat in the diet modulated drug-metabolizing and antioxidant functions, no interactions between GO and dietary fat were observed. These results indicate that GO and its allyl sulfide components, as well as dietary lipid, modulate drug-metabolizing and antioxidant enzyme activities. The action of GO appears to be independent of dietary lipid content.

Anticarcinogenic Effect and Modification of Cytochrome P450 2E1 by Dietary Garlic Powder in Diethylnitrosamine-Initiated Rat Hepatocarcinogenesis

“…Total CYP contents were not influenced by the carcinogen treatment (Table 3), consistent with some findings that show that the total CYP content was unchanged when the rats were fed DAS, DADS, and garlic oil (Reicks and Crankshaw, 1996;Sheen et al, 1999). However, the contents in the control groups decreased only in the 5.0% garlic powder diet group when compared to the basal diet group (Table 3).…”

“…There was no significant difference in the final body weight of the basal and garlic diet fed rats (Table 2). However, the oral intubation and natural consumption of DAS, DADS, and garlic oil significantly decreased the body weight of rats, showing the adverse effects of OSCs and garlic oil (Harber et al, 1994;Sheen et al, 1999). Therefore, our results indicate that dietary garlic (2.0 and 5.0%) could inhibit DEN-initiated hepatocarcinogenesis, but has no effect on body weight gain and dietary intake.…”

Allium vegetables and organosulfur compounds: do they help prevent cancer?

“…Garlic and onion oils stimulated the activity of GPX and inhibited the decreased ratio of reduced to oxidized glutathione produced by 12-O-tetradecanoylphorbol-13-acetate in epidermal cells (98). GPX activity was also increased in animal tissues with DAS (99), DADS and garlic oil (89). DAS and DADS also increased the activity of glutathione reductase, and garlic oil increased the activity of superoxide dismutase (89).…”

GAMBARAN HEMATOLOGI MENCIT (<em>Mus musculus</em>) MODEL TOKSISITAS SUBKRONIS

“…Semua komponen bawang putih (Allium sativum) dapat meningkatkan kadar gluthation dalam sel darah merah. Salah satu komponen senyawa sulfur yang berfungsi meningkatkan level glutathione sel darah merah (Sheen, et al, 1999). Sehingga ekstrak bawang putih tunggal tidak terbukti menimbulkan efek toksik pada jumlah eritrosit.…”