Diallyl trisulfide modulates cell viability and the antioxidation and detoxification systems of rat primary hepatocytes

This study investigated the effects of various concentrations of diallyl trisulfide (DATS) and incubation times on cell viability, glutathione (GSH) content, and GSH-related enzyme activity in rat primary hepatocytes. Isolated and cultured primary rat hepatocytes were used as an experimental model. Cells were treated with 0 (control), 0.025, 0.05, or 0.25 mmol/L DATS for 0, 4, 8, or 24 h. After 24 h of treatment, some cells were incubated in fresh medium without DATS for an additional 24 h (48-h incubations). Based on lactate dehydrogenase (LDH) leakage and morphological examination, hepatocytes treated with 0.025 mmol/L DATS did not differ from the control cells at 4, 8, 24, and 48 h of incubation. However, LDH leakage was higher than in the control cells (P < 0.05) when the hepatocytes were treated with 0.05 or 0.25 mmol/L DATS for 4 h or more. The intracellular GSH levels of hepatocytes treated with 0.025 or 0.05 mmol/L DATS were higher than those of the control cells (P < 0.05), whereas those treated with 0.25 mmol/L DATS did not differ. The activity of glutathione reductase (GRd) was higher than in the control cells at 24 h (P < 0.05) when the hepatocytes were treated with 0.025 mmol/L DATS. When the hepatocytes were treated with 0.025 mmol/L DATS, the activity of glutathione S-transferase (GST) was higher than in the control cells at 48 h (P < 0.05). In hepatocytes treated with 0.05 mmol/L DATS, the activity of GST and glutathione peroxidase (GPx) was higher than in the control cells (P < 0.05) at 24 and 48 h of incubation. The results indicate that 0.025 or 0.05 mmol/L DATS could enhance antioxidation and detoxification capabilities by increasing the intracellular GSH level and the activity of GPx, GRd, or GST in rat primary hepatocytes. However, 0.05 or 0.25 mmol/L DATS might adversely affect the viability of hepatocytes

Metabolites of diallyl disulfide and diallyl sulfide in primary rat hepatocytes

The objectives of this study were to analyse and identify the metabolites of diallyl disulfide (DADS) and diallyl sulfide (DAS) in primary rat hepatocytes prepared by collagenase perfusion. According to the results, allyl mercaptan (AM) and allyl methyl sulfide (AMS) were the metabolites of DADS. The highest amount of AMS (0.93 +/- 0.08 mu g/ml at 90 min) was much less than that of AM (46.2 +/- 6.6 mu g/ml at 60 min). Combined with the Purge and Trap using a gas chromatography-mass spectrometry (GC-MS) system, it is very useful to detect the trace amounts of metabolites in primary rat hepatocytes. Results also showed that AMS was a metabolite of DAS. The highest amount of AMS in the extracellular fluid of hepatocytes was 0.63 +/- 0.16 mu g/ml at 30 min of incubation. (C) 2000 Elsevier Science Ltd. All rights reserved

Effect of diallyl sulfide and diallyl disulfide, the active principles of garlic, on the aflatoxin B-1-induced DNA damage in primary rat hepatocytes

The objective of this study was to investigate the effect of the active principles in garlic-diallyl sulfide (DAS) and diallyl disulfide (DADS)-on aflatoxin B-1 (AFB(1))-induced DNA damage in primary rat hepatocytes. Primary rat hepatocytes, induced with DNA damage using 10 muM AFB(1) were used as an experimental model. According to the results of LDH leakage, 0.5 and 2 mM of DAS or 0.5 and 1 mM of DADS significantly increased the viability of hepatocytes compared with the AFB(1) controls after 4, 8 and 24 h treatment (P <0.05). According to the results of unscheduled DNA synthesis (UDS) test. 0.5 and 2 mM of DAS or 0.5 acid 1 mM of DADS could significantly decrease the DNA damage induced by AFB(1) (P<0.05). Furthermore, 0.5 and 2 mM DAS or 0.5 and 1 mM DADS could increase the glutathione S-transferase (GST) and glutathione peroxidase (GPx) activities as compared with the AFB(1) controls after 24 h treatment (P<0.05). Results of immunoblot analysis of cytosolic GST isoenzyme indicate that the levels of GST isoform Ya, Yb2 and Yc were markly increased after treatment with 0.5 and 2 mM DAS or 0.5 and 1 mM DADS compared with the AFB(1) control. These results indicate that 0.5 and 2 mM DAS or 0.5 and 1 mM DADS might protect hepatocytes from AFB(1)-induced DNA damage via increasing the activities of GST and GPx. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved