Role of medium-chain triglycerides in the alcohol-mediated cytochrome P450 2E1 induction of mitochondria.
Study Goal
The researchers aimed to determine whether replacing dietary long-chain triglycerides (LCT) with medium-chain triglycerides (MCT) could mitigate alcohol-induced mitochondrial CYP2E1 induction, oxidative stress, and liver injury.
Results Summary
The study found that replacing all dietary fat with MCT (32% of calories) significantly reduced mitochondrial and microsomal CYP2E1 levels, oxidative stress (4-HNE), and restored mitochondrial glutathione (GSH) levels, while also decreasing liver steatosis and inflammation. A partial replacement (16% MCT) was ineffective.
Population
Rats fed alcohol-containing Lieber-DeCarli liquid diets.
Effective Dosage
16% or 32% of total calories as MCT.
Duration
21 days.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
alcohol containing Lieber-DeCarli liquid diet | increase | mitochondrial CYP2E1 | Rats | - | significant increase | #1 |
alcohol containing Lieber-DeCarli liquid diet | increase | microsomal CYP2E1 | Rats | - | significant increase | #2 |
alcohol-MCT 32% diet | decrease | CYP2E1 in mitochondria | Rats | 40% | significantly reduced | #3 |
alcohol-MCT 32% diet | decrease | CYP2E1 in microsomes | Rats | 30% | significantly reduced | #4 |
alcohol containing Lieber-DeCarli liquid diet | increase | mitochondrial 4-hydroxynonenal (4-HNE) | Rats | - | significantly raised | #5 |
alcohol-MCT 16% diet | increase | mitochondrial 4-hydroxynonenal (4-HNE) | Rats | - | significantly raised | #6 |
alcohol-MCT 32% diet | decrease | mitochondrial 4-hydroxynonenal (4-HNE) | Rats | - | brought it down to control levels | #7 |
alcohol consumption | decrease | Mitochondrial reduced glutathione (GSH) | Rats | - | significantly lowered | #8 |
alcohol-MCT 32% diet | increase | Mitochondrial reduced glutathione (GSH) | Rats | - | increased to almost normal levels | #9 |
alcohol-MCT 32% diet | decrease | alcohol-induced steatosis | Rats | - | decreased | #10 |
alcohol-MCT 32% diet | decrease | triglycerides | Rats | - | diminution | #11 |
alcohol-MCT 32% diet | decrease | pro-inflammatory cytokine tumor necrosis factor-alpha | Rats | - | diminution | #12 |
BACKGROUND: Chronic alcohol consumption is known to induce cytochrome P450 2E1 (CYP2E1) leading to lipid peroxidation, mitochondrial dysfunction and hepatotoxicity. We showed that replacement of dietary long-chain triglycerides (LCT) by medium-chain triglycerides (MCT) could be protective. We now wondered whether the induction of mitochondrial CYP2E1 plays a role and whether liver injury could be avoided through mitochondrial intervention. METHODS: Rats were fed 4 different isocaloric liquid diets. The control group received our standard dextrin-maltose diet with intake limited to the average consumption of the 3 alcohol groups fed ad libitum the alcohol containing Lieber-DeCarli liquid diet. The fat was either 32% of calories as LCT (alcohol), or 16% as LCT + 16% as MCT (alcohol-MCT 16%), or 32% as MCT only (alcohol-MCT 32%). RESULTS: After 21 days, compared to the controls, the alcohol and both alcohol-MCT groups had a significant increase in mitochondrial CYP2E1 (p < 0.05 for both). As shown before, the same was found for the microsomal CYP2E1. When MCT replaced all the fat, like in the alcohol-MCT 32% group, CYP2E1 was significantly reduced by 40% in mitochondria (p < 0.05) and 30% in microsomes (p < 0.01). In mitochondria, 4-hydroxynonenal (4-HNE), a parameter of oxidative stress, paralleled CYP2E1. Compared to controls, alcohol and alcohol-MCT 16% significantly raised mitochondrial 4-HNE (p < 0.001), whereas the alcohol-MCT 32% diet brought it down to control levels (p < 0.001). Mitochondrial reduced glutathione (GSH) was also significantly lowered by alcohol consumption (p < 0.05), and it increased to almost normal levels with alcohol-MCT 32% (p = 0.006). These changes in the mitochondria reflected the reduction observed in total liver in which alcohol-MCT 32% decreased the alcohol-induced steatosis with a diminution of triglycerides (p < 0.001) and of the pro-inflammatory cytokine tumor necrosis factor-alpha (p < 0.001). CONCLUSION: Mitochondria participate in the induction of CYP2E1 by alcohol and contribute to lipid peroxidation and GSH depletion. Thus, lipid composition of the diet is an important determinant for the beneficial effect of MCT, with a diet containing a mixture of LCT/MCT being ineffective.