Mitochondrial dysfunction, oxidative stress, ER stress and mitochondria-ER crosstalk alterations in a chemical rat model of Huntington's disease: Potential benefits of bezafibrate.

Redox homeostasis, mitochondrial functions, and mitochondria-endoplasmic reticulum (ER) communication were evaluated in the striatum of rats after 3-nitropropionic acid (3-NP) administration, a recognized chemical model of Huntington's disease (HD). 3-NP impaired redox homeostasis by increasing malondialdehyde levels at 28 days, decreasing glutathione (GSH) concentrations at 21 and 28 days, and the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD) and glutathione S-transferase at 7, 21, and 28 days, catalase at 21 days, and glutathione reductase at 21 and 28 days. Impairment of mitochondrial respiration at 7 and 28 days after 3-NP administration was also observed, as well as reduced activities of succinate dehydrogenase (SDH) and respiratory chain complexes. 3-NP also impaired mitochondrial dynamics and the interactions between ER and mitochondria and induced ER-stress by increasing the levels of mitofusin-1, and of DRP1, VDAC1, Grp75 and Grp78. Synaptophysin levels were augmented at 7 days but reduced at 28 days after 3-NP injection. Finally, bezafibrate prevented 3-NP-induced alterations of the activities of SOD, GPx, SDH and respiratory chain complexes, DCFH oxidation and on the levels of GSH, VDAC1 and synaptophysin. Mitochondrial dysfunction and synaptic disruption may contribute to the pathophysiology of HD and bezafibrate may be considered as an adjuvant therapy for this disorder.

Extreme urinary betaine losses in type 2 diabetes combined with bezafibrate treatment are associated with losses of dimethylglycine and choline but not with increased losses of other osmolytes.

PURPOSE: Betaine deficiency is a probable cardiovascular risk factor and a cause of elevated homocysteine. Urinary betaine excretion is increased by fibrate treatment, and is also often elevated in diabetes. Does fibrate further increase betaine excretion in diabetes, and does it affect the plasma concentrations and excretions of related metabolites and of other osmolytes? METHODS: Samples from a previous study of type 2 diabetes were selected if participants were taking bezafibrate (n = 32). These samples were compared with participants matched for age and gender and not on a fibrate (comparator group, n = 64). Betaine, related metabolites, and osmolytes were measured in plasma and urine samples from these 96 participants. RESULTS: Median urinary betaine excretion in those on bezafibrate was 5-fold higher than in the comparator group (p < 0.001), itself 3.5-fold higher than the median reported for healthy populations. In the bezafibrate group, median dimethylglycine excretion was higher (9-fold, p < 0.001). Excretions of choline, and of the osmolytes myo-inositol, taurine and glycerophosphorylcholine, were not significantly different between groups. Some participants excreted more betaine than usual dietary intakes. Several betaine fractional clearances were >100 %. Betaine excretion correlated with excretions of the osmolytes myo-inositol and glycerophosphorylcholine, and also with the excretion of choline and N,N-dimethylglycine, but it was inconclusive whether these relationships were affected by bezafibrate therapy. CONCLUSIONS: Increased urinary betaine excretions in type 2 diabetes are further increased by fibrate treatment, sometimes to more than their dietary intake. Concurrent betaine supplementation may be beneficial.

The effect of bezafibrate and omega-3 fatty acids on lymphocyte cytokine release and systemic inflammation in patients with isolated hypertriglyceridemia.

PURPOSE: The aim of this study was to compare the effects of fibrates and omega-3 fatty acids on lymphocyte secretory function and systemic inflammation in patients with isolated hypertriglyceridemia. METHODS: The study included 107 patients with isolated hypertriglyceridemia who received bezafibrate (200 mg twice daily), omega-3 fatty acids (1 g twice daily) or placebo for 12 weeks. The lipid profile, fasting and 2-h post-glucose load plasma glucose levels, homeostasis model assessment index (HOMA), plasma high-sensitivity C-reactive protein (hsCRP) levels and lymphocyte release of interleukin-2, interferon-γ and tumor necrosis factor-α were assessed at baseline, on the day of randomization, and after 4 and 12 weeks of treatment. RESULTS: Both bezafibrate and omega-3 fatty acids reduced plasma triglyceride levels. Bezafibrate additionally decreased total and low-density lipoprotein-cholesterol levels and the HOMA and insignificantly decreased post-glucose load plasma glucose, as well as increased high-density lipoprotein-cholesterol. Bezafibrate treatment was associated with a reduction in lymphocyte release of interleukin-2, interferon-γ and tumor necrosis factor-α, which was accompanied by a reduction in plasma hsCRP levels. Omega-3 fatty acid did not significantly reduce lymphocyte cytokine release and plasma hsCRP. The anti-inflammatory effects of both drugs did not correlate with their action on plasma lipids, but in the case of the former the effect was related to the improvement in insulin sensitivity. CONCLUSION: Our results indicate that bezafibrate is superior to omega-3 fatty acid in inhibiting systemic inflammation and lymphocyte secretory function.

Enhanced myopathy following administration of hypolipidemic agents under urethane anesthesia.

The enhanced effect of urethane anesthesia on the serum creatine kinase (CPK) level following administration of hypolipidemic agents was examined to develop a convenient experimental screening method for drug-induced myopathy. After oral administration of a hypolipidemic agent to rats, 25% urethane solution was infused intravenously at a very low rate using a microinfusion pump. Blood samples were collected 7 h after drug administration and the risk of myopathy was evaluated based on the CPK level. When bezafibrate (BF), simvastatin (SV), or pravastatin (PV) (50-500 mg/kg) was orally administered under urethane infusion, enhanced elevation of the serum CPK level was observed dose dependently for BF and SV, but not for PV. The elevation of serum CPK was much higher with BF than with SV or PV. In addition, when SV or PV (50-500 mg/kg) was coadministered with 50 mg/kg of BF, there was a striking increase in the serum CPK level as compared with the drug alone. Without urethane infusion, no significant elevation in serum CPK level was observed even at a high dose of these hypolipidemic agents. These phenomena suggest that the urethane anesthesia enhanced the elevation of the serum CPK level following administration of hypolipidemic agents. We propose that this method is a simple and speedy screening test for drug-induced myopathy.

Evaluation of the phototoxic properties of some hypolipidemics in vitro: fenofibrate exhibits a prominent phototoxic potential in the UVA and UVB region.

As some fibric acid derivatives have been reported to exhibit photosensitizing effects in vivo, the antilipemic drugs fenofibrate, bezafibrate, clofibrate, and gemfibrozil were tested for their phototoxic potential in vitro by a photohemolysis test using human erythrocytes and different irradiation sources. In this system only fenofibrate revealed strong phototoxic properties, which were dependent both on the drug concentration and the irradiation doses. Above a surface dose of 40 J/cm2 UVA of an UVA (320-400 nm)-rich irradiation source or 1.6 J/cm2 UVB/0.8 J/cm2 UVA of an UVB (280-320 nm)-rich irradiation source human red blood cells were completely photohemolysed in the presence of fenofibrate. Bezafibrate- and gemfibrozil-induced photohemolysis remained beneath 10%, and clofibrate showed no phototoxicity at all. As the phototoxic potential of fenofibrate lies in the UVB and UVA range, this might be of relevance with regard to clinical photosensitivity.

Comparison of the efficacy and tolerance of a garlic preparation vs. bezafibrate.

The efficacy and tolerance of a garlic preparation (Sapec, Kwai) was investigated in a randomized double-blind study vs. bezafibrate. This multi-centre study was conducted in 5 general medical practices and involved 98 patients with primary hyperlipoproteinaemia. The daily doses of the active substances were 900 mg of garlic powder (standardized as to 1.3% alliin) and 600 mg of bezafibrate, respectively. The pre-phase with placebo lasted 6 weeks, the treatment period covered 12 weeks. All patients were advised to observe a low-fat "step-1 diet" for the duration of the study. The 98 case report forms allowed the statistical evaluation of total cholesterol, HDL cholesterol and triglyceride levels for 94 patients, and of LDL cholesterol values for 92 patients. In the course of the treatment both study medications caused a statistically highly significant reduction in total cholesterol, in LDL cholesterol and triglycerides, and an increase in HDL cholesterol. However, there was no significant difference in the efficacies of both medication groups. Side effects were mentioned by 5 patients each in both treatment groups, none of which led to the withdrawal of the patients. Concerning the garlic preparation, there was no correlation between the perception of garlic odour and the influence on the cholesterol level.