Reduction of atherosclerotic lesions in rabbits treated with etoposide associated with cholesterol-rich nanoemulsions

Elaine R Tavares1, Fatima R Freitas1, Jayme Diament1, Raul C Maranhão1,21Heart Institute of the Medical School Hospital (InCor), University of São Paulo, São Paulo, Brazil; 2Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, BrazilObjectives: Cholesterol-rich nanoemulsions (LDE) bind to low-density lipoprotein (LDL) receptors and after injection into the bloodstream concentrate in aortas of atherosclerotic rabbits. Association of paclitaxel with LDE markedly reduces the lesions. In previous studies, treatment of refractory cancer patients with etoposide associated with LDE had been shown devoid of toxicity. In this study, the ability of etoposide to reduce lesions and inflammatory factors in atherosclerotic rabbits was investigated.Methods: Eighteen New Zealand rabbits were fed a 1% cholesterol diet for 60 days. Starting from day 30, nine animals were treated with four weekly intravenous injections of etoposide oleate (6 mg/kg) associated with LDE, and nine control animals were treated with saline solution injections.Results: LDE-etoposide reduced the lesion areas of cholesterol-fed animals by 85% and intima width by 50% and impaired macrophage and smooth muscle cell invasion of the intima. Treatment also markedly reduced the protein expression of lipoprotein receptors (LDL receptor, LDL-related protein-1, cluster of differentiation 36, and scavenger receptor class B member 1), inflammatory cytokines (interleukin-1β and tumor necrosis factor-α), matrix metallopeptidase-9, and cell proliferation markers (topoisomerase IIα and tubulin).Conclusion: The ability of LDE-etoposide to strongly reduce the lesion area and the inflammatory process warrants the great therapeutic potential of this novel preparation to target the inflammatory-proliferative basic mechanisms of the disease.Keywords: atherosclerosis treatment, drug delivery, LDL-receptor

Simultaneous transfer of cholesterol, triglycerides, and phospholipids to high-density lipoprotein in aging subjects with or without coronary artery disease

OBJECTIVE: To verify whether the capacity of high-density lipoprotein (HDL) to simultaneously receive nonesterified cholesterol, triglycerides, cholesteryl esters, and phospholipids changes with aging and the presence of coronary artery disease. DESIGN: Cross-sectional study with biochemical analyses. SUBJECTS: Eleven elderly patients with coronary artery disease (74±5 years) were compared with the following groups of non-coronary artery disease subjects (referred to as "healthy"): 25 young (25±5 years), 25 middle-aged (42± years), and 25 elderly subjects (75±8 years). METHODS: Plasma samples were incubated with a nanoemulsion labeled with radioactive lipids; the transfer of the lipids from the nanoemulsion to the HDL was measured in chemically precipitated HDL. HDL size and paraoxonase-1 activity were also determined. RESULTS: The transfer of cholesteryl esters and phospholipids to high-density lipoprotein was significantly greater (p<0.001) in healthy elderly subjects than in the middle-aged and younger subjects. Non-esterified cholesterol and triglyceride transfer was not different among these three groups. The HDL size was significantly greater (p<0.001) in healthy elderly subjects than in the middle-aged and younger subjects. The paraoxonase-1 activity was similar among the groups. Compared with healthy elderly subjects, coronary artery disease elderly subjects had significantly less (p<0.05) transfer of non-esterified cholesterol, triglycerides, and cholesteryl esters to the HDL and a significantly smaller (p<0.05) HDL size. CONCLUSION: Because lipid transfer is enhanced in healthy elderly subjects but not in those with coronary artery disease, increasing lipid transfer to HDL may be a protective mechanism against the disease

Polimorfismo do promotor do gene da leptina está associado ao aumento de leptina plasmática e IMC em mulheres brasileiras

Variants in leptin gene (LEP) have been implicated in the pathogenesis of obesity. The relationship between LEP G-2548A polymorphism and obesity-related traits was evaluated in a sample of Brazilian women (n = 228) who were randomly selected from two clinical centers in Sao Paulo city. Blood samples were collected for DNA extraction, plasma leptin and serum lipids measurements. LEP G-2548A genotypes were identified by a PCR- RFLP strategy using the endonuclease Alw44I. LEP G-2548A was associated with obesity after adjustment for covariates (age, hypertension, coronary artery disease, smoking and physical activity). Women carrying G allele had a four times higher risk of obesity than the A allele carriers (OR: 4.11, CI95%: 1.06-15.90, p = 0.041). G allele was also related to increased plasma leptin (p = 0.024) and body mass index (p = 0.027). Hypertension, hyperglycemia, dyslipidemia and coronary artery disease were associated with obesity. However LEP G-2548A polymorphism was not related to these variables. All together these data suggest that LEP G-2548A polymorphism has an important role in regulating plasma leptin levels and body mass index in women.Variantes no gene da leptina (LEP) foram implicados na patogênese da obesidade. A relação entre o polimorfismo LEP G-2548A e as características relacionadas com a obesidade foram avaliadas em mulheres brasileiras (n = 228), que foram selecionadas randomicamente de dois centros de pesquisa clínica na cidade de São Paulo. As amostras de sangue foram coletadas para extração de DNA e determinações de leptina plasmática e lipídeos séricos. Os genótipos do LEP G-2548A foram identificados pela estratégia de PCR-RFLP, empregando a endonuclease Alw44I. O polimorfismo LEP G-2548A foi associado com obesidade, após ajuste para as covariáveis: idade, hipertensão, doença arterial coronariana, tabagismo e atividade física. Mulheres com alelo G tiveram quatro vezes maior risco de obesidade que as portadoras do alelo A (OR: 4,11, CI95%: 1,06-15,90; p = 0,041). O alelo G também foi relacionado com leptina plasmática (p = 0,024) e o índice de massa corporal (p = 0,027) aumentado. A hipertensão, a hiperglicemia, a dislipidemia e a doença arterial coronariana foram associadas com obesidade. Entretanto, o polimorfismo LEP G-2548A não foi relacionado com essas variáveis. Os resultados deste estudo são sugestivos de que o polimorfismo LEP G-2548A tem papel importante na regulação da leptina plasmática e no índice de massa corporal em mulheres

Efeitos indesejáveis dos hipolipemiantes: condutas na prática clínica Adverse effects of hypolipemic drugs: how to treat in clinical practice

Os fármacos hipolipemiantes, apesar de diminuírem a morbimortalidade por doença coronariana, não são destituídos de efeitos indesejáveis. Estes freqüentemente são transitórios, mas podem ocorrer alterações clínicas e laboratoriais que exigem especial atenção e diferentes condutas. Neste artigo, os autores relatam fundamentalmente como proceder diante do comprometimento muscular e hepático, considerados efeitos adversos mais relevantes dos hipolipemiantes. De modo sucinto, apontam os demais efeitos e a respectiva conduta.<br>Hypolipemic drugs improve coronary morbidity and mortality and appear to be safe; nevertheless appropriate monitoring is recommended. Adverse effects are reported that are frequently transitory. Severe adverse effects are infrequent, but clinicians must correctly screen them; symptoms and laboratory changes must be carefully interpreted. Often they call for special treatment and replacement of the hypolipemic drugs in use. This article emphasizes how to treat dyslipidemia if skeletal muscle and liver involvement are present. Briefly other adverse effects are also reported