Alain R. Rodríguez-Orozco

Protective effects of dietary avocado oil on impaired electron transport chain function and exacerbated oxidative stress in liver mitochondria from diabetic rats.

Electron transport chain (ETC) dysfunction, excessive ROS generation and lipid peroxidation are hallmarks of mitochondrial injury in the diabetic liver, with these alterations also playing a role in the development of non-alcoholic fatty liver disease (NAFLD). Enhanced mitochondrial sensitivity to lipid peroxidation during diabetes has been also associated to augmented content of C22:6 in membrane phospholipids. Thus, we aimed to test whether avocado oil, a rich source of C18:1 and antioxidants, attenuates the deleterious effects of diabetes on oxidative status of liver mitochondria by decreasing unsaturation of acyl chains of membrane lipids and/or by improving ETC functionality and decreasing ROS generation. Streptozocin-induced diabetes elicited a noticeable increase in the content of C22:6, leading to augmented mitochondrial peroxidizability index and higher levels of lipid peroxidation. Mitochondrial respiration and complex I activity were impaired in diabetic rats with a concomitant increase in ROS generation using a complex I substrate. This was associated to a more oxidized state of glutathione, All these alterations were prevented by avocado oil except by the changes in mitochondrial fatty acid composition. Avocado oil did not prevented hyperglycemia and polyphagia although did normalized hyperlipidemia. Neither diabetes nor avocado oil induced steatosis. These results suggest that avocado oil improves mitochondrial ETC function by attenuating the deleterious effects of oxidative stress in the liver of diabetic rats independently of a hypoglycemic effect or by modifying the fatty acid composition of mitochondrial membranes. These findings might have also significant implications in the progression of NAFLD in experimental models of steatosis.

Efecto de la pentoxifilina sobre la evolución de la nefropatía diabética

BACKGROUND AND OBJECTIVE Diabetic nephropathy (DN) is the principal cause of end-chronic kidney disease. Metabolic and hemodynamic components are directly involved. However, convincing data have shown that inflammation participates in the diabetic complications. The aim of this study was to investigate whether the inhibition of the inflammation and pro-inflammatory cytokines with pentoxifylline (PXF) attenuate the progression of the DN. SUBJECTS AND METHOD In a prospective, randomized, double-blind, placebo- controlled study, we evaluated the effect of PXF (1200 mg daily) during 12 months, in 34 patients with incipient or established DN. Evaluated parameters were inflammation, pro-inflammatory cytokines and urinary albumin excretion (UAE). RESULTS PXF treatment had a reno-protective effect determined by a significant reduction in the UAE in both incipient and established (p<0,01) DN patient. This effect was attributed to a reduction in the C-reactive protein, interleukin-6, tumor necrosis factor-alpha and leptin serum levels (p<0,01). CONCLUSIONS PXF treatment caused regression and prevented the progression of renal damage. Thus, PXF should be used in the preventive treatment of DN. These results showed that inflammation and pro-inflammatory cytokines are related to the progression of diabetic nephropathy.

Avocado Oil Improves Mitochondrial Function and Decreases Oxidative Stress in Brain of Diabetic Rats

Diabetic encephalopathy is a diabetic complication related to the metabolic alterations featuring diabetes. Diabetes is characterized by increased lipid peroxidation, altered glutathione redox status, exacerbated levels of ROS, and mitochondrial dysfunction. Although the pathophysiology of diabetic encephalopathy remains to be clarified, oxidative stress and mitochondrial dysfunction play a crucial role in the pathogenesis of chronic diabetic complications. Taking this into consideration, the aim of this work was to evaluate the effects of 90-day avocado oil intake in brain mitochondrial function and oxidative status in streptozotocin-induced diabetic rats (STZ rats). Avocado oil improves brain mitochondrial function in diabetic rats preventing impairment of mitochondrial respiration and mitochondrial membrane potential (ΔΨm), besides increasing complex III activity. Avocado oil also decreased ROS levels and lipid peroxidation and improved the GSH/GSSG ratio as well. These results demonstrate that avocado oil supplementation prevents brain mitochondrial dysfunction induced by diabetes in association with decreased oxidative stress.

OriginalEfecto de la pentoxifilina sobre la evolución de la nefropatía diabéticaEffect of pentoxifylline on the evolution of diabetic nephropathy

BACKGROUND AND OBJECTIVE Diabetic nephropathy (DN) is the principal cause of end-chronic kidney disease. Metabolic and hemodynamic components are directly involved. However, convincing data have shown that inflammation participates in the diabetic complications. The aim of this study was to investigate whether the inhibition of the inflammation and pro-inflammatory cytokines with pentoxifylline (PXF) attenuate the progression of the DN. SUBJECTS AND METHOD In a prospective, randomized, double-blind, placebo- controlled study, we evaluated the effect of PXF (1200 mg daily) during 12 months, in 34 patients with incipient or established DN. Evaluated parameters were inflammation, pro-inflammatory cytokines and urinary albumin excretion (UAE). RESULTS PXF treatment had a reno-protective effect determined by a significant reduction in the UAE in both incipient and established (p<0,01) DN patient. This effect was attributed to a reduction in the C-reactive protein, interleukin-6, tumor necrosis factor-alpha and leptin serum levels (p<0,01). CONCLUSIONS PXF treatment caused regression and prevented the progression of renal damage. Thus, PXF should be used in the preventive treatment of DN. These results showed that inflammation and pro-inflammatory cytokines are related to the progression of diabetic nephropathy.

Vitaminas antioxidantes en asma

Asthma is a condition of unknown etiology characterized by chronic airway inflammation. Cells that mediate the inflammatory response generate reactive oxygen species that, together with other respiratory tract naturally-occurring oxidant species, produce a rupture of the redox balance, generating oxidative stress. It has been proposed that oxidative stress can be reverted by supplemental or dietary intake of antioxidant vitamins such as vitamin A, C, D and E, and this way relieve, improve or protect people with asthma. In this research, observational and placebo-controlled trials with regard to the role of antioxidant vitamins in the course of asthma, published between 1979 and 2016, were reviewed. The search engines were Google and Google Scholar, whereas consulted databases were PubMed and The Cochrane Library. There were 75 articles relevant to the subject that were found and reviewed, and it was concluded that it is not clear if the intake of supplements of these vitamins has any beneficial clinical effect on asthma control. Further controlled, longer trials are needed to elucidate the role of these nutrients in the course of asthma.

Comparative effects of avocado oil and losartan on blood pressure, renal vascular function, and mitochondrial oxidative stress in hypertensive rats

OBJECTIVE Angiotensin II (Ang-II) antagonism alleviates hypertensive kidney damage by improving mitochondrial function and decreasing oxidative stress. This condition also is associated with altered renal vascular tone due to enhanced constriction by Ang-II. Thus, approaches ameliorating these events are desirable to alleviate kidney damage. Avocado oil, a source of antioxidants and oleic acid, is known to improve mitochondrial function, while oleic acid has antihypertensive effects. Therefore, the aim of this study was to test whether avocado oil counteracts, to a similar degree as the Ang-II blocker losartan, the deleterious effects of hypertension on blood pressure, renal vascular performance, kidney mitochondrial function, and oxidative stress. METHODS Hypertensive rats induced with Nω-nitro-l-arginine methyl ester (L-NAME) were supplemented during 45 d with avocado oil or losartan. Vascular responses were analyzed in perfused kidney. Membrane potential, reactive oxygen species levels, and glutathione were analyzed in isolated kidney mitochondria. RESULTS In hypertensive rats, avocado oil decreased 21.2% and 15.5% diastolic and systolic blood pressures, respectively, and alleviated impaired renal vasodilation. Hypertension decreased membrane potential by 83.7% and augmented reactive oxygen species levels by 51% in mitochondria fueled with a complex I substrate, whereas it augmented the levels of oxidized glutathione in 48%. These alterations were normalized by avocado oil at a comparable degree to losartan. CONCLUSIONS Because avocado oil mimicked the effects of losartan, we propose that the effects of avocado oil might be mediated by decreasing the actions of Ang-II on mitochondria. These results suggest that avocado oil intake might be a nutritional approach to attenuate the deleterious effects of hypertension on kidney.