Dietary avocado oil supplementation attenuates the alterations induced by type I diabetes and oxidative stress in electron transfer at the complex II-complex III segment of the electron transport chain in rat kidney mitochondria

Abstract

Impaired complex III activity and reactive oxygen species (ROS) generation in mitochondria have been identified as key events leading to renal damage during diabetes. Due to its high content of oleic acid and antioxidants, we aimed to test whether avocado oil may attenuate the alterations in electron transfer at complex III induced by diabetes by a mechanism related with increased resistance to lipid peroxidation. 90 days of avocado oil administration prevented the impairment in succinate-cytochrome c oxidoreductase activity caused by streptozotocin-induced diabetes in kidney mitochondria. This was associated with a protection against decreased electron transfer through high potential chain in complex III related to cytochromes c + c1 loss. During Fe(2+)-induced oxidative stress, avocado oil improved the activities of complexes II and III and enhanced the protection conferred by a lipophilic antioxidant against damage by Fe(2+). Avocado oil also decreased ROS generation in Fe(2+)-damaged mitochondria. Alterations in the ratio of C20:4/C18:2 fatty acids were observed in mitochondria from diabetic animals that not were corrected by avocado oil treatment, which yielded lower peroxidizability indexes only in diabetic mitochondria although avocado oil caused an augment in the total content of monounsaturated fatty acids. Moreover, a protective effect of avocado oil against lipid peroxidation was observed consistently only in control mitochondria. Since the beneficial effects of avocado oil in diabetic mitochondria were not related to increased resistance to lipid peroxidation, these effects were discussed in terms of the antioxidant activity of both C18:1 and the carotenoids reported to be contained in avocado oil.

Effects of diabetes on oxidative and nitrosative stress in kidney mitochondria from aged rats

“…These reports are also in concordance with the free radical theory of aging, which states that accumulation of oxidative damage occurring through the lifespan of the organisms due to normal metabolism leads to cell dysfunction, senescence and death (Sanz and Rhoda 2008). The observation about increased lipid peroxidation in kidney mitochondria of diabetic rats is conflictive with recent data about no effects of STZ-induced diabetes in basal levels of lipid peroxidation and augmented resistance to in vitro-induced lipid peroxidation (Ortiz-Avila et al 2013). The probable reason for these discrepancies is that, as stated above, that experiments were carried out in younger,~3-4 month-old rats.…”

Chemical characterization of commercial and single-variety avocado oils

“…Technologically, the high amount of monounsaturated FA is closely related to the high oxidative stability of oils, since oils with high amounts of polyunsaturated FA are more susceptible to an oxidation process due to the number of double bonds available to react with oxygen. Nutritionally, the consumption of oleic acid has been reported as healthy, supported by the positive effects of the consumption of avocado oil, as already cited in the introduction (Lerman-Gaber et al, 1994, Ortiz-Avila et al, 2013Carvajal-Zarrabal et al, 2014).…”

“…This fact has been used as support for studies that aim to prove the beneficial health effects of this oil, such as a reduction in effects from diabetes, oxidative stress on the mitochondrial membrane and cardiovascular disease markers (Ortiz-Avila et al, 2013;CarvajalZarrabal et al, 2014).…”

Effect of Evolvulus alsinoides on lipid metabolism of streptozotocin induced diabetic rats

“…Phospholipids levels increased in tissues of streptozotocin diabetic rats [18][19][20][21] . Administration of whole plant ethanol extract of E. alsinoides and glibenclamide decreased the levels of phospholipids in both liver and kidney.…”