Semen Quality and Sperm Function Loss by Hypercholesterolemic Diet Was Recovered by Addition of Olive Oil to Diet in Rabbit

et al. (2013) Semen Quality and Sperm Function Loss by Hypercholesterolemic Diet Was Recovered by Addition of Olive Oil to Diet in Rabbit. PLoS ONE 8(1): e52386. doi:10.1371/journal.pone.0052386 Semen Quality and Sperm Function Loss by Hypercholesterolemic Diet Was Recovered by Addition of Olive Oil to Diet in Rabbit Tania E. Saez Lancellotti 0 Paola V. Boarelli 0 Aida A. Romero 0 Abi K. Funes 0 Macarena Cid-Barria 0 Mara E. Cabrillana 0 Mara A. Monclus 0 Layla Simo n 0 Amanda E. Vicenti 0 Miguel W. Forne s 0 Shree Ram Singh, National Cancer Institute, United States of America 0 1 Laboratorio de Investigaciones Androlo gicas de Mendoza (LIAM), Instituto de Histolog a y Embriolog a (IHEM), Facultad de Ciencias Me dicas, Universidad Nacional de Cuyo, Centro Cient fico Tecnol o gico (CCT) - Consejo Nacional de Investigaciones Cient ficas y Te cnicas (CONICET) , Mendoza , Argentina , 2 Instituto de Investigaciones, Facultad de Ciencias Me dicas, Universidad del Aconcagua , Mendoza , Argentina Fat increment (0.05% cholesterol, chol) in standard diet promoted a significant increase in serum and sperm membrane chol, which ultimately altered membrane-coupled sperm specific functions: osmotic resistance, acrosomal reaction, and sperm capacitation in White New Zealand rabbits. These changes were also associated with a reduction in motility percentage and appearance of abnormal sperm morphology. The present study was carried out to evaluate the effect of dietary olive oil (OO, 7% v/w) administration to several male hypercholesterolemic rabbits (hypercholesterolemic rabbits, HCR) with altered fertility parameters. These HCR males were achieved by feeding normal rabbits with a high-fat diet (0.05% chol). HCR were associated with a modest non-significant increase in body weight (standard diet, 4.0860.17 Kg, versus high-fat diet, 4.3760.24 Kg). Hypercholesterolemic rabbits presented a marked decrease in semen volume, sperm cell count, and percentage of sperm motility, associated with a significant increase in sperm cell abnormalities. Moreover, sperm capacitation measured by the characteristic phosphorylated protein pattern in and induced acrosomal reaction were also altered suggesting sperm dysfunction. However, the administration of OO (for 16 weeks) to rabbits that were fed with 50% of the high-fat diet normalized serum chol. Curiously, OO supply succeeded to attenuate the seminal and sperm alterations observed in HCR group. Administration of OO alone did not cause any significant changes in above mentioned parameters. These data suggest that OO administration to HCR male rabbits recovers the loss of semen quality and sperm functionality. - Funding: Funding provided by Program 20112014, Secretary of Science and Technology (SECyT), National University of Cuyo; and Projects 2011, 2012, 2013, Committee of Investigations of Aconcagua University (CIUDA), Aconcagua University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. . These authors contributed equally to this work. The relationship between obesity/hypercholesterolemia and reduced male fertility has been reported clinically and in experimental models [112]. The effect of high cholesterol (chol) intake and its impact in different tissue/organs has also been described in several models [13]. The deleterious impact on reproductive tissues has been studied in rabbits and other species [6,7,10,1418]. Changes in lipid content in testis [19] and epididymal cells [20] were reported in normal or genetically reprogrammed animals. But few papers were focused on the addition of natural products in the food as a protective diet, in order to avoid sperm alteration [14,15]. In the experimental setting, male animals fed with a high-fat diet were associated with deleterious changes in semen and sperm cells. Alterations reported include decreased volume semen and sperm number associated with an increase in sperm abnormal morphology in rabbit and mouse models [12,16,21,22]. Furthermore, fat-enriched diets - fat from animal source - also had an impact on cell function, such as sperm cell functionality [12,22]. Changes in sperm membrane chol concentration and distribution lead to alteration of membrane-coupled sperm specific functions: sperm motility, membrane osmotic resistance to hipoosmotic shock, sperm capacitation and induced acrosomal reaction (AR) were all significantly reduced; probably due to an increase in membrane chol content [12]. Capacitation and AR are processes required for fertilizing the oocyte in vivo. During sperm capacitation, a number of changes occur at the sperm surface such as membrane protein and lipid re-organization. These changes are likely to result in the capacitated state which characteristically allows the sperm to bind the pellucid zone and immediately thereafter to acrosome react [2325]. Olive oil, a component of Mediterranean diet, has been proposed by several studies as a protective agent against vascular injury promoted by acquired hypercholesterolemia [26]. Interheart studies [13], population studies [27] and animal models [28,29] analyzed the negative effect of chol serum increase and the corresponding protection by OO administration. In the present report we took advantage of our established rabbit model of diet-induced hypercholesterolemia [12] to assess whether OO administration can recover semen and sperm parameters altered in dietary acquired hypercholesterolemia. We found that supplementing fat diet with OO improved not only serum cholesterol level but also semen quality and sperm function. Materials and Methods Ethics statement The animal studies described here were reviewed and approved by the animal care and use committee of School of Medicine, National University of Cuyo (Institutional Committee for Use of Laboratory Animals, IACUC [30]). Reagents Unless otherwise stated, all chemicals and solvents of the highest grade available were obtained from Sigma (St. Louis, MO, USA) and Merck (Darmstadt, Germany). Olive oil (OO) used corresponds to virgin OO. Animals and diets For the purposes of this study, twenty fertile male White New Zealand rabbits (517 months old of age, acquired from Don Cipriano farm, Mendoza, Argentina) were caged individually during 12 months with a photoperiod of 12 hours light/day and a temperature ranging from 1825uC. Animals were fed ad libitum with a standard rabbit diet following our previous animal model [12]. At five months of age (experimental time = 0 months), rabbits were divided into two groups (4/12 animals each) maintaining the average of body weight in both experimental groups. The first group (4 animals), which served as control (designated normal cholesterolemic rabbits, NCR, Figure 1), continued fed with standard cereal-based chow for this specie during the entire experiment (normal diet, ND (...truncated)