Dr. Ron’s Research Review – February 1, 2012

This week’s research review presents the effects of olive oil and coconut oil on 3beta-HSD.

Animals fed with the olive oil and coconut oil diets showed the highest testicular levels of antioxidants in addition to significantly high levels of testosterone and 3beta- or 17beta-hydroxysteroid dehydrogenase enzymes. (Hurtado de Catalfo, de Alaniz et al. 2008)

The activity of both key enzymes involved in testosterone biosynthesis (3-beta-HSD and 17-beta-HSD) was higher in olive and coconut oil groups. (Hurtado de Catalfo, de Alaniz et al. 2009)

Dr. Ron


Articles

Dietary lipids modify redox homeostasis and steroidogenic status in rat testis

            (Hurtado de Catalfo, de Alaniz et al. 2008) Download

OBJECTIVE: The present study explored the effect of dietary oils on lipid composition, antioxidant status, and the activity of the main steroidogenic enzymes in the testis. METHODS: Forty Wistar rats were randomly assigned to one of four groups (n = 10) fed for 60 d on the same basal diet plus different lipid sources as commercial oils: soybean, olive, coconut, or grapeseed. After sacrifice, testicular lipids and fatty acid composition, free radical biomarkers, antioxidant levels, hormones, and steroidogenic enzymes were determined. RESULTS: The lipid composition of diets produced significant changes in neutral/phospholipids, free/esterified cholesterol, and plasmalogen proportion. Fatty acid patterns of these lipids were also strongly modified, influencing the double bond index. We also found a close correlation between the type of diet and the generation of free radicals. The oxidative stress in testes was higher with the grapeseed oil-supplemented diet and decreased with the other diets in this order: soybean oil > olive oil > coconut oil. Animals fed with the olive oil and coconut oil diets showed the highest testicular levels of antioxidants in addition to significantly high levels of testosterone and 3beta- or 17beta-hydroxysteroid dehydrogenase enzymes. CONCLUSION: Different oils in the diets strongly modified the homeostasis of the testicular antioxidant defense system and, in consequence, affected steroidogenic function, showing a clear correlation with the damage induced. According to our results, an appropriate mixture of olive and soybean oils could be a healthy recommendation.

Influence of commercial dietary oils on lipid composition and testosterone production in interstitial cells isolated from rat testis

            (Hurtado de Catalfo, de Alaniz et al. 2009) Download

The aim of this study was to examine the influence of dietary fat on lipid composition, as well as on the steroidogenic function of interstitial cells isolated from Wistar rats that had been fed semi-synthetic diets containing four different commercial oils (S soybean, O olive, C coconut, and G grape seed). Steroidogenic enzyme activities, lipid composition, and androgen production were measured in testicular interstitial cells. Lipid analysis included measurement of the contents of major lipid subclasses (neutral lipids, polar lipids, free and esterified cholesterol), as well as principal polar and neutral lipid fatty acyl compositions. Significant differences in lipid composition were observed among the groups, most of them reflecting the specific fatty acyl composition of the diet tested. Testosterone concentration was higher in O and C groups compared with S or G. In agreement with this observation, the activity of both key enzymes involved in testosterone biosynthesis (3-beta-HSD and 17-beta-HSD) was higher in O and C groups with significant differences between them (O > C). A significant negative correlation was found between cellular testosterone production and cellular cholesterol ester content. Additionally, testosterone concentration directly correlated with cholesterol levels. We conclude that dietary oils qualitatively and quantitatively modified the lipid composition of interstitial cells, producing either a direct or indirect regulatory effect on testicular steroidogenic function.

References

Hurtado de Catalfo, G. E., M. J. de Alaniz, et al. (2008). "Dietary lipids modify redox homeostasis and steroidogenic status in rat testis." Nutrition 24(7-8): 717-26.

Hurtado de Catalfo, G. E., M. J. de Alaniz, et al. (2009). "Influence of commercial dietary oils on lipid composition and testosterone production in interstitial cells isolated from rat testis." Lipids 44(4): 345-57.