Avocado Paste Phenolics Mitigate a High-Fat Diet-Induced Plasma HDL Decrease in Male Wistar Rats, by Altering the mRNA Expression of Hepatic SCARB1.

Avocado paste (AP) is the main industrial byproduct of its processing, and retains various phenolic compounds (PCs). PCs are known to normalize the plasma lipid profile, but those from avocado byproducts have been minimally studied. We report the normalizing effects of an AP-derived phenolic extract (PE) on the plasma lipid profile of male Wistar rats. A standard (SD) and high-fat diet (HFD) were formulated, and the same diets were supplemented with 1 g/kg of diet of PE (SD + PE and HFD + PE). Rats were fed these diets during an 8-week period. The HFD induced signs of dyslipidemia, but PE treatment countered the decrease in HDL. Relative mRNA expression (real-time PCR) of the hepatic HDL receptor (SCARB1) increased in both groups (SD + PE and HFD + PE), while the LDR receptor (LDLR) increased in SD + PE group. The mRNA expression of apolipoproteins APOA1 and APOB was unaffected. We conclude that PCs from AP can counter a diet-induced decrease in plasma HDL by acting on the mRNA expression of its hepatic receptor.

Sub-chronic consumption of a phenolic-rich avocado paste extract induces GLP-1-, leptin-, and adiponectin-mediated satiety in Wistar rats.

Avocado paste (AP) is a phenolic-rich byproduct of avocado oil extraction. The effects of sub-chronic consumption of diets supplemented with an AP phenolic extract (PE) were analyzed. A standard diet (SD), high-fat diet (HFD), and these supplemented with PE (SD + PE and HFD + PE) were used. Significantly increased satiety was observed in PE-supplemented groups, according to less food consumption (-15% in SD + PE vs. SD, and -11% in HFD + PE vs. HFD), without changes in weight gain or percentage of adipose tissue. PE-supplemented groups had an increased plasma concentration ( + 16% in SD + PE vs. SD, and +26% in HFD + PE vs. HFD) and relative mRNA expression (+74% in SD + PE vs. SD, and +46% in HFD + PE vs. HFD) of GLP-1; an increase in plasma leptin and adiponectin was independent of their mRNA expression. Our results suggest that AP-derived PE exerts a satiety effect in vivo, possibly mediated by GLP-1, leptin, and adiponectin. PRACTICAL APPLICATIONS: Minimizing food waste is a top priority in most of the world, thus, researchers seek methods to reintroduce industrial fruit and vegetable byproducts into the food processing chain. The present work highlights the potential of avocado byproducts as sources of bioactive phenolic compounds, whose sub-chronic consumption (8 weeks) exerts a satiety action in vivo. Avocado farming is resource-intensive, making it of relevance to producers and processing industries to avoid discarding its byproducts as much as possible.

Phenolic compounds that cross the blood-brain barrier exert positive health effects as central nervous system antioxidants.

The blood-brain barrier (BBB) is a physical structure whose main function is to strictly regulate access to circulating compounds into the central nervous system (CNS). Vegetable-derived phenolic compounds have been widely studied, with numerous epidemiologic and interventional studies confirming their health-related bioactivities across multiple cells, organs and models. Phenolics are non-essential xenobiotics, and should theoretically be unable to cross the BBB. The present work summarizes current experimental evidence that reveals that not only are phenolic compounds able to cross the BBB and bioaccumulate in the brain, but there is some stereoselectivity, which suggests the presence of specific transporters that allow them to reach the brain. Some molecules cross the BBB intact, while others do so only after being biotransformed or metabolized elsewhere. Once inside the CNS, they prevent or counter oxidative stress, which maintains the molecular, cellular, structural and functional integrity of the brain, and subsequently, overall human health.