Pre-Conception Avocado Powder Diet Decreases Fetal Viability Despite Increasing Placental Energetics in C57BL/6J Mice

Abstract

Objectives To investigate the effects of commercial avocado powder (Hass variety) during pre-conception and gestation on metabolic and reproductive aspects of C57BL/6J mice dams. Methods Female C57BL/6J mice were kept on either a control (AIN 93; CON) or avocado (dextrose and sucrose replacement with 25% commercial avocado power; AVO) isoenergetic diet for 6 weeks prior to conception and during pregnancy (n = 8 per group). Body weight and dietary intake were daily recorded. At day 17 of pregnancy (E17), an intraperitoneal glucose tolerance test (IPGTT) was done. At E18, dams were euthanized by cervical dislocation. Blood was collected for lipid analysis. Maternal liver, placental and foetal weights and sexing were recorded. 1H Nuclear Magnetic Resonance metabolomics was performed in maternal liver and placenta. Results Pre-conception body weight was higher in AVO damns despite similar dietary intake. At E1, average weight was similar in both groups, ∼21 g. AVO diet promoted a hypolipidemic effect where dams showed a tendency to reduce triacylglycerol, total cholesterol and VLDL in 27% and LDL in 43%. AVO dams presented a significant 6% increase in the AUC in the IPGTT (P < 0.05). Body weight at E18 of AVO was 16% lower than the CON dams (P < 0.05). Fetal, placental weights and placental efficiency were similar between groups. However, AVO dams had 25% less viable fetuses and more number of reabsorption spots (P < 0.05). Liver metabolite profile from AVO dams were similar to CON, except for a significant 2-fold increase in glucose and 1.6-fold increase in the fumarate: succinate ratio. Placentas from male fetuses were more susceptible to changes in metabolites compared to female's, in both groups. Male placentas from AVO compared to CON dams had significant increase in methionine, phenylalanine and 3-hydroxybutyrate and increased glucose, lactate and glutamate contents (P < 0.09). Female placentas from AVO dams showed higher contents of AMP, IMP (P < 0.05) and lactate (P < 0.09). A significant interaction between diet and sex for choline content was found, with an increase in its content in male placenta from AVO. Conclusions The hypolipidemic effect of AVO diet might have contributed to its negative effects on reproduction. Whilst, placenta from both sexes seem to be energetically competent and with high availability of methyl donors. Funding Sources CAPES and FAPERJ.