Maternal diet supplemented with African walnuts enhances cortico-hippocampal gene expression and histomorphology in rat offspring

ABSTRACT

Background

The brain is built up during pregnancy. How it functions afterwards depends on how the expectant mother's diet nourishes it. Walnuts contain significant quantities of polyunsaturated fatty acids (PUFAs) and bioactive phytochemicals, which enhance brain health and function even with advancing age. This study examined the effects of a walnut-enriched diet (WED) on corticohippocampal histoarchitecture and gene expression in rat offspring.

Materials and methods

Twenty-eight female adult Wistar rats (n= 7) averaging about 185 g in weight were used for this study. After mating, pregnant dams were split randomly into four groups: A (standard rat chow/control), B (WED from GD 0 – PND 21), C (WED from GD 0 – PND 1), D (WED from PND 1 – PND 21). Offspring of dams were sacrificed at adolescence (PND 35), with brain tissues of interest harvested for subsequent analyses.

Results

We observed no significant correlates in litter size, body, and brain weights across the experimental groups. Histomorphology revealed no distortion in cellular layering and delineation of cells in the PFC and dentate gyrus of both control and WED groups. Nissl staining intensity was enhanced in the offspring of dams exposed to WED versus the control, indicating improved proteostasis. Upregulated mRNA expression of DNMT3a, H2Ax, OPA1, and BDNF was observed in cortical and hippocampal tissues of WEDexposed offspring compared with the control group.

Conclusion

A diet enriched with African walnuts during early development induced changes predictive of cognitive improvements and enhanced stress-response signalling, plasticity, and neural resilience in rat offspring.

KEYWORDS:

• neurodevelopment
• nutrition
• walnuts
• epigenetics
• plasticity
• neuroprotection‌
• neural resilience
• Wistar rats

Acknowledgement

Our deep appreciation goes to Dr Olaposi Omotuyi of the Center for Bio-computing and Drug Development, Adekunle Ajasin University, Akungba-Akoko, Nigeria, for technical assistance with gene expression assays.

Availability of data

Derived data supporting the findings of this study are available from the corresponding author on request.

Author’s contribution

TTA – research implementation, data analysis, and manuscript report; IG – data interpretation, image analysis, and manuscript revision; BUE – research design and protocol compliance.

Competing interests

The authors declare that the results from this study have not been previously published in any language anywhere and are not under simultaneous consideration by another journal and that all authors approve its publication. There are no conflicts of interest, financial or otherwise.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Tolulope T. Arogundade

Tolulope T. Arogundade obtained his M.Sc. degree in Anatomy from the University of Ilorin, Ilorin, Nigeria. He currently holds a teaching and research associate position with Redeemer’s University Ede, Nigeria. His research interests include multimodal approaches in studying neurodevelopmental forecasts, inflammation, and neurodegeneration in animal models.

Ismail Gbadamosi

Ismail Gbadamosi is a doctoral researcher at the Nencki Institute of Experimental Biology in Warsaw, Poland. His research topics comprise molecular mechanisms of neurodegenerative diseases and employing phytomedicine to remediate pathobiological trajectory of neuroinflammation.

Bernard U. Enaibe

Bernard U. Enaibe is a professor of Anatomy at the University of Ilorin, Ilorin, Nigeria. He received his PhD in Human Anatomy from the Obafemi Awolowo University, Nigeria in 2009. His research focus include developmental neuroscience, neurotoxicology and histochemistry.