Chinese scientists show that the use of nano-encapsulated suspensions not only benefits the absorption of DHA by the fetal brain, but also in the brain of the mother of the fetus and her offspring.
In subsequent behavioral assessments, the DHA nanoencapsulation (FO) diet showed improved learning and memory compared to the normal fish oil (FO) diet.
“Our team innovated nano-encapsulation technology, which has been shown to be an effective technology for protecting DHA from oxidation in vivo, thereby improving the absorption and effectiveness of DHA,” said Dr. Wang Yi, lead author and assistant professor of the study at Hong Kong Polytechnic University.
“Our results also showed that the technology can help cross the blood-brain barrier in DHA delivery. We therefore believe that the technology could be further applied to improve the efficiency of drug delivery to the brain, for example for patients with dementia or Alzheimer’s disease. “
Because DHA is highly unsaturated and is prone to oxidation and degradation under acidic conditions, the research team is unsure whether the intake of DHA is effectively delivered and absorbed by a supplementation regimen in vivo.
DHA is highly concentrated in the human brain and cerebral cortex, particularly as structural lipid components of biomembranes, and is essential for the development and function of the brain.
Extensive research has identified its role in synaptic processes, neuronal differentiation and growth, and the regulation of neurotransmission and neuroinflammation.
Zein, an edible corn protein.
Together with Dr. Yi, Professor Wong Man-sau, another professor at the university, and colleagues used zein, an edible corn protein, as an encapsulation material to mimic the milk fat globule membrane and protect DHA from oxidation.
This material forms a core-shell structure to protect DHA in fish oil during stomach digestion and to aid DHA absorption in the brain, intestines and placenta.
Next, they took two groups of six maternal mice each and fed them normal fish oil (Normal FO) and nano-encapsulated fish oil (Nano FO), respectively.
The team found that DHA levels in the duodenum and jejunum in the nano-FO group were significantly higher than in the normal FO group.
“The result implies that DHA, protected by the encapsulating structure from oxidation and degradation under acidic conditions of the stomach, is successfully released in the upper two parts of the small intestine of the Nano FO group,” the team said.
Additional results showed that DHA levels in the brain of the maternal nano-FO mice were significantly higher, suggesting that DHA delivery via the nano-FO was more effective at crossing the blood-brain barrier.
The brain benefits from high DHA levels .
Further experiments on the offspring of the maternal mice yielded remarkable evidence of early brain development in mice in the face of the nanoencapsulation suspension of DHA.
Here the researchers divided the mice into six groups of 10 each. They were either fed without a DHA meal; Zein; normal low dose fish oil (normal FO low); normal high-dose fish oil (normal FO-high); Nano-Encapsulated Low Dose Fish Oil (Nano FO-Low); and nano-encapsulated high-dose fish oil (Nano FO-high).
It was observed that three groups, Normal FO-high, Nano FO-low, and Nano FO-high, spent more time on new objects than on familiar objects, indicating an advanced learning and memorizing ability.
In the Nano FO-High group, higher levels of brain-derived neurotrophic factor (BDNF) were found in the hippocampus.
BDNF, a protein “switched on” by DHA, is involved in the survival of brain neurons and promotes the growth of new ones.
These mice also demonstrated better spatial learning and memory skills in the Y-maze experiment, an assessment of rodents’ willingness to explore new environments.
“The nano-encapsulation of zein has great potential for delivery of drugs and nutrients to the brain and across the placenta to the fetus with no toxicity concerns,” the study concluded.
Source: Nanomedicine: Nanotechnology, Biology and Medicine
Published online: doi.org/10.1016/j.nano.2018.09.006.
“A biomimetic of the nano-encapsulation suspension of the milk structure to improve the absorption of DHA by the mother and fetus to improve early brain development.”
Authors: Jie Zeng et al.