Astaxanthin, New Research!

Recently, a study from the team of Professor Zhang Xumei and Associate Professor Liu Huan of Tianjin Medical University, and the research team of Professor Zhang Xuguang of By-Health Nutrition and Health Research Institute found for the first time that astaxanthin can delay age-related learning and recognition by inducing autophagy. cognitive ability and exercise ability, and autophagy as an important mechanism affecting aging, suggesting that astaxanthin may be a potential dietary supplement with anti-aging properties.

As a member of the carotenoid family, astaxanthin has its own antioxidant properties. Its antioxidant capacity is more than 100 times that of vitamin E, and it is known as a "super antioxidant".

In 2010, Haematococcus pluvialis was approved as a new resource food by the former Ministry of Health, and the main ingredient is astaxanthin. Haematococcus pluvialis-derived astaxanthin is also used in health food, and the currently approved health functions include antioxidant and immunity enhancement.

In recent years, astaxanthin has received a lot of attention in anti-aging. Previous studies have found that astaxanthin can promote autophagy in multiple organs such as kidney, liver and lung, and play a role in delaying aging. Thanks to the unique water-oil solubility of astaxanthin, it can quickly cross the blood-brain barrier, so will astaxanthin play a similar role in the brain?

The team of Professor Zhang Xumei and Associate Professor Liu Huan of Tianjin Medical University, and the research team of Professor Zhang Xuguang of By-Health Nutrition and Health Research Institute found that astaxanthin can delay age-related cognitive and exercise decline by inducing autophagy. The research results have been published in the authoritative journal "Nutritional Neuroscience" in April 2022.

The researchers first investigated whether astaxanthin could improve age-related cognitive and motor decline, so they conducted the first experiments in which they divided 6-month-old male SAMP10 mice* into four groups, 12 animals in each group were given three different doses of astaxanthin, low (0.4mg/g), medium (0.8mg/g), and high (1.6mg/g) for 3 months, and normal aging SAMR1 Mice and SAMP10 mice not supplemented with astaxanthin served as controls.

The results show that astaxanthin supplementation can improve the decline of learning and memory ability and exercise ability caused by aging, but this improvement effect is not related to the dose itself. The three groups of mice supplemented with different doses of astaxanthin showed no significant difference in learning and memory ability and exercise ability.

Researchers speculate that astaxanthin improves learning and memory ability and exercise ability, and the mechanism of delaying brain aging may include the following three points:

Attenuates neuronal damage in the cerebral cortex and hippocampus

By observing the morphology of neurons in the cerebral cortex and hippocampus CA1 area, the researchers found that the distribution of neurons in mice without astaxanthin was more sparse and disordered, showing mild swelling and degeneration in morphology, indicating that the hippocampus appeared Neurodegenerative changes. Astaxanthin supplementation can delay neuronal degeneration and stimulate neuronal survival, indicating that astaxanthin can partially prevent neurodegenerative changes in the brain.

Up-regulation of autophagy genes induces autophagy

In addition to the neuronal changes observed, the researchers also found that the three groups of mice supplemented with astaxanthin had significantly higher expression of LC3 II/LC3 I (an indicator of autophagy activity) and Beclin-1 (a key regulatory protein complex in autophagy). increased, while the expression of p62 (an autophagy protein, negatively correlated with autophagic activity) was significantly decreased. The results showed that astaxanthin supplementation increased the level of autophagy in brain cells, and moderate doses (0.8 mg/g) of astaxanthin had the best effect on promoting autophagy.

Regulation of signaling pathways to affect autophagy

In addition to relying on autophagy proteins, there are some signaling pathways that also affect autophagy. The experimental results showed that supplementation with astaxanthin would reduce the expression of IGF-1 and p-Akt, thereby inhibiting the activity of mTOR and increasing the level of FoxO3a. Among the three different dose groups, the medium-dose astaxanthin group inhibited mTOR and increased FoxO3a. The level effect is the best. This seems to imply that astaxanthin can affect autophagy by regulating two signaling pathways, IGF-1/Akt/mTOR and IGF-1/Akt/FoxO3a.

In order to prove that astaxanthin delays brain aging mainly through autophagy, the researchers did a second batch of experiments. They set up another group to add autophagy inhibitor 3-MA to astaxanthin, and found that adding autophagy In the inhibitor group, the autophagy induced by astaxanthin was partially offset, and the improvement effect of astaxanthin on learning and memory ability and exercise ability was not as good as before, which further confirmed that astaxanthin induces autophagy by to slow down brain aging.