The astaxanthin molecule has some unique properties that lead to strong antioxidant and anti-inflammatory effects. As a result, astaxanthin has a wide range of health benefits for the human body.
The broad range of health benefits astaxanthin provides as a neutraceutical for human is well known. Among these reported health benefits are protection of skin against UV irradiation, faster muscle recovery after exercise and promotion of joint and cardiovascular system health. But what properties of the astaxanthin molecule make it so unique? Why does the compound have such a positive effect on so many different systems of our bodies?
A Unique Carotenoid with Powerful Antioxidant Capabilities
Astaxanthin is a carotenoid compound with deep red coloring properties. The broad positive effect of astaxanthin on the human body is due to its unique molecular structure and amphipathic nature. Astaxanthin has a long chain of alternating double and single bonds that allows the molecule to delocalize unpaired electrons from free radicals and thereby stabilizing them. In other words, it can absorb and neutralize reactive oxygen species (ROD) without becoming unstable itself. Unlike some other antioxidants like beta-carotene or vitamin C at high concentrations, astaxanthin does not switch to pro-oxidant behavior under oxidative stress. This resistance to becoming pro-oxidant makes astaxanthin more consistently protective.
Amphipathic Nature: The Key to Cellular Protection
Another vital feature of the astaxanthin molecule are the polar groups (hydroxyl and keto groups) at each end of the molecule. This gives the molecule the amphipathic nature; the largest part of the compound is lipid-soluble, but the polar groups make each end of the molecule water-soluble. The reason why this is an important feature is that this makes astaxanthin have similar solubility properties to phospholipids, which are the main components of cell membranes. As a result, astaxanthin molecules are capable of spanning the lipid bilayer of cell membranes, positioning the polar ends at the inner and outer surfaces of the cell membrane, and the non-polar middle chain within the membrane core. This orientation lets astaxanthin intercept reactive oxygen species (ROS) both inside and outside the membrane, protecting lipids from peroxidation.
Anti-Inflammatory Mechanisms: Direct and Indirect
The anti-inflammatory properties of astaxanthin are both direct and indirect. Studies have shown that astaxanthin can directly downregulate COX-2 and iNOS expression, which reduces the production of prostaglandin and nitric oxide – two major inflammatory mediators. It also modulates Nrf2, a transcription factor that upregulates the cell’s own antioxidant enzymes. The indirect anti-inflammatory effects are mostly a result of reduced oxidative stress. Reactive oxygen species (ROS) activate pro-inflammatory transcription factors, and by scavenging them, astaxanthin reduces inflammatory gene expression. Also, because astaxanthin embeds itself in cell membranes, it helps maintaining membrane integrity and prevents lipid peroxidation, which otherwise would trigger inflammation.
A Molecule with Broad Systemic Benefits
Reactive oxygen species (ROS) and inflammation are known to have negative effects on a large variety of systems in the human body – and this is why the antioxidant and anti-inflammatory properties of astaxanthin are capable of having such diverse positive effects.
