Health Benefits of Marine Ingredients: Astaxanthin, Seaweed, and Algae

What are seaweed, algae, and astaxanthin?

Astaxanthin, a potent carotenoid, is primarily derived from microalgae, while seaweed and other algae encompass a broad spectrum of macroscopic and microscopic photosynthetic organisms.

Seaweeds are macroscopic marine algae, broadly classified into red, brown, and green varieties based on their pigmentation, and are rich in minerals, carbohydrates, and proteins² (Figure 1).

Figure 1: Sargassum sp.

Taken from:  Abdi G, Karande VC, Mohammed A, Abbasi Tarighat M, Wen Goh K, Abdul Kari Z, Seong Wei L, Ahmad Mohd Zain MR, Mohammadi M, Ee Lee G and Barwant MM (2022) Pharmacological potential of Sargassum sp. of west coast of Maharashtra Kunkeshwar, India. Front. Mar. Sci. 9:1011218. doi: 10.3389/fmars.2022.1011218

In contrast, microalgae such as Haematococcus pluvialis are microscopic, unicellular organisms renowned for their biosynthesis of potent carotenoids like astaxanthin³. Astaxanthin, a xanthophyll carotenoid, is particularly noted for its exceptional antioxidant capacity, significantly surpassing that of other well-known antioxidants such as beta-carotene and alpha-tocopherol⁴.

How are they sourced for industry purposes?

The industrial sourcing of these compounds leverages the rapid growth rates and high metabolic plasticity of microalgae, enabling efficient cultivation for targeted compound extraction⁵. Specifically, Haematococcus pluvialis is extensively cultivated for its high astaxanthin content, which exhibits a broad spectrum of pharmacological effects, including anti-inflammatory, anti-diabetic, and neuroprotective properties^6,7.

Despite these promising attributes, astaxanthin’s clinical applicability is often hampered by its poor bioavailability, low stability, and limited solubility, necessitating advanced formulation strategies for enhanced therapeutic efficacy⁸. Furthermore, the diverse biochemical profiles of various algae and seaweeds yield a wide array of co-nutrients, including specific B vitamins and polyphenols, which can synergistically enhance the bioavailability and therapeutic impact of astaxanthin⁹.

For instance, the xanthophylls found in algae, such as fucoxanthin from brown seaweeds, are recognized for their anti-tumor and anti-inflammatory activities. Zeaxanthin is a structural isomer of lutein. Both isomers are usually found in various foods, mainly found in green leafy vegetables and algae¹⁰.

The microalga Haematococcus pluvialis is recognized as the optimal natural source of astaxanthin^11,12 (Figure 2), while other microalgae such as Chlorella zofingiensis also show promise¹³.

Figure 2: Light microscopic images of H. pluvialis cells in life cycle

(A) Green vegetative motile cell; (B) Green vegetative palmella cell; (C) Astaxanthin accumulating palmella cell in transition to aplanospore; (D) Astaxanthin accumulated aplanospore cell. Scale bar: 10 μm. Taken from: Shah MMR, Liang Y, Cheng JJ and Daroch M (2016) Astaxanthin-Producing Green Microalga Haematococcus pluvialis: From Single Cell to High Value Commercial Products. Front. Plant Sci. 7:531. doi: 10.3389/fpls.2016.00531

Therapeutic potential of these natural compounds

Therapeutic potential of these natural compounds includes immune-modulatory, antioxidative, and anti-inflammatory properties, contributing to overall health and disease prevention^14,15.

Astaxanthin exhibits superior antioxidant capabilities compared to other common antioxidants¹⁶. Its unique molecular structure enables efficient quenching of singlet oxygen and scavenging of free radicals^17,18. Furthermore, astaxanthin demonstrates neuroprotective effects by reducing pro-inflammatory cytokine expression and reactive oxygen species production¹⁹.

Beyond astaxanthin, marine natural products from seaweeds present diverse bioactivities, including anti-aging, anti-cancer, anti-diabetic, and fertility-enhancing properties²⁰. Marine algae are significant sources of proteins, fatty acids, carbohydrates, vitamins, and minerals with applications in pharmaceutical and nutraceutical industries²¹.

Seaweeds are rich in bioactive metabolites and represent a promising resource for drug development^22,23. They contain pigments like fucoxanthin, polysaccharides like fucoidan, and a wide range of micronutrients¹⁵. Their bioactive compounds, such as phycocyanin, lutein, zeaxanthin, and β-carotene, further support their role as a functional food source¹⁴.

Marine algae are considered underexploited bioresources with strong biomedical potential²⁴, showing antioxidant, antibacterial, antiviral, and anti-inflammatory effects²⁴.

Neuroprotective effects are also observed, particularly through modulation of pathways such as NF-κB/Akt and MAPK^25,26, contributing to protection against neurodegenerative diseases²¹. Additional evidence highlights the importance of secondary metabolites and sulfated phenolic compounds in delivering antioxidant and antimicrobial benefits^23,26,27.

Seaweed bioactives such as phycobiliproteins and fucoidans further contribute to antioxidant, anti-inflammatory, and antiviral effects²⁸. Their complex composition – including saccharides, proteins, phenolics, fatty acids, vitamins, and minerals – makes them highly valuable for dietary applications^14,29.

Astaxanthin for eye health and skin protection

Astaxanthin plays a key role in protecting ocular tissues from oxidative stress and supporting retinal health. Additional carotenoids such as lutein and zeaxanthin contribute to protection against oxidative damage in the eye³⁰.

Marine bioactives also modulate inflammatory pathways by influencing macrophage activity and reducing cytokine production^31,32. Compounds such as astaxanthin and fucoxanthin reduce IL-6 and oxidative stress, contributing to neuroprotection²⁶.

They also attenuate microglial activation, relevant in neurodegenerative diseases such as Parkinson’s disease³³. Phlorotannins from brown algae exhibit strong antioxidant properties and modulate oxidative stress-related enzymes^34,29,35, making them promising candidates for nutraceutical and pharmaceutical use^22,36.

Seaweed in supplements and functional food

Seaweed extracts are widely used in functional foods due to their bioactive compounds such as phlorotannins and carotenoids^37,38. These compounds provide immunomodulatory and antioxidant benefits^34,39,32.

Polysaccharides like fucoidan and laminarin contribute to immune enhancement and show anti-diabetic and antimicrobial effects¹⁵. Brown algae compounds like fucoxanthin regulate oxidative stress and inflammation⁴⁰.

Algae omega potential in supplementation

Phlorotannins and other algal metabolites also show potential in neurodegenerative disease prevention⁴¹.

Algae are rich in omega-3 fatty acids, essential for cardiovascular and cognitive health⁴². These compounds improve neuronal membrane function and synaptic plasticity⁴³, supporting memory and learning⁴⁴.

Sustainability of algal omega-3

Algae cultivation represents a sustainable alternative to fish-derived omega-3 sources, reducing environmental impact and overfishing^45,46.

Conclusion

Marine-derived bioactives, particularly astaxanthin and seaweed compounds, offer significant therapeutic potential. Their mechanisms include reducing oxidative stress, modulating inflammation, and protecting against neurodegeneration^47–50.

Microalgae-derived compounds such as lutein and sulfated polysaccharides further contribute to antioxidant defense and disease prevention⁵¹. Their rich composition makes them promising ingredients for functional foods and nutraceuticals targeting chronic and neurodegenerative diseases⁵².

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