Origin and Extraction of Chlorella Active Peptides​

Chlorella, a unicellular green alga, thrives in various aquatic environments. It is rich in proteins, and through specific enzymatic hydrolysis or fermentation processes, these proteins can be broken down into smaller peptide fragments, namely Chlorella active peptides. The extraction process is a delicate balance of science and technology. First, Chlorella cells need to be disrupted to release their protein – rich contents. This can be achieved through mechanical methods such as high – pressure homogenization or sonication, or by using chemical agents in a more controlled manner. After that, specific proteases are added to cleave the proteins into peptides. Advanced separation techniques like chromatography and ultrafiltration are then employed to purify and isolate the desired active peptides from the complex mixture.​

Diverse Biological Activities​

Antioxidant Powerhouse​

One of the most well – studied functions of Chlorella active peptides is their potent antioxidant activity. In our bodies, oxidative stress occurs when there is an imbalance between the production of free radicals and the body’s ability to neutralize them. These free radicals can damage cells, proteins, and DNA, leading to various health issues such as premature aging, inflammation, and chronic diseases. Chlorella active peptides, with their unique amino acid sequences, can act as free radical scavengers. For example, certain peptides contain amino acids like cysteine, which has a thiol group that can donate a hydrogen atom to a free radical, thereby stabilizing it and preventing further oxidative damage. In a study, human skin cells treated with a novel tripeptide (cysteine – alanine – serine, CAS) derived from Chlorella vulgaris showed an increment in antioxidant genes, suggesting enhanced protection against reactive oxygen species (ROS). This antioxidant property not only benefits the skin by protecting it from UV – induced damage and maintaining its youthful appearance but also has implications for overall health, potentially reducing the risk of diseases associated with oxidative stress.​

Regulation of Lipid Metabolism​

Research has also indicated that Chlorella active peptides may play a role in regulating lipid metabolism. High levels of lipids in the blood, such as triglycerides and cholesterol, are risk factors for cardiovascular diseases. Some Chlorella – derived peptides have been found to inhibit the activity of pancreatic lipase, an enzyme responsible for the digestion and absorption of dietary fats. By suppressing pancreatic lipase, these peptides can reduce the amount of fat absorbed from the diet, leading to a decrease in blood lipid levels. In an experiment using high – sugar diet – fed Caenorhabditis elegans as a model, a purified peptide fraction from Chlorella pyrenoidosa (PES) was shown to have good hypolipidemic activity. At a concentration of 1 mg/mL, it inhibited lipid deposition by 22.5% and reduced the levels of triglyceride and total cholesterol by 27.4% and 29.4% respectively. This discovery holds great promise for the development of functional foods or nutraceuticals to manage lipid – related health problems.​

Neuroprotective Effects​

Emerging evidence suggests that Chlorella active peptides may have neuroprotective properties, which could be beneficial for neurodegenerative diseases. Alzheimer’s disease, for instance, is characterized by the accumulation of extracellular beta – amyloid (Aβ) plaques and intracellular tau neurofibrillary tangles, leading to neuronal apoptosis and cognitive impairment. Studies on Chlorella pyrenoidosa short – chain peptides (CPPs) have shown that peptides with molecular weights of 1 – 3 kDA and 3 – 10 kDA could elevate the survival rate of Aβ1 – 42 or L – glutamic acid – injured N2a cells in vitro. These treatments also inhibited Aβ and tau neurofibrillary tangles in N2a cells and prevented progressive neuronal cellular damage by suppressing inflammatory cytokines. In an in – vivo Aβ1 – 42 – induced Alzheimer’s disease mouse model, the 1 – 3 kDA or 3 – 10 kDA CPPs could improve spatial cognition and learning memory, and a decreased cell loss ratio was observed in the CA1 – CA3 hippocampal regions. Although more research is needed to fully understand the underlying mechanisms, these findings open up new possibilities for the prevention or treatment of neurodegenerative disorders.​

Antimicrobial and Anti – inflammatory Potential​

Chlorella active peptides have also demonstrated antimicrobial and anti – inflammatory activities. In the context of periodontal diseases, which are caused by infectious bacteria and are associated with inflammation in the periodontium, Chlorella vulgaris peptides (CVP) have shown some interesting effects. The CVP with molecular weights of 3 – 10 kDA and 10 – 30 kDA were found to inhibit the growth of bacteria such as Streptococcus mutans, Streptococcus sanguis, and Porphyromonas gingivalis. In addition, they elevated the survival rate of SCC – 4 and RAW264.7 cells under lipopolysaccharide (LPS) – treatment and reduced osteoclast numbers. In an in – vivo study, mice treated with CVP 3 – 10 kDA gel showed a significantly reduced oral bacterial count and MCP – 1 (a marker of inflammation), possibly by regulating TLR4 signaling and inhibiting inflammatory cytokines such as IL – 6 and TNF – α. This indicates that Chlorella active peptides could potentially be developed into novel therapies for infectious and inflammatory diseases.​

Future Perspectives​

The study of Chlorella active peptides is still in its early stages, but the potential applications are vast. As research continues to unfold, we may see the development of new drugs, functional foods, and nutraceuticals based on these peptides. However, there are also challenges to overcome. For example, improving the efficiency of peptide extraction and purification processes to make large – scale production more economically viable. Additionally, more in – depth studies are needed to fully understand the safety and long – term effects of these peptides when consumed or used in medical applications.​

In conclusion, Chlorella active peptides represent a fascinating area of research with great potential for improving human health. Their diverse biological activities, from antioxidant and lipid – regulating to neuroprotective and antimicrobial effects, make them a promising candidate for various applications in the fields of medicine, nutrition, and cosmeceuticals. With further research and development, these tiny peptides derived from the humble Chlorella microalga could play a significant role in enhancing our well – being and quality of life.​