Abstract:

Chlorella is a kind of single-celled green algae, which is rich in high-quality protein, linolenic acid, polysaccharides, nucleotides, peptides, vitamins, trace elements and other substances, showing anti-virus, anti-cancer, anti-oxidation, anti-inflammatory functions, etc. Its nutrient composition and biological activity are becoming a research hotspot in recent years. Herein, Chlorella was used as a substrate material to produce Chlorella ferment for cosmetics by fermentation with Lactobacillus plantarum. Taking the Chlorella fermentation product as the research object, the study on its anti-aging effect in vitro and evaluation of its safety were carried out through a variety of methods such as human fibroblast proliferation test, type Ⅰ collagen content test （ELISA）, ABTS free radical scavenging test and the human body closed patch test. The results showed that the Chlorella fermentation product with a volume fraction of 10% could increase the survival rate of human skin fibroblasts, reaching 185.71%±2.25% （P<0.01）, and meanwhile the ability of human skin fibroblasts to synthesize type I collagen was improved, which was 4.43±0.34 times of the negative control （P<0.01）. The Chlorella fermentation product could effectively scavenge ABTS free radicals in a dose-dependent model. When the volume fraction reached 40.5%, the scavenging rate against ABTS free radicals reached 62.73%±1.4% （P<0.01）. The results of the human closed patch test showed that the Chlorella fermentation product had good skin safety. In summary, the Chlorella fermentation product can promote the proliferation of human fibroblasts, increase the content of type I collagen, and scavenge ABTS free radicals, thereby exhibiting good anti-aging effects and good safety to the human body. This provides a better basis for the development and utilization of Chlorella in the field of cosmetics.

Key words: Chlorella, fermentation, raw material of cosmetics, anti-aging, safety