Abstract:

The branch of Lycium barbarum was taken as the main research object. Flavonoids were extracted from Chinese wolfberry branches by microbial fermentation and alcohol extraction, respectively. The results show that the content of flavonoids obtained by microbial fermentation is higher than that obtained by alcohol extraction, indicating that microbial fermentation can improve the content of active components. 1,1-diphenyl-2-trinitrophenylhydrazine （DPPH） colorimetry was used to detect the DPPH scavenging ability of the fermentation broth and alcohol extract of barbarum. The results show that the 50% inhibition concentration （IC₅₀） of DPPH free radical scavenging efficiency of the fermentation liquid and alcohol extract of Chinese wolfberry branches are 20.61 and 25 μg/mL, respectively, indicating that the microbial fermentation liquid has a stronger DPPH free radical scavenging ability. Macroporous adsorption resin was used to isolate and purify flavonoids from the fermentation liquid of Lycium barbarum. The level of reactive oxygen （ROS） in normal human somatic cells is controlled in a very low range, but in an illness state, ROS production can rapidly increase and cause human abnormalities or tissue lesions. The content of ROS in fibroblasts was determined, and the results show that flavonoids from Lycium barbarum has a good scavenging effect on ROS. MTT assay was used to detect the toxicity of the purified flavonoids to fibroblasts （HDF） and human immortalized keratinocytes （HaCaT）. The results show that the survival rate of cells is the highest when the mass concentration of 1 μg/mL of flavonoids is added, so 1 μg/mL of flavonoids is selected as the final concentration. The effects of 2 h treatment of the flavonoids on the content of inflammatory cytokines were investigated, the results show that protein antibody TNF-AIP3 expression is down-regulated; IL6 is up-regulated, and IL8 （CXCL8） expression is down-regulated. IL-6, IL-8 and TNF-AIP3 play an important role in inflammatory response. When inflammation occurs, the expression levels of these three factors change, further promoting the inflammatory response and promoting the progression of the disease. Therefore, using microbial fermentation to extract the branches of Lycium barbarum and add them to pharmaceutical industry or food production can not only reuse resources, but also have certain anti-inflammatory and anti-oxidation effects.

Key words: Chinese wolfberry branches, fermentation, flavonoids, reactive oxygen species, anti-inflammatory