Abstract:

Total saponins, 30% and 60% ethanol crude extracts from Allium chinense were tested on different microorganisms.
The antimicrobial activity of total saponins was determined using filter slice method. In order to explore their antimicrobial
mechanisms from physiological metabolic aspects, glucose content was determined through DNS test, catalase activity was
tested by direct ultraviolet spectrophotometric method, and total protein of bacteria was measured by Bradford method.
The results showed that total saponins had excellent antimicrobial activity against Saccharomycete, Tritirachium album and
Staphylococcus aureus, but very weak or without inhibitory effect against others test microorganisms. At the same time,
glucose utilization rate, catalase activity, and protein content in these microorganisms were reduced and some protein spectra
were weakened obviously even disappeared in the presence of Allium chinense saponins. Based on our current knowledge, the
possible antimicrobial mechanism of total saponins was due to the reduced glucose utilization efficiency in microorganisms,
then affecting their growth and proliferation, reducing the activity of key enzymes in physiological metabolism and suppressing
the synthesis of relevant proteins, and finally executing the antibacterial effect. This study will provide theoretical and practical
application value to reduce the utilization of currently available antibiotics and develop natural antimicrobial drugs.

Key words: Allium chinense, total saponins, antimicrobial activity, antimicrobial mechanism