Polygonati rhizoma fermentation by Monascus ruber and evaluation of fermentation products in vitro

This study investigated the conditions for polygonati rhizoma (PR) fermentation by Monascus ruber and the lipid-lowering activity of the resulting product. Monascus ruber was used for the solid-state fermentation of PR, and the response surface method was used to optimize the fermentation culture medium parameters. The optimal fermentation system yielded a maximum monacolin K concentration of 21.82 ± 0.34 mg/g. The fermentation conditions were as follows: 12.5 mmol/kg of L-glutamic acid, 0.64 mmol/kg of cyclic adenosine monophosphate , 3.0 wt% of yeast extract powder, a fermentation period of 15 days, and a fermentation temperature of 30 ℃. The binding capacities of unfermented PR, “Nine-Steam-Nine-Bask” processed Polygonati rhizoma (NPR), and Monascus ruber solid-state fermented polygonati rhizoma (MPR) to sodium cholate, sodium taurocholate , and sodium glycolate were determined. MPR showed a stronger bile acid-binding capacity than unfermented PR. In addition, MPR exhibited the highest cholesterol inhibitory capacity of 51.43±1.41 %. Thus, MPR can be used as a potential antilipemic agent with potent hypolipidemic effects.