Effect of fermentation modification on the physicochemical characteristics and anti-aging related activities of Polygonatum kingianum polysaccharides.

In order to fully investigate the anti-aging value of the plants polysaccharides, the fermentation method was applied to modify the Polygonatum kingianum polysaccharides (PKPS), and the ultra-filtration was used to further segment the hydrolyzed polysaccharides. It was found that the fermentation induced an increase in the in vitro anti-aging-related activities of PKPS including antioxidant, hypoglycemic and hypolipidemic activity, and cellular aging-delaying ability. In particular, the low Mw fraction PS2-4 (10-50 kDa) separated from the fermented polysaccharide exhibited superior anti-aging activity on experimental animals. PS2-4 extended the Caenorhabditis elegans lifespan by 20.70 %, with an increased effect of 10.09 % compared to the original polysaccharide; it was also more effective than the original one in improving movement ability and reducing lipofuscin accumulation of worms. This fraction was screened as the optimal anti-aging active polysaccharide. After fermentation, the main molecular weight distribution of PKPS changed from 50-650 kDa to 2-100 kDa, and the chemical composition and monosaccharide composition also changed; the initial rough and porous microtopography turned into smooth state. These alterations in physicochemical characteristics suggest that fermentation exerted an influence on the structure of PKPS, which contributed to the enhanced anti-aging activity, indicating that fermentation was promising in the structural modification of polysaccharides.

Comparison of laxative and antioxidant activities of raw, processed and fermented Polygoni Multiflori radix.

AIM: To observe the anti-oxidative activity and adverse laxative effect of raw, traditional processed and fermented products of Polygoni Multiflori Radix (PMR), and furthermore, to evaluate the fermentation method used in the processing procedure of PMR. METHODS: In vitro ferric reducing antioxidant power (FRAP) assay was carried out to evaluate the anti-oxidative activity. Modulation of normal defecation and effect on gastrointestinal motility in mice were carried out to investigate their adverse laxative effect. RESULTS: Fermented PMR induced less severe laxative adverse effect than Polygoni Multiflori Radix Praeparata (PMRP). PMR fermented with Rhizopus sp. (FB) could modulate the defecation significantly. The gastrointestinal motility was inhibited by PMRP and PMR fermented with Rhizopus oryzae (FA). FA and FB showed better antioxidant activity than PMRP in 50% and 95% ethanol group. Contents of 2, 3, 5, 4'-tetrahydroxy-stilbene-2-O-ß-D-glucoside (TSG) were reduced significantly after traditional processing but maintained after fermentation. Emodin and physcion were increased after traditional processing and fermented with Rhizopus oryzae. CONCLUSION: All processing procedure, including fermentation, might reduce its anti-oxidative activity. However, most of the processed products could lessen the adverse effect on gastrointestinal tract compared to PMR. Fermentation with Rhizopus oryzae was considered as a promising processing method of PMR.