Effects of acetyl groups on the prebiotic properties of glucomannan extracted from Artemisia sphaerocephala Krasch seeds.

This study explores the structural modification of glucomannan extracted from Artemisia sphaerocephala Krasch seeds (60S) to assess the impact of acetyl groups on its prebiotic characteristics. The structural changes were examined, with a focus on the degree of acetyl group substitution (DS). Both deacetylation and acetylation had limited influence on the molecular properties of 60S. Despite these modifications, the apparent viscosity of all samples remained consistently low. In vitro fermentation experiments revealed that Escherichia-Shigella decreased as DS increased, while Bacteroides ovatus was enriched. Acetylation had no significant impact on the utilization rate of 60S but led to a reduction in the production of propionic acid. Furthermore, untargeted metabolomics analysis confirmed the changes in propionic acid levels. Notably, metabolites such as N-acetyl-L-tyrosine, γ-muricholic acid, and taurocholate were upregulated by acetylated derivatives. Overall, acetyl groups are speculated to play a pivotal role in the prebiotic properties of 60S.

Cascade Catalytic Nanoparticles Selectively Alkalize Cancerous Lysosomes to Suppress Cancer Progression and Metastasis.

Lysosomes are critical in modulating the progression and metastasis for various cancers. There is currently an unmet need for lysosomal alkalizers that can selectively and safely alter the pH and inhibit the function of cancer lysosomes. Here an effective, selective, and safe lysosomal alkalizer is reported that can inhibit autophagy and suppress tumors in mice. The lysosomal alkalizer consists of an iron oxide core that generates hydroxyl radicals (•OH) in the presence of excessive H+ and hydrogen peroxide inside cancer lysosomes and cerium oxide satellites that capture and convert •OH into hydroxide ions. Alkalized lysosomes, which display impaired enzyme activity and autophagy, lead to cancer cell apoptosis. It is shown that the alkalizer effectively inhibits both local and systemic tumor growth and metastasis in mice. This work demonstrates that the intrinsic properties of nanoparticles can be harnessed to build effective lysosomal alkalizers that are both selective and safe.

The anti-obesity effects exerted by different fractions of Artemisia sphaerocephala Krasch polysaccharide in diet-induced obese mice.

Artemisia sphaerocephala Krasch polysaccharide (ASKP) consists of two main fractions, 60P (molecular weight at 551 kDa) and 60S (molecular weight at 39 kDa). The anti-obesity effects of ASKP and its two fractions were investigated in high-fat-diet-fed mice and showed similar capability in efficiently preventing the development of obesity. The final body weight and body weight gain of obesity mice model were reduced by 12.44% and 35.33% by ASKP, 10.63% and 34.35% by 60P, and 7.82% and 20.04% by 60S. They also showed similar efficiency to ameliorate dyslipidemia, systematic inflammation, and gut dysbiosis. The colonic genes of barrier integrity were significantly upregulated and the genes of hepatic lipid metabolism and that of colonic inflammatory response were suppressed. They attenuated the gut dysbiosis in obese mice, such as the significant enrichment of beneficial genera (Bifidobacterium and Olsenella) and suppression of harmful ones (Mucispirillum and Helicobacter). Significant enrichment of carbohydrate metabolism associated with the promotion of short-chain fatty acid production and decrease of the metabolisms related to obesity and gut dysbiosis (valine, leucine, and isoleucine biosynthesis, and nitrogen metabolism) were also observed by the administration of ASKP, 60P, and 60S. Overall, these polysaccharides showed potential in acting as prebiotics in preventing high-fat-diet-induced obesity.

Prebiotic properties of different polysaccharide fractions from Artemisia sphaerocephala Krasch seeds evaluated by simulated digestion and in vitro fermentation by human fecal microbiota.

Artemisia sphaerocephala Krasch polysaccharide (ASKP) and its two fractions-60P (branched xylan) and 60S (branched glucomannan), were subjected to simulated gastrointestinal digestion and in vitro fermentation by human fecal microbiota. The results showed that all polysaccharide fractions could transit through gastrointestinal tract without dramatic degradation and be utilized by gut microbiota. ASKP exhibited the highest depletion rate and highest capability to decrease the pH than its fractions. Meanwhile, 60S showed the stronger capability to increase the production of propionic acid and reduce the ratio of acetic acid to propionic acid. At the phylum level, all polysaccharides efficiently reduced the Firmicutes/Bacteroidetes ratio and relative abundance of Proteobacteria, with ASKP being the most capable to suppress the proliferation of Proteobacteria. At the genus level, ASKP and 60P markedly promoted the growth of Bacteroidetes, and 60S promoted the growth of Parabacteroides and Collinsella. Prediction on metabolic function revealed that polysaccharide administration could dramatically change the metabolic profile of bacteria compared with fructooligosaccharides. Besides, all the polysaccharides dramatically promoted the bile acid metabolism. Compared with 60S, ASKP and 60P showed stronger ability to suppress the metabolisms on carbohydrate and amino acid. In summary, both ASKP and its two fractions showed the prebiotic potentials.