The effect of the molecular weight of blackberry polysaccharides on gut microbiota modulation and hypoglycemic effect in vivo.

Blackberry polysaccharides with certain molecular weight distribution have good bioactivity. In this research, type 2 diabetes mice were used to investigate the hypoglycemic effect of blackberry polysaccharides with three different molecular weights, BBP (603.59 kDa), BBP-8 (408.13 kDa) and BBP-24 (247.62 kDa), through gut microbiota modulation. Blackberry polysaccharides exhibited stronger hypoglycemic activity after degradation, and the FBG of BBP, BBP-8 and BBP-24 was reduced to 20.21 ± 4.17 mmol L-1, 20.6 ± 7.23 mmol L-1 and 17.32 ± 6.59 mmol L-1 and OGTT-AUC was reduced by 14.76%, 19.80% and 25.04%, respectively, after 8-week intervention. Furthermore, 16S rRNA gene sequencing analysis indicated that BBP, BBP-8 and BBP-24 could reshape the diversity and composition of the gut microbiota. From 0 to 4 weeks, the F/B of BBP, BBP-8 and BBP-24 reduced by 56.44%, 47.19% and 62.04%, reaching 3.39, 6.54, and 3.11 in the 8th week, respectively, which suggested the faster utilization of BBP-24. Moreover, the intervention the three blackberry polysaccharides increased the relative abundance of the targeted beneficial bacteria Oscillospira and Bacteroidaceae Bacteroides and decreased the relative abundance of the pathogenic bacterium Allobaculum. In general, the result demonstrated that blackberry polysaccharides with a lower molecular weight are more easily fermented, making the theoretical basis for the development of blackberry polysaccharides as a probiotic food to rapidly regulate intestinal flora for type 2 diabetes.

Construction of blackberry polysaccharide nano-selenium particles: Structure features and regulation effects of glucose/lipid metabolism in HepG2 cells.

In this study, blackberry polysaccharide-selenium nanoparticles (BBP-24-3Se) were first prepared via Na2SeO3/Vc redox reaction, followed by coating with red blood cell membrane (RBC) to form core-shell structure polysaccharide-selenium nanoparticles (RBC@BBP-24-3Se). The particle size of BBP-24-3Se (167.1 nm) was increased to 239.8 nm (RBC@BBP-24-3Se) with an obvious core-shell structure after coating with RBC. FT-IR and XPS results indicated that the interaction between BBP-24-3 and SeNPs formed a new C-O···Se bond with valence state of Se0. Bioassays indicated that RBC coating markedly enhanced both the biocompatibility and bioabsorbability of RBC@BBP-24-3Se, and the absorption rate of RBC@BBP-24-3Se in HepG2 cells was 4.99 times higher than that of BBP-24-3Se at a concentration of 10 µg/mL. Compared with BBP-24-3Se, RBC@BBP-24-3Se possessed significantly heightened protective efficacy against oxidative damage and better regulation of glucose/lipid metabolism disorder induced by palmitic acid in HepG2 cells. Mechanistic studies demonstrated that RBC@BBP-24-3Se could effectively improve PI3K/AKT signaling pathway to promote glucose metabolism, inhibit the expression of lipid synthesis genes and up-regulate the expression of lipid-decomposing genes through AMPK signaling pathway to improve lipid metabolism. These results provided a theoretical basis for developing a new type of selenium supplement for the treatment of insulin resistance.

Effects of N-succinyl-chitosan coating on properties of astaxanthin-loaded PEG-liposomes: Environmental stability, antioxidant/antibacterial activities, and in vitro release.

Astaxanthin (AST) has outstanding antioxidant and anti-inflammation bioactivities, but the low biocompatibility and stability limit its application in foods. In this study, N-succinyl-chitosan (NSC)-coated AST polyethylene glycol (PEG)-liposomes were constructed to enhance the biocompatibility, stability, and intestinal-targeted migration of AST. The AST NSC/PEG-liposomes were uniform in size, had larger particles, greater encapsulation efficiency, and better storage, pH, and temperature stability than the AST PEG-liposomes. AST NSC/PEG-liposomes exerted stronger antibacterial and antioxidant activities against Escherichia coli and Staphylococcus aureus than AST PEG-liposomes. The NSC coating not only protects AST PEG-liposomes from gastric acid but also prolongs the retention and sustained release of AST NSC/PEG-liposomes depending on the intestinal pH. Moreover, caco-2 cellular uptake studies showed that AST NSC/PEG-liposomes had higher cellular uptake efficiency than AST PEG-liposomes. And AST NSC/PEG-liposomes were taken up by caco-2 cells through clathrin mediated endocytic, macrophage pathways and paracellular transport pathway. These results further proved that AST NSC/PEG-liposomes delayed the release and promoted the intestinal absorption of AST. Hence, AST PEG-liposomes coated with NSC could potentially be used as an efficient delivery system for therapeutic AST.

Cytotoxic activity of kenaf (Hibiscus cannabinus L.) seed extract and oil against human cancer cell lines

<p><b>OBJECTIVE</b>To examine the cytotoxic properties of both the kenaf (Hibiscus cannabinus L.) seed extract and kenaf seed oil on human cervical cancer, human breast cancer, human colon cancer and human lung cancer cell lines.</p><p><b>METHODS</b>The in vitro cytotoxic activity of the kenaf (Hibiscus cannabinus L.) seed extract and kenaf seed oil on human cancer cell lines was evaluated by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and sulforhodamine B assays. Cell morphological changes were observed by using an inverted light microscope.</p><p><b>RESULTS</b>The kenaf seed extract (KSE) exhibited a lower IC50 than kenaf seed oil (KSO) in all of the cancer cell lines. Morphological alterations in the cell lines after KSE and KSO treatment were observed. KSE and KSO possessed effective cytotoxic activities against all the cell lines been selected.</p><p><b>CONCLUSIONS</b>KSE and KSO could be potential sources of natural anti-cancer agents. Further investigations on using kenaf seeds for anti-proliferative properties are warranted.</p>