Regulating effects of phytosterol esters-loaded emulsions stabilized with green tea polysaccharide conjugates and Tween on lipids in KKAy mice

Tea Polysaccharide Ameliorates High-Fat Diet-Induced Renal Tubular Ectopic Lipid Deposition via Regulating the Dynamic Balance of Lipogenesis and Lipolysis

Renal tubular ectopic lipid deposition (ELD) plays a significant role in the development of chronic kidney disease, posing a great threat to human health. The present work aimed to explore the intervention effect and potential molecular mechanism of a purified tea polysaccharide (TPS3A) on renal tubular ELD. The results demonstrated that TPS3A effectively improved kidney function and slowed the progression of tubulointerstitial fibrosis in high-fat-diet (HFD)-exposed ApoE-/- mice. Additionally, TPS3A notably suppressed lipogenesis and enhanced lipolysis, as shown by the downregulation of lipogenesis markers (SREBP-1 and FAS) and the upregulation of lipolysis markers (HSL and ATGL), thereby reducing renal tubular ELD in HFD-fed ApoE-/- mice and palmitic-acid-stimulated HK-2 cells. The AMPK-SIRT1-FoxO1 axis is a core signal pathway in regulating lipid deposition. Consistently, TPS3A significantly increased the levels of phosphorylated-AMPK, SIRT1, and deacetylation of Ac-FoxO1. However, these effects of TPS3A on lipogenesis and lipolysis were abolished by AMPK siRNA, SIRT1 siRNA, and FoxO1 inhibitor, resulting in exacerbated lipid deposition. Taken together, TPS3A shows promise in ameliorating renal tubular ELD by inhibiting lipogenesis and promoting lipolysis through the AMPK-SIRT1-FoxO1 signaling pathway.

Green tea polysaccharide conjugates and bovine serum albumin have a synergistic effect in improving the emulsification ability

Our previous study revealed that green tea polysaccharide conjugate (gTPC) has emulsion effect, but its emulsifying ability is weak. In order to improve the emulsification ability of gTPC, gTPC and bovine serum albumin (BSA) were combined to form five different mass proportions of the TPC/BSA (TB) complex: TPC/BSA: 5:1, 5:2, 5:3, 5:4, and 5:5 w/w. We observed that the 5:5 w/w TB emulsion was more hydrophobic and surface-active. Furthermore, the emulsions prepared using 50.00 wt% medium-chain triglycerides exhibited the best stability. In addition, the TB emulsion exhibited stability in adverse environments of pH, salt, and heat; in particular, under salt conditions, no significant changes were observed in zeta potential. Subsequently, in vitro simulated digestion experiments were performed to investigate the use of TB emulsions for β-carotene encapsulation. We observed that the encapsulation efficiency for β-carotene was approximately 90.0 %; it was subsequently released in the intestine.

Physicochemical and Rheological Properties of Succinoglycan Overproduced by Sinorhizobium meliloti 1021 Mutant

Commercial bacterial exopolysaccharide (EPS) applications have been gaining interest; therefore, strains that provide higher yields are required for industrial-scale processes. Succinoglycan (SG) is a type of bacterial anionic exopolysaccharide produced by Rhizobium, Agrobacterium, and other soil bacterial species. SG has been widely used as a pharmaceutical, cosmetic, and food additive based on its properties as a thickener, texture enhancer, emulsifier, stabilizer, and gelling agent. An SG-overproducing mutant strain (SMC1) was developed from Sinorhizobium meliloti 1021 through N-methyl-N'-nitro-N-nitrosoguanidine (NTG) mutation, and the physicochemical and rheological properties of SMC1-SG were analyzed. SMC1 produced (22.3 g/L) 3.65-fold more SG than did the wild type. Succinoglycan (SMC1-SG) overproduced by SMC1 was structurally characterized by FT-IR and 1H NMR spectroscopy. The molecular weights of SG and SMC1-SG were 4.20 × 105 and 4.80 × 105 Da, respectively, as determined by GPC. Based on DSC and TGA, SMC1-SG exhibited a higher endothermic peak (90.9 °C) than that of SG (77.2 °C). Storage modulus (G') and loss modulus (G″) measurements during heating and cooling showed that SMC1-SG had improved thermal behavior compared to that of SG, with intersections at 74.9 °C and 72.0 °C, respectively. The SMC1-SG's viscosity reduction pattern was maintained even at high temperatures (65 °C). Gelation by metal cations was observed in Fe3+ and Cr3+ solutions for both SG and SMC1-SG. Antibacterial activities of SG and SMC1-SG against Escherichia coli and Staphylococcus aureus were also observed. Therefore, like SG, SMC1-SG may be a potential biomaterial for pharmaceutical, cosmetic, and food industries.