Millettia speciosa Champ cellulose-based hydrogel as a novel delivery system for Lactobacillus paracasei: Its relationship to structure, encapsulation and controlled release.

We report for the first time the usage of Millettia speciosa Champ cellulose (MSCC) and carboxymethylcellulose (MSCCMC) for the fabrication of 3D-network hydrogel as delivery system for probiotics. The structural features, swelling behavior and pH-responsiveness of MSCC-MSCCMC hydrogels and their encapsulation and controlled-release behavior for Lactobacillus paracasei BY2 (L. paracasei BY2) were mainly studied. Structural analyses demonstrated that MSCC-MSCCMC hydrogels with porous and network structures were successfully synthesized through the crosslinking of -OH groups between MSCC and MSCCMC molecules. An increasing concentration of MSCCMC significantly improved the pH-responsiveness and swelling ability of the MSCC-MSCCMC hydrogel toward neutral solvent. Besides, the encapsulation efficiency (50.38-88.91 %) and release (42.88-92.86 %) of L. paracasei BY2 were positively correlated with the concentration of MSCCMC. The higher the encapsulation efficiency was, the higher the release in the target intestine. However, due to the existence of bile salts, controlled-release behavior decreased the survivor rate and physiological state (degrading cholesterol) of encapsulating L. paracasei BY2. Even so, the number of viable cells encapsulated by hydrogels still reached the minimum effective concentration in the target intestine. This study provides an available reference for the practical application of hydrogels fabricated from the cellulose of the Millettia speciosa Champ plant for probiotic delivery.

Regulation of Hepatocellular Cholesterol Metabolism By Lactobacillus Paracasei BY2 and Its Embedding Delivery.

In this study, five strains of lactic acid bacteria (LAB) with excellent cholesterol-lowering ability were screened from fermented foods. The gastrointestinal stress resistance, intestinal adhesion, and bacteriostasis abilities were evaluated to obtain the best LAB. And then, high-cholesterol HepG2 cell model was further prepared to explore the cholesterol-lowering mechanism of the LAB. Finally, pH-sensitive hydrogel prepared by Millettia speciosa Champ. carboxymethyl cellulose and Millettia speciosa Champ. cellulose was first applied to the microencapsulation of LAB. As a result, Lactobacillus paracasei BY2 (LP-BY2) exhibited higher cholesterol-lowering activity, intestinal adhesion, and bacteriostasis abilities compared with other LAB. Furthermore, it was found that LP-BY2 could reduce the cholesterol level by regulating the expression of key genes that involved in cholesterol synthesis (HMGCR and SREBP-2), uptake (LDLR), and outflow (LXR-α, ABCA1, ABCG5, ABCG8, and CYP7A1) in liver. At the same time, microencapsulation significantly enhanced the survival rate and cholesterol-lowering ability of LP-BY2 after gastrointestinal digestion. This study will provide an available reference for the application of Lactobacillus in prevention and treatment of hypercholesterolemia.