[Different processed products of Polygonati Rhizoma treat Alzheimer's disease in rats: urine metabolomics based on UPLC-Q/TOF-MS].

The study investigated the effects of different processed products of Polygonati Rhizoma(black bean-processed Polygonati Rhizoma, BBPR; stewed Polygonati Rhizoma, SPR) on the urinary metabolites in a rat model of Alzheimer's disease(AD). Sixty SPF-grade male SD rats were randomized into a control group, a model group, a donepezil group, a BBPR group, and a SPR group, with twelve rats in each group. Other groups except the control group were administrated with D-galactose injection(100 mg·kg~(-1)) once a day for seven weeks. The control group was administrated with an equal volume of normal saline once a day for seven consecutive weeks. After three weeks of D-galactose injection, bilateral hippocampal Aß_(25-35) injections were performed for modeling. The rats were administrated with corresponding drugs(10 mL·kg~(-1)) by gavage since week 2, and the rats in the model and control group with an equal volume of double distilled water once a day for 35 continuous days. The memory behaviour and pathological changes in the hippocampal tissue were observed. The untargeted metabolites in the urine were detected by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q/TOF-MS). Principal component analysis(PCA) and orthogonal partial least square-discriminant analysis(OPLS-DA) were employed to characterize and screen differential metabolites and potential biomarkers, for which the metabolic pathway enrichment analysis was conducted. The results indicated that BBPR and SPR increased the new object recognition index, shortened the escape latency, and increased the times of crossing the platform of AD rats in the Morris water maze test. The results of hematoxylin-eosin(HE) staining showed that the cells in the hippocampal tissue of the drug administration groups were closely arranged. Moreover, the drugs reduced the content of interleukin-6(IL-6, P<0.01) and tumor necrosis factor-α(TNF-α) in the hippocampal tissue, which were more obvious in the BBPR group(P<0.05). After screening, 15 potential biomarkers were identified, involving two metabolic pathways: dicoumarol pathway and piroxicam pathway. BBPR and SPR may alleviate AD by regulating the metabolism of dicoumarol and piroxicam.

Ascorbate exacerbates iron toxicity on intestinal barrier function against Salmonella infection.

Ascorbic acid is often used to enhance iron absorption in nutritional interventions, but it produces pro-oxidant effects in the presence of iron. This study aimed to evaluate ascorbate's role in iron toxicity on intestinal resistance against foodborne pathogens during iron supplementation/fortification. In polarized Caco-2 cell monolayers, compared to the iron-alone treatment, the iron-ascorbate co-treatment caused more than 2-fold increase in adhesion, invasion and translocation of Salmonella enterica serovar Typhimurium. According to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, lactate dehydrogenase release and transepithelial electrical resistance, the iron-ascorbate co-treatment resulted in reduced cell viability and increased impairment of cell membrane and paracellular permeability compared to the iron-alone treatment. Butylated hydroxytoluene protected cells against these prooxidant toxicities of ascorbate. Ascorbate completely restored iron-induced intracellular oxidant burst and depletion of cytosolic antioxidant reserve, according to dichlorodihydrofluorescein fluorescence and intracellular reduced glutathione levels. In Salmonella-infected C57BL/6 mice, iron-ascorbate co-supplementation resulted in greater loss of body weight and appetite, lower survival rate, shorter colon length, heavier intestinal microvilli damage, and more intestinal pathogen colonization and translocation than the iron-alone supplementation. Overall, ascorbate would exacerbate iron toxicity on intestinal resistance against Salmonella infection through pro-oxidant impairment of intestinal epithelial barrier from extracellular side and/or by facilitating intestinal pathogen colonization.

Microalgae aqueous extracts exert intestinal protective effects in Caco-2 cells and dextran sodium sulphate-induced mouse colitis.

Microalgae are emerging as a good source of natural nutraceuticals. Here, we examined the intestinal protective effects of microalgae aqueous extracts (MAEs) from Chlorella pyrenoidosa, Spirulina platensis, and Synechococcus sp. PCC 7002 in human intestinal epithelial Caco-2 cells and dextran sodium sulphate (DSS)-induced colitis in C57BL/6 mice. MAEs displayed intestinal barrier-protective activities in Caco-2 cells by increasing the expression of heat shock protein (Hsp)-27 and tight junction proteins of occludin and claudin-4 and attenuating the H2O2-induced intracellular reactive oxygen species production, plasma membrane impairment and apoptosis. They also showed anti-inflammatory potential in tumor necrosis factor (TNF)-α-, interleukin (IL)-1ß- and H2O2-stimulated Caco-2 cells by suppressing the secretion of IL-8 and the expression of cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS). The 8 d daily intragastric administration of MAEs during and after 4 d DSS exposure effectively alleviated colitis symptoms of weight loss, diarrhea, rectal bleeding, and colon shortening and histopathology, protected intestinal barrier function by increasing colonic Hsp-25, occludin and claudin-4, and attenuated colonic and systemic inflammation by suppressing colonic myeloperoxidase activity, production of TNF-α, IL-1ß and IL-6, expression of COX-2 and iNOS, and peripheral leukocytosis, monocytosis and granulocytosis. Microalgae can thus serve as a functional food to maintain gut health.

Triterpenoid glycosides from Stauntonia chinensis.

A new bidesmoside triterpenoid saponin, named stauntoside C1 (1), along with three known saponins (2-4) was isolated from Stauntonia chinensis DC. (Lardizabalaceae). Their structures were established by means of spectral and chemical methods as 3-O-beta-D-xylopyranosyl-(1 --> 2)-O-beta-D-xylopyranosyl-(1 --> 3)-O-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (1), scabiosaponin E (2), sieboldianoside B (3), and kizutasaponin K(12) (4).