Traces of zinc oxide nanoparticles (ZnO NPs) used may be found in the liver and kidney. The aim of this study is to determine the optimal viability assay for using with ZnO NPs and to assess their toxicity to human hepatocyte (L02) and human embryonic kidney (HEK293) cells. Cellular morphology, mitochondrial function (MTT assay), and oxidative stress markers (malondialdehyde, glutathione (GSH) and superoxide dismutase (SOD)) were assessed under control and exposed to ZnO NPs conditions for 24 h. The results demonstrated that ZnO NPs lead to cellular morphological modifications, mitochondrial dysfunction, and cause reduction of SOD, depletion of GSH, and oxidative DNA damage. The exact mechanism behind ZnO NPs toxicity suggested that oxidative stress and lipid peroxidation played an important role in ZnO NPs-elicited cell membrane disruption, DNA damage, and subsequent cell death. Our preliminary data suggested that oxidative stress might contribute to ZnO NPs cytotoxicity.

Chlorogenic acid (CGA) is a bioactive substance with anti-inflammatory activities. Clusters of CD36 have been suggested to be widely involved in inflammatory damage. However, the mechanism of CGA protecting against LPS-induced inflammation involving the CD36 regulation is unclear. Here, we demonstrated that CGA protected against LPS-induced cell death and decreased the production of ROS. Moreover, the SOD, CAT, and GSH-Px activities were also upregulated in CGA-treated cells during LPS stimulation. CGA reduced COX-2 and iNOS expression and IL-1β, IL-6, and TNF-α secretion in LPS-stimulated RAW264.7 macrophages. In addition, CGA treatment widely involved in immune-related signaling pathways, including NF-κB signaling, NOD-like receptor signaling, and IL-17 signaling using transcriptomic analysis and CD36 also markedly reduced during CGA pretreatment in LPS-induced RAW264.7 cells. Furthermore, the CD36 inhibitor SSO attenuated inflammation and oxidative stress by enabling activation of the AMPK/PGC-1α cascade. These results indicate that CGA might provide benefits for the regulation of inflammatory diseases by modulating CD36/AMPK/PGC-1α to alleviate oxidative stress.

Maltodextrin (MD), the hydrolyzed starch product, is a promising alternative ingredient to improve the quality of starch-based foods. The effects of MD on the physicochemical, microstructural, and cooking properties of sweet potato starch (SPS) noodles, as well as the mechanism of SPS-MD interactions, are discussed. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results indicated that MD at a suitable concentration can improve the ordered structure of SPS-MD gels. The cooking loss showed lower values of 1.47–2.16% at 0.5–2.0 wt% MD. For the texture properties, an increase in hardness and chewiness occurred at first with the addition of MD, followed by a decreasing trend, showing a maximum value at 2.0 wt% of MD. The pasting and thermal results verified the increased stability of the starch granules with MD < 3 wt%. Additionally, SPS formed a solid-like gel with MD, and the main interaction forces between SPS and MD were hydrogen bonding. The scanning electron microscopy results revealed that the higher concentrations of MD (>3 wt%) loosened the gel structure and markedly increased the pore size. These results help us to better understand the interaction mechanism of the SPS-MD complex and facilitate the development of SPS-based gel products.

Different dietary fibers have distinct structures, leading to significant variations in their laxative effects. To explore how these structural differences impact constipation intervention, a 14-day study was conducted on loperamide-induced constipated mice using five dietary fibers: soluble dietary fiber from steamed sweet potato (SDF-S), oat β-glucan (OB), polydextrose (PD), arabinogalactan (AG), and inulin (IN). The results showed that four fibers, excluding PD, significantly improved gastrointestinal (GI) transit rate (p < 0.05), although PD had the highest fecal moisture, it was significantly different from the lowest IN (p < 0.05). AG and IN resulted in higher 6 h fecal weights compared to other fibers. SDF-S and OB were more effective in modulating serum levels of gastrointestinal hormones. The different monosaccharide compositions and glycosidic bonds of these fibers led to distinct changes in gut microbiota composition and SCFA profiles. Galactose and arabinose in AG were linked to increased abundance of Lachnospiraceae_UCG-006, Bacteroides, and Odoribacter, promoting butyrate fermentation, which is positively correlated with GI transit rate. Glucose in SDF-S, OB, and PD favored acetate fermentation positively correlated with fecal moisture. Fructose in IN encouraged the proliferation of Muribaculaceae_unclassified and Ruminococcus, associated with butyrate fermentation and increased 6 h stool weight, respectively. The β-glycosidic bonds in OB may lead to high butyrate production through the selective proliferation of Lachnospiraceae_unclassified. Minor components like fucose, rhamnose, and ribose were positively correlated with the abundance of Oscillospiraceae_unclassified, Anaerotignum, and Lachnospiraceae_unclassified. In conclusion, the unique monosaccharide compositions and glycosidic bond differences in dietary fibers selectively promote the proliferation of fiber-degrading and butyrate-producing bacteria, resulting in varied effects on constipation relief.

To investigate the role of gastrointestinal (GI) polysaccharide fermentation in alleviating constipation, two polysaccharide fractions were isolated from a soluble fiber extract with determined anti-constipation activity: a 2.04 kDa neutral fraction (SSP-1) contained 99.29% glucose, and a 41.66 kDa acidic fraction (SSP-2) contained 63.85% uronic acid. After mice were given loperamide for 14 d to induce constipation, the GI transit rate increased significantly in the SSP-1 group (p < 0.05) but not in the SSP-2 group. The stool weight in the SSP-2 group was significantly higher than that in SSP-1 (383.60 mg vs. 226.23 mg) (p < 0.05). Both SSP-1 and SSP-2 groups had significantly increased serum gastrin and motilin levels (p < 0.05) and changes in their fecal short-chain fatty acid (SCFA) profiles, while SSP-1 showed better fermentation properties than SSP-2 in terms of statistically higher fecal contents of acetic acid and total SCFAs (p < 0.05). Bioinformatic analysis indicated that SSP-1 upregulated bacteria such as Oscillibacter to improve SCFA metabolism and stimulate GI hormone secretion, while SSP-2 had less influence on the gut microbiota. These results suggest that the neutral polysaccharide with superior GI fermentation properties exerted beneficial effects on constipation, while the less fermentable pectic fraction might act as a stool-bulking agent.

The influence of steaming treatment on the soluble dietary fiber (SDF) of sweet potato was investigated. The SDF content increased from 2.21 to 4.04 g/100 g (in dry basis) during 20 min of steaming. The microcosmic morphology of the fractured cell wall indicated the release of SDF components during steaming. The SDF from fresh (SDF-F) and 20 min steamed (SDF-S) sweet potato was characterized. The neutral carbohydrates and uronic acid levels in SDF-S were significantly higher than SDF-F (59.31% versus 46.83%, and 25.36% versus 9.60%, respectively) (p < 0.05). The molecular weight of SDF-S was smaller than SDF-F (5.32 kDa versus 28.79 kDa). The probiotic property was evaluated by four Lactobacillus spp. fermentation in vitro with these SDF as carbon source, using inulin as the references. SDF-F showed the best proliferation effects on the four Lactobacillus spp. in terms of the OD₆₀₀ and pH in cultures, and the highest production of propanoic acid and butyric acid after 24 h fermentation. SDF-S presented higher Lactobacillus proliferation effects, but slight lower propanoic acid and butyric acid production than inulin. It was concluded that 20 min of steaming released SDF with inferior probiotic properties, which might derive from the degraded pectin, cell wall components, and resistant dextrin.