The characteristic of ulcerative colitis (UC) is extensive colonic mucosal inflammation. Moringa oleifera (M. oleifera) is a medicine food homology plant, and the polysaccharide from M. oleifera leaves (MOLP) exhibits antioxidant and anti-inflammatory activity. The aim of this study to investigate the potential effect of MOLP on UC in a mouse model as well as the underlying mechanism. Dextran sulfate sodium (DSS) 4% in drinking water was given for 7 days to mice with UC, at the same time, MOLP (25, 50, and 100 mg/kg/day) was intragastric administered once daily during the experiment. Structural analysis revealed that MOLP had an average molecular weight (Mw) of 182,989 kDa and consisted of fucose, arabinose, rhamnose, galactose, glucose, xylose, mannose, galactose uronic acid, glucuronic acid, glucose uronic acid and mannose uronic acid, with a percentage ratio of 1.64, 18.81, 12.04, 25.90, 17.57, 12.01, 3.51, 5.28, 0.55, 1.27, and 1.43%, respectively. In addition, the features of MOLP were identified by Fourier-transform infrared (FT-IR) and spectra, X-ray diffraction (XRD). The results showed that MOLP exhibited protective efficacy against UC by alleviating colonic pathological alterations, decreasing goblet cells, crypt destruction, and infiltration of inflammatory cells caused by DSS. Furthermore, MOLP notably repressed the loss of zonula occludens-1 (ZO-1) and occludin proteins in mucosal layer, as well as up-regulating the mRNA expression of interleukin-10 (IL-10) and peroxisome proliferator-activated receptor-γ (PPAR-γ), whereas down-regulating the activation of Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), nuclear factor-kappa B (NF-κB) signaling pathway and the production of pro-inflammatory cytokines. Therefore, these results will help understand the protective action procedure of MOLP against UC, thereby providing significance for the development of MOLP.

Extensive efforts are underway to overcome the rising prevalence of antibiotic resistance. Combination therapy may be a potential method to treat multidrug-resistant (MDR) bacterial infections. In this study, tea tree essential oil (TTO) nanoemulsion (nanoTTO) was used in combination with antibiotics to kill microbes. Results showed that nanoTTO enhanced the activities of multiple antibiotics against MDR Escherichia coli (E. coli), and its antimicrobial activity was not changed against bacteria that were cultured in the presence of nanoTTO for 30 passages. Further studies to visualize and quantify intracellular antibiotics concentrations identified that nanoTTO increased the drug accumulation in MDR E. coli by disrupting outer and inner membranes and inhibiting the AcrAB–TolC efflux pump involved in membrane permeability. In addition, nanoTTO was effective in enhancing antibiotic efficacy in the Galleria mellonella infection model and mouse peritonitis model, suggesting a potential strategy against MDR bacterial infections.

Aims We determined the synergistic effects of tea tree essential oil nano-emulsion (nanoTTO) and antibiotics against multidrug resistant (MDR) bacteria in vitro and in vivo. Then the underlying mechanism of action of nanoTTO was investigated. Methods and Results Minimum inhibitory concentrations and fractional inhibitory concentration index (FICI) were determined. The transepithelial electrical resistance (TEER) and the expression of tight junction (TJ) protein of IPEC-J2 cells were measured to determine the in vitro efficacy of nanoTTO in combination with antibiotics. A mouse intestinal infection model evaluated the in vivo synergistic efficacy. Proteome, adhesion assays, quantitative real-time PCR, and scanning electron microscopy were used to explore the underlying mechanisms. Results showed that nanoTTO was synergistic (FICI ≤ 0.5) or partial synergistic (0.5 < FICI < 1) with antibiotics against MDR Gram-positive and Gram-negative bacteria strains. Moreover, combinations increased the TEER values and the TJ protein expression of IPEC-J2 cells infected with MDR E. coli. The in vivo study showed that the combination of nanoTTO and amoxicillin improved the relative weight gain and maintained the structural integrity of intestinal barriers. Proteome showed that type 1 fimbriae D-mannose specific adhesin of E. coli was downregulated by nanoTTO. Then, nanoTTO reduced bacterial adhesion and invasion and inhibited the mRNA expression of fimC, fimG, and fliC, and disrupted bacterial membranes.

Moringa oleifera (MO) is a widely used as the nutritious and non-traditional feed supplementation containing kinds of bioactive substances. However, the enhancement effect of Moringa oleifera leaf Polysaccharide (MOLP) as a feed additive in broilers growth performance and immunity remains unclear. In this study, MOLP was obtained by water extraction and alcohol precipitation method, then purified with Trichloroacetic acid (TCA) assay. Chickens were randomly divided into 4 groups, to receive different doses of MOLP (0, 0.1, 0.2, 0.4g/kg) in feed for 3 weeks. The body weight gain (BWG) and feed consumption were recorded for feed conversion ratio (FCR) and average daily feed intake (ADFI) calculation. Broiler chickens were sacrificed and sampled on day 14, 21, 28 (D 14, D 21, and D 28) respectively. Serological indicators, including total protein (TP), albumin (ALB), globulin (GLO), and creatinine (CREA) were detected. ELISA kits were applied for detecting the levels of immunoglobulin A (IgA), immunoglobulin G (IgG), interleukin-2 (IL-2), and tumor necrosis factor (TNF-α). From D 21 to D 28, the results showed that middle dose of MOLP significantly increased BWG and ADFI as well as liver and bursa indexes when compared with the control group. In addition, TP and GLO were also increased (P<0.05). All MOLP treatments enhanced the serum concentrations of IgG and IL-2 (P<0.01). Furthermore, results of quantitative RT-PCR showed that high dose of MOLP treatment significantly increased (P<0.001) the mRNA expression levels of IL-2 and TNF-α of chickens relative to the control group. In conclusion, the results showed that MOLP supplementation contributed to improve growth performance and immune response in broiler chickens, and MOLP could be considered as a promising feed additive.