Polysaccharides derived from mushrooms have potential to control blood sugar, reduce insulin resistance and prevent diabetic complications. The intracellular polysaccharopeptides of Trametes versicolor (TV) have been used as immunologic and oncologic adjuvants. The aim of this study was to investigate the potential activities and mechanisms of extracellular polysaccharopeptides (ePSP) obtained from TV strain LH-1 on regulating glucose homeostasis. Human hepatoma HepG2 cells incubated with normal glucose (5.5 mM, NG model), high glucose (33 mM, HG model), or high glucose (33 mM) plus high insulin (10⁻⁷ M, HGI model) concentrations were administered with TV LH-1 ePSP (50, 100, and 1000 μg/ml) for 24 hr. Glucose uptake of HepG2 cells, determined by flow cytometry, was significantly decreased in the HG and HGI models with insulin stimulation, suggesting insulin resistance of these cells; however, ePSP reversed this decrease in a dose-dependent manner (one-way ANOVA, p<0.05). In the HG and HGI models, ePSP significantly increased glycogen content, insulin receptor substrate-2 protein and phosphorylated AMP-activated protein kinase (AMPK), as determined by western blot analysis. In addition, ePSP significantly increased glucokinase in the NG and HG models, increased membrane glucose transporter-1 and decreased glycogen synthase kinase-3β in the HGI model, and increased glucose-6-phosphatase in the NG and HGI models (one-way ANOVA, p<0.05). In summary, TV LH-1 ePSP may elevate cellular glucose uptake to regulate glucose homeostasis via the activation of AMPK and glycogen synthesis in an insulin-independent manner. These results suggest that TV LH-1 ePSP may be a nutraceutical with anti-hyperglycemic activity.

Healthy aging is defined as the process of developing and maintaining functional ability in older age with intrinsic capacity, the composite of all the physical and mental capacities of an individual, being the core. This study was conducted to explore the intervention effects of improved dietary quality on intrinsic capacity. A prospective single-group interventional quasi-experimental study with 59 functional independent older adults from retirement homes were recruited. Texture-modified plant-based dietary supplements were provided. In addition, dietary intake, functional ability, and intrinsic capacity in vitality, locomotion, cognition, and psychological capacity were assessed. Vitality was captured by nutritional status, muscle strength, and cardiorespiratory endurance. Locomotor capacity was assessed based on the performance of physical fitness in backscratch test, chair-sit-and-reach test, chair-stand test, one-foot-standing test, and gaits peed. Psychomotor capacity and cognition were measured by using 15-item Geriatric Depression Scale (GDS-15) and Mini-Mental State Examination (MMSE), respectively. In a 4-month of intervention, after controlling for baseline values and covariates, participants with higher dietary intervention adherence showed a significant improvement over time in vitality captured by cardiorespiratory endurance (P_interaction = 0.009) and significant improvement in locomotion captured by gait speed (P_clusters = 0.034). A significant decrease in the chair-stand test (P_time = <0.001) and MMSE (P_time = 0.022) was observed during the four months of intervention. Enhanced intrinsic capacity further contributed to the improvement of ADL over time (P_interaction = 0.034). In conclusion, healthy eating enhances intrinsic capacity in vitality and locomotion thus promoting functional ability among older adults.

Chronic inflammation accompanied by arginine deficiency, immune dysfunction, and excess nitric oxide (NO) production is a clinical condition found in patients with peritonitis. A previous study showed that the nonselective NOS inhibitor N^G-nitro-L-arginine methyl ester (L-NAME) may facilitate the metabolism of the immune nutrient arginine without altering NO homeostasis in rats with sub-acute peritonitis. Here, we investigated the effects of L-NAME on the immunocytic subpopulation distribution and response. Male Wistar rats with cecal puncture-induced peritonitis were administered parenteral nutrition solutions supplemented with 0 (CPP group), 5 (LNA group), 25 (MNA group) or 50 (HNA group) mg·kg⁻¹·day⁻¹ of L-NAME for 7 days. Parenteral-fed sham-operated rats (TPN group) and orally-fed healthy rats (R group) were included as controls. The TPN group had significantly increased spleen weights and levels of plasma nitrite/nitrate (NOx), circulating white blood cells (WBC), and splenocytic T cells, as well as significantly decreased levels of cytotoxic T- and B-leukocytes and B-splenocytes compared to the R group. The CPP group had significantly decreased levels of plasma NOx and concanavalin (Con) A-stimulated interferon (IFN)-γ and interleukin (IL)-2 production by leukocytes and significantly increased production of Con A-stimulated tumor necrosis factor (TNF)-α and lipopolysaccharide (LPS)-stimulated IFN-γ in the leukocytes. In addition, the LNA and MNA groups had significantly decreased spontaneous IL-6 and Con A-stimulated TNF-α and IFN-γ production by the leukocytes while the HNA group had significantly increased LPS-stimulated TNF-α and Con A-stimulated IFN-γ and IL-2 production by the splenocytes compared to the CPP group. Low-dose L-NAME infusion may suppress proinflammatory and T-helper-1 (Th1) response in leukocytes, and high-dose infusion may activate the proinflammatory response in splenic macrophages and Th1 response in T-splenocytes in rats with sub-acute peritonitis.

Plant-rich diets alleviate oxidative stress and gut dysbiosis and are negatively linked to age-associated chronic disorders. This study examined the effects of consuming plant-based, antioxidant-rich smoothies and sesame seed snacks (PBASS) on antioxidant ability and gut microbial composition in older adults. Healthy and sub-healthy older adults (n = 42, 79.7 ± 8.6 years old) in two senior living facilities were given PBASS for 4 months. Blood and fecal samples were collected from these individuals at the baseline and after 2 and 4 months of PBASS consumption. After 2 months, serum levels of albumin and high-density lipoprotein-cholesterol and the ratio of reduced to oxidized glutathione (GSH/GSSG) had increased significantly and erythrocytic glutathione, GSH/GSSG and superoxide dismutase activity had decreased significantly compared with baseline levels (p < 0.05). After 4 months, red blood cells, hematocrit, serum blood urea nitrogen and erythrocyte glutathione peroxidase activity had decreased significantly, whereas plasma and erythrocyte protein-bound sulfhydryl groups had increased significantly. Furthermore, plasma glutathione and total antioxidant capacity were significantly greater after 2 months and increased further after 4 months of PBASS consumption. The results of next generation sequencing showed that PBASS consumption prompted significant decreases in observed bacterial species, their richness, and the abundance of Actinobacteria and Patescibacteria and increases in Bacteroidetes in feces. Our results suggest that texture-modified, plant-based snacks are useful nutrition support to benefit healthy ageing via the elevation of antioxidant ability and alteration of gut microbiota.