A Flavonoid Concentrate from Moringa Oleifera Lam. Leaves Extends Exhaustive Swimming Time by Improving Energy Metabolism and Antioxidant Capacity in Mice.

Moringa oleifera Lam. leaves contain various nutrients and bioactive compounds. The present study aimed to assess the anti-fatigue capacity of a flavonoids concentrate purified from M. oleifera Lam. leaves. The total flavonoids in the purified extract were analyzed by ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-MS/MS). The mice were supplemented with purified M. oleifera Lam. leaf flavonoid-rich extract (MLFE) for 14 days. The weight-loaded forced swimming test was used for evaluating exercise endurance. The 90-min non-weight-bearing swimming test was carried out to assess biochemical biomarkers correlated to fatigue and energy metabolism. UPLC-MS/MS analysis identified 83 flavonoids from MLFE. MLFE significantly increased the swimming time by 60%. Serum lactate (9.9 ± 0.9 vs. 8.9 ± 0.7), blood urea nitrogen (BUN) (8.8 ± 0.8 vs. 7.2 ± 0.5), and nonesterified fatty acid (NEFA) (2.4 ± 0.2 vs. 1.7 ± 0.3) were significantly elevated; phosphoenolpyruvate carboxykinase (PEPCK), glucokinase (GCK), and nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA expression were significantly downregulated; and heme oxygenase 1 mRNA expression was significantly upregulated in muscle after swimming. MLFE supplement significantly decreased serum lactate (8.0 ± 1.0 vs. 9.9 ± 0.9), BUN (8.6 ± 0.4 vs. 8.9 ± 0.8), and NEFA (2.3 ± 0.4 vs. 2.4 ± 0.2) and increased the protein and mRNA expression of GCK, PEPCK, and Nrf2. The enhancement of glucose metabolism and antioxidant function by MLFE contributes partly to its anti-fatigue action.

Vitamin B6 alleviates chronic sleep deprivation-induced hippocampal ferroptosis through CBS/GSH/GPX4 pathway.

Several studies have found that sleep deprivation (SD) can lead to neuronal ferroptosis and affect hippocampal function. However, there are currently no effective interventions. Vitamin B6 is a co-factor for key enzymes in the transsulfuration pathway which is critical for maintaining cell growth in the presence of cysteine deprivation. The results showed that SD inhibited cystine-glutamate antiporter light chain subunit xCT protein expression and caused cysteine deficiency, which reduced the synthesis of the glutathione (GSH) to trigger neuronal ferroptosis. Nissl staining further revealed significant neuronal loss and shrinkage in the CA1 and CA3 regions of the hippocampus in SD mice. Typical ferroptotic indicators characterized by lipid peroxidation and iron accumulation were showed in the hippocampus after sleep deprivation. As expected, vitamin B6 could alleviate hippocampal ferroptosis by upregulating the expression of cystathionine beta-synthase (CBS) in the transsulfuration pathway, thereby replenishing the intracellular deficient GSH and restoring the expression of GPX4. Similar anti-ferroptotic effects of vitamin B6 were demonstrated in HT-22 cells treated with ferroptosis activator erastin. Furthermore, vitamin B6 had no inhibitory effect on erastin-induced ferroptosis in CBS-knockout HT22 cells. Our findings suggested chronic sleep deprivation caused hippocampal ferroptosis by disrupting the cyst(e)ine/GSH/GPX4 axis. Vitamin B6 alleviated sleep deprivation-induced ferroptosis by enhancing CBS expression in the transsulfuration pathway.

Riboflavin deficiency reduces bone mineral density in rats by compromising osteoblast function.

Insufficient riboflavin intake has been associated with poor bone health. This study aimed to investigate the effect of riboflavin deficiency on bone health in vivo and in vitro. Riboflavin deficiency was successfully developed in rats and osteoblasts. The results indicated that bone mineral density, serum bone alkaline phosphatase, bone phosphorus, and bone calcium were significantly decreased while serum ionized calcium and osteocalcin were significantly increased in the riboflavin-deficient rats. Riboflavin deficiency also induced the reduction of Runx2, Osterix, and BMP-2/Smad1/5/9 cascade in the femur. These results were further verified in cellular experiments. Our findings demonstrated that alkaline phosphatase activities and calcified nodules were significantly decreased while intracellular osteocalcin and pro-collagen I c-terminal propeptide were significantly increased in the riboflavin-deficient osteoblasts. Additionally, the protein expression of Osterix, Runx2, and BMP-2/Smad1/5/9 cascade were significantly decreased while the protein expression of p-p38 MAPK were significantly increased in the riboflavin-deficient cells compared to the control cells. Blockage of p38 MAPK signaling pathway with SB203580 reversed these effects in riboflavin-deficient osteoblastic cells. Our data suggest that riboflavin deficiency causes osteoblast malfunction and retards bone matrix mineralization via p38 MAPK/BMP-2/Smad1/5/9 signaling pathway.

[Effects of nutritional preparation on HPO axis function and energy metabolism in uterus and ovary of rats exposed to intermittent cold].

Objective: To investigate the effects of a self-designed nutritional preparation on hypothalamic-pituitary-ovarian (HPO) axis function and energy metabolism in female SD rats exposed to intermittent cold. Methods: Female SD rats were divided into control group, cold exposure group and nutritional preparation group. The control group and cold exposure group were given distilled water by daily gavage, and the nutritional preparation group was given nutritional preparation intragastrically. After the treatment, the cold exposure group and nutritional preparation group were exposed to -10℃ in a cabin for 4 h every day. After being treated for 14 days, the serum, uterus and ovary of rats were collected. The serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and other hormone indicators were detected by enzyme-linked immunosorbent assay (ELISA) and colorimetry was used to detect ATPase and other energy metabolism related indicators. Results: Compared with the control group, cold exposure significantly up-regulated the protein expressions of FSHR and LHR, and notably enhanced the activity of Na+-K+-ATPase and Ca2+-Mg2+-ATPase in ovary and uterus (P<0.05). Nutritional preparation down-regulated the protein expressions of FSHR and LHR, and inhibited the activity of ATPase in ovary and uterus (P<0.05) compared with the cold exposure group. Conclusion: Nutritional preparations can effectively improve the expressions of HPO axis related receptors and abnormal energy metabolism in uterus and ovary caused by intermittent cold exposure.

[Antifatigue effects of the composition of Moringa oleifera leaves and Polygonatum polysaccharide and its mechanisms].

Objective: To investigate the anti-fatigue effects of composition of Moringa oleifera leaves and Polygonatum polysaccharide, and to explore the mechanisms. Methods: Thirty male Kunming mice were randomly divided into control (C) and composition of Moringa oleifera leaves and Polygonatum polysaccharide group (MP). There were 15 mice in each group. Group C was given distilled water and the group MP was given composition intragastriclly every day. The volume was 0.5 ml. After 14 days of treatment, weight-bearing swimming experiment was conducted, and exhaustive swimming time was recorded. The bearing weight was 3% of the body weight. In another experiment, 48 male Kunming mice were randomly divided into quiet control group (QC), swimming control group (SC) and composition group (MP). There were 16 mice in each group. The QC and SC groups were given distilled water intragastrically, and the group MP was treated with composition every day for 14 days. The volume was 0.5 ml. On the day 15, 30 minutes after intragastriclly administration of distilled water, blood, liver and hind leg muscle of the QC group were collected immediately. The SC and MP groups were subjected non-weight-bearing swimming experiment, and blood, liver and hind leg muscle were collected after swimming. The fatigue related indexes, oxidant/antioxidant parameters and energy metabolism indicators in serum and tissues were determined by commercial kits. Results: The exhaustive swimming time of mice in MP group was significantly longer than that in the C group (P<0.05). Compared with the control group, non-weight-bearing swimming decreased the contents of serum glucose and GSH, the contents of hepatic glycogen and ATP, the hepatic activities of SOD, LDH and ATPase, and muscle activity of GSH-Px (P< 0.05). However, serum levels of BUN and MDA were increased (P<0.05). Compared with the SC group, the composition remarkably increased the contents of serum glucose and hepatic glycogen, increased serum content of GSH, enhanced hepatic activities of SOD, LDH and ATPase and muscle activity of GSH-Px, and increased the hepatic content of ATP (P<0.05). However, the serum level of BUN was decreased (P<0.05). Conclusion: The Moringa oleifera leaves and Polygonatum polysaccharide composition possesses anti-fatigue effects. Anti-oxidant and improving energy metabolism could be the important mechanisms.

Quercetin positively affects gene expression profiles and metabolic pathway of antibiotic-treated mouse gut microbiota.

Quercetin has a wide range of biological properties that can be used to prevent or decrease particular inflammatory diseases. In this study, we aimed to investigate the gene expression profile and metabolic pathway of the gut microbiota of an antibiotic-treated mouse model administered quercetin. Blood, feces, and intestinal tissue samples were collected and metagenomic sequencing, enzyme-linked immunosorbent assay, and western blot analysis were used to detect variations. The results showed that the quercetin-treated group exhibited increased levels of health beneficial bacterial species, including Faecalibaculum rodentium (103.13%), Enterorhabdus caecimuris (4.13%), Eggerthella lenta (4%), Roseburia hominis (1.33%), and Enterorhabdus mucosicola (1.79%), compared with the model group. These bacterial species were positively related to butyrate, propionate, and intestinal tight junction proteins (zonula occludens-1 and occludin) expression, but negatively related to serum lipopolysaccharide and tumor necrosis factor-α level. In addition, the metabolic pathway analysis showed that dietary quercetin significantly enhanced spliceosomes (111.11%), tight junctions (62.96%), the citrate cycle (10.41%), pyruvate metabolism (6.95%), and lysine biosynthesis (5.06%), but decreasing fatty acid biosynthesis (23.91%) and N-glycan (7.37%) biosynthesis. Furthermore, these metabolic pathway changes were related to relative changes in the abundance of 10 Kyoto Encyclopedia of Genes and Genomes genes (K00244, K00341, K02946, K03737, K01885, k10352, k11717, k10532, K02078, K01191). In conclusion, dietary quercetin increased butyrate-producing bacterial species, and the acetyl-CoA-mediated increased butyrate accelerated carbohydrate, energy metabolism, reduced cell motility and endotoxemia, and increased the gut barrier function, thereby leading to healthy colonic conditions for the host.

Remote cyclic compression ameliorates myocardial infarction injury in rats via AMPK-dependent pathway.

BACKGROUND: Remote ischemic conditioning (RIC) displays a cardioprotective role in acute myocardial infarction (AMI). Since interruption of blood vessel is not an essential trigger of remote cardioprotection, tissue compression may play a prominent part in the effect. The purpose of this study was to confirm the protective effect of tissue compression on AMI and the underlying mechanisms. METHODS AND RESULTS: Rat model of AMI was induced by ligation of the left anterior descending coronary artery. Remote cyclic compression (RCC) on forelimb was applied to AMI rats for 3 days after the operation. RCC postconditioning displayed cardioprotective effects against AMI injury by limiting infarct size, alleviating cardiac dysfunction, and suppressing cardiomyocyte apoptosis. In addition, RCC postconditioning induced myocardial autophagy as evidenced by increased LC3-II and Beclin-1 and reduced mTOR levels. Furthermore, RCC treatment upregulated AMPK phosphorylation in the context of AMI hearts. AMPK inhibitor Compound C administration markedly abrogated RCC-mediated cardioprotective effect, as evidenced by decreased infarct size and cardiac function. CONCLUSION: Our results indicated that RCC postconditioning could attenuate AMI injury through inhibiting apoptosis and promoting autophagy via AMPK signaling pathway. The research provided a novel perspective for studying the cardioprotection of RIC and possible therapeutic strategy for managing AMI injury.

Remote Conditioning by Rhythmic Compression of Limbs Ameliorated Myocardial Infarction by Downregulation of Inflammation via A2 Adenosine Receptors.

Background: Remote ischemic conditioning (RIC) is a cardioprotective phenomenon, yet transient ischemia is not a requisite trigger for remote cardioprotection. In fact, RIC is a stimulus compound containing interruption of the blood vessel and tissue compression. In this study, we evaluate the effects of remote tissue compression on infarct size after myocardial infarction and explore its preliminary mechanisms. Methods and Results: We used a murine model of myocardial infarction to assess ischemia injury and identified remote conditioning by rhythmic compression on forelimb as a novel cardioprotective intervention. We show that the cardioprotective signal transduction of remote conditioning from the trigger limb to the heart involves the release of adenosine. Our results demonstrate that A2a and A2b receptors are indispensable parts for cardioprotection of remote conditioning, which is linked to its anti-inflammatory properties by the subsequent activation of cAMP/PKA/NF-κB axis. Conclusion: Our results establish a new connection between remote tissue compression and cardiovascular diseases, which enhances our cognition about the role of tissue compression on RIC cardioprotection.

Riboflavin deficiency alters cholesterol homeostasis partly by reducing apolipoprotein B100 synthesis in HepG2 cells.

Riboflavin deficiency led to lower blood cholesterol level and higher content of hepatic cholesterol in rats and the mechanisms are not clarified yet. We hypothesized that riboflavin deficiency might alter cholesterol homeostasis via apolipoprotein B100, one of the important proteins in cholesterol transport. To test this hypothesis, HepG2 cells were cultured in riboflavin-deficient media for 4 days to develop riboflavin deficiency. Compared to riboflavin-sufficient cells, the mRNA (0. 37 ± 0.04 vs 1.03 ± 0.29 relative expression level, n = 3) and protein expressions of apolipoprotein B100 (intracellular: 173.7 ± 14.4 vs 254.8 ± 47.2 µg/mg protein; extracellular: 93.8 ± 31.1 vs 161.6 ± 23.9 µg/mg protein; n = 3) were significantly reduced in riboflavin-deficient cells (P < 0.05). Endoplasmic reticulum oxidoreductin 1 and protein disulfide isomerase, two enzymes involved in the oxidative folding of apolipoprotein B100, were also lower remarkably in expression at both mRNA and protein levels. Meanwhile, intracellular cholesterol was increased (256.3 ± 17.1 µM/g protein vs 181.4 ± 23.9 µM/g protein, n = 4) and extracellular cholesterol decreased (110.0 ± 23.2 µM/g protein vs 166.2 ± 34.6 µM/g protein, n = 4) significantly in riboflavin-deficient cells (P < 0.05). Very low-density lipoprotein was also diminished (29.0 ± 6.1 µM/g protein vs 67.0 ± 11.0 µM/g protein, n = 4) in the culture media (P < 0.05). These findings suggest that riboflavin deficiency alters cholesterol homeostasis partly by reducing apolipoprotein B100 synthesis in HepG2 cells.

Quercetin improves gut dysbiosis in antibiotic-treated mice.

The diversity and activity of the gut microbiota residing in humans and animals are significantly influenced by the diet. Quercetin, one of the representative polyphenols in human diets, possesses a wide range of biological properties. The aim of this study was to investigate the prebiotic effects of quercetin in antibiotic-treated mice. Gut dysbiosis was successfully induced in mice by treatment with an antibiotic cocktail. Gas chromatography and 16S rDNA high-throughput sequencing techniques were used to investigate short-chain fatty acid content and gut microbial diversity and composition. The results showed that quercetin supplementation significantly improved the diversity of the gut bacterial community in antibiotic-treated mice (P < 0.05). Meanwhile, intestinal barrier function was also recovered remarkably as indicated by a decrease in the content of serum d-lactic acid and the activity of serum diamine oxidase (P < 0.05). The length of intestinal villi and mucosal thickness were also significantly increased in response to quercetin treatment (P < 0.05). Furthermore, the production of butyrate in faeces was enhanced significantly in quercetin-treated mice (P < 0.05). In conclusion, quercetin is effective in recovering gut microbiota in mice after antibiotic treatment and may act as a prebiotic in combatting gut dysbiosis.