Osteoprotective effect of green tea polyphenols and annatto-extracted tocotrienol in obese mice is associated with enhanced microbiome vitamin K-2 biosynthetic pathways
JOURNAL OF NUTRITIONAL BIOCHEMISTRY
Authors: Elmassry, Moamen M.; Chung, Eunhee; Cao, Jay J.; Hamood, Abdul N.; Shen, Chwan-Li
The role of the gut microbiome in bone health has received significant attention in the past decade. We investigated the effects of green tea polyphenols (GTP) and annatto-extracted tocotrienols (AT) on bone properties and gut microbiome in obese mice. Male mice were assigned to a two (no AT vs. 400 mg/kg diet AT) x two (no GTP vs. 0.5% w/v GTP) factorial design, namely control, G, T, and G+T group respectively, for 14 weeks. The 4th lumbar vertebra (LV-4) and femur were harvested for bone microstructural analysis using mu-CT. Microbiome analysis using 16S rRNA gene sequencing of cecal feces was performed. AT increased bone volume at distal femur. GTP increased serum procollagen type 1 N-terminal propeptide concentration, bone volume at the distal femur and the LV-4, and trabecular number at distal femur; whereas GTP decreased trabecular separation at distal femur. Interactions between GTP and AT were observed in serum C-terminal telopeptide of type I collagen level (control>G=T=G+T) as well as the cortical bone area (control= G >= control) at femur mid-diaphysis. Redundancy analysis showed a significant difference in the gut microbiome profile among different groups and the relative abundance of Akkermansia muciniphila, Clostridum saccharogumia, and Subdoligranulum variabile was increased in the GTP- and AT-supplemented groups. Functional profiling of the gut microbiome showed the combination of GTP and AT induced biosynthetic pathways for vitamin K-2. Our results suggest that GTP and AT supplementation benefits bone properties in obese mice through modifying gut microbiome composition and function. (C) 2020 Elsevier Inc. All rights reserved.
Changes in Serum Levels and Gene Expression of PGC-1 alpha in The Cardiac Muscle of Diabetic Rats: The Effect of Dichloroacetate and Endurance Training
Authors: Nasab, Hamed Rezaei; Habibi, Abdol Hamid; Nikbakht, Masoud; Rashno, Mohammad; Shakerian, Saeed
Objective: Physical activity leads to changes in the level of gene expression in different kinds of cells, including changes in mitochondrial biogenesis in the myocardium in diabetic patients. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1 alpha) is a gene that plays an important role in regulating mitochondrial biogenesis. The purpose of this study was to investigate changes in serum levels and cardiac muscle expression of PGC-1 alpha in diabetic rats in response to the administration of dichloroacetate (DCA) and endurance training. Materials and Methods: In this experimental study, 64 male Wistar rats were selected and randomly divided into eight groups after induction of diabetes with streptozotocin (STZ). The endurance training protocol was performed on a treadmill for 6 weeks. Intraperitoneal injection of DCA of 50 mg/kg body weight was used for the inhibition of Pyruvate Dehydrogenase Kinase 4 (PDK4) in the myocardium. Gene expression were measured using real-time polymerase chain reaction (PCR). One-way ANOVA and Tukey's test were used to statistically analyze the data. Results: The results of the study showed that PDK4 gene expression in the endurance training group, diabetes+endurance training group, diabetes+endurance training+DCA group and endurance training+DCA group was higher compared to the control group. Expression of PGC-1 alpha was higher in the endurance training group compared to the control group but was lower compared to the control group in diabetes+endurance training+DCA group and diabetes+DCA group (P<0.05). Conclusion: Considering that PGC-1 alpha plays an important role in mitochondrial biogenesis, it is likely that by inhibiting PDK4 and subsequently controlling oxidation of fatty acid (FA) in the heart tissue, oxidative stress in the heart tissue of diabetic patients will be reduced and cardiac efficiency will be increased.