Effects of Biotin Supplementation in the Diet on Adipose Tissue cGMP Concentrations, AMPK Activation, Lipolysis, and Serum-Free Fatty Acid Levels

20(S)-Ginsenoside Rg2 amino acid derivatives for anti hemorrhagic shock: Synthesis, characterization and evaluation

The purpose of this study is to screen a novel Rg2 derivative for anti hemorrhagic shock. Eight Rg2 amino acid ester derivatives were designed and synthesized, and their effects on hypoxia and shock were studied. Among them, the derivative 1 (D1) exhibited excellent anti hypoxia by promoting survival rate of H9c2 cells damaged by hypoxia. D1 improved physiological indicators of the rats in hemorrhagic shock, such as blood pressure, heart rate, lactate, acid-base balance, and alleviate oxidative stress and inflammatory damage. Its latent mechanisms were explored by a method of plasma metabolomics based on UPLC-QTOF-MS. As a result, a total of 16 biomarkers were identified involving 6 metabolic pathways. The results of this study contained that the derivative 1 could be considered as potent drug candidates for anti shock and deserved further research and development.

Elucidating the mechanisms underlying the anti-hyperlipidemic effects of Laportea bulbifera using integrated serum metabolomics and network pharmacology

Hyperlipidemia is a chronic metabolic disorder characterized by alterations in lipid metabolism as well as other pathways. Laportea bulbifera, an indigenous medicinal plant of Chinese herbal medicine, exhibits therapeutic effects on hyperlipidemia, but the mechanisms remain unclear. This study investigated the potential mechanisms underlying the anti-hyperlipidemic effects of L. bulbifera using an integrated strategy based on metabolomics and network pharmacology methods that were established to investigate the potential mechanism of anti-hyperlipidemia effect of L. bulbifera. First, the therapeutic effects of L. bulbifera on body weight reduction and biochemical indices were assessed. Next, 18 significant metabolites distinguishing the control and model groups were identified based on serum metabolomics and multivariate analyses. Then, a compound-target network was constructed by linking L. bulbifera and hyperlipidemia using network pharmacology. Three metabolic pathways involved in treating hyperlipidemia were identified. Finally, five crucial targets were selected by constructing a bionetwork starting from the compounds and ending in the metabolites. This study established an integrated strategy based on metabolomics coupled with network pharmacology and revealed the mechanism underlying the protective effects of L. bulbifera against hyperlipidemia for the first time.

Biotin Enhances Testosterone Production in Mice and Their Testis-Derived Cells

Late-onset hypogonadism, a male age-related syndrome characterized by a decline in testosterone production in the testes, is commonly treated with testosterone replacement therapy, which has adverse side effects. Therefore, an alternative treatment is highly sought. Supplementation of a high dosage of biotin, a water-soluble vitamin that functions as a coenzyme for carboxylases involved in carbohydrate, lipid, and amino acid metabolism, has been shown to influence testis functions. However, the involvement of biotin in testis steroidogenesis has not been well clarified. In this study, we examined the effect of biotin on testosterone levels in mice and testis-derived cells. In mice, intraperitoneal treatment with biotin (1.5 mg/kg body weight) enhanced testosterone levels in the serum and testes, without elevating serum levels of pituitary luteinizing hormone. To investigate the mechanism in which biotin increased the testosterone level, mice testis-derived I-10 cells were used. The cells treated with biotin increased testosterone production in a dose- and time-dependent manner. Biotin treatment elevated intracellular cyclic adenosine monophosphate levels via adenylate cyclase activation, followed by the activation of protein kinase A and testosterone production. These results suggest that biotin may have the potential to improve age-related male syndromes associated with declining testosterone production.

Nutraceutical Prevention of Diabetic Complications—Focus on Dicarbonyl and Oxidative Stress

Oxidative and dicarbonyl stress, driven by excess accumulation of glycolytic intermediates in cells that are highly permeable to glucose in the absence of effective insulin activity, appear to be the chief mediators of the complications of diabetes. The most pathogenically significant dicarbonyl stress reflects spontaneous dephosphorylation of glycolytic triose phosphates, giving rise to highly reactive methylglyoxal. This compound can be converted to harmless lactate by the sequential activity of glyoxalase I and II, employing glutathione as a catalyst. The transcription of glyoxalase I, rate-limiting for this process, is promoted by Nrf2, which can be activated by nutraceutical phase 2 inducers such as lipoic acid and sulforaphane. In cells exposed to hyperglycemia, glycine somehow up-regulates Nrf2 activity. Zinc can likewise promote glyoxalase I transcription, via activation of the metal-responsive transcription factor (MTF) that binds to the glyoxalase promoter. Induction of glyoxalase I and metallothionein may explain the protective impact of zinc in rodent models of diabetic complications. With respect to the contribution of oxidative stress to diabetic complications, promoters of mitophagy and mitochondrial biogenesis, UCP2 inducers, inhibitors of NAPDH oxidase, recouplers of eNOS, glutathione precursors, membrane oxidant scavengers, Nrf2 activators, and correction of diabetic thiamine deficiency should help to quell this.

Dietary High-Dose Biotin Intake Activates Fat Oxidation and Hepatic Carnitine Palmitoyltransferase in Rat

This study investigated the effects of dietary high-dose biotin intake on fat oxidation in rats using respiratory gas analysis, and evaluated fatty-acid oxidation-related enzyme activities and gene expressions in the liver. Five-week-old male Sprague-Dawley rats were fed a control diet and three biotin-supplemented diets (additive biotin concentration: 0.05%, 0.10%, and 0.20% of diet) for 3 wk. In 2 wk, fat oxidation in the 0.20% biotin-supplemented diet group was higher than that in the 0.05% biotin-supplemented diet group; however, the energy expenditure and carbohydrate oxidation were unchanged between the dietary groups. At the end of 3 wk, body weight and epididymal white adipose tissue weight reduced in the 0.20% biotin diet group, and hepatic triglyceride levels tended to decrease. Additionally, increased plasma adiponectin concentration and hepatic mitochondrial carnitine palmitoyltransferase activity as well as decreased hepatic acetyl-CoA carboxylase 2 gene expression were observed in the 0.20% biotin-supplemented diet group compared with those in the control group. These results provide strong evidence that dietary high-dose biotin intake activated fat oxidation due to the increase in hepatic β-oxidation, which may contribute to the decrease in hepatic triglyceride concentration and white adipose tissue weight.

The effect of adenosine monophosphate-activated protein kinase on lipolysis in adipose tissue: an historical and comprehensive review

CONTEXT

Lipolysis is one of the most important pathways for energy management, its control in the adipose tissue (AT) is a potential therapeutic target for metabolic diseases. Adenosine Mono Phosphate-activated Protein Kinase (AMPK) is a key regulatory enzyme in lipids metabolism and a potential target for diabetes and obesity treatment.

OBJECTIVE

The aim of this work is to analyse the existing information on the relationship of AMPK and lipolysis in the AT.

METHODS

A thorough search of bibliography was performed in the databases Scopus and Web of Knowledge using the terms lipolysis, adipose tissue, and AMPK, the unrelated publications were excluded, and the documents were analysed.

RESULTS

Sixty-three works were found and classified in 3 categories: inhibitory effects, stimulatory effect, and diverse relationships; remarkably, the newest researches support an upregulating relationship of AMPK over lipolysis.

CONCLUSION

The most probable reality is that the relationship AMPK-lipolysis depends on the experimental conditions.

Role of vitamins in the metabolic syndrome and cardiovascular disease

The prevalence of metabolic syndrome and cardiovascular disease has increased and continues to be the leading cause of mortality worldwide. The etiology of these diseases includes a complex phenotype derived from interactions between genetic, environmental, and nutritional factors. In this regard, it is common to observe vitamin deficiencies in the general population and even more in patients with cardiometabolic diseases due to different factors. Vitamins are essential micronutrients for cellular metabolism and their deficiencies result in diseases. In addition to its role in nutritional functions, increasingly, vitamins are being recognized as modulators of genetics expression and signals transduction, when consumed at pharmacological concentrations. Numerous randomized preclinical and clinical trials have evaluated the use of vitamin supplementation in the prevention and treatment of metabolic syndrome and cardiovascular disease. However, it is controversy regarding its efficacy in the treatment and prevention of these diseases. In this review, we investigated chemical basics, physiological effect and recommended daily intake, problems with deficiency and overdose, preclinical and clinical studies, and mechanisms of action of vitamin supplementation in the treatment and prevention of metabolic syndrome and cardiovascular disease.

Effect of biotin supplementation on fatty acid metabolic pathways in 3T3-L1 adipocytes

Several studies have shown that pharmacological concentrations of biotin decrease serum lipid concentrations and the expression of lipogenic genes. Previous studies on epididymal adipose tissue in mice revealed that 8 weeks of dietary biotin supplementation increased the protein abundance of the active form of AMPK and the inactive forms acetyl CoA carboxylase (ACC)-1 and - 2, and decreased serum free fatty acid concentrations but did not affect lipolysis. These data suggest that pharmacological concentrations of the vitamin might affect fatty acid metabolism. In this work, we investigated the effects of pharmacological biotin concentrations on fatty acid synthesis, oxidation, and uptake in 3T3-L1 adipocytes. Similar to observations in mice, biotin-supplemented 3T3-L1 adipose cells increased the protein abundance of active ^T172 -AMPK and inactive ACC-1 and -2 forms. No changes were observed in the expression of the transcriptional factor PPARα and carnitine-palmitoyltransferase-1 (CPT-1). Radiolabeled assays indicated a decrease in fatty acid synthesis; an increase in fatty acid oxidation and fatty acid incorporation rate into the lipid fraction between control cells and biotin-supplemented cells. The data revealed an increase in the mRNA abundance of the fatty acid transport proteins Fatp1 and Acsl1 but not Cd36 or Fatp4 mRNA. Furthermore, the abundance of glycerol phosphate acyl transferase-3 protein was increased. Triglyceride content was not affected. Lipid droplet numbers showed an increase and their areas were smaller in the biotin-supplemented group. In conclusion, these data indicate that biotin supplementation causes a decrease in fatty acid synthesis and an increase in its oxidation and uptake. © 2018 BioFactors, 45(2):259-270, 2019.

Reuniting overnutrition and undernutrition, macronutrients, and micronutrients

Over-nutrition and its late consequences are a dominant theme in medicine today. In addition to the health hazards brought on by over-nutrition, the medical community has recently accumulated a roster of health benefits with obesity, grouped under "obesity paradox." Throughout the world and throughout history until the 20^th century, under-nutrition was a dominant evolutionary force. Under-nutrition brings with it a mix of benefits and detriments that are opposite to and continuous with those of over-nutrition. This continuum yields J-shaped or U-shaped curves relating body mass index to mortality. The overweight have an elevated risk of dying in middle age of degenerative diseases while the underweight are at increased risk of premature death from infectious conditions. Micronutrient deficiencies, major concerns of nutritional science in the 20^th century, are being neglected. This "hidden hunger" is now surprisingly prevalent in all weight groups, even among the overweight. Because micronutrient replacement is safe, inexpensive, and predictably effective, it is now an exceptionally attractive target for therapy across the spectrum of weight and age. Nutrition-related conditions worthy of special attention from caregivers include excess vitamin A, excess vitamin D, and deficiency of magnesium.

Effects of dietary biotin supplementation on glucagon production, secretion, and action

OBJECTIVE

Despite increasing evidence that pharmacologic concentrations of biotin modify glucose metabolism, to our knowledge there have not been any studies addressing the effects of biotin supplementation on glucagon production and secretion, considering glucagon is one of the major hormones in maintaining glucose homeostasis. The aim of this study was to investigate the effects of dietary biotin supplementation on glucagon expression, secretion, and action.

METHODS

Male BALB/cAnN Hsd mice were fed a control or a biotin-supplemented diet (1.76 or 97.7 mg biotin/kg diet) for 8 wk postweaning. Glucagon gene mRNA expression was measured by the real-time polymerase chain reaction. Glucagon secretion was assessed in isolated islets and by glucagon concentration in plasma. Glucagon action was evaluated by glucagon tolerance tests, phosphoenolpyruvate carboxykinase (Pck1) mRNA expression, and glycogen degradation.

RESULTS

Compared with the control group, glucagon mRNA and secretion were increased from the islets of the biotin-supplemented group. Fasting plasma glucagon levels were higher, but no differences between the groups were observed in nonfasting glucagon levels. Despite the elevated fasting glucagon levels, no differences were found in fasting blood glucose concentrations, fasting/fasting-refeeding glucagon tolerance tests, glycogen content and degradation, or mRNA expression of the hepatic gluconeogenic rate-limiting enzyme, Pck1.

CONCLUSIONS

These results demonstrated that dietary biotin supplementation increased glucagon expression and secretion without affecting fasting blood glucose concentrations or glucagon tolerance and provided new insights into the effect of biotin supplementation on glucagon production and action.

Dietary Biotin Supplementation Modifies Hepatic Morphology without Changes in Liver Toxicity Markers

Pharmacological concentrations of biotin have pleiotropic effects. Several reports have documented that biotin supplementation decreases hyperglycemia. We have shown that a biotin-supplemented diet increased insulin secretion and the mRNA abundance of proteins regulating insulin transcription and secretion. We also found enlarged pancreatic islets and modified islet morphology. Other studies have shown that pharmacological concentrations of biotin modify tissue structure. Although biotin administration is considered safe, little attention has been given to its effect on tissue structure. In this study, we investigated the effect of biotin supplementation on hepatic morphology and liver toxicity markers. Male BALB/cAnN Hsd mice were fed a control or a biotin-supplemented diet for 8 weeks. Versus the control mice, biotin-supplemented mice had an altered portal triad with dilated sinusoids, increased vascularity, and bile conducts. Furthermore, we observed an increased proportion of nucleomegaly and binucleated hepatocytes. In spite of the liver morphological changes, no differences were observed in the serum liver damage indicators, oxidative stress markers, or antioxidant enzymes. Our data demonstrate for the first time that biotin supplementation affects liver morphology in normal mice, and that these modifications are not paralleled with damage markers.