Role of Callistemon citrinus Leaf Phytosomes Against Oxidative Stress and Inflammation in Rats Fed with a High-Fat-Fructose Diet.

Phytosomes are used as vehicles that carry plant extracts. They exhibit biological activities and possess better bioavailability, bioabsorption, and lower toxicity than drugs. Obesity is an inflammatory state in which oxidative stress is present, which triggers severe effects on the body's organs. This study aimed to evaluate the impact of the extract and phytosomes of Callistemon citrinus on oxidative stress and inflammation in the liver and heart of Wistar rats fed with a high-fat-fructose diet. Phytosomes containing the extract of leaves of C. citrinus were prepared. The antioxidant, pro-inflammatory enzymes, and biomarkers of oxidative stress were evaluated. Among the groups, only the high-fat-fructose group presented an increase in the COX-2, 5-LOX, and MPO inflammatory enzymes, while the XO enzyme exhibited decreased activity. The groups were fed a hypercaloric diet for 15 weeks while orlistat, C. citrinus extract, and phytosomes were administered at three different concentrations, exhibiting enzyme activities similar to those of the control group. It was also observed that the lowest concentration of phytosomes had a comparable effect to the other concentrations. Callistemon citrinus extract can modulate the activities of enzymes involved in the inflammation process. Furthermore, small doses of phytosomes can serve as anti-inflammatory agents.

The Beneficial Effects of Prenatal Biotin Supplementation in a Rat Model of Intrauterine Caloric Restriction to Prevent Cardiometabolic Risk in Adult Female Offspring.

Numerous studies indicate that intrauterine growth restriction (IUGR) can predispose individuals to metabolic syndrome (MetS) in adulthood. Several reports have demonstrated that pharmacological concentrations of biotin have therapeutic effects on MetS. The present study investigated the beneficial effects of prenatal biotin supplementation in a rat model of intrauterine caloric restriction to prevent cardiometabolic risk in adult female offspring fed fructose after weaning. Female rats were exposed to a control (C) diet or global caloric restriction (20%) (GCR), with biotin (GCRB) supplementation (2 mg/kg) during pregnancy. Female offspring were exposed to 20% fructose (F) in drinking water for 16 weeks after weaning (C, C/F, GCR/F, and GCRB/F). The study assessed various metabolic parameters including Lee's index, body weight, feed conversion ratio, caloric intake, glucose tolerance, insulin resistance, lipid profile, hepatic triglycerides, blood pressure, and arterial vasoconstriction. Results showed that GCR and GCRB dams had reduced weights compared to C dams. Offspring of GCRB/F and GCR/F dams had lower body weight and Lee's index than C/F offspring. Maternal biotin supplementation in the GCRB/F group significantly mitigated the adverse effects of fructose intake, including hypertriglyceridemia, hypercholesterolemia, hepatic steatosis, glucose and insulin resistance, hypertension, and arterial hyperresponsiveness. This study concludes that prenatal biotin supplementation can protect against cardiometabolic risk in adult female offspring exposed to postnatal fructose, highlighting its potential therapeutic benefits.

Iron chelation mitigates mitochondrial dysfunction and oxidative stress by enhancing nrf2-mediated antioxidant responses in the renal cortex of a murine model of type 2 diabetes.

Renal iron overload is a common complication of diabetes that leads to oxidative stress and mitochondrial dysfunction in the kidneys. This study investigated the effects of iron chelation using deferiprone on mitochondrial dysfunction and oxidative stress in the renal cortex of a murine model of type 2 diabetes. Diabetic rats were treated with deferiprone (50 mg/kg BW) for 16 weeks. Our results show that iron chelation with deferiprone significantly increased the nuclear accumulation of Nrf2, a transcription factor that regulates the expression of antioxidant enzymes. This led to enhanced antioxidant capacity, reduced production of reactive oxygen species, and improved mitochondrial bioenergetic function in diabetic rats. However, chronic iron chelation led to altered mitochondrial respiration and increased oxidative stress in non-diabetic rats. In conclusion, our findings suggest that iron chelation with deferiprone protects mitochondrial bioenergetics and mitigates oxidative stress in the renal cortex, involving the NRF2 pathway in type 2 diabetes.

Participación del transporte simplástico de las auxinas durante el desarrollo de las plantas / Symplastic transport participation of auxins during plant development

Resumen: La apropiada organogénesis de las plantas, durante su ciclo de vida, propicia su desarrollo y la adaptación a diferentes condiciones am bientales. Diversas fitohormonas regulan el desarrollo vegetal, pero la auxina denominada ácido indol-3-acético (AIA) es una de las más importantes. El AIA se sintetiza en la parte aérea de la planta y se moviliza a los tejidos demandantes por un transporte rápido que utiliza el floema y por el transporte polar de auxinas (TPA). Recientemente, se ha demostrado que las auxinas también se movilizan mediante el transporte simplástico (TS) a través de los plasmodesmos (PD), cuya apertura o cierre está regulada respectivamente por la degradación o la deposición de la callosa. El objetivo del presente trabajo fue profundizar en los avances sobre la participación del transporte simplástico de las auxinas durante el desarrollo vegetal, así como la degradación o deposición de la callosa, en el cierre o apertura de los PD, para regular el desarrollo de algunos órganos de Arabidopsis thaliana. La intervención de las proteínas PDLP5 es determinante para la deposición de la callosa en los PD, lo que regula la distribución de la auxina e impacta en la formación radicular, especialmente en las raíces laterales. La participación del TS es importante para desarrollar la actividad de las auxinas, lo cual favorece la formación radicular, necesaria en la mejora de absorción de nutrientes de las plantas. Este conocimiento puede ser utilizado para mejorar las plantas de interés agronómico.

Abstract: The appropriate organogenesis of plants during their life cycle promotes their development and adaptation to different environmental conditions. Various phytohormones regulate plant development but auxin, called Indole-3-Acetic Acid (IAA), is one of the most important. IAA is synthesized in the aerial part of plant and is mobilized to the demanding tissues by a rapid transport using the phloem and by the polar auxin transport (PAT). Recently, it has been shown that auxins also are mobilized by a symplastic transport (ST) through plasmodesmata (PD), which opening or closing is regulated by the callose degradation or deposition respectively. The objective of the present work was to deepen the analysis on the participation of symplastic transport of auxins during plant development, as well in the callose degradation or deposition, in the closing or opening of the PD, that regulates the development of some organs of Arabidopsis thaliana. The intervention of PDLP5 proteins is decisive for the callose deposition in the PD, which regulates the auxin distribution and impacts root formation, especially at the lateral roots. The participation of TS is important to develop the auxin activity, which favors root formation, necessary for the improvement plant nutrient absorption. This knowledge can be used to improve development plants of agronomic interest.

Use of Callistemon citrinus as a gastroprotective and anti-inflammatory agent on indomethacin-induced gastric ulcers in obese rats.

Background: Obesity leads to an elevated risk of developing gastrointestinal disease such as gastric ulcers. Callistemon citrinus leaf extract has shown antioxidant, antimicrobial, hepatoprotective, and chemoprotective effects against colon cancer. The aim of this study is to evaluate the gastroprotective effect of C. citrinus leaf extract on indomethacin-induced gastric ulcers in obese rats. Methods: Gastric ulcers were induced in female obese Wistar rats using a single oral dose of indomethacin (IND). In the first stage, the rats were fed with a high fat sugar diet (HFSD) for 15 weeks to induce obesity and, at the same time, the diet of the other group of animals included daily administration of ethanolic C. citrinus leaf extract (250 mg/kg) in addition to HFSD. In the second stage, gastric ulcers were induced with IND (30 mg/kg). The gastroprotective activity of C. citrinus, the inflammatory enzyme activities, and cytokines in the stomach were determined. Results: C. citrinus produced a reduction of gastric lesions caused by IND. Myeloperoxidase (MPO), cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX) activities also decreased. Although inflammatory biomarkers such as TNFα, IL-6, AOPP, and leptin were significantly decreased by C. citrinus, adiponectin levels increased. Moreover, C. citrinus decreased weight gain and morphological and biochemical parameters. Conclusion: The use of indomethacin in rats fed with a high fat-sugar diet increased gastric ulcers. Gastroprotective effect of C. citrinus in obese rats is attributed to the reduction of pro-inflammatory cytokines and the inflammatory enzymes.

siRNA Targeting ECE-1 Partially Reverses Pulmonary Arterial Hypertensionassociated Damage in a Monocrotaline Model.

AIMS: The aim of this study was to develop a possible treatment for pulmonary arterial hypertension. BACKGROUND: Pulmonary arterial hypertension (PAH) is a rare disease characterised by a pulmonary arterial pressure greater than 20 mmHg. One of the factors that contribute to PAH is an increase in the production of endothelin-1, a polypeptide that increases vascular resistance in the pulmonary arteries, leading to increased pulmonary arterial pressure and right ventricular hypertrophy. OBJECTIVE: The objective of this study was to design, synthesize, and evaluate two siRNAs directed against endothelin-1 in a rat model of PAH induced with monocrotaline. METHODS: Wistar rats were administered monocrotaline (60 mg/kg) to induce a PAH model. Following two weeks of PAH evolution, the siRNAs were administered, and after two weeks, right ventricular hypertrophy was evaluated using the RV/LV+S ratio, blood pressure, weight, and relative expression of ECE-1 (Endothelin-converting enzyme-1) mRNA (messenger RNA) by RT-PCR (real-time PCR). RESULTS: The monocrotaline group showed an increase in the hypertrophy index and in ECE-1 mRNA, as well as a significant decrease in weight compared to the control group, while in the monocrotaline + siRNA group, a significant decrease was observed in the relative expression of ECE-1 mRNA, as well as in right ventricular hypertrophy. CONCLUSIONS: Based on the above information, we conclude that the administration of siRNAs directed to ECE-1 decreases the damage associated with PAH.

Development and Evaluation of Phytosomes Containing Callistemon citrinus Leaf Extract: A Preclinical Approach for the Treatment of Obesity in a Rodent Model.

Callistemon citrinus has several biological effects; it is anti-inflammatory, anti-obesogenic, antioxidant, hepatoprotection, and chemoprotective. Its bioactive compounds include terpenoids, phenolic acids, and flavonoids which have low oral bioavailability and absorption. This study aimed at developing phytosomes of C. citrinus to improve oral bioavailability and absorption. Phytosomes were formulated with soybean phosphatidylcholine and C. citrinus leaf extract using the thin layer sonication method. Phytosomes were evaluated by scanning electron microscopy (SEM), entrapment efficiency, solubility, and particle size determination. Antioxidant capacity and total phenolic, flavonoid, and terpenoid contents were also measured. The in vivo anti-obesogenic activity was evaluated. Phytosomes loaded with C. citrinus (P C.c) extract had small spherical shapes. The average particle size was 129.98 ± 18.30 nm, encapsulation efficiency 80.49 ± 0.07%, and solubility 90.00%; the stability study presented no significant changes in the average particle size at 20 °C. P C.c presented high antioxidant capacity. For the first time, ellagic acid is reported in this plant. The in vivo obesity study showed a strong anti-obesogenic activity of phytosomes with C. citrinus to reduce 40% body weight as well as morphometric and biochemical parameters.

Antilipidemic and Hepatoprotective Effects of Ethanol Extract of Justicia spicigera in Streptozotocin Diabetic Rats.

Oxidative stress is a factor that contributes to the development of complications in diabetes; however, its effects can be counteracted using exogenous antioxidants that are found in some plants, which is why people turn to traditional medicines in the search for therapeutic treatment. Justicia spicigera has been demonstrated to have the capacity to reduce glycemic levels; however, its effects on non-insulin-dependent organs such as the liver have not been reported. During 30 days of administration of Justicia spicigera ethanol extract, the blood glucose and weight of rats were measured every 5 days. Once the treatment was concluded, the rats were sacrificed. Corporal weight, blood glucose, cholesterol, very-low-density lipoprotein (VLDL), triglycerides, total lipids, and liver profile were reduced in the diabetic condition and normalized with the application of ethanol extract from J. spicigera (EJS). Additionally, there was a significant increase in catalase and superoxide dismutase activity in the control diabetic rats, a decrease in their activity with the extract administration, and no effect on normoglycemic rats. In conclusion, EJS is considered to be capable of reducing oxidative stress by maintaining diminished lipid and liver function profiles in male Wistar rats with streptozotocin-induced diabetes.

siRNA knockdown of angiopoietin 2 significantly reduces neovascularization in diabetic rats.

Diabetes is a disease that leads to proliferative diabetic retinopathy (PDR), which is associated with an increase of new vessels formation due to an overexpression of angiogenic factors, such as angiopoietin 2 (ANGPT2). The aim of this work was to design a siRNA targeting ANGPT2 to decrease the retinal neovascularization associated with PDR. Adult male Wistar rats weighing 325-375 g were used. Diabetes was induced by a single dose of streptozotocin (STZ, 60 mg/kg i.p.). The siRNAs were designed, synthesised, and administered intravitreally at the beginning of diabetes induction (t0), and after 4 weeks of diabetes evolution (t4), subsequently evaluated the retinal neovascularization (junctions and lacunarity) and ANGPT2 expression in the retina by RT-PCR, after 4 weeks of the siRNAs administration. The results showed that the administration of STZ produced significant increases in blood glucose levels, retinal neovascularization (augmented junctions and lower lacunarity), and ANGPT2 expression, while the administration of the ANGPT2-siRNAs at different groups (t0 and t4) reduces the junctions and increases the lacunarity in diabetic rats. Therefore, we conclude that the administration of siRNAs targeting ANGPT2 could be an option to decrease the retinal neovascularization associated with PDR and halt the progression of blindness caused by diabetes.

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.

Changes in expression of orphan receptors GPR99 and GPR107 during the development and establishment of hypertension in spontaneously hypertensive rats.

Hypertension is a disease, which in spite of existing treatments continues to have high morbidity and mortality, which suggests that there are other mechanisms involved in this pathology. In this sense, the orphan receptors are G protein-coupled receptor associated with various pathologies such as GPR99 which has been linked to mice develop left ventricular hypertrophy induced by blood pressure overload while GPR107 with patients with idiopathic pulmonary arterial hypertension. For this reason, the aim of this work was to study if the expression of the orphan receptors GPR99 and GPR107 are modified by arterial hypertension. Male SHR and WKY rats of 6-8 and 10-12 weeks old were used. The weight, systolic blood pressure and heart rate were measured, as well as the mRNA of the receptors GPR99 and GPR107 in the aorta, kidney, heart and brain by RT-PCR, also was realized an in silico analysis to predict which G protein could be coupled the orphan receptor GPR107. Our results showed that receptors GPR99 and GPR107 are expressed in the analyzed tissues and their expression profile tends to change at different ages and with the development of hypertension, for the other hand, the bioinformatics analysis for GPR107 showed that is coupled to Gi protein. Therefore, we do not rule out that GPR99 and GPR107 could be involved in the pathophysiology of hypertension and could be used as targets therapeutic in hypertension.

Silencing of GPR82 with Interference RNA Improved Metabolic Profiles in Rats with High Fructose Intake.

Metabolic syndrome (MS) is a clinical condition, constituted by alterations that lead to the onset of type II diabetes and cardiovascular disease. It has been reported that orphan G-protein-coupled receptor 82 (GPR82) participates in metabolic processes. The aim of this study was to evaluate the function of GPR82 in MS using a small interfering RNA (siRNA) against this receptor. We used Wistar rats of 10-12 weeks of age fed with a high-fructose solution (70%) for 9 weeks to induce MS. Subsequently, the rats were treated with an intrajugular dose of an siRNA against GPR82 and the effects were evaluated on day 3 and 7 after administration. On day 3 the siRNA had a transient effect on decreasing blood pressure and triglycerides and increasing high-density lipoprotein cholesterol, which recovered to the MS control on day 7. Decreased gene expressions of GPR82 mRNA in the aorta and heart were observed on day 3; moreover, decreased gene expression was maintained in the aorta on day 7. Therefore, we conclude that the orphan receptor GPR82 participates in the development of MS induced by fructose and the silencing of this receptor could ameliorate metabolic components.

Nonalcoholic hepatic steatosis: a silent disease / Esteatosis hepática no alcohólica: una enfermedad silente

Alteration of hepatic lipid metabolism can originate an excessive accumulation of lipids and lead to hepatic steatosis emergence and when not related to chronic alcohol consumption, it is known as non-alcoholic fatty liver disease. Being a disease with a complex pathophysiology and with several phases, which encompass different degrees of complexity and severity: simple steatosis, steatohepatitis, fibrosis, cirrhosis and in some cases even liver cancer. Besides, this disease is difficult to diagnose and asymptomatic until it presents complications. As well is related to other metabolic diseases such as obesity, diabetes, dyslipidemias, insulin resistance and metabolic syndrome. Which are a public health problem at the national and global levels. In this review, the pathophysiology, its relationship with metabolic diseases, genetic factors, associated risk factors, epidemiology, clinical manifestations, diagnosis and current pharmacological treatment of non-alcoholic fatty liver disease were analyzed.

La alteración del metabolismo lipídico hepático puede originar una acumulación excesiva de lípidos y llevar a la aparición de esteatosis hepática, que cuando no está relacionada con un consumo crónico de alcohol, se le conoce como enfermedad del hígado graso no alcohólico. Se trata de un padecimiento con una fisiopatología compleja y con varias fases, que abarcan diferentes grados de complejidad y severidad: esteatosis simple, esteatohepatitis, fibrosis, cirrosis y, en algunas ocasiones, hasta cáncer hepático. Además, esta enfermedad es difícil de diagnosticar y pasa inadvertida hasta que presenta complicaciones. También está relacionada con otros padecimientos metabólicos como la obesidad, diabetes, dislipidemias, resistencia a la insulina y síndrome metabólico; las cuales son un problema de salud pública a nivel nacional y mundial. En esta revisión, se analizó la fisiopatología, su relación con enfermedades metabólicas, factores genéticos, factores de riesgo asociados, epidemiología, las manifestaciones clínicas, diagnóstico y el tratamiento farmacológico actual de la esteatosis hepática no alcohólica.

In vitro retention efficiency of temporary type zinc oxide cement for orthodontic forced eruption.

OBJECTIVE: To assess the retention efficiency of three types of temporary zinc oxide cement trademarks on forced eruption using intracranal wire device. METHODS: An in vitro evaluation included intracanal wire device displacement and detachment at 50g load force for 120 days and then the retention resistance at maximum load force. RESULTS: All groups of temporary zinc oxide cements were efficient to support 50g load forces after 120 days. None statistical differences were found between groups. Zinc oxide cements supported a maximum retention load force, which exceeded in more than 84 times the lowest value obtained in controls (420g). CONCLUSION: Zinc oxide cements are efficient to retain intracanal wire devices on forced eruption processes in vitro and allows removal of both when necessary (wire device and cement, respectively).

Protective effect of supplementation with biotin against high-fructose-induced metabolic syndrome in rats.

Several reports have demonstrated that pharmacological concentrations of biotin reduce hyperglycemia, hypertriglyceridemia, and hypertension. We hypothesized that biotin could exert a protective effect on some illness-associated metabolic syndrome. To test this hypothesis, male Wistar rats were fed a diet containing 30% fructose in drinking water and classified into four groups: C, the control group; B, the group receiving biotin (intraperitoneal injection, 2 mg/kg); F, the group receiving fructose (30% w/v); and FB, the group receiving fructose-biotin. The administration of biotin began after the rats had been on a high-fructose diet for 12 weeks and continued for 4 weeks. Our results showed that food and fluid intake were diminished in the F and FB groups. However, the final body weights were similar between the groups. A significant increase in hepatic triglyceride and cholesterol content, plasma cholesterol, triglycerides, transaminases, low-density lipoprotein cholesterol (LDL-c), systolic blood pressure, and vasocontraction, as well as a decrease in high-density lipoprotein cholesterol (HDL-c) were observed in the F group. Glucose tolerance and insulin tolerance were also impaired in the F group. The administration of biotin ameliorated all these changes. Hepatic oxidative stress as well as macrovesicular fatty changes in hepatocytes caused by a high-fructose diet were also improved by biotin. Our findings demonstrate that biotin has a protective role against metabolic syndrome by improving insulin resistance associated with normal hepatic and serum levels of triglyceride and cholesterol, blood pressure, and the prevention of steatosis and hepatic oxidative damage. Therefore, biotin could be used as a therapeutic strategy in the pharmacological treatment of metabolic syndrome.

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

Several studies have shown that pharmacological concentrations of biotin decrease hyperlipidemia. The molecular mechanisms by which pharmacological concentrations of biotin modify lipid metabolism are largely unknown. Adipose tissue plays a central role in lipid homeostasis. In the present study, we analyzed the effects of biotin supplementation in adipose tissue on signaling pathways and critical proteins that regulate lipid metabolism, as well as on lipolysis. In addition, we assessed serum fatty acid concentrations. Male BALB/cAnN Hsd mice were fed a control or a biotin-supplemented diet (control: 1.76 mg biotin/kg; supplemented: 97.7 mg biotin/kg diet) over 8 weeks postweaning. Compared with the control group, biotin-supplemented mice showed an increase in the levels of adipose guanosine 3',5'-cyclic monophosphate (cGMP) (control: 30.3±3.27 pmol/g wet tissue; supplemented: 49.5±3.44 pmol/g wet tissue) and of phosphorylated forms of adenosine 5'-monophosphate-activated protein kinase (AMPK; 65.2%±1.06%), acetyl-coenzyme A (CoA), carboxylase-1 (196%±68%), and acetyl-CoA carboxylase-2 (78.1%±18%). Serum fatty acid concentrations were decreased (control: 1.12±0.04 mM; supplemented: 0.91±0.03 mM), and no change in lipolysis was found (control: 0.29±0.05 µmol/mL; supplemented: 0.33±0.08 µmol/mL). In conclusion, 8 weeks of dietary biotin supplementation increased adipose tissue cGMP content and protein expression of the active form of AMPK and of the inactive forms of acetyl-CoA carboxylase-1 and acetyl-CoA carboxylase-2. Serum fatty acid levels fell, and no change in lipolysis was observed. These findings provide insight into the effects of biotin supplementation on adipose tissue and support its use in the treatment of dyslipidemia.

Hepatic diseases related to triglyceride metabolism.

Triglycerides participate in key metabolic functions such as energy storage, thermal insulation and as deposit for essential and non-essential fatty acids that can be used as precursors for the synthesis of structural and functional phospholipids. The liver is a central organ in the regulation of triglyceride metabolism, and it participates in triglyceride synthesis, export, uptake and oxidation. The metabolic syndrome and associated diseases are among the main concerns of public health worldwide. One of the metabolic syndrome components is impaired triglyceride metabolism. Diseases associated with the metabolic syndrome promote the appearance of hepatic alterations e.g., non-alcoholic steatosis, steatohepatitis, fibrosis, cirrhosis and cancer. In this article, we review the molecular actions involved in impaired triglyceride metabolism and its association with hepatic diseases. We discuss mechanisms that reconcile the chronic inflammation and insulin resistance, and new concepts on the role of intestinal micro-flora permeability and proliferation in fatty liver etiology. We also describe the participation of oxidative stress in the progression of events leading from steatosis to steatohepatitis and fibrosis. Finally, we provide information regarding the mechanisms that link fatty acid accumulation during steatosis with changes in growth factors and cytokines that lead to the development of neoplastic cells. One of the main medical concerns vis-a-vis hepatic diseases is the lack of symptoms at the onset of the illness and, as result, its late diagnosis. The understandings of the molecular mechanisms that underlie hepatic diseases could help design strategies towards establishing markers for their accurate and timely diagnosis.

The hypotriglyceridemic effect of biotin supplementation involves increased levels of cGMP and AMPK activation.

In addition to its role as a carboxylase cofactor, biotin modifies gene expression and has manifold effects on systemic processes. Several studies have shown that biotin supplementation reduces hypertriglyceridemia. We have previously reported that this effect is related to decreased expression of lipogenic genes. In the present work, we analyzed signaling pathways and posttranscriptional mechanisms involved in the hypotriglyceridemic effects of biotin. Male BALB/cAnN Hsd mice were fed a control or a biotin-supplemented diet (1.76 or 97.7 mg of free biotin/kg diet, respectively for 8 weeks after weaning. The abundance of mature sterol regulatory element-binding protein (SREBP-1c), fatty-acid synthase (FAS), total acetyl-CoA carboxylase-1 (ACC-1) and its phosphorylated form, and AMP-activated protein kinase (AMPK) were evaluated in the liver. We also determined the serum triglyceride concentrations and the hepatic levels of triglycerides and cyclic GMP (cGMP). Compared to the control group, biotin-supplemented mice had lower serum and hepatic triglyceride concentrations. Biotin supplementation increased the levels of cGMP and the phosphorylated forms of AMPK and ACC-1 and decreased the abundance of the mature form of SREBP-1c and FAS. These data provide evidence that the mechanisms by which biotin supplementation reduces lipogenesis involve increased cGMP content and AMPK activation. In turn, these changes lead to augmented ACC-1 phosphorylation and decreased expression of both the mature form of SREBP-1c and FAS. Our results demonstrate for the first time that AMPK is involved in the effects of biotin supplementation and offer new insights into the mechanisms of biotin-mediated hypotriglyceridemic effects.