Norma Paniagua-Castro

Spirulina (Arthrospira) Protects Against Cadmium-Induced Teratogenic Damage in Mice

The role of Spirulina (Arthrospira) in preventing cadmium (Cd) teratogenicity in ICR mice was studied. Cd was administered intraperitoneally to female mice at 1.5 mg/kg on gestation day (GD)-7, and Spirulina was given by peroral (intragastric) administration at 62.5, 125, 250, or 500 mg/kg from GD-0 through GD-17 (the day when animals were sacrificed). Because among the mechanisms suggested to account for reproductive damage are oxidative stress and lipoperoxidation, embryonic hydroperoxides were also determined. Treatment with Spirulina at the three highest doses significantly decreased the frequency of fetuses with exencephaly, micrognathia, and skeletal abnormalities induced by Cd. Furthermore, Spirulina treatment significantly and dose-dependently decreased lipid peroxidation, which was dramatically increased by administration of the metal. The results of the present study clearly point to the therapeutic potential of Spirulina in Cd-induced teratogenicity and probably through its antioxidant activity.

Antiobesity and Hypoglycaemic Effects of Aqueous Extract of Ibervillea sonorae in Mice Fed a High-Fat Diet with Fructose

Obesity, type II diabetes, and hyperlipidaemia, which frequently coexist and are strongly associated with oxidative stress, increase the risk of cardiovascular disease. An increase in carbohydrate intake, especially of fructose, and a high-fat diet are both factors that contribute to the development of these metabolic disorders. In recent studies carried out in diabetic rats, authors reported that Ibervillea sonorae had hypoglycaemic activity; saponins and monoglycerides present in the plant could be responsible for the effects observed. In the present study, we determined the effects of an aqueous I. sonorae extract on a murine model of obesity and hyperglycaemia, induced by a high-calorie diet, and the relationship of these effects with hepatic oxidation. A high-fat diet over a period of 8 weeks induced weight gain in the mice and increased triglycerides and blood glucose levels. Simultaneous treatment with I. sonorae aqueous extracts, at doses of 100, 200, and 400 mg/kg, decreased triglycerides and glycaemia levels, prevented an increase in body weight in a dose-dependent manner, and decreased hepatic lipid oxidation at a dose of 200 mg/kg. These data suggest that the aqueous extract from I. sonorae root prevents obesity, dyslipidaemia, and hyperglycaemia induced by a hypercaloric diet; however, high doses may induce toxicity.

Undaria pinnatifida and Fucoxanthin Ameliorate Lipogenesis and Markers of Both Inflammation and Cardiovascular Dysfunction in an Animal Model of Diet-Induced Obesity

Brown algae and its carotenoids have been shown to have a positive influence on obesity and its comorbidities. This study evaluated the effect of Undaria pinnatifida and fucoxanthin on biochemical, physiological and inflammation markers related to obesity and on the expression of genes engaged on white adipose tissue lipid metabolism in a murine model of diet-induced obesity. The treatments improved energy expenditure, β-oxidation and adipogenesis by upregulating PPARα, PGC1α, PPARγ and UCP-1. Adipogenesis was also confirmed by image analysis of the retroperitoneal adipose tissue, by measuring cell area, perimeter and cellular density. Additionally, the treatments, ameliorated adipose tissue accumulation, insulin resistance, blood pressure, cholesterol and triglycerides concentration in serum, and reduced lipogenesis and inflammation by downregulating acetyl-CoA carboxylase (ACC) gene expression, increasing serum concentration and expression of adiponectin as well as downregulating IL-6 expression. Both fucoxanthin and Undaria pinnatifida may be considered for treating obesity and other diseases related.

Pharmacological and Genotoxic Properties of Polyphenolic Extracts of Cedrela odorata L. and Juglans regia L. Barks in Rodents

Evaluation of the phenolic compounds and antioxidant activity of Cedrela odorata L. and Juglans regia L. bark extracts was performed in vitro. Juglans regia showed greater extract concentration and higher antioxidant activity. Hypoglycemic activity in rats was assessed by generating a glucose tolerance curve and determining the area under the curve (AUC). Diabetes was later induced by an injection with streptozotocin (65 mg/kg of b.w.) and confirmed after 24 hours. The extract was administered (200 mg/kg b.w.) over 10 days, and blood glucose was monitored and compared with a control group. The glucose AUC showed a hypoglycemic effect of J. regia and C. odorata in normal rats. Both extracts reduced hepatic lipid peroxidation in diabetic rats. Polyphenolic extracts reduced cholesterol levels in a hypercholesterolemic mouse model and decreased hepatic lipid peroxidation. Polyphenolic extract doses of 100 and 200 mg/kg b.w. were administered alone or with cyclophosphamide (CPA) 50 mg/kg ip, which was used as a positive control. Analyses were performed using leukocytes in a comet assay after 4 and 24 h of treatment. Genotoxic effects were evaluated by the comet assay, which showed that while J. regia extract had no effect, C. odorata extract induced slight damage at 200 mg/kg, with the formation of type 0 and 1 comets.

Neuroprotective effect of Arthrospira (Spirulina) platensis against kainic acid-neuronal death

Abstract Context Arthrospira (Spirulina) platensis (SP) is a cyanobacterium which has attracted attention because of its nutritional value and pharmacological properties. It was previously reported that SP reduces oxidative stress in the hippocampus and protects against damaging neurobehavioural effects of systemic kainic acid (KA). It is widely known that the systemic administration of KA induces neuronal damage, specifically in the CA3 hippocampal region. Objective The present study determines if the SP sub-chronic treatment has neuroprotective properties against KA. Materials and methods Male SW mice were treated with SP during 24 d, at doses of 0, 200, and 800 mg/kg, once daily, and with KA (35 mg/kg, ip) as a single dose on day 14. After the treatment, a histological analysis was performed and the number of atrophic neuronal cells in CA3 hippocampal region was quantified. Results Pretreatment with SP does not protect against seizures induced by KA. However, mortality in the SP 200 and the SP 800 groups was of 20%, while for the KA group, it was of 60%. A single KA ip administration produced a considerable neuronal damage, whereas both doses of SP sub-chronic treatment reduced the number of atrophic neurons in CA3 hippocampal region with respect to the KA group. Discussion The SP neurobehaviour improvement after KA systemic administration correlates with the capacity of SP to reduce KA-neuronal death in CA3 hippocampal cells. This neuroprotection may be related to the antioxidant properties of SP. Conclusion SP reduces KA-neuronal death in CA3 hippocampal cells.

The prothrombotic state associated with obesity-induced hypertension is reduced by cocoa and its main flavanols

BACKGROUND Little is known about the effects of cocoa and its main flavanols on the prothrombotic state associated with the development of hypertension in diet-induced obesity models. PURPOSE To evaluate the effects of cocoa powder, cocoa extract and their main flavanols on plasma biomarkers related to impaired coagulation and fibrinolysis and its association with hypertension and obesity-related metabolic disorders in rats fed a hypercaloric diet. METHODS Male Wistar rats were randomly assigned to 7 treatment groups (n = 7): normal diet (ND); hypercaloric diet control group (HCD); HCD + cocoa powder (CO); HCD + cocoa extract (CO-EX); HCD + (-)-epicatechin (EPI); HCD + (+)-catechin (CAT); and HCD + procyanidin B2 (PB2). Blood pressure was measured using the tail-cuff method (week 7). At the end of the experimental period (week 8), rats were sacrificed and blood samples were collected immediately for coagulation and biochemical analyses. RESULTS Oral administration of CO, CO-EX and their main flavanols significantly decreased plasma biomarkers related to impaired coagulation and fibrinolysis (vWF, FVIII, fibrinogen and PAI-1) in rats fed a hypercaloric diet. These effects were associated with decreased systolic and diastolic blood pressure, aortic oxidative stress (MDA levels) and improvement of dyslipidemia, insulin resistance and circulating markers of inflammation (TNF-α, IL-6 and CRP) compared to the HCD group. CONCLUSION Our results showed that cocoa and its main flavanols may improve endothelial dysfunction and exert their antihypertensive effects by decreasing the prothrombotic state in rats fed a hypercaloric diet. Moreover, improvement of obesity-related metabolic disorders may also contribute to their BP-lowering effect.

Association of the polymorphisms 292 C>T and 1304 G>A in the SLC38A4 gene with hyperglycaemia

The SLC38A4 gene is related to system ‘A’ activity, which seems to be related to impaired gluconeogenesis. The objective of this study was to determine whether the 292 C>T and 1304 G>A polymorphisms of SLC38A4 gene are associated with hyperglycaemia in humans.

Spirulina (Arthrospira) Protects Against Valproic Acid–Induced Neural Tube Defects in Mice

Valproic acid (VPA) is a potent inducer of neural tube defects in human and mouse, its teratogenicity is associated with its potential to generation of free radicals and increase oxidative stress. Furthermore, spirulina (SP) has shown pharmacological properties against teratogenicity, which are attributed to its antioxidant potential. Accordingly, the present study was performed to investigate the influence of SP on the teratogenicity of VPA in imprinting control region mice and the possible mechanisms of action. VPA (sodium valproate) was administered intraperitoneally to mice on gestation day (GD) 8 at a dose of 600 mg/kg. SP was given orally at 125, 250, and 500 mg/kg daily from GD0 through GD18. The most common finding in fetuses with VPA exposure was exencephaly. SP decreased the incidence of this and other malformations and increased levels of superoxide dismutase, catalase, and glutathione peroxidase. In conclusion, these results illustrate the protective action of SP through its antioxidant activity against VPA-induced teratogenicity.

Exploring the structure and conformational landscape of human leptin. A molecular dynamics approach

Leptin is a hormone that regulates energy homeostasis, inflammation, hematopoiesis and immune response, among other functions (Houseknecht et al., 1998; Zhang et al., 1995; Paz-Filho et al., 2010). To obtain its crystallographic structure, it was necessary to substitute a tryptophan for a glutamic acid at position 100, thus creating a mutant leptin that has been reported to have biological activity comparable to the activity of the wild type but that crystallizes more readily. Here, we report a comparative study of the conformational space of WT and W100E leptin using molecular dynamics simulations performed at 300, 400, and 500 K. We detected differences between the interactions of the two proteins with local and distal effects, resulting in changes in the conformation, accessible surface area, compactness, electrostatic potential and dynamic behavior. Additionally, the series of unfolding events that occur when leptin is subjected to high temperature differs for the two constructs. We observed that both proteins are mostly unstructured after 20 ns of MD simulation at 500 K. However, WT leptin maintains a significant amount of secondary structure in helix α2, while the most stable region of W100E leptin is helix α3. Furthermore, we found that the region between residues 25 and 42 might adopt interconverting secondary structures ranging from α-helices and random coils to β-strand structures. Thus, this region can be considered an intrinsically disordered region. This atomistic description supports our understanding of leptin signaling and consequently might facilitate the use of leptin in treatments for the pathophysiologies in which it is implicated.

Glycine decreases developmental damage induced by hyperglycaemia in mouse embryos.

Hyperglycaemia induces neural tube defects and growth retardation in cultured mouse and rat embryos. In this study the possibility that glycine could prevent hyperglycaemia‐induced embryopathy was researched. Early somite mouse embryos were cultured in normal medium, hyperglycaemic medium (50 mmol L−1 glucose), or with glycine (1 mmol L−1) supplementation of normal and hyperglycaemic rat serum for 48 h. The embryo growth and differentiation were determined to estimate developmental and congenital malformations as well as lipid peroxidation levels. Adding glycine to the control culture medium did not affect embryonic development. Whereas the amino acid protected against telencephalon dysmorphogenesis, the decreased DNA content and number of somites, and the morphological score affectation induced by the hyperglycaemic medium, it had no preventive effect on the retarded differentiation of the otic system. Moreover, it prevented the high hyperglycaemia‐induced lipoperoxidation levels of embryonic tissues. Embryos were partially protected from the hyperglycaemia‐induced teratogenesis due to the antioxidative effect of glycine. As no other mechanisms related to the antiglycation or other protective effects of glycine were examined, the mechanism whereby it acted as an antiteratogenic agent needs further study.