Characterization of an Agarophyton chilense oleoresin containing PPARγ natural ligands with insulin-sensitizing effects in a C57BL/6J mouse model of diet-induced obesity and antioxidant activity in Caenorhabditis elegans (original) (raw)
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2021
The biomedical potential of the edible red seaweed Agarophyton chilense (former Gracilaria chilensis) has not been explored. Red seaweeds are enriched in polyunsaturated fatty acids and eicosanoids, which are known natural ligands of the PPARγ nuclear receptor. PPARγ is the molecular target of thiazolidinediones (TZDs), drugs used as insulin sensitizers to treat type 2 diabetes mellitus. TZDs medical use is limited due to undesired side effects, the fact that it has triggered the search for partial agonists without the TZDs side effects. We produced A.chilense oleoresin (Gracilex®) that induces the activation of PPARγ without inducing adipocyte differentiation, similar to PPARγ partial agonists. In a model of high-fat diet-induced obesity in male mice, we showed that treatment with Gracilex® improves insulin sensitivity, normalizing altered glucose and insulin parameters. Gracilex® was enriched in palmitic acid, arachidonic acid, oleic acid, and lipophilic antioxidants such as ß-car...
Antioxidants
Seaweeds are rich in structurally diverse bioactive compounds with promising therapeutic effects. This study aimed to isolate and identify terpenes from the brown alga Padina pavonia and to investigate its antidiabetic activity, pointing to the possible involvement of peroxisome proliferator-activated receptor (PPAR)γ. Type 2 diabetes was induced by feeding rats a high fat diet (HFD) for 4 weeks followed by injection of 35 mg/kg streptozotocin (STZ). The diabetic rats received P. pavonia extract (PPE; 50, 100 and 200 mg/kg) for 4 weeks and samples were collected for analyses. HFD/STZ-induced rats showed hyperglycemia, dyslipidemia, impaired glucose tolerance, decreased insulin, and increased HbA1c and HOMA-IR. PPE ameliorated hyperglycemia and dyslipidemia, and improved glucose tolerance and insulin sensitivity in diabetic rats. Treatment with PPE increased hepatic hexokinase activity and glycogen, suppressed glucose-6-phosphatase, fructose-1,6-biphosphatase, and glycogen phosphoryl...
Evidence-based Complementary and Alternative Medicine, 2013
Mushrooms have been used in folk medicine for thousands of years. In this study, the effect of-glucan-rich extract of P. sajor-caju (GE) on lipid lowering and antioxidant potential was assessed in C57BL/6J mice fed on a high-fat diet. Obesity was induced in C57BL/6J mice by feeding a high-fat diet. The control groups in this study were ND (for normal diet) and HFD (for high-fat diet). The treated groups were ND240 (for normal diet) (240 mg/kg b.w) and HFD60, HFD120, and HFD240 (for high-fat diet), where the mice were administrated with three dosages of GE (60, 120, and 240 mg GE/kg b.w). Metformin (2 mg/kg b.w) served as positive control. GE-treated groups showed significantly reduced body weight, serum lipid, and liver enzymes levels. GE also attenuated protein carbonyl and lipid hydroperoxide levels by increasing the enzymic antioxidants (SOD, CAT, and GPx) activities in the mice. GE-treated groups induced the expression of hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) while downregulated the expression of peroxisome proliferator-activated receptor gamma (PPAR-), sterol regulatory binding protein-1c (SREBP-1c), and lipoprotein lipase (LPL). Hence, GE prevented weight gain in the mice by inducing lipolysis and may be valuable in the formulation of adjuvant therapy for obesity.
Journal of Physiology and Biochemistry
Diabetes mellitus (DM) is a metabolic disease characterized by a high blood sugar level that can cause severe complications to the organism or even death when not treated. However, certain dietary habits and foods may have beneficial effects on this condition. A polyphenolic-rich extract (containing hyperoside, isoquercitrin, quercetin, ellagic acid, and vanillic acid) of Tageres erecta L. (T. erecta) was obtained from yellow and orange flowers using an ethanolic Soxhlet extraction. These extracts were screened for antidiabetic and anti-obesity properties using in vitro and in vivo procedures. The capacity to inhibit the enzymes lipase and α-glucosidase, as well as the inhibition of advance glycation end-products (AGEs) was tested in vitro. Caenorhabditis elegans (C. elegans) was used as an obesity in vivo model to assess extracts effects on fat accumulation using the wild-type strain N2 and a mutant with no N3 fatty acid desaturase activity BX24. Extracts from both cultivars (yello...
Evidence-Based Complementary and Alternative Medicine, 2012
Obesity is a common nutritional disorder associated with type 2 diabetes, cardiovascular diseases, dyslipidemia, and certain cancers. In this study, we investigated the effects ofCitrus ichangensispeel extract (CIE) in high-fat (HF) diet-induced obesity mice. Female C57BL/6 mice were fed a chow diet or an HF diet alone or supplemented with 1% w/w CIE for 8 weeks. We found that CIE treatment could lower blood glucose level and improve glucose tolerance. In the HF+CIE group, body weight gain, serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) levels, and liver triglyceride (TG) and TC concentrations were significantly (P<0.05) decreased relative to those in the HF group. To elucidate the mechanism of CIE on the metabolism of glucose and lipid, related genes expression in liver were examined. In liver tissue, CIE significantly decreased the mRNA expression levels of peroxisome proliferator-activated receptorγ(PPARγ) and its target genes, such as fatty acid ...
Search for new type of PPARγ agonist-like anti-diabetic compounds from medicinal plants
Biological & pharmaceutical bulletin, 2014
Potent ligands of peroxisome proliferator-activated receptor γ (PPARγ) such as thiazolidinediones (pioglitazone, troglitazone, etc.) improve insulin sensitivity by increasing the levels of adiponectin, an important adipocytokine associated with insulin sensitivity in adipose tissue. Several constituents from medicinal plants were recently reported to show PPARγ agonist-like activity in 3T3-L1 cells, but did not show agonistic activity at the receptor site different from thiazolidinediones. Our recent studies on PPARγ agonist-like constituents, such as hydrangenol and hydrangeic acid from the processed leaves of Hydrangea macrophylla var. thunbergii, piperlonguminine and retrofractamide A from the fruit of Piper chaba, and tetramethylkaempferol and pentamethylquercetin from the rhizomes of Kaempferia parviflora, are reviewed.
PPAR-γ (peroxisome proliferator-activated receptor-gamma)-ligand binding activity is the underlying mechanism of potent oral antidiabetic drugs (thiazolidinediones). Plant extracts (black elder (BE), buckwheat (BW), purple coneflower (PC)), which were positively tested to be PPAR-γ-ligands in vitro, did not exert blood glucose-lowering effect in db/db mice, a genetic animal model of human diabetes mellitus type 2 (DMT2). However, the vast majority of patients develop an obesity-associated DMT2 from chronic overnutrition. Thus, preparations of these promising plants were tested in a diet-induced (high-fat) model of DMT2. Aerial parts of BE, BW, and PC were ground and administered to mice fed high-fat diets (0.1 and 1 g/kg diet respectively) for 93 days. Mice fed the low-fat (LF) or the pure high-fat (HF) diet served as controls. At the end of the experiment body composition, hepatic triacylglycerol content and insulin sensitivity were measured. Compared with the HF-group, only the LF...
Levels of obesity in Middle Eastern countries are increasing. Phytochemicals have anti-obesogenic properties as evidenced by prevention of adipocyte differentiation and blocking triacylglyceride (TG) accumulation. In Yemen, Pulicaria jaubertii E. Gamal-Eldin (PJ) is a food additive and a traditional medicine. We tested the hypothesis that phytochemicals present in PJ inhibit adipocytic responses during differentiation of 3T3-L1 preadipocytes to adipocytes. Methanolic extracts of PJ did not block expression of fatty acid binding protein 4 (FABP4) a marker of differentiation but did inhibit TG accumulation. Treatment of 3T3-L1 preadipocytes increased NADPH:quinone oxidoreductase 1 (NQO1), a suppressor of TG accumulation. Further fractionation of the methanolic PJ extract with hexane and dichloromethane (DCM) demonstrated that bioactivity towards TG reduction and elevated expression of NQO1 and other antioxidant genes (glutamate cysteine ligase catalytic unit, glutathione disulfide reductase, glutathione peroxidase (GPx) 4 resided in the DCM fraction. Activity towards depleting GSH and elevating the expression of catalase and GPx3 were found in the DCM and hexane fractions. Analysis by gas chromatography and liquid chromatography coupled with mass spectrometry demonstrated the presence of catechin-like moieties in the DCM and methanolic fractions and suggest that these components were partially responsible for the bioactivity of these fractions. In summary, our data indicate that fractions derived PJ exhibit anti-adipogenic properties in part through the presence of catechin-like compounds.