Beetle (Ulomoides dermestoides) fat improves diabetes: effect on liver and pancreatic architecture and on PPARgamma expression

Ulomoides dermestoides is a beetle traditionally consumed to treat diabetes. In this study, we performed a composition analysis of U. dermestoides to obtain the principal fractions, which were used to assess the effect on glycemia, liver and pancreatic architecture, and PPARγ and GLUT4 expression. Normal mice and alloxan-induced diabetic mice were administered fractions of chitin, protein or fat, and the acute hypoglycemic effect was evaluated. A subacute study involving daily administration of these fractions to diabetic mice was also performed over 30 days, after which the liver and pancreas were processed by conventional histological techniques and stained with hematoxylin and eosin to evaluate morphological changes. The most active fraction, the fat fraction, was analyzed by gas chromatography-mass spectrometry (GC-MS), and PPARγ and GLUT4 mRNA expressions were determined in 3T3-L1 adipocytes. The protein and fat fractions exhibited hypoglycemic effects in the acute as well as in the 30-day study. Only the fat fraction led to elevated insulin levels and reduced glycemia, as well as lower intake of water and food. In the liver, we observed recovery of close hepatic cords in the central lobule vein following treatment with the fat fraction, while in the pancreas there was an increased density and percentage of islets and number of cells per islet, suggesting cellular regeneration. The GC-MS analysis of fat revealed three fatty acids as the major components. Finally, increased expression of PPARγ and GLUT4 was observed in 3T3-L1 adipocytes, indicating an antidiabetic effect.

Potential role of marine algae extract on 3T3-L1 cell proliferation and differentiation: an in vitro approach

BACKGROUND: From ancient times, marine algae have emerged as alternative medicine and foods, contains the rich source of natural products like proteins, vitamins, and secondary metabolites, especially Chlorella vulgaris (C. vulgaris) contains numerous anti-inflammatory, antioxidants and wound healing substances. Type 2 diabetes mellitus is closely associated with adipogenesis and their factors. Hence, we aimed to investigate the chemical constituents and adipo-genic modulatory properties of C. vulgaris in 3T3-L1 pre-adipocytes. RESULTS: We analysed chemical constituents in ethanolic extract of C. vulgaris (EECV) by LC-MS. Results revealed that the EECV contains few triterpenoids and saponin compounds. Further, the effect of EECV on lipid accumulation along with genes and proteins expressions which are associated with adipogenesis and lipogenesis were evaluated using oil red O staining, qPCR and western blot techniques. The data indicated that that EECV treatment increased differentiation and lipid accumulation in 3T3-L1 cells, which indicates positive regulation of adipogenic and lipogenic activity. These increases were associated with up-regulation of PPAR-γ2, C/EBP-α, adiponectin, FAS, and leptin mRNA and protein expressions. Also, EECV treatments increased the concentration of glycerol releases as compared with control cells. Troglitazone is a PPAR-γ agonist that stimulates the PPAR-y2, adiponectin, and GLUT-4 expressions. Similarly, EECV treatments significantly upregulated PPAR-γ, adiponectin, GLUT-4 expressions and glucose utilization. Further, EECV treatment decreased AMPK-α expression as compared with control and metformin treated cells. CONCLUSION: The present research findings confirmed that the EECV effectively modulates the lipid accumulation and differentiation in 3T3-L1 cells through AMPK-α mediated signalling pathway.

Angiogenic response of advanced glycation end products (AGEs) involves PPAR

Diabetes is associated with increased formation of advanced glycation end products (AGEs), which have been implicated in micro and macrovascular complications of diabetes. Our earlier reports showed proangiogenic effect of AGE-bovine serum albumin (BSA). In order to understand the mechanism of AGE-mediated angiogenesis, the possibility of involvement of peroxisome prolifeator activated receptor (PPAR) , a ligand activated transcription factor was examined. The angiogenic effect was studied in chick chorio allantoic membrane (CAM) and by analyzing angiogenic markers in human umbilical vein endothelial cells (HUVECs) in culture. The involvement of PPAR was investigated using synthetic PPAR agonist GW 1929 and antagonist GW 9662 and by RT-PCR. In CAM assay, PPAR antagonist GW 9662 reversed the AGE-induced effect on vascularity. In HUVECs in culture, GW 9662 reversed the effect of AGE-BSA and decreased the expression of CD 31, E-Selectin and VEGF. RT-PCR analysis showed that treatment with AGE-BSA caused upregulation of PPAR mRNA levels. The reversal of the effect of AGE on angiogenesis by treatment with PPAR antagonists and up-regulation of PPAR gene in HUVECs treated with AGE-BSA suggested the possible involvement of PPAR -dependent downstream pathway in mediating the angiogenic effect of AGE.

Probiotics may Reduce Inflammation by Enhancing Peroxisome Proliferator Activated Receptor gamma Activation in HT-29 Cells / 대한소화기학회지

BACKGROUND/AIMS: The peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear receptor highly expressed in the colon which plays an anti-inflammatory role through the inhibition of nuclear factor-kappaB (NF-kappaB) pathway. Probiotics have been shown to exert beneficial effects on inflammatory bowel diseases. However, the exact mechanism by which probiotics exert protection against intestinal inflammation is not well understood. The aims of this study were to evaluate the attenuation of inflammatory response by probiotics in intestinal epithelial cells and to study the association between probiotics and PPARgamma. METHODS: HT-29 human epithelial cells were stimulated with LPS (20microgram/mL) and probiotics, Lactobacillus casei (L. casei) (10(5)-10(7) cfu/mL), or with LPS (20microgram/mL) alone for 24 hours. Interleukin-8 (IL-8), cyclooxygenase-2 (COX-2), toll-like receptor-4 (TLR-4) and PPARgamma mRNA expressions were assessed by RT-PCR. IL-8 protein secretion was measured by ELISA. HT-29 cells were transfected with tk promoter-luciferase plasmid containing a peroxisome proliferator response element (PPRE). After stimulation with L. casei or PPARgamma agonist (15d-PGJ2 or ciglitazone), luciferase activities were measured. RESULTS: LPS induced IL-8, COX-2, TLR-4 mRNA expression, and IL-8 protein secretion in HT-29 cells. Treatment with LPS and L. casei in comparison with LPS stimulation alone lowered IL-8, COX-2, TLR-4 mRNA expression, and IL-8 protein secretion. L. casei increased PPARgamma mRNA expression in dose-dependent manner. L. casei activated PPRE in HT-29 cells transfected with PPRE3-tk-luciferase construct. CONCLUSIONS: Probiotics, L. casei, suppresses the expression of inflammatory mediators in intestinal epithelial cells. The anti-inflammatory action of L. casei might be partially related to PPARgamma activation.