Garlic-derived exosomes carrying miR-396e shapes macrophage metabolic reprograming to mitigate the inflammatory response in obese adipose tissue.

Low-grade chronic inflammation originating from the adipose tissue and imbalance of lipid metabolism in the liver are the main drivers of the development of obesity and its related metabolic disorders. In this work, we found that garlic-derived exosomes (GDE) supplementation improved insulin resistance, altered the levels of inflammatory cytokines in serum and epididymal white adipose tissue (eWAT) by decreasing the accumulation of macrophages in HFD-fed mice. Meanwhile, we also observed that GDE regulated the expression of 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3), one of the critical glycolytic enzymes, to shape the metabolic reprograming of macrophage induced by lipopolysaccharide (LPS) and mitigate the inflammatory response in adipocytes via macrophage-adipocyte cross-talk. Data from small RNA sequencing, bioinformatical analysis and the gene over-expression revealed that miR-396e, one of the most abundant miRNAs of GDE, played a critical role in promoting the metabolic reprogramming of macrophage by directly targeting PFKFB3. The findings of this study not only provide an in-depth understanding of GDE protecting against inflammation in obesity but supply evidence to study the molecular mechanisms associated with the interspecies communication.

5'-AMP-activated protein kinase plays an essential role in geniposide-regulated glucose-stimulated insulin secretion in rat pancreatic INS-1 ß cells.

Our previous work showed that geniposide affected glucose-stimulated insulin secretion (GSIS) via regulating glucose uptake and metabolism in pancreatic ß cells; however, the molecular mechanisms remain largely unknown. Substantial evidence suggests that activation of 5'-AMP-activated protein kinase (AMPK) plays a central role in GSIS. Here, we aim to determine the role of AMPK on geniposide-regulated GSIS in rat pancreatic INS-1 cells. The results demonstrated that 6-[4-(2-piperidin-1-yletoxy)-phenyl]-3-pyridin-4-yl-pyrazolo[1,5-α] pyrimidine (Compound C; an AMPK inhibitor) significantly attenuated the effects of geniposide on glucose uptake, energy metabolism, and insulin secretion in INS-1 cells. We also observed that geniposide induced phosphorylation of acetyl-CoA carboxylase (ACC), a marker of AMPK activity, in a time-dependent manner in INS-1 cells; however, in the presence of Compound C, the influence of geniposide on ACC phosphorylation was obviously inhibited. Furthermore, the knockdown of AMPK protein with AMPK siRNA treatment decreased the effects of geniposide on glucose uptake, adenosine triphosphate production, and GSIS. All these data indicate that AMPK plays an essential role in geniposide-regulated GSIS in pancreatic ß cells.

The flower of Edgeworthia gardneri (wall.) Meisn. suppresses adipogenesis through modulation of the AMPK pathway in 3T3-L1 adipocytes.

ETHNOPHARMACOLOGICAL RELEVANCE: The flower of Edgeworthia gardneri (Wall.) Meisn., locally named "Lvluohua, ", has been widely used as Tibetan folk medicine for the treatment of metabolic diseases for a long time. AIM OF THIS STUDY: To evaluate the anti-adipogenesis effect of ethyl acetate extract of the flower of E. gardneri (EEG extract) in 3T3-L1 adipocytes. MATERIALS AND METHODS: Obesity-related parameters such as lipid accumulation and TG content were determined by Oil red O staining and enzymatic kit, respectively. Western blotting was used to determine the expressions of peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein-α (C/EBPα), phosphorylated adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC). Moreover, main constituents of EEG extract were analyzed by high performance liquid chromatography (HPLC). RESULTS: EEG extract decreased the lipid and triglyceride (TG) accumulations during the differentiation process and down-regulated the adipogenesis-related transcriptional factors PPARγ and C/EBPα. EEG extract treatment increased AMPK and ACC phosphorylation. In addition, pretreatment with AMPK inhibitor, weakened the inhibitory effects of EEG extract on the expressions of PPARγand C/EBPα. HPLC analysis indicated that tiliroside was the main constituent in EEG extract. CONCLUSIONS: These results suggest that EEG extract may exert anti-adipogenic effects through modulation of the AMPK signaling pathway.

In vitro Screening and Evaluation of 37 Traditional Chinese Medicines for Their Potential to Activate Peroxisome Proliferator-Activated Receptors-γ.

BACKGROUND: Peroxisome proliferator-activated receptors (PPAR)-γ is widely used as an attractive target for the treatment of type 2 diabetes mellitus. Thiazolidinediones, the agonists of PPARγ, has been popularly utilized as insulin sensitizers in the therapy of type 2 diabetes whereas numerous severe side-effects may also occur concomitantly. OBJECTIVE: The PPARγ activation activity of different polar extracts, including petroleum ether, ethyl acetate, n-butanol, residual of ethanol, the precipitate part of water and the supernatant of water extracts, from 37 traditional Chinese medicines were systematically evaluated. MATERIALS AND METHODS: HeLa cells were transiently co-transfected with the re-constructed plasmids of GAL4-PPARγ-ligand binding domain and pGL4.35. The activation of PPARγ by different polarity extracts were evaluated based on the PPARγ transactivation assay and rosiglitazone was used as positive control. RESULTS: Seven medicines (root bark of Lycium barbarum, Anoectochilus sroxburghii, the rhizome of Phragmites australis, Pterocephalus hookeri, Polygonatum sibiricum, fruit of Gleditsia sinensis, and Epimedium brevicornu) were able to significantly activate PPARγ. CONCLUSION: As seven medicines were able to activate PPARγ, the anti-diabetic activity of them is likely to be mediated by this nuclear receptor. SUMMARY: Lots of the tested medicinal products had activation effects on activating PPARγEthyl acetate extracts of root bark of L.barbarum, rhizome of P.saustralis and fruit of G.siasinensis showed good PPARγ activation effect similar or higher than that of positive control, 0.5 µg/mL rosiglitazonePetroleum ether extracts of A.roxburghii, P. hookeri, P. sibiricum, E.brevicornu also can significantly activate PPARγ, the effects of them were higher than t0.5 µg/mL rosiglitazoneSchisandra chinensis (Turcz.) Baill., the fruit Cornus officinalis Siebold and Zucc., Alisma plantago-aquatica L. and the root of Trichosanthes Kirilowii Maxim., traditional anti-diabetic mediciness in China, had no effects on the activation of PPARγ. Abbreviations used: PPARγ: Peroxisome Proliferator-activated Receptors-γ, TCMs: Traditional Chinese medicines, TZDs: Thiazolidinediones, LBD: Ligand binding domain, DMSO: Dimethyl sulfoxide, FBS: Fetal bovine serum, DMEM: Dulbecco's modified Eagle's medium.

In vitro evaluation of dual agonists for PPARγ/ß from the flower of Edgeworthia gardneri (wall.) Meisn.

ETHNOPHARMACOLOGICAL RELEVANCE: In Tibet, the flower of Edgeworthia gardneri (Wall.) Meisn., locally named "Lvluohua, [symbols: see text]", has been traditionally used to treat diabetes mellitus for many years. AIM OF THIS STUDY: To evaluate the activity of dual agonists for PPARγ/ß from the flower of E.gardneri in vitro. MATERIALS AND METHODS: HeLa cells were transiently co-transfected with the re-constructed plasmids of pBIND-PPARγ-LBD or pBIND-PPARß-LBD and rL4.35. The activities of crude extracts, secondary fractions and compounds from the flower of E.gardneri were evaluated with the transfected cells. Rosiglitazone (at 0.5 µg/mL) and L-165041 (at 0.5 µg/mL) were used as the positive controls for PPARγ and PPARß respectively. RESULTS: The results demonstrated that n-hexane, ethyl acetate and n-butanol extracts from the flower of E.gardneri were able to significantly activate PPARγ and PPARß respectively, and the activity of ethyl acetate extract was much better. We further observed that, among the 11 secondary fractions of ethyl acetate extract, the fr. 9 could activate PPARγ and PPARß significantly. Moreover, umbelliferone (from fr.9) and pentadecanoic acid could activate PPARγ and PPARß at the same time. CONCLUSIONS: The extracts from the flower of E.gardneri could significantly activate PPARγ and PPARß. Besides, umbelliferone and pentadecanoic acid isolated from the flower of E.gardneri were the new agonists for PPARγ and PPARß.

Geniposide decreases the level of Aß1-42 in the hippocampus of streptozotocin-induced diabetic rats.

Although cognitive dysfunction in diabetic patients has been explored extensively, diabetic complications of the central nervous system have not been studied. We have reported previously that geniposide has neurotrophic and neuroprotective activities with the activation of glucagons-like peptide 1 receptor, and regulates glucose-stimulated insulin secretion in vitro. But the role of geniposide on diabetic complications, especially on the neurodegenerative diseases, remains to be investigated. In this study, we investigated the effect of geniposide on the level of Aß1-42 in the hippocampi of streptozotocin-induced diabetic rats and explored its possible mechanism. The results demonstrated that, accompanied with the improvement of insulin and blood glucose, treatment with geniposide decreased the Aß1-42 level and improved the expression of insulin-degrading enzyme, which is the key degrading enzyme of Aß peptide. The results of present study will help to understand the biochemical mechanisms of neuronal dysfunction and death in diabetes and to develop an efficient therapeutic strategy on Alzheimer's disease.