Cell-type dependent regulation of pluripotency and chromatin remodeling genes by hydralazine.

BACKGROUND: The generation of induced pluripotent stem cells has opened the field of study for stem cell research, disease modeling and drug development. However, the epigenetic signatures present in somatic cells make cell reprogramming still an inefficient process. This epigenetic memory constitutes an obstacle in cellular reprogramming. Here, we report the effect of hydralazine (HYD) and valproic acid (VPA), two small molecules with proven epigenetic activity, on the expression of pluripotency genes in adult (aHF) and neonatal (nbHF) human fibroblasts. METHODS: aHF and nbHF were treated with HYD and/or VPA, and viability and gene expression assays for OCT4, NANOG, c-MYC, KLF4, DNMT1, TET3, ARID1A and ARID2 by quantitative PCR were performed. aHF and nbHF were transfected with episomal plasmid bearing Yamanaka factors (OCT4, SOX2, KLF4 and c-MYC) and exposed to HYD and VPA to determine the reprogramming efficiency. Methylation sensitive restriction enzyme (MSRE) qPCR assays were performed on OCT4 and NANOG promoter regions. Immunofluorescence assays were carried out for pluripotency genes on iPSC derived from aHF and nbHF. RESULTS: HYD upregulated the expression of OCT4 (2.5-fold) and NANOG (fourfold) genes but not c-Myc or KLF4 in aHF and had no significant effect on the expression of all these genes in nbHF. VPA upregulated the expression of NANOG (twofold) in aHF and c-MYC in nbHF, while it downregulated the expression of NANOG in nbHF. The combination of HYD and VPA canceled the OCT4 and NANOG overexpression induced by HYD in aHF, while it reinforced the effects of VPA on c-Myc expression in nbHF. The HYD-induced overexpression of OCT4 and NANOG in aHDF was not dependent on demethylation of gene promoters, and no changes in the reprogramming efficiency were observed in both cell populations despite the downregulation of epigenetic genes DNMT1, ARID1A, and ARID2 in nbHF. CONCLUSIONS: Our data provide evidence that HYD regulates the expression of OCT4 and NANOG pluripotency genes as well as ARID1A and ARID2 genes, two members of the SWI/SNF chromatin remodeling complex family, in normal human dermal fibroblasts.

5-Aza-2'-Deoxycytidine and Valproic Acid in Combination with CHIR99021 and A83-01 Induce Pluripotency Genes Expression in Human Adult Somatic Cells.

A generation of induced pluripotent stem cells (iPSC) by ectopic expression of OCT4, SOX2, KLF4, and c-MYC has established promising opportunities for stem cell research, drug discovery, and disease modeling. While this forced genetic expression represents an advantage, there will always be an issue with genomic instability and transient pluripotency genes reactivation that might preclude their clinical application. During the reprogramming process, a somatic cell must undergo several epigenetic modifications to induce groups of genes capable of reactivating the endogenous pluripotency core. Here, looking to increase the reprograming efficiency in somatic cells, we evaluated the effect of epigenetic molecules 5-aza-2'-deoxycytidine (5AZ) and valproic acid (VPA) and two small molecules reported as reprogramming enhancers, CHIR99021 and A83-01, on the expression of pluripotency genes and the methylation profile of the OCT4 promoter in a human dermal fibroblasts cell strain. The addition of this cocktail to culture medium increased the expression of OCT4, SOX2, and KLF4 expression by 2.1-fold, 8.5-fold, and 2-fold, respectively, with respect to controls; concomitantly, a reduction in methylated CpG sites in OCT4 promoter region was observed. The epigenetic cocktail also induced the expression of the metastasis-associated gene S100A4. However, the epigenetic cocktail did not induce the morphological changes characteristic of the reprogramming process. In summary, 5AZ, VPA, CHIR99021, and A83-01 induced the expression of OCT4 and SOX2, two critical genes for iPSC. Future studies will allow us to precise the mechanisms by which these compounds exert their reprogramming effects.

Alpha-1-Antichymotrypsin: A Common Player for Type 2 Diabetes and Alzheimer's Disease.

BACKGROUND: Numerous studies have shown a significant association between Type 2 Diabetes Mellitus (T2D) and Alzheimer's Disease (AD), two pathologies affecting millions of people worldwide. Chronic inflammation and oxidative stress are two conditions common to these diseases, also affecting the activity of the serpin Alpha-1-antichymotrypsin (ACT), but a possible common role for this serpin in T2D and AD remains unclear. OBJECTIVE: To explore the possible regulatory networks linking ACT to T2D and AD. MATERIALS AND METHODS: A bibliographic search was carried out in PubMed, Medline, Open-i, ScienceDirect, Scopus, and SpringerLink for data indicating or suggesting association among T2D, AD, and ACT. Searched terms like "alpha-1-antichymotrypsin", "type 2 diabetes", "Alzheimer's disease", "oxidative stress", "pro-inflammatory mediators" among others were used. Moreover, common therapeutic strategies between T2D and AD as well as the use of ACT as a therapeutic target for both diseases were included. RESULTS: ACT has been linked with the development and maintenance of T2D and AD and studies suggest their participation through the activation of inflammatory pathways and oxidative stress, mechanisms also associated with both diseases. Likewise, evidences indicate that diverse therapeutic approaches are common to both diseases. CONCLUSION: Inflammatory and oxidative stresses constitute a crossroad for T2D and AD, where ACT could play an important role. In-depth research on ACT involvement in these two dysfunctions could generate new therapeutic strategies for T2D and AD.

Enhanced proliferative capacity of human preadipocytes achieved by an optimized cultivating method that induces transient activity of hTERT.

Human mesenchymal stromal cells (MSC) are an important tool for basic and translational research. Large amounts of MSC are required for in vitro and in vivo studies, however, the limited life-span and differentiation ability in vitro hamper their optimal use. Here we report that 1:1 mixture of L15 and mTeSR1 culture media increased the life-span of IPI-SA3-C4, a normal non-immortalized human subcutaneous preadipocyte strain by 20% while retaining their adipogenic capacity and stable karyotype. The increased proliferative capacity was accompanied by increased expression of the stem markers POU5F1, SOX2, MYC and hTERT, and inhibition of hTERT activity abolished the growth advantage of L15-mTeSR1. Consequently, the described MSC culture would considerably enhance the utility of MSC for in vitro studies.

A human preadipocyte cell strain with multipotent differentiation capability as an in vitro model for adipogenesis.

Murine 3T3 cell lines constitute a standard model system for in vitro study of mammalian adipogenesis although they do not faithfully reflect the biology of the human adipose cells. Several human adipose cell lines and strains have been used to recapitulate human adipogenesis in vitro, but to date there is no generally accepted in vitro model for human adipogenesis. We obtained a clonal strain of human subcutaneous adipose stromal cells, IPI-SA3-C4, and characterized its utility as an in vitro model for human subcutaneous adipogenesis. IPI-SA3-C4 cells showed a high proliferative potential for at least 30 serial passages, reached 70 cumulative population doublings and exhibited a population doubling time of 47 h and colony forming efficiency of 12% at the 57th cumulative population doublings. IPI-SA3-C4 cells remained diploid (46XY) even at the 56th cumulative population doublings and expressed the pluripotency markers POU5F1, NANOG, KLF4, and MYC even at 50th cumulative population doublings. Under specific culture conditions, IPI-SA3-C4 cells displayed cellular hallmarks and molecular markers of adipogenic, osteogenic, and chondrogenic lineages and showed adipogenic capacity even at the 66th cumulative population doublings. These characteristics show IPI-SA3-C4 cells as a promising potential model for human subcutaneous adipogenesis in vitro.

Circulating microRNAs overexpressed in macrosomia: an experimental and bioinformatic approach.

Low birth weight (LBW) and macrosomia have been associated with later-in-life metabolic alterations. The aim of this study was to elucidate whether the expression levels of circulating microRNAs (c-miRNAs) associated with adult metabolic diseases are also dysregulated in newborns with LBW or macrosomia. The expression levels of five microRNAs (miRNAs) associated with metabolic diseases were quantified in dried blood spots of newborns with adequate birth weight, LBW and macrosomia by stem-loop real-time polymerase chain reaction. miR-29a-5p, miR-126-3p, miR-221-3p, and miR-486-5p were significantly overexpressed in newborns with macrosomia and showed no significant change in the LBW group compared to normal weight controls. miR-320a showed no statistical difference among groups. We predicted the putative target genes and pathways of the overexpressed miRNAs with bioinformatic tools. Bioinformatic analyses of overexpressed miRNAs predicted target genes involved in carbohydrate metabolism, participate in FoxO and PI3K/Akt signaling pathways, and are associated with diabetes, obesity, and cardiovascular diseases. The overexpression of circulating miR-29a-5p, miR-126-3p, miR-221-3p, and miR-486-5p may explain the increased risk of obesity and diabetes associated with macrosomia. The use of dried blood spots from newborn screening cards to quantify miRNAs expression levels could be an early and minimally invasive predictive tool for these metabolic alterations.

Expression of the Biologically Active Insulin Analog SCI-57 in Nicotiana Benthamiana.

Diabetes mellitus is a growing problem worldwide; however, only 23% of low-income countries have access to insulin, and ironically it costs higher in such countries than high-income ones. Therefore, new strategies for insulin and insulin analogs production are urgently required to improve low-cost access to therapeutic products, so as to contain the diabetes epidemic. SCI-57 is an insulin analog with a greater affinity for the insulin receptor and lower thermal degradation than native insulin. It also shows native mitogenicity and insulin-like biological activity. In this work, SCI-57 was transiently expressed in the Nicotiana benthamiana (Nb) plant, and we also evaluated some of its relevant biological effects. An expression plasmid was engineered to translate an N-terminal ubiquitin and C-terminal endoplasmic reticulum-targeting signal KDEL, in order to increase protein expression and stability. Likewise, the effect of co-expression of influenza M2 ion channel (M2) on the expression of insulin analog SCI-57 (SCI-57/M2) was evaluated. Although using M2 increases yield, it tends to alter the SCI-57 amino acid sequence, possibly promoting the formation of oligomers. Purification of SCI-57 was achieved by FPLC cation exchange and ultrafiltration of N. benthamiana leaf extract (NLE). SCI-57 exerts its anti-diabetic properties by stimulating glucose uptake in adipocytes, without affecting the lipid accumulation process. Expression of the insulin analog in agroinfiltrated plants was confirmed by SDS-PAGE, RP-HPLC, and MS. Proteome changes related to the expression of heterologous proteins on N. benthamiana were not observed; up-regulated proteins were related to the agroinfiltration process. Our results demonstrate the potential for producing a biologically active insulin analog, SCI-57, by transient expression in Nb.

Circulating microRNAs in human obesity: a systematic review.

Context: Differential expression profiles of microRNAs have been reported in human obesity suggesting a miRNAs role in the development of obesity and associated disorders. Objective: To review circulating microRNAs (c-miRNAs) dysregulated in human obesity and to predict their possible target genes. Methods: We performed a systematic review on PubMed database (PROSPERO, CRD42017077742) for original works on c-miRNAs and human obesity and recorded c-miRNAs with differential expression profiles. Potential target genes and metabolic pathways for dysregulated miRNAs with at least two independent reports were searched using bioinformatic tools. Results: Twenty-two c-miRNAs are overexpressed, nine underexpressed and two c-miRNAs dysregulated in both directions in people with obesity compared to lean controls. Bioinformatic analyses suggest these c-miRNAs target on genes associated with fatty acid metabolism and PI3k/Akt pathway. Conclusion: Literature records 33 c-miRNAs confirmedly dysregulated in human obesity. Their predicted target genes are involved in pathways that could explain the development of obesity and its comorbidities. Further research will clarify the role of these miRNAs on metabolic diseases and their usefulness for the prognosis, prevention and treatment of obesity.

Smilax aristolochiifolia Root Extract and Its Compounds Chlorogenic Acid and Astilbin Inhibit the Activity of α-Amylase and α-Glucosidase Enzymes.

Regulating activities of α-amylase and α-glucosidase through the use of specific inhibitors is a main strategy for controlling type 2 diabetes. Smilax aristolochiifolia root decoctions are traditionally used in Mexico as hypoglycemic and for weight loss, but the active principles and mechanisms underlying such putative metabolic effects are yet unknown. Here, we isolated the major bioactive compounds from a hydroethanolic extract of S. aristolochiifolia root by fast centrifugal partition chromatography and evaluated their effects against pancreatic α-amylase and yeast α-glucosidase. A chlorogenic acid-rich fraction (CAF) inhibited α-amylase activity with an IC50 value of 59.28 µg/mL in an uncompetitive manner and α-glucosidase activity with an IC50 value of 9.27 µg/mL in a noncompetitive mode. Also, an astilbin-rich fraction (ABF) inhibited α-glucosidase activity with an IC50 value of 12.30 µg/mL, in a noncompetitive manner. CAF inhibition α-amylase was as active as acarbose while both CAF and ABF were 50-fold more potent inhibitors of α-glucosidase than acarbose. The molecular docking results of chlorogenic acid and astilbin with α-amylase and α-glucosidase enzymes correlated with the inhibition mechanisms suggested by enzymatic assays. Our results prove that S. aristolochiifolia roots contain chlorogenic acid and astilbin, which inhibit carbohydrates-hydrolyzing enzymes, suggesting a new mechanism for the hypoglycemic effect reported for this plant.

Analysis of MicroRNA Expression in Newborns with Differential Birth Weight Using Newborn Screening Cards.

Birth weight is an early predictor for metabolic diseases and microRNAs (miRNAs) are proposed as fetal programming participants. To evaluate the use of dried blood spots (DBS) on newborn screening cards (NSC) as a source of analyzable miRNAs, we optimized a commercial protocol to recover total miRNA from normal birth weight (NBW, n = 17-20), low birth weight (LBW, n = 17-20) and high birth weight (macrosomia, n = 17-20) newborns and analyzed the relative expression of selected miRNAs by stem-loop RT-qPCR. The possible role of miRNAs on the fetal programming of metabolic diseases was explored by bioinformatic tools. The optimized extraction of RNA resulted in a 1.2-fold enrichment of miRNAs respect to the commercial kit. miR-33b and miR-375 were overexpressed in macrosomia 9.8-fold (p < 0.001) and 1.7-fold, (p < 0.05), respectively and miR-454-3p was overexpressed in both LBW and macrosomia (19.7-fold, p < 0.001 and 10.8-fold, p < 0.001, respectively), as compared to NBW. Potential target genes for these miRNAs are associated to cyclic-guanosine monophosphate (cGMP)-dependent protein kinase (PKG), mitogen-activated protein kinase (MAPK), type 2 diabetes, transforming growth factor-ß (TGF-ß)and Forkhead box O protein (FoxO) pathways. In summary, we improved a protocol for analyzing miRNAs from NSC and provide the first evidence that birth weight modifies the expression of miRNAs associated to adult metabolic dysfunctions. Our work suggests archived NSC are an invaluable resource in the search for fetal programming biomarkers.

neo-Clerodane Diterpenoids from Salvia polystachya Stimulate the Expression of Extracellular Matrix Components in Human Dermal Fibroblasts.

Eleven neo-clerodane diterpenoids (1-11) including the new analogues 1, 2, and 10, and 3',5,6,7-tetrahydroxy-4'-methoxyflavone (12) were isolated from the aerial parts of Salvia polystachya. Polystachyne G (1) and 15-epi-polystachyne G (2) were isolated as an epimeric mixture, containing a 5-hydroxyfuran-2(5H)-one unit in the side chain at C-12 of the neo-clerodane framework. Polystachyne H (10) contains a 1(10),2-diene moiety and a tertiary C-4 hydroxy group. The structures of these compounds were established by analysis of their NMR spectroscopic and MS spectrometric data. The absolute configurations of compounds 3, 4, and 10 were determined through single-crystal X-ray diffraction analysis. The antibacterial, antifungal, and phytotoxic activities of the diterpenoids were determined. In addition, the stimulatory effect of the expression of extracellular matrix components of nine of the isolates (1-8 and 11) was assayed. Compounds 1-4, 8, and 11 increased the expression of the genes codifying for type I, type III, and type V collagens and for elastin.

Anthelmintic effect of Psidium guajava and Tagetes erecta on wild-type and Levamisole-resistant Caenorhabditis elegans strains.

ETHNOPHARMACOLOGICAL RELEVANCE: Psidium guajava and Tagetes erecta have been used traditionally to treat gastrointestinal parasites, but their active metabolites and mechanisms of action remain largely unknown. AIM OF THE STUDY: To evaluate the anthelmintic potential of Psidium guajava and Tagetes erecta extracts on Levamisole-sensitive and Levamisole-resistant strains of the model nematode Caenorhabditis elegans. MATERIALS AND METHODS: Aqueous extracts of Psidium guajava (PGE) and Tagetes erecta (TEE) were assayed on locomotion and egg-laying behaviors of the wild-type (N2) and Levamisole-resistant (CB193) strains of Caenorhabditis elegans. RESULTS: Both extracts paralyzed wild-type and Levamisole-resistant nematodes in a dose-dependent manner. In wild-type worms, TEE 25mg/mL induced a 75% paralysis after 8h of treatment and PGE 25mg/mL induced a 100% paralysis after 4h of treatment. PGE exerted a similar paralyzing effect on N2 wild-type and CB193 Levamisole-resistant worms, while TEE only partially paralyzed CB193 worms. TEE 25mg/mL decreased N2 egg-laying by 65% with respect to the untreated control, while PGE did it by 40%. CONCLUSIONS: Psidium guajava leaves and Tagetes erecta flower-heads possess hydrosoluble compounds that block the motility of Caenorhabditis elegans by a mechanism different to that of the anthelmintic drug Levamisole. Effects are also observable on oviposition, which was diminished in the wild-type worms. The strong anthelmintic effects in crude extracts of these plants warrants future work to identify their active compounds and to elucidate their molecular mechanisms of action.

SerpinA3g participates in the antiadipogenesis and insulin-resistance induced by tumor necrosis factor-α in 3T3-F442A cells.

Tumor necrosis factor alpha (TNF-α) is a proven modulator of adipose metabolism, but the mechanisms by which this cytokine affects the development and function of adipose tissue have not been fully elucidated to date. Using differential display analysis, in this study, we demonstrate that gene expression of the serine protease inhibitor A3g (SerpinA3g) is specifically induced in 3T3-F442A preadipocytes by TNF-α but not by other adipogenic inhibitors, such as retinoic acid (RA) or transforming growth factor type beta (TGF-ß). The specific induction of SerpinA3g by TNF-α was confirmed by RT-PCR in both preadipose and terminally differentiated 3T3-F442A cells. The knockdown of SerpinA3g using small interfering RNA prevented the antiadipogenesis elicited by TNF-α in 3T3-F442A cells but not the antiadipogenesis induced by RA or TGF-ß. SerpinA3g-silenced 3T3-F442A cells also did not display TNF-α-induced insulin resistance. Our results demonstrate that SerpinA3g is specifically induced by TNF-α in 3T3-F442A cells, regardless of their stage of differentiation, and participates in the antiadipogenesis and insulin resistance induced by this cytokine. Our results suggest that SerpinA3g plays a role in the TNF-α modulation of adipose tissue development and metabolism. Additional studies are warranted regarding the mechanisms mediating adipose SerpinA3g effects.

Ibervillea sonorae (Cucurbitaceae) induces the glucose uptake in human adipocytes by activating a PI3K-independent pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Ibervillea sonorae (S. Watson) Greene (Cucurbitaceae), a plant used for the empirical treatment of type 2 diabetes in México, exerts antidiabetic effects on animal models but its mechanism of action remains unknown. The aim of this study is to investigate the antidiabetic mechanism of an Ibervillea sonorae aqueous extract (ISE). MATERIALS AND METHODS: Non-toxic ISE concentrations were assayed on the glucose uptake by insulin-sensitive and insulin-resistant murine and human cultured adipocytes, both in the absence or the presence of insulin signaling pathway inhibitors, and on murine and human adipogenesis. Chemical composition of ISE was examined by spectrophotometric and HPLC techniques. RESULTS: ISE stimulated the 2-NBDGlucose uptake by mature adipocytes in a concentration-dependent manner. ISE 50 µg/ml induced the 2-NBDG uptake in insulin-sensitive 3T3-F442A, 3T3-L1 and human adipocytes by 100%, 63% and 33%, compared to insulin control. Inhibitors for the insulin receptor, PI3K, AKT and GLUT4 blocked the 2-NBDG uptake in murine cells, but human adipocytes were insensitive to the PI3K inhibitor Wortmannin. ISE 50 µg/ml also stimulated the 2-NBDG uptake in insulin-resistant adipocytes by 117% (3T3-F442A), 83% (3T3-L1) and 48% (human). ISE induced 3T3-F442A adipogenesis but lacked proadipogenic effects on 3T3-L1 and human preadipocytes. Chemical analyses showed the presence of phenolics in ISE, mainly an appreciable concentration of gallic acid. CONCLUSION: Ibervillea sonorae exerts its antidiabetic properties by means of hydrosoluble compounds stimulating the glucose uptake in human preadipocytes by a PI3K-independent pathway and without proadipogenic effects.

Isoorientin reverts TNF-α-induced insulin resistance in adipocytes activating the insulin signaling pathway.

Isoorientin (ISO) is a plant C-glycosylflavonoid with purported antidiabetic effects but unexplored mechanisms of action. To gain insight into its antidiabetic mechanisms, we assayed nontoxic ISO concentrations on the 2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2-deoxy-d-glucose (2-NBDG) uptake by murine 3T3-F442A and human sc adipocytes. In insulin-sensitive adipocytes, ISO stimulated the 2-NBDG uptake by 210% (murine) and 67% (human), compared with insulin treatment. Notably, ISO also induced 2-NBDG uptake in murine (139%) and human (60%) adipocytes made resistant to insulin by treatment with TNF-α, compared with the incorporation induced in these cells by rosiglitazone. ISO induction of glucose uptake in adipocytes was abolished by inhibitors of the insulin signaling pathway. These inhibitors also blocked the proper phosphorylation of insulin signaling pathway components induced by ISO in both insulin-sensitive and insulin-resistant adipocytes. Additionally, ISO stimulated the transcription of genes encoding components of insulin signaling pathway in murine insulin-sensitive and insulin-resistant adipocytes. In summary, we show here that ISO exerts its antidiabetic effects by activating the insulin signaling pathway in adipocytes, reverts the insulin resistance caused in these cells by TNF-α by stimulating the proper phosphorylation of proteins in this signaling pathway, and induces the expression of genes encoding these proteins.

Antidiabetic effects of Justicia spicigera Schltdl (Acanthaceae).

ETHNOPHARMACOLOGICAL IMPORTANCE: Justicia spicigera is a plant species used for the Teenak (Huesteca Potosina) and Mayan (Yucatan peninsula) indigenous for the empirical treatment of diabetes, infections and as stimulant. AIM OF THE STUDY: To evaluate the cytotoxicity, antioxidant and antidiabetic properties of J. spicigera. MATERIALS AND METHODS: The effects of ethanolic extracts of J. spicigera (JSE) on the glucose uptake in insulin-sensitive and insulin-resistant murine 3T3-F442A and human subcutaneous adipocytes was evaluated. The antioxidant activities of the extract of JSE was determined by ABTS and DPPH methods. Additionally, it was evaluated the antidiabetic properties of JSE on T2DM model. RESULTS: JSE stimulated 2-NBDG uptake by insulin-sensitive and insulin-resistant human and murine adipocytes in a concentration-dependent manner with higher potency than rosiglitazone 1mM. JSE showed antioxidant effects in vitro and induced glucose lowering effects in normoglycemic and STZ-induced diabetic rats. CONCLUSION: The antidiabetic effects of administration of J. spicigera are related to the stimulation of glucose uptake in both insulin-sensitive and insulin-resistant murine and human adipocytes and this evidence justify its empirical use in Traditional Medicine. In addition, J. spicigera exerts glucose lowering effects in normoglycemic and STZ-induced diabetic rats.

Magnolia dealbata Zucc and its active principles honokiol and magnolol stimulate glucose uptake in murine and human adipocytes using the insulin-signaling pathway.

Some Magnolia (Magnoliaceae) species are used for the empirical treatment of diabetes mellitus, but the antidiabetic properties of Magnolia dealbata have not yet been experimentally validated. Here we report that an ethanolic extract of Magnolia dealbata seeds (MDE) and its active principles honokiol (HK) and magnolol (MG) induced the concentration-dependent 2-NBDG uptake in murine 3T3-F442A and human subcutaneous adipocytes. In insulin-sensitive adipocytes, MDE 50 µg/ml induced the 2-NBDG uptake by 30% respect to insulin, while HK and MG, 30 µM each, did it by 50% (murine) and 40% (human). The simultaneous application of HK and MG stimulated 2-NBDG uptake by 70% in hormone-sensitive cells, on which Magnolia preparations exerted synergic effects with insulin. In insulin-resistant adipocytes, MDE, HK and MG induced 2-NBDG uptake by 57%, 80% and 96% respect to Rosiglitazone (RGZ), whereas HK and MG simultaneously applied stimulated 2-NBDG uptake more efficiently than RGZ (120%) in both murine and human adipocytes. Inhibitors of the insulin-signaling pathway abolished the glucose uptake induced by Magnolia dealbata preparations, suggesting that their antidiabetic effects are mediated by this signaling pathway. In addition, MDE, HK and MG exerted only mild to moderate proadipogenic effects on 3T3-F442A and human preadipocytes, although the combined application of HK and MG markedly increased the lipid accumulation in both cell types. In summary, Magnolia dealbata and its active principles HK and MG stimulate glucose uptake in insulin-sensitive and insulin-resistant murine and human adipocytes using the insulin signaling pathway.

Antimicrobial and cytotoxic effects of Mexican medicinal plants.

The antimicrobial effects of the Mexican medicinal plants Guazuma ulmifolia, Justicia spicigera, Opuntia joconostle, O. leucotricha, Parkinsonia aculeata, Phoradendron longifolium, P. serotinum, Psittacanthus calyculatus, Tecoma stans and Teucrium cubense were tested against several human multi-drug resistant pathogens, including three Gram (+) and five Gram (-) bacterial species and three fungal species using the disk-diffusion assay. The cytotoxicity of plant extracts on human cancer cell lines and human normal non-cancerous cells was also evaluated using the MTT assay. Phoradendron longifolium, Teucrium cubense, Opuntia joconostle, Tecoma stans and Guazuma ulmifolia showed potent antimicrobial effects against at least one multidrug-resistant microorganism (inhibition zone > 15 mm). Only Justicia spicigera and Phoradendron serotinum extracts exerted active cytotoxic effects on human breast cancer cells (IC50 < or = 30 microg/mL). The results showed that Guazuma ulmifolia produced potent antimicrobial effects against Candida albicans and Acinetobacter lwoffii, whereas Justicia spicigera and Phoradendron serotinum exerted the highest toxic effects on MCF-7 and HeLa, respectively, which are human cancer cell lines. These three plant species may be important sources of antimicrobial and cytotoxic agents.

Mexican medicinal plants used for cancer treatment: pharmacological, phytochemical and ethnobotanical studies.

AIM OF THE STUDY: This review provides a summary of Mexican medicinal flora in terms of ethnobotanical, pharmacology, and chemistry of natural products related to anticancer activity. MATERIALS AND METHODS: Bibliographic investigation was carried out by analyzing recognized books and peer-reviewed papers, consulting worldwide accepted scientific databases from the last five decades. Mexican plants with attributed anti-cancer properties were classified into six groups: (a) plant extracts that have been evaluated for cytotoxic effects, (b) plant extracts that have documented anti-tumoral effects, (c) plants with active compounds tested on cancer cell lines, (d) plants with novel active compounds found only in Mexican species, (e) plants with active compounds that have been assayed on animal models and (f) plants with anti-cancer ethnopharmacological references but without scientific studies. RESULTS: Three hundred plant species belonging to 90 botanical families used for cancer treatment have been recorded, of which only 181 have been experimentally analyzed. The remaining 119 plant species are in use in empirical treatment of diseases consistent with cancer symptomatology. Only 88 of the plant extracts experimentally studied in in vitro cellular models have demonstrated active cytotoxic effects in at least one cancer cell line, and 14 out of the 88 have also been tested in vivo with the results that one of them demonstrated anti-neoplasic effects. A total of 187 compounds, belonging to 19 types of plant secondary metabolites, have been isolated from 51 plant extracts with active cytotoxic effects, but only 77 of these compounds (41%) have demonstrated cytoxicity. Seventeen of these active principles have not been reported in other plant species. However, only 5 compounds have been evaluated in vivo, and 3 of them could be considered as active. CONCLUSION: Clearly, this review indicates that it is time to increase the number of experimental studies and to begin to conduct clinical trials with those Mexican plants and its active compounds selected by in vitro and in vivo activities. Also, the mechanisms of action by which plant extracts and their active compounds exert anti-cancer effects remain to be studied.

Dystrophins and DAPs are expressed in adipose tissue and are regulated by adipogenesis and extracellular matrix.

The dystrophin-associated protein complex (DAPC), consisting of dystrophin, dystroglycans, sarcoglycans, dystrobrevins and syntrophins, provides a linkage between the cytoskeleton and the extracellular matrix. The disruption of DAPC leads to Duchenne/Becker muscular dystrophy and other neuromuscular diseases. Although adipose-derived stem cells had been used for the experimental treatment of Duchenne/Becker disease with promising results, little is known on the expression and function of DAPC in adipose tissue. Here we show that visceral and subcutaneous rat adipose depots express mRNAs for all known dystrophin isoforms, utrophin, α- and ß-dystrobrevins, and α-, ßI-, ßII-, and γII-syntrophins. Visceral and subcutaneous rat preadipocytes express Dp116 and Dp71 mRNAs and proteins, and this expression is differentially regulated during adipogenesis. Rat preadipocytes also express ß-dystrobrevin, α-, ßI-, ßII- and γII-syntrophins, ß-dystroglycan and ß-, δ-, and ε-sarcoglycans with no changes during adipogenesis. We also show that α-dystrobrevin increases their expression during adipose differentiation and extracellular matrix differentially regulates the expression of dystrophin isoforms mRNAs during adipogenesis. Our results show that DAPC components are expressed in adipose tissues and suggest that this complex has a role on the adipose biology.