phenanthrenes and Insulin-Resistance

Polycystic ovary syndrome (PCOS) is a complex heterogeneous disorder characterized by androgen excess and ovulatory dysfunction; it is now known to be closely linked to metabolic syndrome. Recent research suggests that insulin resistance plays an important role in the pathogenesis of PCOS which may lead to the excessive production of androgens by ovarian theca cells. Currently there is no single drug that can treat both the reproductive and metabolic complications of the disorder. Existing pharmaceutical agents such as hormonal therapies have been associated with side effects and are not appropriate for PCOS women with infertility. Additionally, insulin sensitizing agents useful for treating the metabolic abnormalities in PCOS have limited efficacy for treating reproductive aspects of the disorder. Chinese herbal medicines have a long history of treating gynaecological problems and infertility and therefore may be a novel approach to the treatment of PCOS. Current research demonstrates that the compounds isolated from herbs have shown beneficial effects for PCOS and when combined in an herbal formula can target both reproductive and metabolic defects simultaneously. Therefore, further investigation into Chinese herbal medicine in the treatment of PCOS is warranted.

Topics: Androgens; Berberine; Drugs, Chinese Herbal; Female; Ginsenosides; Glucosides; Humans; Insulin Resistance; Monoterpenes; Phenanthrenes; Phytotherapy; Polycystic Ovary Syndrome; Resveratrol; Stilbenes; Theca Cells

Epidemiological studies show that the burden of polycyclic aromatic hydrocarbons in human body is associated with the occurrence of insulin resistance and diabetes. In the present study, pregnant mice were exposed to phenanthrene (Phe) at doses of 0, 60 and 600 μg/kg body weight of by gavage once every 3 days. The female F1 mice at 120 days of age showed no change in their fasting glucose levels (FGLs) but exhibited significantly decreased homeostasis model assessment (HOMA) β-cell (49% and 43%) and significantly downregulated pancreatic proinsulin gene (ins2) transcription. The downregulation of transcription factors, such as PDX1, PAX4 and FGF21, indicated impaired development and function of β-cells. The significantly reduced α-cell mass in 60 and 600 μg/kg groups, and the significantly downregulated expression of proglucagon gene gcg and ARX in the 600 μg/kg group suggested that the development and function of α-cells had been impacted. The males exhibited significantly increased FGLs (1.14- and 1.15-fold) in Phe exposed treatments and significantly elevated HOMA β-cell (3.15-fold) in the 600 μg/kg group. Upregulated ins2 transcription and FGF21 protein in male mice prenatally exposed to 600 μg/kg Phe suggested that these animals appeared compensatory enhancement in β-cell function. The reduced serum estradiol levels and downregulated pancreatic estrogen receptor α and β were responsible for the dysfunction of β-cells in the females. In the males, the significantly elevated androgen levels in the 600 μg/kg group might be related to the upregulated ins2 transcription, and the increased expression of pancreatic FGF21 further demonstrated the enhancement of β-cell potential. The results will be helpful for assessing the risk of developing diabetes in adulthood after prenatal exposure to phenanthrene.

Topics: Animals; Female; Insulin; Insulin Resistance; Islets of Langerhans; Male; Mice; Phenanthrenes; Sex Characteristics

Epidemiological studies have indicated that polycyclic aromatic hydrocarbons were related to diabetes and insulin resistance. However, studies in mammals on the development of diabetes caused by polycyclic aromatic hydrocarbons are lacking. Pregnant mice were orally exposed to phenanthrene (0, 60 and 600 μg kg

Topics: Animals; Blood Glucose; Female; Glucose; Glucose Intolerance; Homeostasis; Humans; Insulin; Insulin Resistance; Male; Maternal Exposure; Mice; Phenanthrenes; Pregnancy; Prenatal Exposure Delayed Effects

Epidemiological evidence shows that the body burden of polycyclic aromatic hydrocarbons (PAHs) is related to the disruption of glucose homeostasis. However, the contribution of PAHs to the development of diabetes remains poorly documented. In the current work, male Kunming mice received phenanthrene (Phe) (5, 50, and 500 ng/kg) by gavage administration once every 2 days for 28 weeks. The significant elevation of homeostasis model assessment-insulin resistance (HOMA-IR) and HOMA-β cell, accompanied by hyperinsulinemia, indicated the occurrence of insulin resistance. The suppression of the insulin receptor signaling pathway in skeletal muscle might be responsible for glucose intolerance. Under the nonobese state, the serum levels of resistin, tumor necrosis factor-α, and interleukin-6 were elevated, whereas the levels of adiponectin were reduced. These changes in adipocytokine levels were consistent with their transcription in white adipose tissue. The promoter methylation levels of

Topics: Adiponectin; Animals; Blood Glucose; Glucose Intolerance; Insulin; Insulin Resistance; Male; Mice; Phenanthrenes

Macrophages infiltrated in adipose tissue play a key role in obesity. Some traditional pharmaceutical compounds may shift the polarization of recruited macrophages to improve metabolic homeostasis. TanshinoneⅡA (TAN2A) is a major active component of Salvia miltiorrhiza, a traditional anti-inflammatory cardiovascular medicine. In our study, we firstly constructed a phenanthroimidazole derivative of TAN2A named TAN20 by chemical synthesis, then identified its structure by chromatography and hydrogen spectroscopy, and finally examined its effects on immunometabolic responses. We found that TAN20 significantly induced the alternatively-activated (M2) rather than the classically-activated macrophages (M1), mainly through releasing the type II cytokines. Such effects were more pronounced than that from TAN2A. Compared to TAN2A, TAN20 substantially reduced body weight, decreased serum free fatty acid and HOMA-IR, and increased insulin sensitivity in obesity-induced diabetic mice. These effects of TAN20 were further validated on diabetic cynomolgus monkeys, which are closer to human physiological conditions. Taken together, our findings explicitly showed that TAN20 significantly polarized the macrophage and improved metabolic homeostasis in obesity-induced diabetic models, suggesting that TAN20 may be a potential drug against diabetes and obesity.

Topics: Abietanes; Adipose Tissue; Animals; Anti-Obesity Agents; Blood Glucose; Body Weight; Cell Differentiation; Cell Polarity; Cytokines; Diabetes Mellitus, Experimental; Diet, High-Fat; Fatty Acids, Nonesterified; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Macaca fascicularis; Macrophage Activation; Male; Mice; Mice, Inbred C57BL; Obesity; Phenanthrenes; RAW 264.7 Cells

Insulin resistance causes type 2 diabetes; therefore, increasing insulin sensitivity is a therapeutic approach against type 2 diabetes. Activating AMP-activated protein kinase (AMPK) is an effective approach for treating diabetes, and reduced insulin receptor substrate-1 (IRS-1) protein levels have been suggested as a molecular mechanism causing insulin resistance. Thus, dual targeting of AMPK and IRS-1 might provide an ideal way to treat diabetes. We found that 15,16-dihydrotanshinone I (DHTS), as a C1-Ten protein tyrosine phosphatase inhibitor, increased IRS-1 stability, improved glucose tolerance and reduced muscle atrophy. Identification of DHTS as a C1-Ten inhibitor revealed a new function of C1-Ten in AMPK inhibition, possibly through regulation of IRS-1. These findings suggest that C1-Ten inhibition by DHTS could provide a novel therapeutic strategy for insulin resistance-associated metabolic syndrome through dual targeting of IRS-1 and AMPK.

Topics: AMP-Activated Protein Kinases; Animals; Cell Line; Enzyme Activation; Furans; Glucose; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Male; Metabolic Syndrome; Mice; Mice, Inbred C57BL; Muscle, Skeletal; Muscular Atrophy; Phenanthrenes; Protein Tyrosine Phosphatases; Quinones; Signal Transduction

To investigate the effects of cryptotanshinone (CRY), an active component of Chinese medicine, on ovarian androgen production, insulin resistance (IR), and glucose metabolism in mice.. Animal model and in vitro tissue model.. University-affiliated laboratory.. Mice.. Ovarian IR was induced by dexamethasone (DEX) in vivo. Animals were randomized to receive CRY treatment for 3 days or not. Ovulation rates, serum steroid levels, and glucose uptake in ovaries were quantified, and proteins in the phosphatidylinositol 3-hydroxy kinase pathway were measured. In vitro ovarian IR was also induced by DEX for 3 days. Ovarian steroid hormone secretion and glucose uptake were measured, and the hormone-synthesizing enzymes were determined by semiquantitative reverse transcription-polymerase chain reaction.. Ovarian glucose uptake, in vivo ovulation rate, serum and culture medium steroid level, and molecular expression of phosphatidylinositol 3-hydroxy kinase and steroidogenic enzymes.. Dexamethasone significantly increased ovulation rates in vivo and increased T and E2 production and decreased ovarian glucose uptake in vivo and in vitro. Cryptotanshinone significantly reduced ovulation rates in vivo and decreased T and estrogen production in vitro. Cryptotanshinone attenuated the inhibition of DEX on AKT2 and suppressed the up-regulation of CYP11 and CYP17 expression by DEX.. Cryptotanshinone reversed DEX-induced androgen excess and ovarian IR in mice through activation of insulin signaling and the regulation of glucose transporters and hormone-synthesizing enzymes. This suggests a potential role for CRY in treating the ovulatory dysfunction associated with PCOS.

Topics: Animals; Blood Glucose; Dexamethasone; Disease Models, Animal; Estradiol; Female; Gene Expression Regulation, Enzymologic; Glucose Metabolism Disorders; Glucose Transport Proteins, Facilitative; Insulin; Insulin Resistance; Mice; Ovary; Ovulation; Phenanthrenes; Phosphatidylinositol 3-Kinase; Polycystic Ovary Syndrome; Proto-Oncogene Proteins c-akt; Signal Transduction; Steroid 17-alpha-Hydroxylase; Testosterone; Tissue Culture Techniques

This trial explores 1) prenatally androgenized (PNA) rats as a model of polycystic ovary syndrome (PCOS) and 2) reproductive and metabolic effects of cryptotanshinone in PNA ovaries. On days 16-18 of pregnancy, 10 rats were injected with testosterone propionate (PNA mothers) and 10 with sesame oil (control mothers). At age 3 mo, 12 female offspring from each group were randomly assigned to receive saline and 12 cryptotanshinone treatment during 2 wk. Before treatment, compared with the 24 controls, the 24 PNA rats had 1) disrupted estrous cycles, 2) higher 17-hydroxyprogesterone (P = 0.030), androstenedione (P = 0.016), testosterone and insulin (P values = 0.000), and glucose (P = 0.047) levels, and 3) higher areas under the curve (AUC) for glucose (AUC-Glu, P = 0.025) and homeostatic model assessment for insulin resistance (HOMA-IR, P = 0.008). After treatment, compared with vehicle-treated PNA rats, cryptotanshinone-treated PNA rats had 1) improved estrous cycles (P = 0.045), 2) reduced 17-hydroxyprogesterone (P = 0.041), androstenedione (P = 0.038), testosterone (P = 0.003), glucose (P = 0.036), and insulin (P = 0.041) levels, and 3) lower AUC-Glu (P = 0.045) and HOMA-IR (P = 0.024). Western blot showed that cryptotanshinone reversed the altered protein expressions of insulin receptor substrate-1 and -2, phosphatidylinositol 3-kinase p85α, glucose transporter-4, ERK-1, and 17α-hydroxylase within PNA ovaries. We conclude that PNA model rats exhibit reproductive and metabolic phenotypes of human PCOS and that regulation of key molecules in insulin signaling and androgen synthesis within PNA ovaries may explain cryptotanshinone's therapeutic effects.

Topics: 17-alpha-Hydroxyprogesterone; Androgens; Androstenedione; Animals; Drugs, Chinese Herbal; Female; Glucose; Insulin; Insulin Resistance; Models, Animal; Ovary; Phenanthrenes; Polycystic Ovary Syndrome; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Wistar; Reproduction; Signal Transduction; Testosterone

To investigate the impact of protein kinase B (Akt2) allele deletion on testicular reproductive function, and to discuss the regulatory effect of Cryptotanshinone on the reproductivity of male mice with Akt2 allele deletion and its molecular mechanism.. Fifteen Akt2 +/+ male mice were randomly divided into Groups A (baseline control, n = 7) and B (stimulation, n = 8), and another 29 Akt2 -/- male mice into C (baseline control, n = 7), D (stimulation, n = 8), E (solvent, n = 7) and F (Cryptotanshinone, n = 7). Groups B and D underwent human chorionic gonadotropin (HCG) stimulation tests at 5 IU / 20 g, while A and C received physiological saline, all for 4 hours; Group F were given gastric lavage of Cryptotanshinone, while E solvent only, at 600 mg/kg twice a day for 8 weeks, both subjected to oral glucose tolerance tests (OGTT) at 2 g/kg before and after the treatment. The body and bilateral testis weights were obtained, the serum testosterone (T) level measured, and the expressions of testicular steroid hormone synthesis and glycometabolism-related genes determined by RT-PCR.. OGTT showed that the level of blood glucose was significantly higher in Groups C and D than in A and B ([10.38 +/- 1.42] and [10.96 +/- 1.81] mmol/L vs [7.92 +/- 0.63] and [8.32 +/- 0.44] mmol/L, P < 0.05), but had no significant differences at different time points in E and F (P > 0.05). The testis weight was remarkably higher in Groups C and D than in A and B ([0.17 +/- 0.01] and [0.17 +/- 0.01] g vs [0.15 +/- 0.01] and [0.15 +/- 0.02] g, P < 0.05), but exhibited no obvious difference in E and F, nor were there any significant differences in body weight among different groups (P > 0.05). The serum T level was markedly higher in Group C than in A ([9.08 +/- 1.59] nmol/L vs [6.42 +/- 0.95] nmol/L, P < 0.05), but evidently lower in F than in E ([5.94 +/- 0.49] nmol/L vs [8.18 +/- 1.44] nmol/L, P < 0.05). The baseline expression levels of Cyp11, Cyp17, 3B-HSD, Star, Gsk3beta, Erk-1, and MCM2 mRNA were significantly higher in Group C than in A (P < 0.05). After HCG stimulation, the expressions of Cyp11, Cyp17, 3B-HSD, and Star mRNA were remarkably increased in B and D, but with no obvious difference between the two groups (P > 0.05), while the expressions of Cyp11, Cyp17, 3B-HSD, Star, Gsk3beta, Erk-1, and MCM2 mRNA markedly decreased in F as compared with E (P < 0.05).. Akt2 gene deletion may affect glycometabolism and testicular function, and cause abnormal glycometabolism and androgen secretion in male mice, whose molecular mechanism is associated with the elevated expressions of the key glycometabolic molecules and of the key enzymes for androgen synthesis. Cryptotanshinone can reduce the levels of androgens by down-regulating the expressions of the key enzymes for androgen synthesis.

Topics: Androgens; Animals; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Phenanthrenes; Proto-Oncogene Proteins c-akt; Sequence Deletion