Displaying publications 1 - 20 of 31 in total

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  1. Arifin SA, Paternoster S, Carlessi R, Casari I, Ekberg JH, Maffucci T, et al.
    Biochim Biophys Acta Mol Cell Biol Lipids, 2018 09;1863(9):1132-1141.
    PMID: 29883799 DOI: 10.1016/j.bbalip.2018.06.007
    The gastrointestinal tract is increasingly viewed as critical in controlling glucose metabolism, because of its role in secreting multiple glucoregulatory hormones, such as glucagon like peptide-1 (GLP-1). Here we investigate the molecular pathways behind the GLP-1- and insulin-secreting capabilities of a novel GPR119 agonist, Oleoyl-lysophosphatidylinositol (Oleoyl-LPI). Oleoyl-LPI is the only LPI species able to potently stimulate the release of GLP-1 in vitro, from murine and human L-cells, and ex-vivo from murine colonic primary cell preparations. Here we show that Oleoyl-LPI mediates GLP-1 secretion through GPR119 as this activity is ablated in cells lacking GPR119 and in colonic primary cell preparation from GPR119-/- mice. Similarly, Oleoyl-LPI-mediated insulin secretion is impaired in islets isolated from GPR119-/- mice. On the other hand, GLP-1 secretion is not impaired in cells lacking GPR55 in vitro or in colonic primary cell preparation from GPR55-/- mice. We therefore conclude that GPR119 is the Oleoyl-LPI receptor, upstream of ERK1/2 and cAMP/PKA/CREB pathways, where primarily ERK1/2 is required for GLP-1 secretion, while CREB activation appears dispensable.
    Matched MeSH terms: Islets of Langerhans/drug effects; Islets of Langerhans/metabolism
  2. Choy KW, Zain ZM, Murugan DD, Giribabu N, Zamakshshari NH, Lim YM, et al.
    Front Pharmacol, 2021;12:632169.
    PMID: 33986669 DOI: 10.3389/fphar.2021.632169
    Type 2 diabetes mellitus is characterized by both resistance to the action of insulin and defects in insulin secretion. Bird's nest, which is derived from the saliva of swiftlets are well known to possess multiple health benefits dating back to Imperial China. However, it's effect on diabetes mellitus and influence on the actions of insulin action remains to be investigated. In the present study, the effect of standardized aqueous extract of hydrolyzed edible bird nest (HBN) on metabolic characteristics and insulin signaling pathway in pancreas, liver and skeletal muscle of db/db, a type 2 diabetic mice model was investigated. Male db/db diabetic and its euglycemic control, C57BL/6J mice were administered HBN (75 and 150 mg/kg) or glibenclamide (1 mg/kg) orally for 28 days. Metabolic parameters were evaluated by measuring fasting blood glucose, serum insulin and oral glucose tolerance test (OGTT). Insulin signaling and activation of inflammatory pathways in liver, adipose, pancreas and muscle tissue were evaluated by Western blotting and immunohistochemistry. Pro-inflammatory cytokines were measured in the serum at the end of the treatment. The results showed that db/db mice treated with HBN significantly reversed the elevated fasting blood glucose, serum insulin, serum pro-inflammatory cytokines levels and the impaired OGTT without affecting the body weight of the mice in all groups. Furthermore, HBN treatment significantly ameliorated pathological changes and increased the protein expression of insulin, and glucose transporters in the pancreatic islets (GLUT-2), liver and skeletal muscle (GLUT-4). Likewise, the Western blots analysis denotes improved insulin signaling and antioxidant enzyme, decreased reactive oxygen species producing enzymes and inflammatory molecules in the liver and adipose tissues of HBN treated diabetic mice. These results suggest that HBN improves β-cell function and insulin signaling by attenuation of oxidative stress mediated chronic inflammation in the type 2 diabetic mice.
    Matched MeSH terms: Islets of Langerhans
  3. Syukri Y, Taher M, Martien R, Lukitaningsih E, Nugroho AE, Zakaria ZA
    Adv Pharm Bull, 2021 Jan;11(1):171-180.
    PMID: 33747864 DOI: 10.34172/apb.2021.018
    Purpose:
    Insulin resistance is a characteristic of non-insulin-dependent diabetes mellitus associated with obesity and caused by the failure of pancreatic beta cells to secrete sufficient amount of insulin. Andrographolide (AND) improves beta-cell reconstruction and inhibits fat-cell formation. This research aimed to improve the delivery of water-insoluble AND in self-nanoemulsifying (ASNE) formulation, tested in streptozotocin (STZ)-induced diabetic rats and 3T3-L1 preadipocyte cells.
    Methods:
    A conventional formulation of AND in suspension was used as a control. The experimental rats were orally administered with self-nanoemulsifying (SNE) and suspension of AND for 8 days. Measurements were performed to evaluate blood glucose levels in preprandial and postprandial conditions. Immunohistochemistry was used to assess the process of islet beta cell reconstruction. In vitro study was performed using cell viability and adipocyte differentiation assay to determine the delivery of AND in the formulation.
    Results:
    ASNE lowered blood glucose levels (day 4) faster than AND suspension (day 6). The histological testing showed that ASNE could regenerate pancreatic beta cells. Therefore, ASNE ameliorated pancreatic beta cells. The in vitro evaluation indicated the inhibition of adipocyte differentiation by both AND and ASNE, which occurred in a time-dependent manner. ASNE formulation had better delivery than AND.
    Conclusion:
    ASNE could improve the antidiabetic activity by lowering blood glucose levels, enhancing pancreatic beta cells, and inhibiting lipid formation in adipocyte cells.
    Matched MeSH terms: Islets of Langerhans
  4. Chia LL, Jantan I, Chua KH, Lam KW, Rullah K, Aluwi MF
    Front Pharmacol, 2016;7:291.
    PMID: 27625609 DOI: 10.3389/fphar.2016.00291
    Tocotrienols (T3) are well-known for their antioxidant properties besides showing therapeutic potential in clinical complications such as hyperlipidemia induced by diabetes. The aim of this study was to determine the effects of δ-T3, γ-T3, and α-T3 on insulin secretion-associated genes expression of rat pancreatic islets in a dynamic culture. Pancreatic islets freshly isolated from male Wistar rats were treated with T3 for 1 h at 37°C in a microfluidic system with continuous operation. The cells were collected for total RNA extraction and reverse-transcribed, followed by measurement of insulin secretion-associated genes expression using quantitative real-time polymerase chain reaction. Molecular docking experiments were performed to gain insights on how the T3 bind to the receptors. Short-term exposure of δ- and γ-T3 to pancreatic β cells in a stimulant glucose condition (16.7 mM) significantly regulated preproinsulin mRNA levels and insulin gene transcription. In contrast, α-T3 possessed less ability in the activation of insulin synthesis level. Essentially, potassium chloride (KCl), a β cell membrane depolarising agent added into the treatment further enhanced the insulin production. δ- and γ-T3 revealed significantly higher quantitative expression in most of the insulin secretion-associated genes groups containing 16.7 mM glucose alone and 16.7 mM glucose with 30 mM KCl ranging from 600 to 1200 μM (p < 0.05). The findings suggest the potential of δ-T3 in regulating insulin synthesis and glucose-stimulated insulin secretion through triggering pathway especially in the presence of KCl.
    Matched MeSH terms: Islets of Langerhans
  5. Motshakeri M, Ebrahimi M, Goh YM, Othman HH, Hair-Bejo M, Mohamed S
    PMID: 24516503 DOI: 10.1155/2014/379407
    The edible seaweed Sargassum polycystum (SP) is traditionally used against several human diseases. This investigation evaluated the effects of two dietary doses of SP ethanolic and aqueous extracts on the pancreatic, hepatic, and renal morphology of type 2 diabetic rats (T2DM). T2DM was induced by feeding rats on high calorie diet followed by a low dose streptozotocin. Changes in the diabetic rat organs in SP treated groups with different doses of extracts were compared with normal rats, diabetic control rats, and metformin treated rats. After 22 days of treatment, the pathological lesions of the livers and kidneys in the diabetic rats were quantitatively and qualitatively alleviated (P < 0.05) by both the SP extracts at 150 mg/kg body weight and by metformin. All the treated diabetic groups revealed marked improvement in the histopathology of the pancreas compared with the control diabetic group. Oral administration of 300 mg/kg body weight of aqueous and ethanolic extracts of SP and metformin revealed pancreas protective or restorative effects. The seaweed extracts at 150 mg/kg body weight reduced the liver and kidney damages in the diabetic rats and may exert tissue repair or restoration of the pancreatic islets in experimentally induced diabetes to produce the beneficial homeostatic effects.
    Matched MeSH terms: Islets of Langerhans
  6. Hafizur RM, Hameed A, Shukrana M, Raza SA, Chishti S, Kabir N, et al.
    Phytomedicine, 2015 Feb 15;22(2):297-300.
    PMID: 25765836 DOI: 10.1016/j.phymed.2015.01.003
    Although the anti-diabetic activity of cinnamic acid, a pure compound from cinnamon, has been reported but its mechanism(s) is not yet clear. The present study was designed to explore the possible mechanism(s) of anti-diabetic activity of cinnamic acid in in vitro and in vivo non-obese type 2 diabetic rats. Non-obese type 2 diabetes was developed by injecting 90 mg/kg streptozotocin in 2-day-old Wistar pups. Cinnamic acid and cinnamaldehyde were administered orally to diabetic rats for assessing acute blood glucose lowering effect and improvement of glucose tolerance. Additionally, insulin secretory activity of cinnamic acid and cinnamaldehyde was evaluated in isolated mice islets. Cinnamic acid, but not cinnamaldehyde, decreased blood glucose levels in diabetic rats in a time- and dose-dependent manner. Oral administration of cinnamic acid with 5 and 10 mg/kg doses to diabetic rats improved glucose tolerance in a dose-dependent manner. The improvement by 10 mg/kg cinnamic acid was comparable to that of standard drug glibenclamide (5 mg/kg). Further in vitro studies showed that cinnamaldehyde has little or no effect on glucose-stimulated insulin secretion; however, cinnamic acid significantly enhanced glucose-stimulated insulin secretion in isolated islets. In conclusion, it can be said that cinnamic acid exerts anti-diabetic activity by improving glucose tolerance in vivo and stimulating insulin secretion in vitro.
    Matched MeSH terms: Islets of Langerhans/drug effects*
  7. Ghazalli N, Wu X, Walker S, Trieu N, Hsin LY, Choe J, et al.
    Stem Cells Dev, 2018 07 01;27(13):898-909.
    PMID: 29717618 DOI: 10.1089/scd.2017.0160
    Pluripotent stem cells may serve as an alternative source of beta-like cells for replacement therapy of type 1 diabetes; however, the beta-like cells generated in many differentiation protocols are immature. The maturation of endogenous beta cells involves an increase in insulin expression starting in late gestation and a gradual acquisition of the abilities to sense glucose and secrete insulin by week 2 after birth in mice; however, what molecules regulate these maturation processes are incompletely known. In this study, we aim to identify small molecules that affect immature beta cells. A cell-based assay, using pancreatic beta-like cells derived from murine embryonic stem (ES) cells harboring a transgene containing an insulin 1-promoter driven enhanced green fluorescent protein reporter, was used to screen a compound library (NIH Clinical Collection-003). Cortisone, a glucocorticoid, was among five positive hit compounds. Quantitative reverse transcription-polymerase chain reaction analysis revealed that glucocorticoids enhance the gene expression of not only insulin 1 but also glucose transporter-2 (Glut2; Slc2a2) and glucokinase (Gck), two molecules important for glucose sensing. Mifepristone, a pharmacological inhibitor of glucocorticoid receptor (GR) signaling, reduced the effects of glucocorticoids on Glut2 and Gck expression. The effects of glucocorticoids on ES-derived cells were further validated in immature primary islets. Isolated islets from 1-week-old mice had an increased Glut2 and Gck expression in response to a 4-day treatment of exogenous hydrocortisone in vitro. Gene deletion of GR in beta cells using rat insulin 2 promoter-driven Cre crossed with GRflox/flox mice resulted in a reduced gene expression of Glut2, but not Gck, and an abrogation of insulin secretion when islets were incubated in 0.5 mM d-glucose and stimulated by 17 mM d-glucose in vitro. These results demonstrate that glucocorticoids positively regulate glucose sensors in immature murine beta-like cells.
    Matched MeSH terms: Islets of Langerhans/metabolism
  8. Osman M, Adnan A, Salmah Bakar N, Alashkham F
    Pol J Pathol, 2012 Dec;63(4):248-54.
    PMID: 23359194 DOI: 10.5114/pjp.2012.32772
    The research purpose was to experimentally investigate the effect of allicin administration on the levels of main type 1 diabetes (IDDM) autoantibodies which are anti-islet cell antibodies (ICA) with an attempt to find a relation between this immunological effect and histological and/or biochemical findings. We have evaluated, with the help of ELISA kits, the levels of ICA and serum insulin in male Sprague-Dawley rats with Streptozotocin-induced IDDM in addition to pancreatic histological findings. The four groups (6 rats each) under study received or not different intraperitoneal doses of allicin for a period of 30 days. Daily intraperitoneal administration of allicin (either at as low dose of 8 mg/kg or high dose of 16 mg/kg) for up to 30 days to type 1 diabetic rats effectively reduces levels of anti-islet cell antibodies and in addition, reduced the level of insulin due to damaged Langerhans islet cell was significantly increased in the serum due to a repairing tissue process in pancreatic tissues. These experimental results suggest that allicin treatment has a therapeutic protective effect against autoimmune reactions occurring in IDDM. The data may provide new strategies for using allicin to be recommended as an excellent candidate in the clinical management, control, and prevention of IDDM.
    Matched MeSH terms: Islets of Langerhans/immunology
  9. Tai ES, Lim SC, Chew SK, Tan BY, Tan CE
    Diabetes Res Clin Pract, 2000 Aug;49(2-3):159-68.
    PMID: 10963828 DOI: 10.1016/s0168-8227(00)00152-2
    We studied insulin resistance and beta-cell function with reference to ethnic group, glucose tolerance and other coronary artery disease risk factors in a cross section of the Singapore population which comprises Chinese, Malays and Asian Indians. 3568 individuals aged 18-69 were examined. Blood pressure, anthropometric data, blood lipids, glucose and insulin were assayed in the fasting state. Glucose and serum insulin were measured 2 h after an oral glucose challenge. Insulin resistance and beta-cell function were calculated using homeostasis model assessment. Asian Indians had higher insulin resistance than Chinese or Malays. Impaired glucose tolerance (IGT) and diabetes mellitus (DM) were associated with greater insulin resistance and impaired beta-cell function compared to normal glucose tolerance (NGT). Insulin resistance was positively correlated with blood pressure in women and total cholesterol, LDL cholesterol and triglyceride in both men and women. It was negatively correlated with HDL cholesterol and LDL/apolipoprotein B ratio. beta-cell function showed no significant correlations with the cardiovascular risk factors studied. It appears that both impaired beta-cell function and insulin resistance are important for the development of hyperglycemia whereas insulin resistance alone seems more important in the development of coronary artery disease as it correlates with several known coronary artery disease risk factors.
    Matched MeSH terms: Islets of Langerhans/physiology
  10. Nazaimoon WM, Azmi KN, Rasat R, Ismail IS, Singaraveloo M, Wan Mohamad WB, et al.
    Med J Malaysia, 2000 Sep;55(3):318-23.
    PMID: 11200711
    This study determined the prevalence and significance of autoantibodies to GAD65 (GAD Ab), insulin (IAA), tyrosine-like phosphatase (IA2) and islet-cell (ICA) in a group of 213 young Malaysian Type 1 diabetics, diagnosed before the age of 40 years. Venous blood was taken at fasting, and at 6 minutes post-glucagon (1 mg i.v.). IAA was detected in 47.4%, GAD Ab in 33.8%, IA2 in 8.9% and ICA in 1.4% of the subjects. When based on post-glucagon C-peptide level of 600 pmol/L, 172 (80.7%) patients had inadequate pancreatic reserve, while the remainder 41(19.3%) showed normal response. The autoantibodies, either alone or in combination, were detectable in both groups of patients; higher prevalence in those with poor or no beta-cell function (73.3% versus 46.3%, p = 0.0001). Although the prevalence of GAD Ab was highest in newly diagnosed patients (< 5 years), unlike IA2 and ICA, the marker remained detectable in 24-25% of those patients with long-standing disease. Nineteen patients could probably belong to the "latent autoimmune diabetes in adults (LADA)" subset, where pancreatic reserve was adequate but patients had detectable autoantibodies and insulin-requiring. On the other hand, 68 of the 213 patients (32%) were seronegative, but presented with near or total beta-cell destruction. Thus, as has also been suggested by others, there is indeed etiological differences between the Asian and the Caucasian Type 1 diabetics, and, there is also the possibility that other, but unknown autoantigens are involved in causing the pancreatic damage.
    Matched MeSH terms: Islets of Langerhans/immunology
  11. Hani H, Allaudin ZN, Mohd-Lila MA, Sarsaifi K, Rasouli M, Tam YJ, et al.
    Xenotransplantation, 2017 05;24(3).
    PMID: 28397308 DOI: 10.1111/xen.12302
    BACKGROUND: Dead islets replaced with viable islets are a promising offer to restore normal insulin production to a person with diabetes. The main reason for establishing a new islet source for transplantation is the insufficiency of human donor pancreas while using xenogeneic islets perhaps assists this problem. The expression of PDX1 is essential for the pancreas expansion. In mature β-cells, PDX1 has several critical roles such as glucose sensing, insulin synthesis, and insulin secretion. In this study, we aimed to evaluate the expression of pancreatic duodenal homeobox-1 (PDX1) in treated caprine islets in culture and to assess the protective effects of antioxidant factors on the PDX1 gene in cultured caprine islets.

    MATERIALS AND METHODS: Purified islets were treated with serum-free, serum, IBMX, tocopherol, or IBMX and tocopherol media. Quantitative polymerase chain reaction and Western blotting were carried out to compare the expression levels of PDX1 in treated purified islets cultured with different media.

    RESULTS: Islets treated with IBMX/tocopherol exhibited the highest fold change in the relative expression of PDX1 on day 5 post-treatment (relative expression: 6.80±2.08), whereas serum-treated islets showed the lowest fold changes in PDX1 expression on day 5 post-treatment (0.67±0.36), as compared with the expression on day 1 post-treatment. Insulin production and viability tests of purified islets showed superiority of islet at supplemented serum-free media with IBMX/tocopherol compared to other cultures (53.875%±1.59%).

    CONCLUSIONS: Our results indicated that supplemented serum-free medium with tocopherol and IBMX enhances viability and PDX1 gene expression compared to serum-added and serum-free media.

    Matched MeSH terms: Islets of Langerhans/cytology; Islets of Langerhans/drug effects; Islets of Langerhans/physiology*
  12. Homayoun Hani, Mohd-Azmi Mohd-Lila, Rasedee Abdullah, Zeenathul Nazariah Allaudin, Kazhal Sarsaifi, Faez Firdaus Jesse Abdullah
    MyJurnal
    Diabetes is one of the major life-threatening health problems worldwide today. It is one of the most fastgrowing diseases that cause many health complications and a leading cause of decreasing life expectancy and high mortality rate. Many studies have suggested several different types of intervention to treat Type 1 diabetes such as insulin therapy, islet transplantation, islet xenotransplantation and stem cell therapy. However, issues regarding the efficacy, cost and safety of these treatments are not always well addressed. For decades, diabetes treatments with few side effects and long-lasting insulin independence has remained one of the most challenging tasks facing scientists. Among the treatments mentioned above, application of human islet transplantation in patients with type 1 diabetes has progressed rapidly with significant achievement. Again, the lack of appropriate donors for islet transplantation and its high cost have led researchers to look for other alternatives. In this review, we discuss very pertinent issues that are related to diabetes treatments, their availability, advantages, disadvantages and also cost,
    Matched MeSH terms: Islets of Langerhans Transplantation
  13. Taheri Rouhi SZ, Sarker MMR, Rahmat A, Alkahtani SA, Othman F
    BMC Complement Altern Med, 2017 Mar 14;17(1):156.
    PMID: 28288617 DOI: 10.1186/s12906-017-1667-6
    BACKGROUND: Type 2 diabetes mellitus (T2DM) is associated with hyperglycemia, inflammatory disorders and abnormal lipid profiles. Several functional foods have therapeutic potential to treat chronic diseases including diabetes. The therapeutic potential of pomegranate has been stated by multitudinous scientists. The present study aimed to evaluate the effects of pomegranate juice and seed powder on the levels of plasma glucose and insulin, inflammatory biomarkers, lipid profiles, and health of the pancreatic islets of Langerhans in streptozotocin (STZ)-nicotinamide (NAD) induced T2DM Sprague Dawley (SD) rats.

    METHODS: Forty healthy male SD rats were induced to diabetes with a single dose intra-peritoneal administration of STZ (60 mg/kg b.w.) - NAD (120 mg/kg b.w.). Diabetic rats were orally administered with 1 mL of pomegranate fresh juice (PJ) or 100 mg pomegranate seed powder in 1 mL distilled water (PS), or 5 mg/kg b.w. of glibenclamide every day for 21 days. Rats in all groups were sacrificed on day 22. The obtained data was analyzed by SPSS software (v: 22) using One-way analysis of variance (ANOVA).

    RESULTS: The results showed that PJ and PS treatment had slight but non-significant reduction of plasma glucose concentration, and no impact on plasma insulin compared to diabetic control (DC) group. PJ lowered the plasma total cholesterol (TC) and triglyceride (TG) significantly, and low-density lipoproteins (LDL) non-significantly compared to DC group. In contrast, PS treatment significantly raised plasma TC, LDL, and high-density lipoproteins (HDL) levels compared to the DC rats. Moreover, the administration of PJ and PS significantly reduced the levels of plasma inflammatory biomarkers, which were actively raised in diabetic rats. Only PJ treated group showed significant repairment and restoration signs in islets of Langerhans. Besides, PJ possessed preventative impact against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals almost 2.5 folds more than PS.

    CONCLUSIONS: Our findings suggest that active constituents with high antioxidant properties present in PJ are responsible for its anti-hyperlipidemic and anti-inflammatory effects, likewise the restoration effect on the damaged islets of Langerhans in experimental rats. Hence, the pharmacological, biochemical, and histopathological profiles of PJ treated rats obviously indicated its helpful effects in amelioration of diabetes-associated complications.

    Matched MeSH terms: Islets of Langerhans/drug effects; Islets of Langerhans/metabolism; Islets of Langerhans/pathology
  14. Lokman FE, Gu HF, Wan Mohamud WN, Yusoff MM, Chia KL, Ostenson CG
    PMID: 24319481 DOI: 10.1155/2013/727602
    Aims. To evaluate the antidiabetic properties of borapetol B known as compound 1 (C1) isolated from Tinospora crispa in normoglycemic control Wistar (W) and spontaneously type 2 diabetic Goto-Kakizaki (GK) rats. Methods. The effect of C1 on blood glucose and plasma insulin was assessed by an oral glucose tolerance test. The effect of C1 on insulin secretion was assessed by batch incubation and perifusion experiments using isolated pancreatic islets. Results. An acute oral administration of C1 improved blood glucose levels in treated versus placebo groups with areas under glucose curves 0-120 min being 72 ± 17 versus 344 ± 10 mmol/L (P < 0.001) and 492 ± 63 versus 862 ± 55 mmol/L (P < 0.01) in W and GK rats, respectively. Plasma insulin levels were increased by 2-fold in treated W and GK rats versus placebo group at 30 min (P < 0.05). C1 dose-dependently increased insulin secretion from W and GK isolated islets at 3.3 mM and 16.7 mM glucose. The perifusions of isolated islets indicated that C1 did not cause leakage of insulin by damaging islet beta cells (P < 0.001). Conclusion. This study provides evidence that borapetol B (C1) has antidiabetic properties mainly due to its stimulation of insulin release.
    Matched MeSH terms: Islets of Langerhans
  15. Mohamad Buang ML, Seng HK, Chung LH, Saim AB, Idrus RB
    Arch Med Res, 2012 Jan;43(1):83-8.
    PMID: 22374243 DOI: 10.1016/j.arcmed.2012.01.012
    BACKGROUND AND AIMS: Tissue engineering strategy has been considered as an alternative treatment for diabetes mellitus due to lack of permanent pharmaceutical treatment and islet donors for transplantation. Various cell lines have been used to generate functional insulin-producing cells (IPCs) including progenitor pancreatic cell lines, embryonic stem cells (ESCs), umbilical cord blood stem cells (UCB-SCs), adult bone marrow stem cells (BMSCs), and adipose tissue-derived stem cells (ADSCs).

    METHODS: Human ADSCs from lipoaspirated abdominal fat tissue was differentiated into IPCs following a two-step induction protocol based on a combination of alternating high and low glucose, nicotinamide, activin A and glucagon-like peptide 1 (GLP-1) for a duration of 3 weeks. During differentiation, histomorphological changes of the stem cells towards pancreatic β-islet characteristics were observed via light microscope and transmission electron microscope (TEM). Dithizone (DTZ) staining, which is selective towards IPCs, was used to stain the new islet-like cells. Production of insulin hormone by the cells was analyzed via enzyme-linked immunosorbent assay (ELISA), whereas its hormonal regulation was tested via a glucose challenge test.

    RESULTS: Histomorphological changes of the differentiated cells were noted to resemble pancreatic β-cells, whereas DTZ staining positively stained the cells. The differentiated cells significantly produced human insulin as compared to the undifferentiated ADSCs, and its production was increased with an increase of glucose concentration in the culture medium.

    CONCLUSIONS: These initial data indicate that human lipoaspirated ADSCs have the potential to differentiate into functional IPCs, and could be used as a therapy to treat diabetes mellitus in the future.

    Matched MeSH terms: Islets of Langerhans/metabolism; Islets of Langerhans/physiology
  16. Noor H, Hammonds P, Sutton R, Ashcroft SJ
    Diabetologia, 1989 Jun;32(6):354-9.
    PMID: 2668082
    In Malaysia, Tinospora crispa extract is taken orally by Type 2 (non-insulin-dependent) diabetic patients to treat hyperglycaemia. We have evaluated the claimed hypoglycaemic property by adding aqueous extract to the drinking water of normal and alloxan-diabetic rats. After one week, fasting blood glucose levels were significantly (p less than 0.01) lower and serum insulin levels were significantly (p less than 0.01) higher in treated diabetic animals (10.4 +/- 1.0 mmol/l and 12.8 +/- 1.1 muU/ml respectively) compared to untreated diabetic controls (17.4 +/- 1.7 mmol/l and 8.0 +/- 0.7 muU/ml respectively). The insulinotropic action of T. crispa was further investigated in vitro using isolated human or rat islets of Langerhans and HIT-T15 cells. In static incubations with rat islets and HIT-T15 B cells, the extract induced a dosage dependent stimulation and potentiation of basal and glucose-stimulated insulin secretion respectively. This insulinotropic effect was also evident in perifused human and rat islets and HIT-T5 B-cells. The observations that (i) in all three models insulin secretory rates rapidly returned to basal levels on removal of the extract and (ii) in rat islets, a second challenge with T. crispa induced an additional, stimulated response, are all consistent with physiological release of insulin by B cells. Moreover, the rate of HIT-T15 glucose utilisation was not affected by incubation with T. crispa, suggesting that the cells were viable throughout. These are the first studies to provide biochemical evidence which substantiates the traditional claims for an oral hypoglycaemic effect of Tinospora crispa, and which also show that the hypoglycaemic effect is associated with increased insulin secretion.
    Matched MeSH terms: Islets of Langerhans/drug effects; Islets of Langerhans/metabolism*
  17. Aziz MSA, Giribabu N, Rao PV, Salleh N
    Biomed Pharmacother, 2017 May;89:135-145.
    PMID: 28222394 DOI: 10.1016/j.biopha.2017.02.026
    Stingless bee honey (SLBH) has been claimed to possess multiple health benefits. Its anti-diabetic properties are however unknown. In this study, ability of SLBH from Geniotrigona thoracica stingless bee species in ameliorating pancreatic damage and in maintaining metabolic profiles were investigated in diabetic condition.

    METHODS: SLBH at 1 and 2g/kg/b.w. was given orally to streptozotocin (STZ)-nicotinamide-induced male diabetic rats for 28days. Metabolic parameters (fasting blood glucose-FBG and lipid profiles-LP and serum insulin) were measured by biochemical assays. Distribution and expression level of insulin, oxidative stress marker i.e. catalase, inflammatory markers i.e. IKK-β, TNF-α, IL-1β and apoptosis marker i.e. caspase-9 in the pancreatic islets were identified and quantified respectively by immunohistochemistry. Levels of NF-κβ in pancreas were determined by enzyme-linked immunoassay (ELISA).

    RESULTS: SLBH administration to diabetic male rats prevented increase in FBG, total cholesterols (TC), triglyceride (TG) and low density lipoprotein (LDL) levels. However, high density lipoprotein (HDL) and serum insulin levels in diabetic rats receiving SLBH increased. Additionally, histopathological changes and expression level of oxidative stress, inflammation and apoptosis markers in pancreatic islets of diabetic rats decreased with increased expression level of insulin in the islets. LC-MS analysis revealed the presence of several compounds in SLBH that might be responsible for these effects.

    CONCLUSIONS: SLBH has great potential to be used as agent to protect the pancreas against damage and dysfunction where these could account for its anti-diabetic properties.

    Matched MeSH terms: Islets of Langerhans/drug effects; Islets of Langerhans/pathology
  18. Batumalaie K, Qvist R, Yusof KM, Ismail IS, Sekaran SD
    Clin Exp Med, 2014 May;14(2):185-95.
    PMID: 23584372 DOI: 10.1007/s10238-013-0236-7
    Type 2 diabetes consists of progressive hyperglycemia, insulin resistance, and pancreatic β-cell failure which could result from glucose toxicity, inflammatory cytokines, and oxidative stress. In the present study, we investigate the effect of pretreatment with Gelam honey (Melaleuca spp.) and the individual flavonoid components chrysin, luteolin, and quercetin, on the production of reactive oxygen species (ROS), cell viability, lipid peroxidation, and insulin content in hamster pancreatic cells (HIT-T15 cells), cultured under normal and hyperglycemic conditions. Phenolic extracts from a local Malaysian species of Gelam honey (Melaleuca spp.) were prepared using the standard extraction methods. HIT-T15 cells were cultured in 5 % CO2 and then preincubated with Gelam honey extracts (20, 40, 60, and 80 μg/ml) as well as some of its flavonoid components chrysin, luteolin, and quercetin (20, 40, 60, and 80 μM), prior to stimulation by 20 and 50 mM of glucose. The antioxidative effects were measured in these cultured cells at different concentrations and time point by DCFH-DA assay. Pretreatment of cells with Gelam honey extract or the flavonoid components prior to culturing in 20 or 50 mM glucose showed a significant decrease in the production of ROS, glucose-induced lipid peroxidation, and a significant increase in insulin content and the viability of cells cultured under hyperglycemic condition. Our results show the in vitro antioxidative property of the Gelam honey and the flavonoids on the β-cells from hamsters and its cytoprotective effect against hyperglycemia.
    Matched MeSH terms: Islets of Langerhans/drug effects*; Islets of Langerhans/physiology
  19. Vakhshiteh F, Allaudin ZN, Lila MA, Abbasiliasi S, Ajdari Z
    Mol Biotechnol, 2015 Jan;57(1):75-83.
    PMID: 25218408 DOI: 10.1007/s12033-014-9803-8
    Transplantation of islets of Langerhans that have been isolated from whole pancreas is an attractive alternative for the reversal of Type 1 diabetes. However, in vitro culture of isolated pancreatic islets has been reported to cause a decrease in glucose response over time. Hence, the improvement in islet culture conditions is an important goal in islet transplantation. Heme Oxygenase-1 (HO-1) is a stress protein that has been described as an inducible protein with the capacity of preventing apoptosis and cytoprotection via radical scavenging. Therefore, this study was aimed to assess the influence of endogenous HO-1 gene transfer on insulin secretion of caprine islets. The full-length cDNA sequence of Capra hircus HO-1 was determined using specific designed primers and rapid amplification of cDNA ends of pancreatic tissue. The HO-1 cDNA was then cloned into the prokaryotic expression vectors and transfected into caprine islets using lipid carriers. Efficiency of lipid carriers to transfect caprine islets was determined by flow cytometry. Insulin secretion assay was carried out by ovine insulin ELISA. The finding demonstrated that endogenous HO-1 gene transfer could improve caprine islet function in in vitro culture. Consequently, strategies using HO-1 gene transfer to islets might lead to better outcome in islet transplantation.
    Matched MeSH terms: Islets of Langerhans/enzymology*
  20. Vethakkan SR, Walters JM, Gooley JL, Boston RC, Kay TW, Goodman DJ, et al.
    Transplantation, 2014 Jan 27;97(2):e9-11.
    PMID: 24434489 DOI: 10.1097/01.TP.0000437565.15965.67
    Matched MeSH terms: Islets of Langerhans Transplantation*
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