Pancreatic beta cell protection/regeneration with phytotherapy

Although currently available drugs are useful in controlling early onset complications of diabetes, serious late onset complications appear in a large number of patients. Considering the physiopathology of diabetes, preventing beta cell degeneration and stimulating the endogenous regeneration of islets will be essential approaches for the treatment of insulin-dependent diabetes mellitus. The current review focused on phytochemicals, the antidiabetic effect of which has been proved by pancreatic beta cell protection/regeneration. Among the hundreds of plants that have been investigated for diabetes, a small fraction has shown the regenerative property and was described in this paper. Processes of pancreatic beta cell degeneration and regeneration were described. Also, the proposed mechanisms for the protective/regenerative effects of such phytochemicals and their potential side effects were discussed.Embora medicamentos disponíveis atualmente sejam úteis no controle de complicações da Diabetes, complicações aparecem em grande número de pacientes. Considerando-se a fisiopatologia do Diabetes, a prevenção da degeneração de células beta e o estímulo da regeneração endógena de ilhotas será abordagem essencial para o tratamento de diabetes mellitus insulino-dependente. A presente revisão aborda compostos fitoquímicos, cujo efeito é provado na proteção/regeneração de células beta de pâncreas. Entre centenas de plantas que têm sido investigadas para o diabetes, pequena fração tem mostrado propriedade regenerativa, que será descrita neste trabalho. Os processos de degeneração e de regeneração das células beta do pâncrease são descritos. Além disso, mecanismos propostos para efeitos de proteção e regeneração desses compostos fitoquímicos e seus possíveis efeitos colaterais também serão discutidos neste trabalho

Novel cilostamide analogs, phosphodiesterase 3 inhibitors, produce positive inotropic but differential lusitropic and chronotropic effects on isolated rat atria

Objective(s): Recently, we showed that some new synthetic compounds structurally related to cilostamide (4-(1,2-dihydro-2-oxoquinolin-6-hydroxy)- N-cyclohexyl-N-methylbutanamide), a selective phosphodiesterase 3 (PDE3) inhibitor, produce inotropic effect comparable to that of IBMX (3-isobutyl-1-methylxanthine), a non-selective PDE inhibitor, but with differential chronotropic effect. In this investigation, we compared the pharmacological effects of these compounds as potential cardiotonic agents using the spontaneously beating atria model. Materials and Methods: In each experiment, rats were treated with reserpine.  The atrium was isolated and mounted in an organ bath. We assessed chronotropic and inotropic effects using cumulativelogconcentration-response curves of isoprenaline alone or in combination of each test-compound. Results: Majority of test compounds augment atria contraction force (ACF) significantly but with different potencies on atrium contraction rate. Cilostamide, MCPIP ([4-(4-methyl piperazin-1-yl)-4-oxobutoxy)-4-methylquinolin-2(1H)-one]), methyl carbostyril compounds- (mc1), mc2 and mc5 increased the isoprenaline effect on ACF synergistically. But, mc6 failed to potentiate the effect of isoprenalin; mc3 and mc4 did not increase ACF, which may be because of their higher hydrophilic nature. It was interesting that mc2, alone or in combination with isoprenaline, produced the highest inotropic effect while it did not affect the basal contraction rate and almost blocked the isoprenaline chronotropic effect. Conclusion: Combination of mc2 with isoprenaline had synergistic effect on inotropic effect, but this combination reduced isoprenaline chronotropic effect; therefore, these effects cannot be related to reducing B-adrenergic receptors activity. These compounds showed different effects; probably all of them were not mediated via PDE3 inhibition and other mechanisms are involving

Pancreatic beta cell protection/regeneration with phytotherapy

Although currently available drugs are useful in controlling early onset complications of diabetes, serious late onset complications appear in a large number of patients. Considering the physiopathology of diabetes, preventing beta cell degeneration and stimulating the endogenous regeneration of islets will be essential approaches for the treatment of insulin-dependent diabetes mellitus. The current review focused on phytochemicals, the antidiabetic effect of which has been proved by pancreatic beta cell protection/regeneration. Among the hundreds of plants that have been investigated for diabetes, a small fraction has shown the regenerative property and was described in this paper. Processes of pancreatic beta cell degeneration and regeneration were described. Also, the proposed mechanisms for the protective/regenerative effects of such phytochemicals and their potential side effects were discussed

Effect of hydro-alcoholic extract of Vaccinium arctostaphylos on insulin release from rat-isolated langerhans islets

Introduction: Vaccinium arctostaphylos is one of the medicinal plants used in the treatment of diabetes. But the mechanisms responsible for its antidiabetic action have not been well defined. This study was undertaken to investigate the possible effect of V. arctostaphylos on insulin release from rat-isolated Langerhans islets. Materials and Methods : The islets were incubated in the presence of 3 or 10 mM glucose with or without milrinone (0.1 and 0.01%) and hydro-alcoholic extract of V. arctostaphylos (0.1 and 0.1%) for 60 min. The concentration of insulin was measured in samples of incubation medium. Results: The increase of glucose concentration in incubation medium from 3 to 10 mM resulted in a significant increase of insulin secretion. Milrinone at 0.1 mM significantly increased insulin release evoked by 10 mM glucose. However, none of the extract concentrations affected the insulin release. Conclusion: Our data demonstrated that V. arctostaphylos had no insulinotropic property and its effects on diabetes mediated by other mechanisms which should be clarified in future studies

Effect of Ganoderma lucidum hydroalcoholic extract on insulin release in rat-isolated pancreatic islets

Objective: Ganoderma Lucidum (G. Lucidum) has been suggested to increase serum insulin level.This study was undertaken to investigateits direct effect on the islets of Langerhans. Material and Methods: Male albino Wistar rats were anesthetized and the islets were isolated after digestion of the pancreas with collagenase. The islets were incubated for 60 min in Krebs bicarbonate buffer containing 3 or 10 mM glucose in the presence of hydroalcoholic extract of G. Lucidum (1 mg/ml), 3-isobutyl-1-methylxanthine (IBMX, 100 µM) or vehicle. Results: Exposure of islets to the extract increased insulin secretion at basal (3 mM) glucose concentration. Increase of glucose concentration to 10 mM resulted in a significant increase in the rate of insulin secretion. While the IBMX could augment insulin release evoked by 10 mM glucose, the extract failed to modify it. Conclusion: Our results demonstrate that G. lucidum acts directly on the Langerhans islets to increase basal insulin release.

Antihyperlipidemic Effect of a Polyherbal Mixture in Streptozotocin-Induced Diabetic Rats

The effects of a polyherbal mixture containing Allium sativum, Cinnamomum zeylanicum, Citrullus colocynthis, Juglans regia, Nigella sativa, Olea europaea, Punica granatum, Salvia officinalis, Teucrium polium, Trigonella foenum, Urtica dioica, and Vaccinium arctostaphylos were tested on biochemical parameters in diabetic rats. The animals were randomized into three groups: (1) normal control, (2) diabetic control, and (3) diabetic rats which received diet containing 15% (w/w) of this mixture for 4 weeks. Diabetes was induced by intraperitoneal injection of streptozotocin (55 mg/kg). At the end of experiment, the mixture had no significant effect on serum hepatic enzymes, aspartate aminotransferase, and alanine aminotransferase activities. However, the level of fasting blood glucose, water intake, and urine output in treated group was lower than that in diabetic control rats ( < 0.01). Also, the levels of triglyceride and total cholesterol in polyherbal mixture treated rats were significantly lower than those in diabetic control group ( < 0.05). Our results demonstrated that this polyherbal mixture has beneficial effects on blood glucose and lipid profile and it has the potential to be used as a dietary supplement for the management of diabetes

Antihyperlipidemic Effect of a Polyherbal Mixture in Streptozotocin-Induced Diabetic Rats

The effects of a polyherbal mixture containing Allium sativum, Cinnamomum zeylanicum, Citrullus colocynthis, Juglans regia, Nigella sativa, Olea europaea, Punica granatum, Salvia officinalis, Teucrium polium, Trigonella foenum, Urtica dioica, and Vaccinium arctostaphylos were tested on biochemical parameters in diabetic rats. The animals were randomized into three groups: (1) normal control, (2) diabetic control, and (3) diabetic rats which received diet containing 15% (w/w) of this mixture for 4 weeks. Diabetes was induced by intraperitoneal injection of streptozotocin (55 mg/kg). At the end of experiment, the mixture had no significant effect on serum hepatic enzymes, aspartate aminotransferase, and alanine aminotransferase activities. However, the level of fasting blood glucose, water intake, and urine output in treated group was lower than that in diabetic control rats (P<0.01). Also, the levels of triglyceride and total cholesterol in polyherbal mixture treated rats were significantly lower than those in diabetic control group (P<0.05). Our results demonstrated that this polyherbal mixture has beneficial effects on blood glucose and lipid profile and it has the potential to be used as a dietary supplement for the management of diabetes

Effects of C-peptide on adipocytes and mesenchymal stem cells in human adipose tissue

Recent studies suggest that proinsulin connecting peptide (C-peptide) may show physiological functions in various tissues. This study was aimed to determine whether C-peptide could be involved in the regulation of lipolysis, adiponectin release, and function of mesenchymal stem cells (MSCs) in adipose tissue. Human subcutaneous adipose tissue was cultured in the presence of C-peptide and lipolysis was determined by glycerol measurement in the conditioned media. Effect of C-peptide on adiponectin secretion was evaluated in differentiated adipocytes. The adipogenic and osteogenic abilities of adipose MSCs were evaluated using Oil Red and Alizarin Red staining, respectively. C-peptide induced a significant decrease in basal lipolysis, a slight decrease (statistically insignificant) in isoproterenol-stimulated lipolysis, and a slight increase in adiponectin secretion at concentration of 8 nM, 16 nM and 4 nM, respectively. It had no effect on adipogenic and osteogenic differentiation of MSCs. However, at concentration of 4 nM, C-peptide significantly increased the proliferative capability of MSCs (p<0.05). These results suggest that C-peptide has physiological effects in human subcutaneous adipose tissue and contributes to the regulation of basal lipolysis and pool of MSCs