Abnormalities in insulin hormone levels leads to a hyperglycemic condition of diabetic mellitus. Hyperglycemia seriously induces organ and system destructions. The excessive accumulation of collagen fiber deposits occurs in inflammatory and reorganization processes of chronic liver diseases in type I insulin-dependent diabetes. Regarding the research objective, glabridin (GLB), an active compound of licorice, was used as a daily supplement (40 mg/kg) in order to decrease hepatocyte destruction and collagen deposition in liver tissue of diabetic animals induced by streptozotocin. A total of 40 were randomly allocated to five groups (each, n=10), control, control treated with GLB (GLB), diabetic rats (DM) injected with single dose of streptozotocin (60 mg/kg) to induce a diabetic condition, diabetic rats receiving GLB (DM+GLB; 40 mg/kg) and diabetic rats treated with glibenclamide (DM+GL; 4 mg/kg). Characteristic histopathological changes in liver cells and tissues of rats were determined by Masson's trichrome staining and transmission electron microscopy (TEM). Western blotting was used to detect the expression of the key markers, collagen type I and fibronectin proteins. The histological investigation of liver tissue of the DM group revealed that the collagen fiber deposition was increased in the periportal, pericentral and perisinusoidal spaces compared with controls. Hepatocytes appeared as small and fragmented cells in TEM examination. Collagenization of the perisinusoidal space was recently demonstrated to represent a new aspect of the microvascular abnormalities and liver fibrosis. Healthy hepatocytes with round nucleus were observed following supplementation of glabridin. In addition, collagen fiber deposition was reduced in the area adjacent to the perisinusoidal space. The expression of collagen type I and fibronectin decreased strongly following glabridin supplementation in DM+GLB rats compared with DM rats, indicating that the hepatic tissue reorganization regained its normal morphology. These findings suggest that it may be beneficial to examine the role of glabridin as a therapeutic agent in diabetes treatment in future research.

The brain is a vital organ that requires a constant blood supply. Stroke occurs when the blood supply to specific parts of the brain is reduced; diabetes is an autonomous risk factor for stroke. The present study aimed to investigate the potential vascular protective effect of gymnemic acid (GM) by assessing the morphological changes of microvasculature, along with VEGFA and angiopoietin-1 (Ang-1) protein expression in the brains of diabetic rats. Rats were divided into five groups, including control, gymnemic control rats (CGM), rats that were rendered diabetic by single injection of 60 mg/kg streptozotocin (STZ), diabetic rats treated with 400 mg/kg GM (STZ + GM) and diabetic rats treated with 4 mg/kg glibenclamide (GL; STZ + GL). After 8 weeks, brain tissues were collected to examine the three-dimensional morphology of the anterior cerebral arteries by vascular corrosion casting. Western blotting was performed to determine VEGFA and Ang-1 expression. Cerebral arteries, arterioles and capillaries were depicted the diameter, thickness and collagen accumulation of the wall, and the results demonstrated narrow diameters, thickened walls and collagen accumulation in the STZ group. After receiving GM, the histopathological changes were similar to that of the control group. Through vascular corrosion casting and microscopy, signs of vessel restoration and improvement were exhibited by increased diameters, and healthy and nourished arterioles and capillaries following treatment with GM. Furthermore, VEGF expression and Ang-1 secretion decreased in the STZ + GM group compared with STZ rats. The results of the present study revealed that GM treatment decreased blood vessel damage in the brain, suggesting that it may be used as a therapeutic target for the treatment of diabetes.

Background: A high prevalence of atherosclerotic vascular lesions has been associated with renal disease and diabetes and is a major cause for increasing deaths from cardiovascular disease. The present study aimed to determine the beneficial effects of gymnemic acids on the kidney microvasculature and to establish their anti-angiogenic properties that are related to the expression of vascular endothelial growth factor (VEGF) protein of segmental and interlobar arteries in induced diabetic rats. Methods: Rats were divided into five groups including the control group (C), control treated with gymnemic acid (CGM), diabetic animals (DM group) that were rendered diabetic by a single dose [60 mg/kg body weight (BW)] of a streptozotocin (STZ) injection, diabetic rats treated with gymnemic acid (400 mg/kg BW) (GM), and diabetic rats treated with glibenclamide (4 mg/kg BW) (GR). After 8 weeks, kidney tissues were collected for histological analysis. In rats with DM, the segmental arteries exhibited increased wall thickness. The kidney microvasculature was examined using the vascular corrosion casting method. Results: Rats with DM presented a decreasing diameter of segmental and interlobar arteries. They were evidently redeveloped and restored in the GM and GR groups. As determined by immunofluorescence, the expression of VEGF was significantly reduced in both the GM and GR groups. Conclusions: The present study demonstrated that gymnemic acid from Gymnemasylvestre may be a promising medical herb for use in the treatment of diabetes and kidney disease.Keywords: diabetes mellitus, segmental artery, interlobar artery, gymnemic acid, vascular architecture

Background:  Diabetes has a significant impact on the impaired function of the reproductive system in the testis.Objective: The aim of this study was to investigate the effects of curcumin from turmeric on structural changes of testicular tissues and microvasculature in STZ-induced diabetic rats.Methods: Rats were injected with a single dose of streptozotocin (60 mg/kg BW) to induce a diabetic condition. Three days after the injection, rats with a blood sugar level > 250 mg/dl were considered diabetic. Rats were allocated to one of three groups, diabetic (DM), diabetic rats receiving curcumin (DMC) (200 mg/kg BW), and control (C). Testicular tissues were studied eight weeks after the treatment using the histological technique. Testicular microvasculature was examined using the vascular corrosion cast technique under a scanning electron microscope (SEM).Results: The testicular tissue of DM group showed damaged seminiferous tubules, spermatocytes, and spermatids with necrosis and germ cells degeneration. Destruction of testicular arteries and veins in pampiniform plexus were demonstrated. The destroyed capillaries, arterioles, and venules demonstrated stenosis and shrinkage. The vessel diameter in all DM groups decreased. In the DMC group which received curcumin, the appearance of all seminiferous tubules, spermatogenic, and sertoli cell was normal. The reconstruction and restoration of testicular artery, pampiniform plexus, capillary network, arterioles, and venules were clear. As a result of curcumin supplementation, the standard and healthy testis microvasculature was restored. The DMC vessels diameter increased back to a quasi normal condition, particularly at the artery, arteriole, and capillary levels.Conclusions: The results provided evident for effects of curcumin could be associated with recovering and improvement of the testicular tissues and microvasculatures in diabetic condition.Keywords: Diabetes mellitus, Streptozotocin, Curcumin, Testis, Microvasculature, Vascular corrosion cast, Scanning electron microscope

Background: Vascular diseases from diabetes typically result in conditions that interfere with the microvascular functions, such as erectile dysfunction (ED) of the penis. It is unrevealed which morphological changes the microvasculature of the penis may result from the treatment and supplementation of curcumin.Objective: This study aims to determine the effects of curcumin, the active compound of turmeric, on penile microvasculature in experimentally induced diabetic rats.Methods:  Rat were divided into three groups, control © and diabetic (DM). Diabetic rats supplemented with curcumin (DMC) (200 mg/kg BW). For induction of a diabetic condition, rats were injected with a single intraperitoneal injection of streptozotocin (60 mg/kg BW). A histological study and vascular corrosion casting along with scanning electron microscopy (SEM) were used to determine a morphological change of microvessels in the penis of rats after 8 weeks of experiments.Results: The histological investigations of penile tissue of DM group revealed thickly lined venous sinuses with smooth but sparse muscle layers. Dorsal arteries (DA) and deep dorsal veins (DV) of the penis were present of narrow lumen and showed thickening of collagen fibers at their wall of tunica media. An increasing thickness of collagen fibers was observed. Vascular corrosion casting revealed critically decreased diameters of DM venous sinus in the penis’ glans, which were observed as shrunken and partially lacking in the distal area of the glans. The diameter of venous sinuses in corpus cavernosum (CC) of DM rats were dilated and the density of venous sinuses was decreased. Interestingly, the signs of vessel restoration and improvement were presented by increasing diameters and recovering with healthy and nourished DA, DV, venous sinus at the area of the glans, and CC of the penis in DMC groups. Conclusion: The results have shown that the effects of curcumin could improve the destruction of the penile microvasculature in induced diabetic rats by STZ. Keywords: Diabetes mellitus, streptozotocin, curcumin, penis, Microvasculature, vascular corrosion cast