Antidiabetic potential of saffron and its active constituents

The prevalence of diabetes mellitus is growing rapidly worldwide. This metabolic disorder affects many physiological pathways and is a key underlying cause of a multitude of debilitating complications. There is, therefore, a critical need for effective diabetes management. Although many synthetic therapeutic glucose-lowering agents have been developed to control glucose homeostasis, they may have unfavorable side effects or limited efficacy. Herbal-based hypoglycemic agents present an adjunct treatment option to mitigate insulin resistance, improve glycemic control and reduce the required dose of standard antidiabetic medications. Saffron (Crocus sativus L.), whilst widely used as a food additive, is a natural product with insulin-sensitizing and hypoglycemic effects. Saffron contains several bioactive β carotenes, which exert their pharmacological effects in various tissues without any obvious side effects. In this study, we discuss how saffron and its major components exert their hypoglycemic effects by induction of insulin sensitivity, improving insulin signaling and preventing β-cell failure, all mechanisms combining to achieve better glycemic control.     

Protective effects of plant-derived natural products on renal complications

Diabetic nephropathy is the leading cause of renal failure worldwide. This debilitating disorder has several underlying pathophysiologic mechanisms, and therefore a variety of pharmacologic agents have been developed to prevent or treat diabetic nephropathy; however, synthetic drugs may possess unfavorable side effects. In response to this, the global use of herbal-based pharmacologic agents is increasing among diabetic patients. Numerous studies have reported therapeutic benefits of herbal-based compounds against diabetes-induced renal dysfunction. These agents can prevent renal dysfunction and improve renal function by blocking or suppressing deleterious pathways such as oxidative stress, inflammation, apoptosis, necrosis, and nitric oxide deprivation that lead to vascular injuries. In the current study, we have reviewed the beneficial properties of the most common herbal agents used in renal complications and diabetic nephropathy.     

A review of the molecular mechanisms of hyperglycemia-induced free radical generation leading to oxidative stress

The prevalence of diabetes is growing worldwide with an increasing morbidity and mortality associated with the development of diabetes complications. Free radical production is a normal biological process that is strictly controlled and has been shown to be important in normal cellular homeostasis, and in the bodies response to pathogens. However, there are several mechanisms leading to excessive free radical production that overcome the normal protective quenching mechanisms. Studies have shown that many of the diabetes complications result from excessive free radical generation and oxidative stress, and it has been shown that chronic hyperglycemia is a potent inducer for free radical production, generated through several pathways and triggering multiple molecular mechanisms. An understanding of these processes may help us to improving our preventive or therapeutic strategies. In this review, the major molecular pathways involved in free radical generation induced by hyperglycemia are described.     

Quantification and characterization of vegetation and functional trait diversity of the riparian zones in protected forest of Kashmir Himalaya,India

Globally, riparian zones along river banks are widely recognized for their vital role in water regulation and conservation of biodiversity. Here, we specifically investigated the floristic and functional diversity of the vegetation of the riparian zones of protected forests in Kashmir Himalaya, India. A random sampling method was used for site selection while a transect method was used for data collection. Data obtained from the field was subjected to taxonomic and functional classification. Floristic analysis revealed a total of 78 species belonging to 68 genera in 40 families, suggesting an unequal distribution of species among families. Nine families contributed half of the species: Rosaceae was the dominant family with nine (12%) species followed by Asteraceae with eight species (10%), while 23 families were monotypic. In terms of functional trait diversity, herbaceous and perennial taxa dominated, and the biological spectrum showed a dominance of the therophytic life form, indicative of disturbed vegetation. The phenological spectrum revealed that the maximum flowering periods starts in March and extends into May, in which a total of 61% of the species were observed to flower. The leading leaf size spectra were mesophyll with 35%, followed by microphyll (31%). Most (64%) of the species had a simple leaf lamina type. The results of the present study serve as a means to evaluate best management practices, assess restoration and mitigation projects, prioritize riparian related resource management decisions, and establish aquatic life use standards.     

Heme oxygenase-1 induction by nitric oxide in RAW 264.7 macrophages is upregulated by a cyclo-oxygenase-2 inhibitor

Unstimulated RAW 264.7 macrophages express negligible heme oxygenase-1 (HO-1) protein but incubation with the nitric oxide (NO) donor spermine nonoate (SPNO) induced HO-1 and weakly cyclo-oxygenase-2 (COX-2) protein. This effect was potentiated by coincubation with the COX-2 selective inhibitor, SC58125. Cells incubated with SPNO showed a strong increase in HO-1 mRNA levels after 4 h with a significant potentiation in the presence of SC58125, which did not modify HO-1 mRNA stability. The induction of HO-1 by NO and its potentiation by anti-inflammatory agents may play a role in inflammatory and immune responses.     

The endothelin system in human and monkey ovaries: in situ gene expression of the different components

The endothelin system is composed of three endothelin isoforms (ET-1, ET-2, and ET-3), the endothelin receptors ETA and ETB, and the endothelin-converting enzyme (ECE). Besides having a major vasoactive role, endothelins have roles in different cell types at a local level. We investigated the presence of the different components of the endothelin system in primate ovaries. Human ovaries and gonadotropin-stimulated monkey ovaries were studied using immunohistochemistry for endothelin, and in situ hybridization with probes for ET-1, ET-2, ET-3, ETA and ETB receptors, and ECE. ET-1 and ETA receptors were detected in endothelial cells and vascular smooth muscle cells, respectively, in stromal vessels adjacent to follicles and corpora lutea. ETB receptors and ET-1 were found in the endothelial cells of capillaries of corpora lutea. ECE was present in internal theca cells of secondary, de Graaf, atretic follicles, and in luteinized granulosa cells of the corpora lutea. The endothelin system components are present in or around the follicles of human and monkey ovaries. Although the components are not expressed in the same cell types, they are synthesized, mainly in follicles, by cells that are in close proximity. Thus, the endothelin system could act in a paracrine manner. ECE expression in steroid-producing cells changes its compartmentalization during follicle maturation.