Author: ScienceIn

Adipokines, mostly produced by white adipose tissues, have been established to be endocrine factors which are also essential in energy homeostasis. More recently, their contribution in fertility regulation has been recommended. Resistin as well as visfatin are unique adipocyte-derived signaling chemicals whose expressions enhance in advanced obesity and are implicated in insulin resistance as well as type-2 diabetes. They are also found to be immune modulators and may participate in aggravating inflammatory responses which may partly explain obesity-mediated systemic inflammation. They are yet much less explored adipokines with potential to regulate metabolic rate, immune homeostasis as well as fertility. These adipokines are shown to be expressed in the hypothalamus in an area in charge of energy balance. Evidence suggest that they can potentially affect the hypothalamo-pituitary-gonadal (HPG) axis thereby modulating reproductive functions. They are also found to be expressed highly by the testes. In rodents, resistin and visfatin may positively modulate Leydig cell number and steroidogenesis. Additionally, visfatin exists in the human spermatozoa and may play role in the sperm maturation. However, reports on the impact of resistin and visfatin on human male fertility are inconsistent. In this article, we review the available literature on the role resistin and visfatin on male reproduction and integrate the mechanisms to discuss if they act as sensor for body energy dyshomeostatis and modulate male reproductive functions as per the metabolic status.

Human reproductive system involve a number of intricate complex interconnected physiological metabolic pathways and metabolites with involvement of overall health of different body organs. Overall health alterations mediated physiological conditions such as obesity, diabetes etc. bring about additional variations in expression and presence of metabolic constituents including kinases, hormones, proteins, peptides. The detailed analysis of various molecules like endocrine hormones, neuropeptides, immunity and inflammation associated kinases and proteins that have an end effect in cells and tissues, and might be playing a role in impacting male reproduction have been deliberated here. A deliberative collection of obesity and infertility related molecules including endocrine hormones, cytokines, adipokines, adiponectin, resistin, visfatin, ghrelin, orexins, leptin, adropin, chemerin, along with diabetes and age related physiological impact analysis on male reproductive system have been included in this selective compilation. An in-depth understanding of changes and introduction of new intermediate molecules for regulation of physiological phenomena like energy homeostasis in obesity regulation and their interlinked associated impact on the male fertility potential would provide a reflection for possible development of new therapeutics.

Adipokines are peptides produced mainly by the fat tissue adipocytes and their levels are sensitive to alterations in metabolic state. While there is little known about the impact of adipokines on male reproductive control, both animal-based experimental data and clinical research suggest that they can influence numerous male fertility indices. Chemerin is a newly found adipokine which is generally recognized as a chemoattractant and chemokine. Chemerin has been correlated with inflammatory reactions and metabolic imbalances, as seen in various metabolic syndromes. A sex dimorphic chemerin expression pattern has also been shown with greater levels in men in comparison to women. Chemerin can thus be offered as a potential new candidate in the connection among metabolic disorders, inflammation and male reproduction. The present article explores the multidimensional metabolic and inflammatory roles of chemerin and discusses its impact upon the male reproduction.

Orexins are hypothalamus-derived neuropeptides with versatile functions. The most explored domains of orexins’ functions are their influence on the central nervous system (CNS) implicated in the regulation of sleep/wakefulness cycle, food intake behavior, energy homeostasis, and cognitive processes. Orexins reportedly bear two isoforms, orexin-A (OXA) and orexin-B (OXB), that act via their specific G protein-coupled receptor (GPCR), OX1R and OX2R. These peptides also play vital roles in various other peripheral organs where they regulate metabolism, neuroendocrine functions, blood pressure, as well as reproductive functions. Interestingly orexins also exhibit immuno-regulatory, anti-inflammatory properties and facilitate the mechanism of obesity resistance. Recent research has also shed light on significant role of orexins, in particular orexin A, in regulating reproductive functions in male since the Leydig cells, Sertoli cells, germ cells in various stages of the development, and even the epididymis and penis, manifest the OXA receptor. It will be intriguing to explore the properties of the orexins in reversing obesity, downregulation of inflammatory responses and mediation of male reproductive functions. The present article thus reviews these multitudinous properties of orexins and comprehends the possible connection among the behavioral, metabolic, anti-inflammatory functions of orexins with their roles in male reproduction.

Lactobacillus and Bifidobacteria are generally accredited as potential anti-diabetic agents, but the mechanism of action is still not clear. This study aimed to investigate the result of administration of Lactobacillus casei and Bifidobacterium bifidum on α-glucosidase enzyme, postprandial blood glucose level, and histological changes that occur in the pancreatic β-cells in streptozotocin (STZ (50 mg/kg body weight)) induced diabetic rats. The experimental diabetic rats were treated with a single dose of L. casei and B. bifidum alone and combination for 28 days. The diabetic animals of a positive control group were treated with the standard hypoglycaemic drug, acarbose (10mg/kg body weight). Maltose and starch tolerance tests were performed. Treatment demonstrated significant hypoglycemic activity, lower postprandial blood glucose levels induced by maltose and starch loading in diabetic rats. The results demonstrated that L. casei and B. bifidum had α-glucosidase inhibitory activity and can reduce blood glucose level observed from the maltose and starch tolerance test. Histological analysis showed treatment prevented the function of pancreatic islets and regenerate degenerated cells.

Discovery of leptin has changed the view of adipose tissue from energy storehouse to active neuroendocrine and immune organ. Adipokineleptin is a16 kDa amino acid protein, encoded by LEP gene, secreted by adipose tissue, and acts through leptin receptor which is a cytokine receptor. Leptin is a central regulator of energy homeostasis by regulating food intake, appetite, satiety and basal metabolism. Leptin acts at each level of hypothalamus pituitary gonadal axis (HPG) and has a key role in initiation, progression of pubertal events and sexual maturation. Leptin acts directly at testicular level and affects the spermatogenesis, sperm quality and capacitation thus have important role in male reproduction and fertility. Leptin receptors are present on every cell involved in innate and adaptive immunity and regulate the functions of these cells. Leptin acts as common link between energy homeostasis, reproduction, stress responses and immune system by modulating common complex neuronal circuits. Leptin is implicated in pathogenesis of multiple disorders like obesity, type 2 diabetes mellitus, Systemic Lupus Erythematosis, osteoarthritis, rheumatoid arthritis, male infertility and other chronic inflammatory disorders. Therapies based on modulating the functions of leptin can be the key area of research in future for treatment of these chronic disorders.