[Effects of endocrine disrupting compounds on hypothalamic-pituitary-gonadal axis and reproductive health a review]

Introduction: The hypothalamic-pituitary-gonadal [HPG] axis controls reproductive function. The hypothalamus secretes GnRH that is transported to the anterior pituitary gland to stimulate the release of the gonadotrophic hormones. Which act on the gonads to stimulate sexual maturation, gametogenesis and steroidogenesis. Although GnRH neurons are a key component of the HPG axis, other neurotransmitters or neuropeptides in the hypothalamus, such as glutamate, GABA, galanin, dopamine and kisspeptin have been suggested to be involved in the regulation of GnRH secretion. In addition to GnRH neurons, pituitary and gonads, some of these neuronal populations such kisspeptin are extremely sensitive to changes in the levels of steroid hormones and endocrine disrupting compounds [EDCs]. Several EDCs, such as pesticides, bisphenol A, phthalates, tamoxifen, phytoestrogens and mycoestrogens can interact with the female and male reproductive system function and lead to disruption of endocrine function. Reproductive system development and function may be susceptible to the effects of such EDCs. By far, the greatest concerns for the potential adverse effects of EDCs have focused on their deleterious impact on reproductive health. It has been demonstrated under laboratory conditions and epidemiological studies that EDCs can exert detrimental effects especially during hormonal critical periods such as fetal and neonatal periods on the reproductive system. This article reviews some evidence that EDCs can impair the HPG axis and reproductive function

Preparation of decellularized three dimentional scaffolds as the model for tissue engineering and their functional assessments in vitro application of blastema tissue

Tissue engineering is based on three main factors including scaffolds, cells and growth factors. Natural scaffolds derived from decellularized tissues and organs have been successfully used in tissue engineering. Decellularization studies have shown that natural scaffolds which maintain their main structure and properties could be a suitable tool for studying cellular behaviors and preparation of such scaffolds is an important part of future research in biology that may have extensive applications in regenerative medicine and tissue engineering. Blastema tissue which is produced after injuries in some organisms has embryonic cell characteristics, and can be a suitable model for evaluation of cell behaviors in various tissues. In this review, the process of decellularization, process involved in preparation of 3D scaffolds derived from extracellular matrix of various tissues including cartilage, bone, gingiva, aorta and bladder, and assessment of their interactions with blastema tissue under in vitro conditions are discussed

[ effects of hydro-alcoholic extract of launaea acanthodes on the blood, urine albumin and bilirubin levels in male hyperglycemic wistar rat]

Nowadays, diabetes and its related methbolic disorders are the main cause of end stage renal disease. The present study aimed to investigate the possible therapeutic effects of Launaea acanthodes hydro-alcoholic extract administration on the serum and urine albumin and bilirubin levels in hyperglycemic rats. Twenty-four male Wistar rats were randomly allocated into four groups; the control, hyperglycemic [STZ; 55 mg/kg], hyperglycemia+ insulin [STZ+Ins; 5 IU/kg/day] and hyperglycemia+extract [STZ+Ext; 150 mg/kg/day]. Blood and urine samples were taken at the end of the 2[nd] and 4[th] weeks of experiment and serum and urine albumin and bilirubin levels were assessed. Although compared to the control group in the 2[nd] week samples in which the serum levels of bilirubin in STZ and STZ+Ext groups were significantly increased, in the 4[th] week only STZ group samples showed significant differences. In the 4[th] week urine samples the level of albumin was remarkably increased in STZ and STZ+Ins while there was no significant difference in the STZ+Ext group samples. These results clearly indicate the beneficial effect of L. acanthodes extract adiminstration in prevention of albumin loss through urine in hyperglycemic status. Therefore it may be concluded that L. acanthodes could be effective in the treatment of metabolic disorders

[Investigating the anti-epileptic and sedative effects of hydroalcoholic extract of Melissa officinalis [Lemon balm] leaf on pentylenetetrazol induced epileptiform seizures in wistar rat]

Since long lasting administration of anti-seizure drugs produces undesirable side effects, many efforts have been made during recent decades to find and replace the chemical drugs by medicinal plants. The aim of present study was to study the antiepileptic [anti-seizure] effects of hydroalcoholic extract of Melissa officinalis on experimental epileptiform seizures, induced by pentylenetetrazol [PTZ] in Wistar rat. After normalization, rats in experimental groups 1, 2 and 3 were injected [i.p] 50, 80 and 120 mg/kg hydroalcoholic extract of Melissa officinalis, respectively. Control animals were injected extract solvent as the same manner. After 30 minutes all rats were injected [i.p] 80 mg/kg PTZ and then examined for epileptiform behaviors for the next 60 minutes. The rate of mortality during the next 24 hour was also recorded. In comparison with control group, in all experimental groups the latent period of tonic-clonic generalized seizure was significantly [P < 0.05] increased. Moreover, the mortality rate was decreased from 90% in control group to 30, 50 and 60% in experimental groups 1, 2 and 3, respectively. It can be concluded that hydroalcoholic extract of Melissa officinalis has potential sedative and anticonvulsant effects and probably exerts its effects through GABAergic system

[Evaluating the protective effects of melissa officinalis on learning deficits of rat's offspring exposed to lead acetate during pre-and postnatal periods]

Lead contamination dramatically influences different body systems especially the central nervous system. Lead absorption during gestational period has deleterious effects on fetal differentiation and development and it may possibly result in learning deficits in adulthood. Recent studies have demonstrated positive effects of Melissa officinalis on memory improvement in some neural disorders. The aim of the present study is to investigate the protective effects of Melissa on learning deficits in lead acetate exposed rats. In this experimental study in department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad [2008-2009], 40 mated Wistar rats were divided into 8 groups as follows: control, negative control [Pb], Melissa [M] and Pb+M, and each in 3 different subgroups. The treatment started from the 7th day of gestation and continued during pregnancy and lactation. The learning ability and memory retention of four months old offspring were tested by complex T-maze. The collected data was analyzed by the SPSS software using one-way ANOVA and Toki test. A significant difference was found between lead exposed group and other groups regarding the time to reach the goal and the number of errors; while there was no meaningful difference between the control and other experimental groups. In lead exposed rats, learning deficits were obviously noticed. Since there was meaningful difference between control and Pb+M subgroups, Melissa can possibly improve learning deficits in lead acetate exposed rats