Epigenetic modulation and apoptotic induction by a novel imidazo-benzamide derivative in human lung adenocarcinoma cells.

PURPOSE: Lung cancer is the most commonly diagnosed and leading cause of cancer death worldwide. Imidazo-benzamides are considered to be good anti-cancer agents. The present study was aimed to investigate the cytotoxicity of a novel imidazo-benzamide derivative N-(2-(3-(tert-butyl)ureido)ethyl)-4-(1H-imidazol-1-yl)benzamide (TBUEIB) in lung cancer cell line A549. METHODS: The antiproliferative activity of TBUEIB was investigated using MTT, LDH and trypan blue assay. The apoptotic potential was investigated using various staining techniques and further confirmed by DNA fragmentation assay and western blotting. RESULTS: TBUEIB inhibited fifty precent A549 cells at a dose of 106 µM. The novel compound was found to exert a modulatory effect on apoptotic marker caspase-3 as well as epigenetic regulatory proteins like DNA Methyltransferase 1 (DNMT1). In silico studies with the compound and other epigenetic proteins such as Histone deacetylase (HDAC) and ubiquitin-like with PHD (plant homeodomain) and RING (Really Interesting New Gene) finger domains 1(UHRF1) showed good modulatory effects. CONCLUSION: The overall results obtained in the study conclude that the novel compound TBUEIB has potential anti-cancer activities, mainly by targeting the expression of DNMT1 enzyme, which may have re-activated the major tumor suppressor genes involved in the cell cycle, leading to the apoptosis of the cancer cells. The results also indicate that the compound has more than one target in the epigenetic pathway implying that the compound may be a potential multi-target compound.

Obesogens and male fertility.

In the last decades, several studies evidenced a decrease in male fertility in developed countries. Although the aetiology of this trend in male reproductive health remains a matter of debate, environmental compounds that predispose to weight gain, namely obesogens, are appointed as contributors because of their action as endocrine disruptors. Obesogens favour adipogenesis by an imbalance of metabolic processes and can be found virtually everywhere. These compounds easily accumulate in tissues with high lipid content. Obesogens change the functioning of male reproductive axis, and, consequently, the testicular physiology and metabolism that are pivotal for spermatogenesis. The disruption of these tightly regulated metabolic pathways leads to adverse reproductive outcomes. Notably, adverse effects of obesogens may also promote disturbances in the metabolic performance of the following generations, through epigenetic modifications passed by male gametes. Thus, unveiling the molecular pathways by which obesogens induce toxicity that may end up in epigenetic modifications is imperative. Otherwise, a transgenerational susceptibility to metabolic diseases may be favoured. We present an up-to-date overview of the impact of obesogens on testicular physiology, with a particular focus on testicular metabolism. We also address the effects of obesogens on male reproductive parameters and the subsequent consequences for male fertility.

Leptospirosis among the self-supporting convicts of Andaman Island during the 1920s--the first report on pulmonary haemorrhage in leptospirosis?

Several researchers had carried out investigations on the possibility of existence of Weil's disease in Andaman Islands during early 20 th century. The first report of a series of confirmed cases of leptospirosis that occurred during 1929 was published in 1931.There were several reports during 1995 to 2009 that described detailed account of leptospirosis including various clinical syndromes. The possibility of pulmonary involvement in leptospirosis being a manifestation historically overlooked rather than newly emerged during the past two decades is examined in this review in the context of Andaman Islands. Two case series of leptospirosis, one occurred in 1929 and the other in 1996-1997 were reviewed with special emphasis on pulmonary involvement and haemorrhagic manifestations. The similarities and differences in the clinical profile of patients of the two case series were analysed. The review shows that respiratory system involvement and pulmonary haemorrhage as evidenced by presence of haemoptysis as a complication of leptospirosis was occurring during 1920s in Andaman Islands. The incidence of pulmonary involvement, however, rose from 9.4 per cent during 1929 to 52 per cent in 1996-1997. The case fatality ratio in patients with pulmonary involvement, which was 50 per cent during 1929 and 42.9 per cent during 1996-1997, was higher than that in cases without pulmonary involvement.Fever, conjunctival congestion, jaundice, vomiting, diarrhoea, hepatomagaly, haemoptysis, haematemesis and subconjunctival haemorrhage were common in both series. The case series in Andaman Islands in 1929 was probably the first report of pulmonary haemorrhage as a manifestation of leptospirosis. The increase in the incidence of pulmonary involvement in leptospirosis in the recent past is probably due to the increase in the density and diversity of its animal vectors,the broadening of the range of circulating serovars and the interactions between the vector and the agent. An increased virulence of Leptospira through gene acquisition and loss on an evolutionary time scale and the resulting change in the gene content, gene order and gene expression cannot be ruled out.

De novo deleterious genetic variations target a biological network centered on Aß peptide in early-onset Alzheimer disease.

We hypothesized that de novo variants (DNV) might participate in the genetic determinism of sporadic early-onset Alzheimer disease (EOAD, onset before 65 years). We investigated 14 sporadic EOAD trios first by array-comparative genomic hybridization. Two patients carried a de novo copy number variation (CNV). We then performed whole-exome sequencing in the 12 remaining trios and identified 12 non-synonymous DNVs in six patients. The two de novo CNVs (an amyloid precursor protein (APP) duplication and a BACE2 intronic deletion) and 3/12 non-synonymous DNVs (in PSEN1, VPS35 and MARK4) targeted genes from a biological network centered on the Amyloid beta (Aß) peptide. We showed that this a priori-defined genetic network was significantly enriched in amino acid-altering DNV, compared with the rest of the exome. The causality of the APP de novo duplication (which is the first reported one) was obvious. In addition, we provided evidence of the functional impact of the following three non-synonymous DNVs targeting this network: the novel PSEN1 variant resulted in exon 9 skipping in patient's RNA, leading to a pathogenic missense at exons 8-10 junction; the VPS35 missense variant led to partial loss of retromer function, which may impact neuronal APP trafficking and Aß secretion; and the MARK4 multiple nucleotide variant resulted into increased Tau phosphorylation, which may trigger enhanced Aß-induced toxicity. Despite the difficulty to recruit Alzheimer disease (AD) trios owing to age structures of the pedigrees and the genetic heterogeneity of the disease, this strategy allowed us to highlight the role of de novo pathogenic events, the putative involvement of new genes in AD genetics and the key role of Aß network alteration in AD.

Immunogenicity of a novel enhanced consensus DNA vaccine encoding the leptospiral protein LipL45.

Leptospirosis is a bacterial zoonotic disease caused by an infection with a spirochete belonging to the genus Leptospira. In animals, leptospirosis displays a wide range of pathologies, including fever, abortion, icterus, and uveitis. Conversely, infection in humans is associated with multi-organ injury, resulting in an increased rate of fatalities. Pathogenic leptospires are able to translocate through cell monolayers at a rate significantly greater than that of non-pathogenic leptospires. Thus, vaccine approaches have been focused on targeting bacterial motility, lipopolysaccharides (LPSs), lipoproteins, outer-membrane proteins (OMPs) and other potential virulence factors. Previous studies have indicated that leptospiral proteins elicit long-lasting immunological memory in infected humans. In the study reported here, the efficacy of a synthetic consensus DNA vaccine developed against the Leptospira membrane lipoprotein LipL45 was tested. After in vivo electroporation (EP) mediated intramuscular immunization with a synthetic LipL45 DNA vaccine (pLipL45) immunized mice developed a significant cellular response along with the development of anti-LipL45-specific antibodies. Specifically, the pLipL45 vaccine induced a significant Th1 type immune response, indicated by the higher production of IL-12 and IFN-γ cytokines. The results presented here are the first demonstration that a LipL45 based DNA immunogen has potential as a anti-Leptospira vaccine.

TCDD and corticosterone on testicular steroidogenesis and antioxidant system of epididymal sperm in rats.

2,3,7,8-Tetrachloro dibenzo-p-dioxin (TCDD), an endocrine-disrupting environmental pollutant, has been found to cause male reproductive toxicity. Glucocorticoids have been found to influence the metabolic pathway of TCDD. Stress, which affects the male reproductive function, is marked by an increase in the level and activity of glucocorticoids in the body. The present study was carried out to understand the effect of TCDD on testicular steroidogenesis and sperm antioxidant system under the influence of increased level of corticosterone in the body. Adult male rats were treated with either TCDD (100 ng/kg bw/ day) or corticosterone (3 mg/kg bw/day) or both for 15 days. Treatment with either TCDD or corticosterone was found to suppress the levels of steroidogenic acute regulatory protein and androgen-binding protein and reduce the activities of steroidogenic enzymes in testis while increasing oxidative stress in ventral prostate, seminal vesicles and epididymal sperm. In rats treated with both TCDD and corticosterone, the suppression of testicular steroidogenesis and increase in oxidative stress observed in ventral prostate, seminal vesicles and epididymal sperm were significant as compared to TCDD alone treated rats. The levels of Fas and FasL proteins were also increased in rats subjected to either TCDD or corticosterone treatment. In rats treated with both compounds, the increase observed in testicular levels of Fas and FasL was significant as compared to TCDD alone treated rats. Effect of TCDD on testicular steroidogenesis and antioxidant system of epididymal sperm may get enhanced under increased level of glucocorticoids in the body.

28-Homobrassinolide: a novel oxysterol transactivating LXR gene expression.

Cholesterol is the template for steroid hormone biosynthesis. Cholesterol homeostasis is regulated by Cyt-P450 oxygenated cholesterols acting as ligands on LXR-α and LXR-ß transcription factors that are now emerging as drug targets. Heterodimerization of LXRs with retinoic acid receptor is considered a prerequisite for target gene activation. Dietary plant oxysterol 28-homobrassinolide (28-HB) is a proven antihyperglycemic and a pro-steroidogenic agent in the rat. Whether 28-HB has a role in LXR gene expression was therefore investigated using oral gavage (15 days) of 28-HB (333 µg/kg b w) to normal and diabetic rat. PCR amplified LXR-α and ß mRNA transcripts from treated rat liver and testis exhibited quantitative differences in their expression. Conformational differences in 28-HB docking to LXR-α and ß binding domains were also noted through in silico studies, LXR-ß adopting lesser specificity. We report that 28-HB transactivates LXR genes in the rat tissues.

Gibberellic acid acts as an agonist of steroidogenesis in male rats.

Testicular steroidogenesis has significant implication in male reproductive function. Although the effects of various signalling molecules on testicular functions have been studied earlier, the influence of the plant hormone gibberellic acid (GA3 ) on steroidogenesis has not been investigated. Acute (4 h) and subacute (15 days) studies using this compound through oral administration (150 µg day(-1) ) to groups of normal and diabetic Wistar male rats were therefore carried out. Results indicate that (i) enhanced activity of steroidogenic markers 3ß-hydroxysteroid dehydrogenase (3ß-HSD), 17ß-hydroxysteroid dehydrogenase (17ß-HSD), elevated tissue testosterone (T) content, increased steroidogenic acute regulatory protein (StAR) and androgen binding protein (ABP) levels with reduced lipid peroxidation and improved antioxidant defence in this treatment group of normal and diabetic rat testis, and (ii) elevated lipid peroxidation and diminished antioxidant defence, with insignificant change in 3ß-HSD and 17ß-HSD activity and testosterone level in acute treatment group of normal and diabetic rats testis, were noted. The observed increase in the activity of testicular 3ß-HSD and 17ß-HSD along with elevated testosterone content established GA3 as an inducer of steroidogenesis in rat.

Kolaviron prevents carbendazim-induced steroidogenic dysfunction and apoptosis in testes of rats.

The study evaluated the protective role of kolaviron (an isolated biflavonoid from the seed of Garcinia kola) and vitamin E in carbendazim-induced reproductive dysfunction in male rats. Adult male Wistar rats were orally exposed to carbendazim (200mg/kg) singly or in combination with kolaviron (100 and 200mg/kg). Exposure to carbendazim significantly decreased the activities of superoxide dismutase and catalase but markedly increased sialic acid concentration and lipid peroxidation in the testes of rats. Western blot analysis revealed that carbendazim treatment decreased the expression of steroid acute regulatory (StAR) protein and androgen binding protein (ABP) with concomitant decrease in activities of steroidogenic enzymes. Germ cell apoptosis in carbendazim-treated rats was confirmed by TUNEL assay. However, pretreatment with kolaviron and vitamin E restored the testicular antioxidant status and steroidogenesis and decreased apoptotic nuclei to near control level in carbendazim-treated rats. Kolaviron may prove useful in combating carbendazim-induced reproductive toxicity.

Nonylphenol induces apoptosis via mitochondria- and Fas-L-mediated pathways in the liver of adult male rat.

Nonylphenol (NP) is an environmental contaminant known to possess estrogenic properties. Humans are constantly exposed to NP by contaminated water and food products. In the present study we sought to investigate whether treatment with low doses of NP induces apoptosis in the liver of adult rats. Rats were administered with NP by oral gavage at the doses of 15,150 and 1500 µg/kg body weight per day for 45 days. Plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were assayed. Apoptosis-related proteins namely cytochrome c, caspase-3, caspase-8, caspase-9, Fas and Fas-l, and expression of bcl-2 mRNA and bax mRNA were examined in the liver. Levels of AST and ALT were increased in the treated rats. Western blot analysis revealed elevation in the levels of cytochrome c, caspase-3, caspase-8, caspase-9, Fas and Fas-l in the liver of NP-treated rats. Decreased expression of bcl-2 mRNA (anti-apoptotic) and increased expression of bax mRNA (apoptotic) were observed in the liver of treated rats. Increased localization of caspase-3 in the hepatocytes and DNA damage were observed in the liver of treated rat. It is concluded that NP induces apoptosis in liver involving both mitochondria-dependent and Fas-Fas-l pathways and thereby, leading to hepatic damage in rats.

Long-term exposure to nonylphenol affects insulin signaling in the liver of adult male rats.

In the present study, we sought to investigate the long-term effects of nonylphenol (NP) on insulin signaling and glucose metabolism in liver. Furthermore, reactive oxygen species (ROS) in liver was evaluated as it is known to induce insulin resistance. Rats were administered NP by oral gavage at the doses of 15, 150 and 1500 µg/ kg body weight per day for 45 days. Hydrogen peroxide (H(2)O(2)) generation and lipid peroxidation were increased, and the activities of antioxidant enzymes were decreased in the liver of NP-treated rats. NP increased the plasma glucose and insulin levels and altered the enzymes of carbohydrate metabolism. Decrease in the protein levels of insulin signaling molecules insulin receptor (IR), IR substrate (IRS)-1, IRS-2 and phosphatidylinositol-3-kinase were observed with parallel increase in H(2)O(2) levels in the liver of NP-treated rats. These results suggest that NP downregulates insulin signaling in liver, which could be due to ROS production and oxidative damage.

Short-term exposure to nonylphenol induces pancreatic oxidative stress and alters liver glucose metabolism in adult female rats.

Nonylphenol is known to have estrogenic properties and has been reported to cause health hazards to animals and humans. The effects of nonylphenol on pancreas are not clearly elucidated. In this study, we sought to evaluate the effects of nonylphenol on the oxidative status of pancreas and consequential effects of nonylphenol on some of the end points of carbohydrate metabolism in the female rats. Rats were administered nonylphenol orally at the doses of 1.5, 15, and 150 mg/kg of body weight per day for 7 days. After 24 h of last dosing, the animals were sacrificed by cervical dislocation. The activities of pancreatic superoxide dismutase and catalase were significantly decreased with a concomitant increase in the levels of H2O2 and lipid peroxidation. Nonylphenol increased plasma insulin levels with a concomitant decrease in the levels of plasma glucose as compared to the control groups of rats. A dose-dependent increase in the activities of liver hexokinase and phosphofructokinase was recorded along with decreased activity of glycogen phosphorylase in liver. Western blot analysis revealed a significant decrease in the levels of GLUT-2. These results show that nonylphenol causes oxidative stress in pancreas and impairs liver glucose homeostasis.

Effect of restraint stress on 2,3,7,8 tetrachloro dibenzo-p-dioxin induced testicular and epididymal toxicity in rats.

Dioxins like 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) impair male reproductive system by increasing the generation of reactive oxygen species (ROS). Glucocorticoids have been found to suppress male reproductive function and also influence TCDD pathway. As stress is characterized by an increase in the level and activity of glucocorticoids, the present experiments were conducted to evaluate the effect of restraint stress on TCDD-induced testicular and epididymal toxicity. Adult male Wistar rats were subjected to either restraint stress (5 hours/day) or TCDD treatment (100 ng/kg b.w./day) or both for 15 days. Restraint stress or TCDD treatment raised the serum level of corticosterone and suppressed the testicular level of steroidogenic acute regulatory (StAR) protein and serum level of testosterone significantly. In the testis and epididymis, restraint stress or TCDD treatment raised the levels of lipid peroxidation and hydrogen peroxide and suppressed the activities of antioxidant enzymes significantly. In rats subjected to both restraint stress and TCDD treatment, a significant increase in the serum level of corticosterone and a significant decrease in the testicular level of StAR protein and serum level of testosterone were observed as compared to rats treated with TCDD alone. A significant increase in the levels of lipid peroxidation and hydrogen peroxide and a significant decrease in the activities of antioxidant enzymes were observed in the testis and epididymis of rats subjected to both restraint stress and TCDD treatment as compared to TCDD alone treated rats. Thus, restraint stress potentiates the adverse effects of TCDD on male reproductive organs.

Effects of corticosterone and 2,3,7,8-tetrachloro- dibenzo-p-dioxin on epididymal antioxidant system in adult rats.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), an endocrine disruptor, causes epididymal toxicity by inducing oxidative stress. Glucocorticoids have been found to influence TCDD action in vitro and in vivo. The present experiments were set up to analyze the effects of TCDD on rat epididymal antioxidant system under the influence of increased corticosterone level. Adult male Wistar/NIN rats (70-80 days old) numbering 24 (six per group) were used in the study. Corticosterone (3 mg/kg body weight per day) or TCDD (100 ng/kg body weight per day) were administered or coadministered to rats for 15 days. Treatment with corticosterone or TCDD decreased the levels of serum testosterone significantly. In caput, corpus, and cauda fractions, administration of corticosterone or TCDD increased the levels of lipid peroxidation and hydrogen peroxide and decreased the activities of superoxide dismutase and catalase significantly. Coadministration of corticosterone and TCDD to rats decreased the levels of serum testosterone significantly as compared with rats treated with TCDD alone. In caput, corpus, and cauda fractions, the levels of lipid peroxidation and hydrogen peroxide were increased and activities of superoxide dismutase and catalase were decreased significantly as compared with rats treated with TCDD alone. Stress, characterized by increased glucocorticoid levels and activity, may enhance TCDD-induced epididymal toxicity.

Methoxychlor induces apoptosis via mitochondria- and FasL-mediated pathways in adult rat testis.

In the past few years, there has been much concern about the adverse health effects of environmental contaminants in general and organochlorine in particular. Studies have shown the repro-toxic effects of long-term exposure to methoxychlor, a member of the organochlorine family. However, the insight into the mechanisms of gonadal toxicity induced by methoxychlor is not well known. In the present study we sought to elucidate the mechanism(s) underpinning the gonadal effects within hours of exposure to methoxychlor. Experimental rats were divided into six groups of four each. Animals were orally administered with a single dose of methoxychlor (50mg/kg body weight) and killed at 0, 3, 6, 12, 24, and 72h post-treatment. The levels and time-course of induction of apoptosis-related proteins like cytochorome C, caspase 3 and procaspase 9, Fas-FasL and NF-kappaB were determined to assess sequential induction of apoptosis in the rat testis. DNA damage was assessed by TUNEL assay and flowcytometry. Administration of methoxychlor resulted in a significant increase in the levels of cytosolic cytochrome c and procaspase 9 as early as 6h following exposure. Time-dependent elevations in the levels of Fas, FasL, pro- and cleaved caspase 3 were observed. The DNA damage was measured and showed time-dependent increase in the TUNEL positive cells, and also by flowcytometry of testicular cells. The study demonstrates induction of testicular apoptosis in adult rats following exposure to a single dose of methoxychlor.

Methoxychlor-induced alteration in the levels of HSP70 and clusterin is accompanied with oxidative stress in adult rat testis.

Methoxychlor, an organochlorine pesticide, has been reported to induce abnormalities in male reproductive tract. However, the insight into the mechanisms of gonadal toxicity induced by methoxychlor is not well known. We investigated whether treatment with methoxychlor would alter the levels of stress proteins, heat shock proteins (HSP), and clusterin (CLU), and oxidative stress-related parameters in the testis of adult male rats. Animals were exposed to a single dose of methoxychlor (50 mg/kg body weight) orally and were terminated at various time points (0, 3, 6, 12, 24, and 72 h) using anesthetic ether. The levels of HSP70, CLU, and the activities of superoxide dismutase (SOD), catalase, and lipid peroxidation levels were evaluated in a 10% testis homogenate. A sequential reduction in the activities of catalase and SOD with concomitant increase in the levels of thiobarbituric acid reactive substance (TBARS) was observed. These changes elicited by methoxychlor were very significant between 6-12 h of posttreatment. Immunoblot analysis of HSP revealed the expression of HSP72, an inducible form of HSP, at certain time points (3-24 h) following exposure to methoxychlor. Similarly, the levels of secretory CLU (sCLU) were also found to be elevated between 3-24 h of treatment. The present data demonstrate methoxychlor-elicited increase in the levels of inducible HSP72 and sCLU, which could be a part of protective mechanism mounted to reduce cellular oxidative damage.

Adjudin-mediated germ cell depletion alters the anti-oxidant status of adult rat testis.

Successful spermatogenesis is dependent on the proper attachment of developing germ cells to Sertoli cells. Manipulation of these interactions by drugs like Adjudin can hamper the development of germ cells and lead to conditions of temporary infertility. Although studies have shown the contraceptive potential of Adjudin, much is not known about its action in the testis. In this study, we sought to investigate the effect of Adjudin on the oxidative status of mammalian testis. Adult male rats were administered with a single dose of Adjudin (50 mg/kg body weight) by oral gavage and were killed at 1, 2, 4, 7, 15, or 30 days of treatment. Adjudin caused a significant increase in the production of hydrogen peroxide and lipid peroxidation from 4 to 7 days after treatment. There was a significant decrease in the activities of anti-oxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and glutathione S-transferase from 4 to 7 days after treatment with Adjudin. However, the state of oxidative stress was less pronounced from 15 to 30 days after Adjudin treatment. The level of androgen binding protein (ABP) remained unchanged following Adjudin treatment. These results show that there is an induction of oxidative stress accompanying adherens junction restructuring which suggests a role for reactive oxygen species in the regulation of these testicular junctions. However, transient elevation in reactive oxygen species levels did not affect androgen transport.

Low dose of 2,3,7,8 tetrachlorodibenzo-p-dioxin induces testicular oxidative stress in adult rats under the influence of corticosterone.

2,3,7,8 Tetrachlorodibenzo-p-dioxin (TCDD), an endocrine disruptor, causes testicular toxicity by increasing the production of reactive oxygen species (ROS). Glucocorticoids have been reported to influence TCDD action in vitro. Stress, characterized by increased glucocorticoid levels, has been found to suppress the testicular function. The present experiments were set up to analyse the effects of a low dose of TCDD on the rat testis under the influence of increased corticosterone levels. TCDD (1 ng/kg b.w./day) and corticosterone (3 mg/kg b.w./day) were administered alone or together to adult male rats for 15 days. Corticosterone administration raised the levels of serum corticosterone and decreased the levels of serum testosterone significantly. In the testicular mitochondrial- and microsomal-rich fractions, corticosterone administration increased the levels of lipid peroxidation and hydrogen peroxide and decreased the activities of antioxidant enzymes like superoxide dismutase and catalase significantly. TCDD administration to rats treated with corticosterone decreased the levels of serum testosterone as compared to rats treated with corticosterone alone. The levels of lipid peroxidation and hydrogen peroxide increased and the activities of superoxide dismutase and catalase were decreased significantly in mitochondrial- and microsomal fractions of the testis of treated rats as compared to those treated with corticosterone alone. It is concluded that stress may enhance the effects of TCDD on the testis.

Lindane induces testicular apoptosis in adult Wistar rats through the involvement of Fas-FasL and mitochondria-dependent pathways.

Lindane, an organochlorine pesticide, is known to impair testicular functions and fertility. To elucidate the mechanism(s) underpinning the gonadal effects of lindane, we sought to investigate the levels of apoptosis-related proteins, namely cytochrome c, caspase-3 and-9, Fas and FasL in the testis of adult rats. Furthermore, the study aims to delineate whether nuclear factor kappa B (NF-kappaB) is involved in meditating the testicular effects of lindane. Animals were administered with a single dose of lindane (5mg/kg body weight) and sacrificed at specific post-treatment intervals (0, 3, 6, 12, 24 and 72h). Significant elevations in the levels of cytosolic cytochrome c with a parallel increase in pro-caspase-9 were observed as early as 6h following exposure. Time-dependent elevations in the levels of Fas, FasL and caspase-3 were observed. Immunofluorescence studies revealed increased colocalization of Fas and caspase-3 in peritubular germ cells. FasL levels were increased in Sertoli and peritubular germ cells. The cytoplasmic levels of NF-kappaB p65 decreased from 3h following exposure with a maximal decline at 12 and 24h. Changes in the localization of NF-kappaB were observed with maximal nuclear translocation in germ cells at 12 and 24h. Terminal deoxynucleotidyl transferase-mediated dUTP nickend-labeling (TUNEL) assay revealed a time-dependent increase in the number of apoptotic cells. Taken together, the data illustrate induction of testicular apoptosis in adult rats following exposure to a single dose of lindane. Early activation of NF-kappaB in contrast to late increase in Fas expression suggests a pro-apoptotic role of NF-kappaB in testicular response to lindane.

Piperine activates testicular apoptosis in adult rats.

Piperine, an alkaloid present in the fruits of commonly used spice pepper, is known to impair reproductive functions. In the present study, piperine was administered to adult male rats at the dose levels of 1, 10, and 100 mg/kg body weight for 30 days to evaluate its effects on the testis. A significant decrease in the activities of antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase in the testis was observed at 10 and 100 mg of piperine administration when compared with the controls. A dose-dependent increase in lipid peroxidation and hydrogen peroxide generation was also observed. Sialic acid levels in the testis were also found to be decreased when piperine was administered at 10 and 100 mg dose levels. Immunofluorescence studies demonstrated a dose-dependent increase in caspase 3 and Fas protein in testicular germ cells after piperine treatment. These observations indicate that piperine induces oxidative stress and thereby triggers apoptosis in the testis, contributing to hampered reproductive functions.