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.

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.

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.

Transient inhibitory effect of methoxychlor on testicular steroidogenesis in rat: an in vivo study.

Methoxychlor, an organochlorine pesticide, has been reported to induce reproductive abnormalities in male reproductive tract. To get more insight into the mechanism(s) of gonadal toxicity provoked by methoxychlor, we investigated whether treatment with methoxychlor at low observed adverse effect level (LOAEL) would alter the activities of steroidogenic enzymes such as Delta(5)3beta-hydroxysteroid dehydrogenase (3beta-HSD) and Delta(5)17beta-hydroxysteroid dehydrogenase (17beta-HSD), the expression levels of steroidogenic acute regulatory (StAR) protein and androgen binding protein (ABP) in the testis of adult male rats. The experimental rats were exposed to a single dose of methoxychlor (50 mg/kg body weight) orally. The rats were killed at 0, 3, 6, 12, 24 and 72 h following treatment using anesthetic ether and testes were collected, processed and used to measure the activities of 3beta-HSD, 17beta-HSD, levels of hydrogen peroxide produced and the expression levels of StAR protein, and ABP. Methoxychlor administration resulted in a sequential reduction in the expression of StAR protein and activities of 3beta-HSD, 17beta-HSD with concomitant increase in the levels of hydrogen peroxide in the testis. These changes were significant between 6-12 h following treatment. The levels of ABP declined at 6-12 h following exposure to methoxychlor. The present study demonstrates transient effect of methoxychlor at LOAEL on testicular steroidogenesis and the possible role of hydrogen peroxide in mediating these effects.

Single exposure to low dose of lindane causes transient decrease in testicular steroidogenesis in adult male Wistar rats.

Substantial evidence has piled up portending the adverse effects of environmental toxicants on male reproduction. Lindane, an organochlorine pesticide, has been reported to perturb testicular functions and hence fertility. To get more insight into the mechanism(s) involved in gonadal effect(s) of lindane, we sought to investigate whether treatment with lindane at a low dose would alter the levels of steroidogenic acute regulatory protein (StAR), androgen binding protein (ABP) and activities of steroidogenic enzymes (3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase) in adult rat. Furthermore, the levels of H2O2 were monitored to delineate the possible role of H2O2 in mediating the testicular effects of lindane. Animals used for experimentation were divided into six groups and four animals were maintained in each group. Animals were administered with a single dose of lindane (5mg/kg body weight) and terminated at specific post-treatment intervals (0h, 3h, 6h, 12h, 24h and 72h) to analyze the early testicular response. Administration of lindane resulted in a sequential reduction in the levels of StAR and the activities of steroidogenic enzymes with a parallel increase in the levels of H2O2. These changes elicited by lindane were significant at 12h and 24h post-treatment. In case of ABP, a significant decline in the level was found at 12h after treatment. These findings demonstrate transient inhibitory effects of lindane on testicular steroidogenesis and the possible role of H2O2 in mediating these effects.

Lindane alters the levels of HSP70 and clusterin in adult rat testis.

Lindane, an organochlorine pesticide, has been reported to induce reproductive abnormalities in male rats and induction of stress is considered to play an important role in the toxicity of lindane. To get more insight into the mechanism(s) involved in gonadal effect(s) of lindane, we sought to investigate whether treatment with lindane would alter the levels of stress proteins (heat shock proteins and clusterin) and change oxidative stress-related parameters (antioxidant enzymes and lipid peroxidation) in the testis of adult male rats. Animals used for experimentation were divided into six groups and four animals were maintained in each group. Animals were administered with a single dose of lindane (5mg/kg body weight) and terminated at specific post-treatment intervals (0, 3, 6, 12, 24 and 72 h) to analyze the early stress response. Administration of lindane resulted in a sequential reduction in the activities of catalase and superoxide dismutase (SOD) with concomitant increase in the levels of lipid peroxidation. These changes elicited by lindane were significant between 6 and 24 h post-treatment. In case of heat shock protein, the level of the constitutive HSP70 remained constant at all post-treatment intervals. However, a significant induction in the level of inducible HSP70 was observed between 6 and 24 h post-treatment. Similarly, the levels of secretory clusterin (sCLU) was found be significantly elevated at 12 and 24 h after treatment. These findings indicate a transitory state of stress induced by lindane in rat testis accompanied by an alteration in the levels of stress proteins, which could be a part of protective mechanism mounted to reduce cellular damage.

Effect of the extract of Thespesia populnea leaves on mice testis.

Male swiss mice were administered with the leaf extract of Thespesia populnea at a daily dose of 400 mg/kg body weight for 15 days and the testis were subjected to structural analysis. The structure of the seminiferous tubule in the testis of treated animal was elongated. Sertoli cells were enlarged in its structure and spermatids became round and disintegrated. It is suggested that the extract of T. populnea treatment leads to pathological changes in the seminiferous tubules, Sertoli cells and spermatids of the testis.