Cytochemical study of spermiogenesis and mature spermatozoa in the lizard Tropidurus itambere (Reptilia, Squamata)

Are bio-based and biodegradable microplastics impacting for blue mussel (Mytilus edulis)?

The substitution of petrochemical plastics by bio-based and biodegradable plastics are in need of an evaluation for the potential toxic impacts that they can have on marine wildlife. This study aims to assess the toxicological effects of polylactic acid microparticles at two concentrations, 10 and 100 μg/L, during 8 days on the blue mussel, Mytilus edulis. No significant oxidative stress (catalase, glutathione-S-transferase and superoxide dismutase activities), neurotoxicity (acetylcholinesterase), or immunotoxicity (lysosomal membrane stability and acid phosphatase activity) were detectable. The multivariate analysis of metabolomic data allowed us to differentiate the individuals according to the exposure. From the loading plot of OPLS-DA, 48 ions down-regulated in the individuals exposed to microplastics. They were identified based on HRMS data as glycerophospholipids.

The role of flavonoid antioxidant, morin in improving procarbazine-induced oxidative stress on testicular function in rat

BACKGROUND

Procarbazine (PCZ) is an effective chemotherapeutic drug used in the treatment of lymphoma; however, oxidative stress-mediated testicular toxicity is a major side effect. Recently, therapeutic intervention using flavonoids against oxidative stress-related pathologies is gaining more attention. Morin (MOR) is a natural flavonoid with proven antioxidant activity. This study was designed therefore to evaluate the potential role of MOR in ameliorating PCZ-induced testicular oxidative stress and altered sperm quality in rat model.

METHODS

A total of 24 male Wistar rats (170-180 g) were randomly assigned into 4 treatment groups: I, control; II, PCZ (2 mg/kg b.w.); III, PCZ (2 mg/kg b.w.) + MOR (100 mg/kg b.w.) simultaneously administered and IV, MOR (100 mg/kg b.w.), and all treatments lasted 14 days.

RESULTS

PCZ treatment displayed significant reduction in sperm number, sperm motility, percentage normal sperm cells, and daily sperm production rate. Meanwhile the activities of testicular enzymes: gamma-glutamyl transferase, acid phosphatase, and lactate dehydrogenase were significantly altered in the PCZ group compared to control. Furthermore, PCZ caused a significant reduction in levels of glutathione and ascorbic acid as well as activities superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase in the testes of PCZ-treated rats. A significant increase in testicular malondialdehyde level was also observed in the PCZ group. MOR treatment, however, significantly restored the altered sperm parameters and biochemical markers in the testis.

CONCLUSIONS

Our data suggest that MOR administration protected against PCZ-induced testicular and spermatotoxicity in rat, by improving testicular antioxidant system.

Fluazifop-p-butyl, an aryloxyphenoxypropionate herbicide, diminishes renal and hepatic functions and triggers testicular oxidative stress in orally exposed rats

Fluazifop- p-butyl (FPB) is a selective aryloxyphenoxypropionate herbicide. Its phytotoxicity mechanism involves inhibition of lipid biosynthesis, free-radical generation, and oxidative stress in vulnerable plants. This study evaluates the impact of orally administered FPB on selected tissues in non-target animal model. Twenty-four male wistar rats (160–180g) were randomized into groups (I–IV). Group-I served as control, while animals in groups II, III, and IV received FPB at 18.75, 37.5, and 75 mg/kg body weight/day p.o., respectively, for 21 days. FPB caused significant ( p < 0.05) increase in plasma biomarkers of renal and hepatic function (urea, creatinine, bilirubin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase) when compared to control. Significant reductions in testicular ascorbic acid, glutathione, and activities of glutathione-S transferase, superoxide dismutase, and catalase were observed in FPB-treated animals when compared to control, in a dose-dependent manner. This was accompanied by increased testicular lipid peroxidation in the treated groups. Furthermore, a significant decrease in testicular acid phosphatase and γ-glutamyl transferase activities was also observed in the FPB-treated groups in a dose-dependent manner compared to control. However, testicular lactate dehydrogenase activity was significantly increased in the FPB-treated rats when compared to control. Additionally, histopathological studies revealed severe interstitial oedema and congestion of testicular blood vessels in the FPB-treated groups. Overall, data from this study suggest that FPB induced hepatotoxicity, nephrotoxicity, and oxidative stress-mediated alteration of testicular functions in rat.

Lectin histochemistry shows the comparative biosynthesis and cellular biodistribution of alpha L-fucose residues in some tissues of tetrapoda representatives

Fucose is a monosaccharide that plays several immunological roles. This study investigated the comparative biosynthesis and cellular biodistribution of fucose residues in some tissues of tetrapoda representatives using lectin histochemistry. In this study, the mouse was used as a representative for mammalian, pigeon for avian, lizard for reptilian, and toad for amphibians. The localization of the fucose residues was seen in several cell types of mice ileum, such as villi microfold (M) cells, goblet cells, some of intestinal crypts cells, and lamina propria cells. In other tetrapoda representatives, fucose was only seen in M cells of lizard ileum and some cells of villi lamina propria of pigeon, lizard, and toad. It was also observed in the pancreatic acinar cells of the mouse and some cell aggregations of pancreatic parenchyma of the lizard. Contrarily, it was not seen either in pigeon or in toad pancreases parenchyma. Spleen of all animals showed the fucose residues in some splenic cells in the red pulp only, barring the white pulp. The liver parenchyma of all tetrapoda representatives hadn't fucose residues. The fucose cellular biodistribution in some cells of tetrapoda representatives differed based on the cell type. In the mouse, it was highly seen in the apical cytoplasm of the villi M cells as well as in the cup-like part of goblet cells. In addition, it was seen as "rings" in the granule membranes of the Ulex europeaus agglutinin I (UEAI(+)) cells in the intestinal crypts cells. Furthermore, the UEAI(+) cells in the lamina propria showed fucose granules in their cytoplasm. There is no clear evidence about the relation between the cellular biosynthesis of fucose residues and mucosal immune cells. The role of fucose residues in the pancreatic acinar cells are not well understood and need further investigations. In this study, fucose residues were synthesized in several types of cells in the mouse ileum, spleen and pancreas as compared with other tetrapoda. The data obtained from this study can help us to get more information about the cellular biodistribution and synthesis of fucose residues in several animal species rather than mammalians.

Multi-biomarker approach using the blue mussel (Mytilus edulis L.) to assess the quality of marine environments: season and habitat-related impacts

Using a comprehensive approach, intertidal, near- and offshore sites in the German Bight were analysed for their environmental quality by assessing the health of blue mussels (Mytilus edulis). During a ten month sampling period mussels were studied with a set of biomarkers comprising lysosomal membrane stability and accumulation of lipofuscin, supplemented by biomarkers indicating nutritional status such as neutral lipids and glycogen in the cells of the digestive gland. Data were analysed in relation to sex, gonadal status, condition index and for the presence of parasites, to determine the overall health status of mussels at the respective sites. Mussels from all sites showed clear signs of stress, indicating an inferior environmental quality throughout the southern German Bight. Further, habitat characteristics such as inundation time and growing on- or off-bottom, as well as seasonal factors, can clearly influence the response of biomarkers in mussels exposed to similar levels of chemical environmental stress.

The reproductive cycle of the male house gecko, Hemidactylus flaviviridis, in relation to plasma steroid concentrations, progesterone receptors, and steroidogenic ultrastructural features, in Oman

The annual testicular cycle of the house gecko Hemidactylus flaviviridis in Oman was studied. Plasma testosterone (T), estradiol (E2) and progesterone (P) concentrations were measured using a sensitive HPLC-MS/MS detection technique. The ultrastructural steroidogenic features in Sertoli and Leydig cells, which were the major source of steriodogenesis, were examined, using transmission electron microscopy (TEM). In addition, progesterone receptors (PR) were examined throughout the testicular cycle, using an immunohistochemical technique. The steroidogenic ultrastructural features were characterized by the presence of smooth endoplasmic reticulum (SER) in the form of cisternal whorls and tubular cisternae, presence of swollen vesiculated mitochondria, and association between SER, mitochondria and lipid droplets. The rise in plasma steroid concentrations was closely associated with the development of the ultrastructural features and PR expression in Leydig and Sertoli cells. During the active phase (November-May), there was a significant rise in plasma steroid concentrations (P<0.05) related to well developed steroidogenic features and strongly expressed PR. During the quiescent phase (June-August) there was a significant decline in plasma steroid concentrations, undeveloped steroiodogenic features and weakly expressed PR. The Renal Sexual Segment (RSS) was fully developed during the active phase. The data provides strong evidence that these ultrastructural steroidogenic features were related to the plasma sex steroid concentrations during the testicular cycle.

Asynchronic steroid activity of Leydig and Sertoli cells related to spermatogenic and testosterone cycle in Phymaturus antofagastensis

The severe environments where Phymaturus lizards inhabit in the Andes highlands and in Patagonia, Argentina, impose restrictions on their reproduction, offering a framework for the development of life history strategies to overcome hard weather conditions. Among them, prolonged female cycles, asynchrony between sexes in receptivity, and sperm storage in males, were described. Asynchrony in the reproductive timing between males and females is a consequence of different energy requirements for gametogenesis, and often imply the existence of cellular mechanisms to enhance fertilization, such as the asynchronic steroid synthesis between testicular compartments, allowing gametogenesis independently of mating. In the present study ultrastructural and hormone assays were combined for the first time in liolaemids. Specifically, morphological features of steroid activity in Leydig and Sertoli cells, and serum testosterone concentrations have been studied in the lizard Phymaturus antofagastensis. Leydig and Sertoli cells presented morphological features characteristic of steroid synthesis during the spermatogenesis, and evident asynchronic steroid production between testicular compartments. Active Sertoli cells and inactive Leydig cells were observed in spring and autumn, while in mid-summer their steroid activity was synchronic in coincidence with maximal abundance of spermatozoa in epididymis. Serum testosterone concentration was at its maximum in mid-summer (126-230 ng ml(-1)), and minimum in late spring (4-24 ng ml(-1)) and early autumn (2-17 ng ml(-1)). In view of these results, P. antofagastensis males show an original approach to adjust their reproductive activity to physiological and environmental constraints at high latitudes and altitudes in the Andean highlands of Argentina.

The use of biomarkers in biomonitoring: a 2-tier approach assessing the level of pollutant-induced stress syndrome in sentinel organisms

The paper outlines a 2-tier approach for wide-scale biomonitoring programmes. To obtain a high level of standardization, we suggest the use of caged organisms (mussels or fish). An "early warning", highly sensitive, low-cost biomarker is employed in tier 1 (i.e. lysosomal membrane stability (LMS) and survival rate, a marker for highly polluted sites). Tier 2 is used only for animals sampled at sites in which LMS changes are evident and there is no mortality, with a complete battery of biomarkers assessing the levels of pollutant-induced stress syndrome. Possible approaches for integrating biomarker data in a synthetic index are discussed, along with our proposal to use a recently developed Expert System. The latter system allows a correct selection of biomarkers at different levels of biological organisation (molecular/cellular/tissue/organism) taking into account trends in pollutant-induced biomarker changes (increasing, decreasing, bell-shape). A selection of biomarkers of stress, genotoxicity and exposure usually employed in biomonitoring programmes is presented, together with a brief overview of new biomolecular approaches.