Heat induced differential pattern of DNA fragmentation in male germ cells of rats.

Spermatogenesis being a highly dynamic processes is highly vulnerable to various stresses including heat stress. Though, the relationship between physiological temperature and male germ cells is certainly immense, the magnitude of spermatozoal damage after exposure to heat is evidently degree and dose dependent. Further, there are contradictory reports related to germ cells apoptosis in relation to temperatures. Thus, currently the dynamics of temperature and time dependence on germ cell apoptosis were studied by modulating the heat treatment strategies. It was observed that the rate of apoptosis increased initially then decreased with time. The DNA fragmentation in the 10,000×g supernatant of testis homogenate of rats that received heat treatment for 15-min, 30-min as well as 45-min treatment with 15-min intermittent period was found to be almost equal. In various heat treated animals, the apoptosis was found to be maximum after day-1 of treatments, which then followed a decreased pattern. These results indicate that there may be an initial induction of apoptosis in the germ cells, which later primed or programmed the other germ cells to activate protective mechanisms against heat induced DNA damage and thus protecting germ cell population to undergo apoptosis at later durations.

Redox modulatory protective effects of ω-3 fatty acids rich fish oil against experimental colitis.

Ulcerative colitis (UC), a form of inflammatory bowel disease (IBD), is an immune-modulated disorder characterized by chronic and recurring inflammatory episodes. Oxidative stress and COX pathway of prostaglandin (PG) biosynthesis are indispensable to pathogenesis of UC. Any imbalance between PGs can compromise the mucosal homeostasis, leading to mucosal damage and chronic inflammation. However, blocking these PGs using classical Cox inhibitors such as non-steroidal anti-inflammatory drugs (NSAIDs) can instead aggravate signs of IBD. Therefore, realizing the need for safer and well tolerable alterative treatment approaches, currently, we evaluated the efficacy of n-3 fatty acids rich fish oil (FO) in the resolution of UC. Using a dextran sodium sulfate (DSS) model of experimental colitis, we have demonstrated that supplementation of FO containing 180 mg EPA and 120 mg DHA for 1 month relieved the signs (diarrhea, bloody stools, weight loss) of colitis-associated inflammation. To understand the biophysical changes associated with FO mediated inflammatory regulation, impedance measurement and Fourier transform infrared spectroscopy (FTIR) were done. These changes were also correlated with oxidative stress through markers such as GST, glutathione peroxidase (GPx), LPO, catalase, protein carbonyl content, GR, etc. in colonic mucosa. The modulation of COX mediated pathways in UC-associated inflammation was observed by protein expressions of various pro-inflammatory cytokines such as TNF-α and enzymes of PG synthesis such as COX-2, PGES, TXAS, and anti-inflammatory PGDS. Refuting the earlier reports that suggested the contradictory effects of FO, in the current study, we evidently demonstrated that the protective effects of FO are mediated through molecular mechanisms involving the redox-regulation of metabolism of key lipid metabolites.

Reduction of Animal Sacrifice in Biomedical Science & Research through Alternative Design of Animal Experiments.

Various upcoming techniques can be used in replacement of experiments requiring animal sacrifice or products of animal sacrifice. In many instances these techniques provide more reproducibility and control of parameter, compared to experiments involving animal or animal products. Use of these techniques can avoid the question of the animal sacrifice during experiment and subsequently permission of ethical approval. In silico simulation, informatics, 3D cell culture models, organ-on-chips are some innovative technology which can reduce the number of animals sacrifice. Scientist evolved some innovative culture procedures and production of animal friendly affinity reagents which are free from the product of animal sacrifice. Direct investigation on human body for treatment as well as further research, electronic health record is also helpful in the reduction of animals sacrifice in biomedical investigations. These techniques and strategies of research can be more cost effective as well as more relevant to various issues related to the human health. Some medical blunder has also been reported after the successful testing of drugs on animal's model. Hence, the reliability of animal experiment in context with human health is questionable. Alternative to animal experiments help to reduce the number of animals required for research up to certain extent but is not able to eliminate the need for animals in research completely. Wisely use of animals in teaching & research is expected and the importance of animal experimentation in futuristic development in life science cannot be ignored.

Conversion of apoptosis to necrosis and the corresponding alteration in the oxidative milieu of male germ cells of rat under acute heat stress: An experimental study.

BACKGROUND: Increased scrotal temperature can disrupt spermatogenesis leading to male infertility. Germ cells being heat sensitive maintain their genetic integrity via protective mechanism originated from the cell itself or by means of cell death. However, qualitative differentiation of how reactive oxygen species and antioxidant enzymes regulate signaling pathways of cellular damage including DNA fragmentation at varied temperatures remains unexplored. OBJECTIVE: The study was designed to evaluate the effects of heat mediated oxidative stress on male germ cells. Also, the time-dependent qualitative variation in the germ cell death was studied. MATERIALS AND METHODS: Thirty male Wistar rats were randomly segregated into five major groups (n=6/each) i.e., Control, 30, 45, 60, and 90-min counterparts according to heat treatment protocol. Quantitation of DNA and DNA ladder studies was performed along with various biochemical parameter like lipid peroxidation (LPO), glutathione, catalase, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutatione reductase (GR), glutathione-s-transferase (GST). RESULTS: Animals receiving heat treatment for 30-min and 45-min revealed systematic and gradual response to heat stress; whereas, 60-min and 90-min treated animals showed a typical and abrupt change of the internal milieu of germ cells. Laddering and smearing effect of damaged DNA in 30 and 45 min and 60 and 90 min heat treated animals was seen respectively. CONCLUSION: As the duration of heat treatment increases, the rate of apoptosis reaches an optimum level, and a further increase in the duration of heat treatment converted the mode of cell death from apoptosis to necrosis, implicitly due to severe oxidative attack.