Zinc oxide nanoparticles: Chemical and green synthesis, characterization, and comparative evaluation of their effects on caprine testis in vitro.

The present research was designed to investigate the potential effects of zinc oxide nanoparticles synthesized by both chemical and green method in caprine testis. In this study, rod-shaped zinc oxide nanoparticles (ZnONPs) with diameter less than 100 nm were prepared by chemical and green method using polyvinyl pyrrolidone (PVP) and Ocimum sanctum leaf extract as stabilizing agents respectively. X-ray diffraction, Fourier transform infrared spectroscopy, LCMS, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and EDX were utilized to characterize the synthesized zinc oxide nanoparticles. The histomorphological alterations of both chemically synthesized and biosynthesized zinc oxide nanoparticles were evaluated after administration of two doses (10 µg/ml and 20 µg/ml) for exposure duration of 4 h and 8 h. Chemically synthesized zinc oxide nanoparticles induced significant damage in testicular cells in dose and time-dependent manner. The Histomorphological changes included desquamation in germinal epithelium, pyknosis in germ cells, increased vacuolization, loss of mature spermatozoa from lumen and wide interstitial space between seminiferous tubules. Protective effects of biosynthesized zinc oxide nanoparticles were recorded at lower dose whereas some alterations were observed when treated with 20 µg/ml for 4 h and 8 h culture duration. The results confirmed that phytochemicals present in leaf extract of O. sanctum mitigated the zinc oxide nanoparticles induced toxicity, proving biosynthesized nanoparticles are better than chemically synthesized nanoparticles.

Effective attenuation of atrazine-induced histopathological changes in testicular tissue by antioxidant N-phenyl-4-aryl-polyhydroquinolines.

Some of the environmental toxicants acting as endocrine disruptors have been associated with health hazards in human and wildlife by modulating hormonal actions. Atrazine, a strong endocrine disruptor, induces detrimental effects on gonads in male and female, and causes impairment of fertility and developmental problems as well as sex alterations. Atrazine decreases the activities of antioxidant enzymes and thus responsible for oxidative stress. Natural antioxidants have shown ability to reduce/slow down the apoptotic effect of atrazine on testicular tissue. In the present study, some N-phenyl-4-aryl-polyhydroquinolines bearing phenolic or/and alkoxy group(s) (6a-6g) were synthesized and evaluated for antioxidant activity in four different assays. Three best compounds (6e-6g) were studied for their ameliorative effect on testicular tissue supplemented with atrazine in vitro.

Inhibitors of apoptosis in testicular germ cells: synthesis and biological evaluation of some novel IBTs bearing sulfonamide moiety.

Pifithrin-α, a known p53 inactivator, inhibits p53-dependant mitochondrial cell death induced by toxins or γ-radiation. It has been found that aromatic IBT analogues of PFT-α are more cytoprotective and nonpeptide-based, isatin sulfonamides selectively inhibit caspases 3 and 7, responsible for mitochondrial mediated apoptosis. Therefore, we envisioned the synthesis of novel IBTs 4 and 5 bearing sulfonamide moiety and observed the mitigating effects of these IBTs in rescue of malathion induced apoptosis in testicular germ cells of goat. Two IBTs (4b; R = CH(3), 5b; R(1) = Cl) showed very high survival rate of cells whereas IBT 4f (R = NO(2)) showed some exceptional behaviour by increasing the apoptosis. These IBTs nullify the cytotoxic effect of malathion on mitochondria, following p53-independent pathway.

N-acetyl-L-cysteine modulates multiple signaling pathways to rescue male germ cells from apoptosis induced by chronic hCG administration to rats.

The present study was aimed to investigate the beneficial effects of N-acetyl-L: -cysteine (NAC, 150 mg/kg bw twice/week) against testicular germ cell apoptosis in rats induced by chronic hCG administration (100 IU/rat/day for 30 days). NAC co-treatment improved serum testosterone, prevented rise in lipid peroxidation, intracellular H(2)O(2) and the activities of antioxidant enzymes in germ cells. Replenishment of intracellular GSH and total antioxidant capacity was seen. There was a marked reduction in TUNEL positive germ cells and expression of caspase-3 (p < 0.01) and PARP cleavage. Pro-apoptotic markers Fas, FasL, caspase-8 were also significantly downregulated. While Bcl-2 was fully restored, rise in Bax, caspase-9, phospho-JNK/JNK and phospho-c-Jun/c-Jun expression was significantly arrested. Anti-apoptotic phospho-Akt/Akt and NF-κB were otherwise found upregulated. Taken together, the above findings demonstrate that NAC intervention rescued the testicular germ cells from demise following chronic hCG treatment through regulation of multiple signaling mechanisms of metazoan apoptosis.

N-acetyl-L-cysteine counteracts oxidative stress and prevents H2O2 induced germ cell apoptosis through down-regulation of caspase-9 and JNK/c-Jun.

The mechanism of H(2)O(2) induced oxidative stress leading to male germ cell apoptosis was earlier reported from our laboratory. In the present study, we investigated the mechanisms by which N-acetyl-L-cysteine (NAC, which is highly cell specific with strong antioxidant and anti-genotoxic properties), stimulated cell survival under such conditions. Co-incubation with 5 mM NAC significantly (P<0.001) reduced the germ cell apoptosis induced by 10 µM H(2)O(2). Lipid peroxidation was brought down with significant restoration of activities of antioxidant enzymes, SOD, GST, and catalase. Expression of pro-apoptotic marker, Bax up-regulated following H(2)O(2) exposure, was reversed back to control levels. In contrast, expression of anti-apoptotic Bcl-2 and phospho-Akt revealed a completely opposite trend. While caspase-8 activity remained unaffected, NAC successfully attenuated the increased activities of caspase-3 and -9 in the H(2) O(2) treated cells. Simultaneously, the increased expression of caspase-9, phospho-JNK, and phospho-c-Jun after H(2)O(2) treatment was down-regulated by NAC. The above findings indicate that the mechanism of inhibition of H(2)O(2) induced male germ cell apoptosis by NAC is mediated through regulation of caspase-9 and JNK.

Changes in trace elements during follicular atresia in goat (Capra hircus) ovary.

Quantitative analysis of follicular fluid and granulosa cells from small, medium and large antral atretic follicles of goat (Capra hircus) ovaries was conducted to study the alterations in trace elements viz zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe). The zinc content was lower in the follicular fluid (0.993 ± 0.001, 0.935 ± 0.002, 1.321 ± 0.001 µg/ml) and granulosa cells (0.867 ± 0.002, 0.801 ± 0.001, 1.073 ± 0.002 µg/mg) of small, medium, and large antral atretic follicles respectively than their respective controls. Copper quantity was higher in the follicular fluid (0.113 ± 0.001, [Formula: see text], 0.224 ± 0.001 µg/ml) and granulosa cells (0.094 ± 0.001, 0.114 ± 0.001, 0.182 ± 0.001 µg/mg) from small, medium, and large antral atretic follicles respectively than their respective controls. Similarly, iron and manganese was also found higher in the follicular fluid and granulosa cells of small, medium, and large antral atretic follicles than their respective controls. The present study provides the basic data on trace elements that can be safely used as atretic marker and will find use in in vitro studies for fertility improvement plan. Thus, help in elevating the number of ovulations and screening of follicles to enhance the success rate in vivo and in vitro fertilization and embryo transfer technology.

Pathways involved in testicular germ cell apoptosis induced by H2O2 in vitro.

H(2)O(2) induces apoptosis in variety of cells; however, the sensitivities of testicular germ cells to H(2)O(2) are not known. In the present study, H(2)O(2), at concentrations in the range 1-10 microM, was found to induce apoptosis in testicular germ cells in vitro. Following 1 h of treatment with 10 microM H(2)O(2), a 10-fold rise in the percentage of apoptotic cells was observed. Induction of germ cell apoptosis was directly associated with a significant (P < 0.01) increase in lipid peroxidation and a concomitant decrease in superoxide dismutase and catalase activity. Examination of apoptotic signalling pathways revealed an increased expression of extrinsic (Fas, FasL and caspase-8) and intrinsic (Bid, Bak, Bad, Bax and caspase-9) markers, as well as p53, along with a simultaneous decrease in the Bcl-2 protein at the highest concentration of H(2)O(2) exposure. Both, c-jun N-terminal kinase and p38 phosphorylated forms were found to be up-regulated. Interestingly, up-regulation of the nuclear transcription factor kappa B was also observed. The respective transcripts for many of the above proteins followed an identical trend. Caspase-3 activity was also estimated to be 30-fold higher. Taken together, the above data indicate that testicular germ cells are prone to apoptosis at very low concentrations of H(2)O(2), the mechanism of which involves extrinsic and intrinsic as well other regulatory pathways.

Bolineol, a novel co-metabolite of strobilurins A, F and G from Bolinea lutea.

A mycelial co-metabolite of strobilurin A, F and G from Bolinea lutea, which we have named bolineol, has been characterised for the first time. Bolineol (methyl 2-hydroxymethyl-3-methyl-6-phenyl-3Z,5E-hexadienoate) has a similar carbon skeleton to strobilurin A but differs in oxidation level. Its structure has been deduced from its spectral characteristics and those of its acetate. The known compound strobilurin F-1 (methyl 2-methoxymethylene-3-methyl-6-(3'-hydroxyphenyl)-3Z,5E-hexadienoate) has been detected in this organism for the first time and converted into its acetate, a new compound, the structure of which was assigned from its spectral data.