Epidemiological reports have indicated a correlation between the increasing bisphenol A (BPA) levels in the environment and the incidence of male infertility. In this study, the protective effects of melatonin on BPA-induced oxidative stress and apoptosis were investigated in the rat testes and epididymal sperm. Melatonin (10 mg/kg body weight (bw)) was injected concurrently with BPA (50 mg/kg bw) for 3 and 6 weeks. The administration of BPA significantly increased oxidative stress in the testes and epididymal sperm. This was associated with a decrease in the serum testosterone level as well as sperm quality, chromatin condensation/de-condensation level, and the percentage of haploid germ cells in the semen. BPA administration caused a significant increase in apoptosis accompanied by a decrease in the expression of the antiapoptotic proteins Bcl-2 in the testes and epididymal sperm. The concurrent administration of melatonin decreased oxidative stress by modulating the levels of glutathione, superoxide dismutase, and catalase as well as the malondialdehyde and hydrogen peroxide concentrations in the testes and sperm. Melatonin sustained Bcl-2 expression and controlled apoptosis. Furthermore, melatonin maintained the testosterone levels, ameliorated histopathological changes, increased the percentages of seminal haploid germ cells, and protected sperm chromatin condensation process, indicating appropriate spermatogenesis with production of functional sperm. In conclusion, melatonin protected against BPA-induced apoptosis by controlling Bcl-2 expression and ameliorating oxidative stress in the testes and sperm. Thus, melatonin is a promising pharmacological agent for preventing the potential reproductive toxicity of BPA following occupational or environmental exposures.

Spirulina platensis (SP) is a filamentous cyanobacterium microalgae with potent dietary phyto-antioxidant, anti-inflammatory and anti-cancerous properties. The present study aimed to investigate the chemopreventive effect of SP against rat liver toxicity and carcinogenesis induced by dibutyl nitrosamine (DBN) precursors, and further characterized its underlying mechanisms of action in HepG2 cell line. Investigation by light and electron microscopy showed that DBN treatment induced severe liver injury and histopathological abnormalities, which were prevented by SP supplementation. The incidence of liver tumors was significantly reduced from 80 to 20% by SP. Immunohistochemical results indicated that both PCNA and p53 were highly expressed in the liver of DBN-treated rats, but were significantly reduced by SP supplementation. Molecular analysis indicated that SP treatment inhibited cell proliferation, which was accompanied by increased p21 and decreased Rb expression levels at 48hrs post-treatment. In addition, SP increased Bax and decreased Bcl-2 expression, indicating induction of apoptosis by 48hrs. This is the first report of the in vivo chemopreventive effect of SP against DBN-induced rat liver cytotoxicity and carcinogenesis, suggesting its potential use in chemoprevention of cancer.

In this study, we examine the ability of arabinoxylan rice bran (MGN-3/Biobran) to enhance the apoptotic effect of paclitaxel (Taxol) at low concentration [2 mg/kg body weight (BW)] in animals bearing Ehrlich ascites carcinoma (EAC) cells and elucidate its mechanisms of action. On Day 8 following tumor cells inoculation, mice bearing tumors were administered MGN-3 alone (40 mg/kg BW), paclitaxel alone, or MGN-3 plus paclitaxel. On Day 30 post-tumor inoculation, we observed significant suppression of tumor volume (TV) with paclitaxel alone (59%), MGN-3 alone (77%), and MGN-3 plus paclitaxel (88%). Inhibition of tumor growth post-treatment with both agents, as compared with either treatment alone, was associated with a decrease in cell proliferation, a marked increase in the sub-G0/G1 population, an increase in DNA damage and apoptosis of tumor cells, and a significant maximization of the apoptosis index (AI)/proliferation index (PrI) ratio. Histopathological and electron microscopy examination of the combined treatment group showed an increase in the degenerative regions of the solid tumor tissue and abundant apoptotic cells. These data suggest that MGN-3 supplementation enhances tumor cell demise in the presence of a low dose of chemotherapeutic agent via apoptotic mechanism.

No abstract

The current work estimated the antitumour efficacy of melatonin (MLT) on the growth of Ehrlich ascites carcinoma cells inoculated intramuscularly into the hind limbs of female BALB/c mice and to compare its effects with those of adriamycin (ADR). After solid tumours developed, the animals were divided into the three following groups: the tumour‐bearing control, MLT‐treated (20 mg/kg body weight) and ADR‐treated (10 mg/kg body weight) groups. The results showed a significant reduction in the tumour masses of the treated animals in comparison with those of the control group. There were a significant decrease in the malondialdehyde level and a significant elevation of the glutathione concentration and the superoxide dismutase and catalase activities in the MLT and ADR groups. The current study indicated the increased expression levels of P53, caspase‐3 and caspase‐9 and the decreased expression levels of the rRNA and Bcl2. The MLT and ADR treatments resulted in histological changes, such as a marked degenerative area, the necrosis of neoplastic cells, the appearance of different forms of apoptotic cells and giant cells with condensed chromatin, and a deeply eosinophilic cytoplasm. The MLT and ADR treatments also significantly decreased the Ki‐67 protein and vascular endothelial growth factor (VEGF) expression levels in the tumour masses. In conclusion, similar to ADR‐treated tumour‐bearing mice, MLT suppressed the growth and proliferation of tumour by inducing apoptosis and by inhibiting tumour vascularization. The current data recommend MLT as a safe natural chemotherapeutic adjuvant to overcome cancer progression after a clinical trial validates these results.

No abstract

Cisplatin (CP) is a widely used anticancer drug; however, it has several side effects such as nephrotoxicity. Ginger, the rhizome of Zingiber officinale, consumed since ancient times has numerous health benefits. The objective of this work was to evaluate the protective effect of ginger extract (GE) against CP-induced nephrotoxicity. CP group displayed a marked renal failure characterized by a significant increase in serum creatinine and blood urea nitrogen (BUN) levels in addition to severe histopathological and ultrastructural renal alterations. Also, CP group showed an increase in the immunohistochemical expression of Bax proapoptotic protein. In contrast, GE+CP group showed significant decrease in the elevated serum creatinine and BUN levels and an improvement in the histopathological and ultrastructural renal injury induced by CP. The overexpression of Bax proapoptotic protein was significantly decreased in the GE+CP group. Hence, the present results indicated that GE has a protective effect against CP-induced renal damage in rats. Thereby, such findings recommended the usage of GE to prevent and/or decrease the renal damage induced by CP chemotherapeutic treatment.

Limited bioavailability of green tea polyphenols hampered their delivery to tumor and hence therapeutic effectiveness. This study investigated the antitumor activity of polyphenon-E (PE) encapsulated into chitosan nanoparticles (CSNPs) in Ehrlich solid tumor in mice. CSNPs-PE, with a particle size of 53-69 nm showed 83% entrapment efficiency and a sustained release of PE in pH = 7.4 at 37°C. The data demonstrated a higher percentage of released drug in case of less crosslinked formulations. Ehrlich ascites carcinoma (EAC) cells (2.5 Â 10 6 /0.2 ml/mouse) were injected subcutaneously in the back of mice. Oral administration of CSNPs-PE for 30 days produced a significant decrease in tumor volume (53%) and weight (60%) compared with free PE and voids CSNPs (72%). Compared with free PE and control, cell cycle revealed G0/G1 arrest associated with decrease in proliferating cell nuclear antigen (PCNA). In tumor tissue of CSNPs-PE treated mice, compared with free PE, there were; 1) induction of Bax and p53, 2) activation of caspases-3,-8 and -9, and CD95, 3) decrease in Bcl-2 expression of 4) inhibition of VEGF and CD31 expressions in tumor tissue. In conclusion, encapsulation of PE into CSNPs provided a good platform for cancer chemotherapy and raised existing application of different polyphenols for nanochemotherapy/ prevention.