Amany A. Tohamy

β-Glucan inhibits the genotoxicity of cyclophosphamide, adriamycin and cisplatin

The inhibitory effects of beta-glucan (betaG), one of the biological response modifiers, on the induction of chromosomal aberrations in the bone marrow and spermatogonial cells of mice treated with various anti-neoplastic drugs were investigated. beta-Glucan (100 mg/kg bw, i.p.) pre-treatment reduced the total number of cells with structural chromosomal aberrations scored after the treatment with cyclophosphamide (CP) (2.5 mg/kg bw, i.p.) adriamycin (ADR) (12 mg/kg bw, i.p.) and cis-diamminedichloroplatinum-II (cisplatin) (5 mg/kg bw, i.p.) by about 41.1, 26.9 and 57.7% in bone marrow and 44.4, 55 and 57.1% in spermatogonial cells, respectively. This protective effect of beta-glucan could be attributed to its scavenging ability to trap free-radicals produced during the biotransformation of these anti-neoplastic drugs. Beta-glucan also markedly restored the mitotic activity of bone marrow cells that had been suppressed by the anti-neoplastic drugs. These results indicate that in addition to the known immunopotentiating activity of beta-glucan, it plays a role in reducing genotoxicity induced by anti-neoplastic drugs during cancer chemotherapy.

Piroxicam-induced hepatic and renal histopathological changes in mice

Piroxicam is a non-steroidal anti-inflammatory drug widely used in rheumatic diseases. The aim of this study was to investigate Piroxicam-induced histopathological changes in livers and kidneys of male albino mice. Methods: Animals were classified into a control group and 4 treated groups. Piroxicam was injected intraperitoneally using 0.3 mg/kg every day for four weeks. Each week a group of mice was sacrificed. Liver and kidneys were obtained for histological and histochemical examination. Animals were classified into a control group and 4 treated groups. Piroxicam was injected intraperitoneally using 0.3 mg/kg every day for four weeks. Each week a group of mice was sacrificed. Liver and kidneys were obtained for histological and histochemical examination. Results: Liver sections appeared with inflammatory cellular infiltration, vacuolated hepatocytes, dilated sinusoids, and increased number of Kupffer cells. Kidney sections appeared with some cellular inflammations. The glomeruli were shrunk resulting in widening of the urinary space. Oedema and vacuolations were noticed in the tubular cells. There was a positive correlation between these pathological changes and the increased treatment periods. Histochemical staining revealed that glycogen and protein contents had decreased in the hepatocytes. This depletion worsened gradually in liver cells after two, three, and four weeks. Similar depletion of the glycogen content was observed in kidney tissue. However, protein content appeared to be slightly decreased in the kidney tubules and glomeruli. Incensement of coarse chromatin in the nuclei of hepatocytes, Kupffer cells and most inflammatory cells were detected by Fuelgen method. Kidney tissues appeared with a severe decrease in coarse chromatin in the nuclei. Liver sections appeared with inflammatory cellular infiltration, vacuolated hepatocytes, dilated sinusoids, and increased number of Kupffer cells. Kidney sections appeared with some cellular inflammations. The glomeruli were shrunk resulting in widening of the urinary space. Oedema and vacuolations were noticed in the tubular cells. There was a positive correlation between these pathological changes and the increased treatment periods. Histochemical staining revealed that glycogen and protein contents had decreased in the hepatocytes. This depletion worsened gradually in liver cells after two, three, and four weeks. Similar depletion of the glycogen content was observed in kidney tissue. However, protein content appeared to be slightly decreased in the kidney tubules and glomeruli. Incensement of coarse chromatin in the nuclei of hepatocytes, Kupffer cells and most inflammatory cells were detected by Fuelgen method. Kidney tissues appeared with a severe decrease in coarse chromatin in the nuclei. Conclusion: Piroxicam has a time-dependent toxic effect on both liver and kidney tissues.

Bone Marrow Cell Therapy on 1,2-Dimethylhydrazine (DMH)-Induced Colon Cancer in Rats

Background/Aims: Stem cell based therapies are being under focus due to their possible role in treatment of various tumors. Bone marrow stem cells believed to have anticancer potential and are preferred for their activities by stimulating the immune system, migration to the site of tumor and ability for inducting apoptosis in cancer cells. The current study was aimed to investigate the tumor suppressive effects of bone marrow cells (BMCs) in 1,2-dimethylhydrazine (DMH)-induced colon cancer in rats. Methods: The rats were randomly allocated into four groups: control, BMCs alone, DMH alone and BMCs with DMH. BMCs were injected intrarectally while DMH was injected subcutaneously at 20 mg/kg body weight once a week for 15 weeks. Histopathological examination and gene expression of survivin, β-catenin and multidrug resistance-1 (MDR-1) by real-time reverse transcription-polymerase chain reaction (RT-PCR) in rat colon tissues. This is in addition to oxidative stress markers in colon were performed across all groups. Results: The presence of aberrant crypt foci was reordered once histopathological examination of colon tissue from rats which received DMH alone. Administration of BMCs into rats starting from zero-day of DMH injection improved the histopathological picture which showed a clear improvement in mucosal layer, few inflammatory cells infiltration periglandular and in the lamina propria. Gene expression in rat colon tissue demonstrated that BMCs down-regulated survivin, β-catenin, MDR-1 and cytokeratin 20 genes expression in colon tissues after colon cancer induction. Amelioration of the colon status after administration of MSCs has been evidenced by a major reduction of lipid peroxidation, nitric oxide, and increasing of glutathione content and superoxide dismutase along with catalase activities. Conclusion: Our findings demonstrated that BMCs have tumor suppressive effects in DMH-induced colon cancer as evidenced by down-regulation of survivin, β-catenin, and MDR-1 genes and enhancing the antioxidant activity.

Evaluation of Genotoxic and Hepatotoxic Effects of Graphene Oxide Nanosheets in Male Albino Mice.

Graphene oxide Nano-sheets (GOs) have a wide range of industrial, biochemical and medical applications regarding their unique physical, chemical and biocompatibility properties. For assessment of toxicological potential of graphene oxide nanosheets ninety male mice were divided into six groups; the control and five treated groups: animals of the control group received an intraperitoneal (i.p) injection of 0.2 ml saline solution (0.9% NaCl) once weekly for eight weeks. The treated groups were received an i.p injection of 10, 50, 100, 250, and 500 µg GOs/kg body weight once weekly, for eight weeks. Animals of all groups were sacrificed after 7, 28, and 56-days post treatment. The present study was conducted to evaluate the genotoxic effects of GOs on mice liver cells using alkali comet assay. In addition, physiological investigations and description of hepatic histopathological alternations were carried out. Results revealed that GOs induced DNA damage (DNA fragmentation), represented in dose and time-dependent increase in % tail DNA migration, tail moment and comet tail length. As well as, a diminish in % head DNA in nuclei of liver of GOs-treated mice versus control groups. The effect of GOs on hepatic superoxide dismutase (SOD), catalase (CAT) activities and glutathione (GSH) level indicated slight decrease at low doses (10 and 50 µg) at all time intervals of experimental period as compared to the control groups. The administration of high doses of GOs (100, 250, and 500 µg) indicated a significant diminish in SOD, CAT activities and decrease in GSH level; with subsequent elevation in malondialdehyde (MDA) levels in liver as compared to control groups. Various hepatic histopathological alternations were dose and time dependent in GO-treated mice versus control. In conclusion, the induction of DNA fragmentation in liver denoting the genotoxicity of GOs in dose and time dependent manner. GOs had the ability for inducing various hepatic alternations in a dose and time dependent manner indicating cytotoxicity presumably by oxidative stress. Thus, GOs should be used under strict control and these serious side effects should be taken into consideration when used in vivo treatments.

Radioprotection of 1,2-dimethylhydrazine-initiated colon cancer in rats using low-dose γ rays by modulating multidrug resistance-1, cytokeratin 20, and β-catenin expression

Ionizing radiation is a widely used therapy for solid tumors. However, high-dose ionizing radiation causes apoptosis, transforms normal cells into tumor cells, and impairs immune functions, leading to the defects in the removal of damaged or tumor cells. In contrast, low-dose radiation has been reported to exert various beneficial effects in cells. This experimental study investigated the effect of γ rays at low dose on the development of colorectal tumor in a 1,2-dimethylhydrazine (DMH)-induced colon cancer. Colorectal tumor model was induced in Wistar rats by subcutaneous injection of DMH (20 mg/kg) once a week for 15 weeks. Starting from zero day of DMH injection, a single low dose of whole-body γ irradiation of 0.5 Gy/week was applied to the rats. A significant reduction in lipid peroxidation, nitric oxide, and elevation in the glutathione content and antioxidant enzyme activity (superoxide dismutase and catalase) were observed after γ irradiation comparing with DMH group. Moreover, γ ray reduced the expressions of multidrug resistance 1 (MDR1), β-catenin, and cytokeratin 20 (CK20) those increased in DMH-treated rats. However, survivin did not change with γ ray treatment. A histopathological examination of the DMH-injected rats revealed ulcerative colitis, dysplasia, anaplasia, and hyperchromasia. An improvement in the histopathological picture was seen in the colon of rats exposed to γ rays. In conclusion, the present results showed that low-dose γ ray significantly inhibited DMH-induced colon carcinogenesis in rats by modulating CK20, MDR1, and β-catenin expression but not survivin expression.

Role of cyclins A and E in endometrial carcinogenesis in breast cancer patients under tamoxifen treatment.

PURPOSE The objective of our study was to determine the relevance of cyclins A and E overexpression in endometrial carcinogenesis in hormone receptor-positive breast cancer patients under tamoxifen therapy. EXPERIMENTAL DESIGN We assessed expression of cyclins A and E in Endometrial cytology samples collected from 36 ER and PR positive breast cancer patients; under tamoxifen treatment by using the Tao-brush non-invasive brushing cytology technique. Cyclins were detected in the collected samples by means of immuno-cytochemistry. The patients included in this study are a cohort of 36 breast cancer patients who were operated upon at the National Cancer Institute - Cairo University in the period from February 2006 to May 2008 and received tamoxifen (TAM) as part of their adjuvant treatment. RESULTS Cyclins A and E were expressed in 17 and 15 of the 36 collected endometrial cytology samples (47.2% and 41.6% respectively). Expression of cyclins A and E was highly correlated to Tamoxifen exposure duration (32 and 43 months respectively) p < 0.001. Tamoxifen median exposure duration was shortened to 21 months in cases showing positivity for either markers, while in cases showing positivity for both cyclins, the median exposure duration was longer (44.5 months) (p < 0.001). Neither cyclin A nor E was detected before median tamoxifen exposure duration of 11 months. Endometrial carcinoma cases had the longest Tamoxifen exposure duration (60 months). CONCLUSION Cyclins A and E expression is involved in the carcinogenesis of endometrium in women with breast cancer and under tamoxifen-treatment. Follow up of the patients using these 2 markers is highly recommended starting from the 12th month.

Studies on the effect of Salvia aegyptiaca and Trigonella foenum graecum extracts on adult male mice

Salvia aegyptiaca (Egyptian sage) and Trigonella foenum graecum (fenugreek) have potential tannins, total flavonoids and total phenolics as examined in vitro in the present study. In addition, the antioxidant effect of Egyptian sage (ESE) and fenugreek (FE) extracts were evaluated in normal male adult mice. Also, there is no evidence about the positive and/or negative effect of those extracts on male fertility. In order to evaluate the beneficial effect of those extracts, liver and kidney functions, lipid peroxidation, nitric oxide. In addition, non-enzymatic and enzymatic antioxidant molecules as glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR) and glutathione-S-transferase (GST) were estimated. Also, histological examination of testis was done. The results revealed that both extract of ESE and FE have potent antioxidant activity by reducing lipid peroxidation and nitric oxide formation in testis tissues of mice. Those activities were extended to non-enzymatic and enzymatic antioxidant defense components such as GSH, CAT, SOD, GR and GST. Additionally, ESE mixed to FE caused enhancement in testis structure with improved seminiferous tubules and spermatozoa. In conclusion, the results obtained showed that ESE and FE may contain some biologically active components that may be active against oxidative stress, and this may be the basis for its traditional use for environmental toxins.