Ömür Karaca

Influence of gilaburu (Viburnum opulus) juice on 1,2-dimethylhydrazine (DMH)-induced colon cancer.

In this study, the effects of gilaburu (Viburnum opulus) juice on colon tumorogenesis were investigated. Eight weeks old Balb-C male mice received subcutaneous injections of 1,2-dimethylhydrazine (DMH) (20 mg/kg body weight) once a week for 12 weeks. Both the sham control (group 1) and the DMH control (group 2) groups received drinking water alone, whereas the mice of groups 3 and 4 received gilaburu juice for 30 weeks (started with first DMH injection) and for 18 weeks (started after last DMH injection), respectively. Eighteen weeks after the last DMH injection, all mice were killed and the histogenesis of colon tumors was investigated from the paraffin-embedded sections of colon, which were stained with hematoxylin–eosin. The sites and incidences of tumoral lesions (low-grade dysplasia, high-grade dysplasia, intramucosal carcinoma and invasive carcinoma) were analyzed and compared with control. The results showed that the body weights of the mice were similar in all the groups. No tumoral lesions were found in group 1. Colon tumors developed in all DMH-treated mice (groups 2, 3 and 4). In these groups, the greatest numbers of tumor lesions were detected in the distal colon, followed by the mid-colon and only a few in the proximal colon. There was a reduction in the mean total number of tumor lesion in groups 3 (8.5) and 4 (8.3), when compared to group 2 (11.3). The incidence of invasive carcinoma in group 3 was significantly lower than group 2 (p < 0.05). On the basis of these results, we conclude that gilaburu juice may be useful for the prevention of colon cancer at the initiation stage.

Effects of intraperitoneal administration of the phenytoin on the skeletal system of rat fetus

This study was conducted on determining the effects of phenytoin on the skeletal system of the fetuses of 13 Wistar Albino rats. The female rats were divided into two groups after the vaginal smear test: the group 1 (control group) included 6 individuals, whereas the group 2 (phenytoin group) comprised 7 animals. A dose of 25mg/kg/day phenytoin was administered intraperitoneally to pregnant rats on the 8th-10th days of pregnancy and fetuses were obtained by C-section on the 20th day. A number of 82 fetuses were observed by double staining technique. Their lengths and weights were measured, revealing the statistically significant differences between the two groups (p<0.001). The lengths of the fetuses in the group 2 were determined as to be 14% shorter and the weights 13% lower compared to those in the group 1. Similarly, number of the fetuses obtained in one gestation decreased 9% in the group 2. Ossification of the skull bones in the fetuses of the group 2 was observed eminently to be deteriorated through using dissection microscope and inspection. Costal separation anomaly was observed in the 10 fetuses of the group 2. The separated-laterally located costal components were not attached to the costal arch. Shape malformations in the last two ribs and wide angularity, particularly in the last six ribs, were also determined. This study has documented that intraperitoneal usage of the pheytoin during pregnancy may cause to different skeletal malformations, even with lower doses, in rat fetuses.

Effect of angiostatin on 1,2-dimethylhydrazine-induced colon cancer in mice

Antiangiogenic therapy is supposed to be an attractive approach for antitumor treatment. Human plasminogen-derived angiostatin K1-3 is one of the most potent antiangiogenic agents known currently. However, it is unclear whether angiostatin has got protective effects on colon cancer. So we investigated the protective effects of angiostatin on 1,2-dimethylhydrazine (DMH)-induced colon cancer in mice. Thirty Balb/C male mice, weighing 25–30 g and 8 weeks of age, were used. Twenty of the mice were treated with DMH subcutaneously (20 mg/kg) once a week for 12 weeks. Six mice died during the DMH injection and surviving mice were divided into two groups (7 mice in DMH and 7 mice in DMH + angiostatin groups). In the angiostatin group, 6 weeks after the last DMH injection the animals were first treated with angiostatin (20 μg/mouse) intraperitoneally and then subcutaneously every 48 h (5 μg/mouse) throughout a period of 12 weeks. The animals were killed after 30 weeks for histopathological examination. When we look at the distribution of lesions in the colon, they mainly occurred in the distal colon. The incidence of mean colonic lesions in a tumor-bearing mouse was 9.85 ± 4.91 in those treated with DMH and 8.71 ± 3.49 in those treated with angiostatin. The incidence of colon tumors was not significantly affected by low dose of angiostatin, and we noticed that the number of lesions decreased by 12% in DMH + angiostatin group compared to the number of the lesions in DMH group, but this decrease was not statistically significant (p > 0.05). The administration period of angiostatin corresponds to the precancerous period and the reduction in the number of lesions could be important for the protective function of angiostatin in DMH + angiostain group. We assume that therapeutic effects of angiostatin are related to its doses, route of administration, frequency and administration period. In addition, we believe that combination of high doses of angiostatin with radiation, gene therapy or chemotherapy might be successful in proper tumor model.

Effect of endostatin on 1,2-dimethylhydrazine-induced colon tumor in mice

Endostatin, one of the most potent negative regulators of angiogenesis, is naturally occurring as an inhibitor of angiogenesis capable of inhibiting tumor growth and their metastases. We aimed to investigate the in vivo activities of low dose of recombinant human endostatin on 1,2-dimethylhydrazine (DMH)-induced mice colon cancer. Thirty male Balb-c mice were injected with DMH (20 mg/kg/week) subcutaneously once a week for 12 weeks to induce colon cancer. Twelve weeks after the last DMH injection, 7 µg rh-endostatin was injected every day for 6 weeks. The animals were killed after 30 weeks for histopathological examination. The weight of the animals, tumor inhibition rates, death rates and the distribution of the lesions in colon were evaluated after the mice were killed. The mean colonic lesions incidence in single tumor bearing mice was 11 ± 4.0 in those treated with DMH and 8.1 ± 3.7 in those treated with endostatin. When we look at the distribution of lesions in the colon, they occurred in the distal colon. At the end of our study, we noticed that the number of lesions decreased by 25% in the group of endostatin, considering the number of the lesions in the group of DMH. But there was no statistical difference between the mice treated with endostatin and those treated with DMH. It will be very significant to identify endostatin therapeutic effects as long as proper dose of endostatin is administrated at the proper time, duration and proper tumor model.