Selenium as a chemopreventive agent in experimentally induced colon carcinogenesis

Table 1 Effect of selenium on body weights of animals subjected to 20 wk of DMH treatment

Groups	Body weight (g)
	0 d	20 wk
I normal control	135 ± 15.00	282 ± 16.43
II DMH	134 ± 16.73	210 ± 15.81d
III selenium	134 ± 15.11	284 ± 37.81
IV DMH + selenium	134 ± 20.70	246 ± 33.61ab

^bP < 0.01 and

^dP < 0.001 by one-way ANOVA followed by LSD test when values are compared with normal control group;

^aP < 0.05 by one-way ANOVA followed by LSD test when values of group IV animals are compared with group II animals. Values are expressed as mean ± SD.

Table 2 Chemopreventive efficacy of selenium on the tumor incidence, tumor multiplicity and tumor size of DMH-induced rat colonic tumors

Groups	Colon tumor incidence (percentage of tumor bearing rats)	Colon tumor multiplicity (mean tumor/animal)	Tumor size (cm)
Normal control	0	0	-
DMH	100%	2.6	0.911 ± 0.196
Selenium	0	0	-
DMH + selenium	60%	1.1	0.609 ± 0.250b

^bP < 0.001 by one way-ANOVA followed by LSD test when values of IV animals were compared with Group II animals. Values are expressed as mean + SD.

Table 3 Effect of selenium on lipid peroxidation and antioxidant enzymes in the colons of rats subjected to 20 wk of DMH treatment

Groups	Lipid peroxidation (nmoles of MDA/min/100 mg protein)	GR (mmol NADPH oxidized/min/mg protein)	GST (μmol of conjugate formed/min/mg protein)	SOD (I.U)	CAT (mmol of H2O2 decom posed/min/mg protein)	GSH (μmol GSH/g tissue)	GPx (mmol NADPH oxidized/min/mg protein)
Normal control	3.229 ± 0.38	1.375 ± 0.066	0.158 ± 0.073	6.430 ± 0.617	1.234 ± 0.200	0.629 ± 0.011	0.706 ± 0.02
DMH	2.237 ± 0.35d	1.708 ± 0.101d	0.033 ± 0.021d	4.438 ± 0.316d	0.794 ± 0.043d	1.089 ± 0.023d	0.434 ± 0.15d
Selenium	3.239 ± 0.20	1.334 ± 0.217	0.137 ± 0.027	6.287 ± 0.524	1.230 ± 0.113	0.637 ± 0.017	0.711 ± 0.015
DMH + selenium	3.032 ± 0.21f	1.546 ± 0.043ac	0.069 ± 0.022b	5.695 ± 0.417af	1.029 ± 0.278c	0.646 ± 0.027f	0.614 ± 0.17df

^aP < 0.05,

^bP < 0.01 and

^dP < 0.001 by one way-ANOVA followed by LSD test when values are compared with control group;

^cP < 0.05 and

^fP < 0.001 by one way-ANOVA followed by LSD test when values of Group IV animals are compared with Group II animals. Values are expressed as mean + SD.