Effects of melatonin on the expression of iNOS and COX-2 in rat models of colitis

Table 1 Effects of MT on CMDI in rats with experimental colitis (^¯x± s, n = 8)

Group	Doses (mg•kg-1)	CMDI
		Acetic acid	TNBS
Normal control		0.0 ± 0.0	0.0 ± 0.0
Model control		2.87 ± 0.64a	3.12 ± 1.12a
Melatonin	2.5	2.12 ± 0.83b	2.33 ± 0.51
Melatonin	5.0	1.75 ± 0.88c	1.66 ± 0.81b
Melatonin	10.0	1.12 ± 0.35c	1.75 ± 0.88b

^aP < 0.01 vs. Normal control;

^bP < 0.05,

^cP < 0.01 vs. Model control.

Table 2 Effects of MT on the colonic NO and PGE₂ levels in rats with experimental colitis (^¯x± s, n = 8)

Group	Doses(mg•kg-1)	NO (μmol•g-1 tissue)		PGE2 (ng•g-1 tissue)
		Acetic acid	TNBS	Acetic acid	TNBS
Normal control		0.174 ± 0.044	0.287 ± 0.069	43.1 ± 32.1	43.1 ± 32.1
Model control		0.327 ± 0.090b	0.533 ± 0.068b	184.5 ± 96.3b	181.3 ± 51.7b
Melatonin	2.5	0.230 ± 0.017d	0.403 ± 0.042d	89.1 ± 59.1c	109.0 ± 33.3d
Melatonin	5.0	0.218 ± 0.018d	0.380 ± 0.029d	76.4 ± 23.6c	89.8 ± 37.7d
Melatonin	10.0	0.189 ± 0.029d	0.340 ± 0.019d	57.1 ± 23.2d	85.9 ± 39.2d

^aP < 0.05,

^bP < 0.01, vs. normal control;

^cP < 0.05,

^dP < 0.01 vs. model control.

Table 3 Effects of MT on the colonic expression of iNOS and COX-2 semi-quantitated in rats with experimental colitis (^¯x± s, n = 6)

Group	Doses(mg•kg-1)	iNOS		COX-2
		Acetic acid	TNBS	Acetic acid	TNBS
Normal control		0.3 ± 0.5	0.3 ± 0.5	0.2 ± 0.4	0.2 ± 0.4
Model control		2.2 ± 0.9b	2.3 ± 0.8b	1.8 ± 0.9b	2.2 ± 0.9b
Melatonin	2.5	1.3 ± 0.5c	1.5 ± 0.5c	1.2 ± 0.4	1.7 ± 0.8
Melatonin	5.0	0.5 ± 0.5d	1.2 ± 0.8c	1.0 ± 0.6	1.3 ± 0.8
Melatonin	10.0	0.3 ± 0.5d	0.7 ± 0.8d	0.5 ± 0.5 c	0.8 ± 0.8c

^aP < 0.05,

^bP < 0.01 vs. Normal control;

^cP < 0.05,

^dP < 0.01 vs. Model control.