Beneficial effect of an omega-6 PUFA-rich diet in non-steroidal anti-inflammatory drug-induced mucosal damage in the murine small intestine

Table 1 Composition and fatty acid profile of the diet

Ingredient	Fat diet	Nutrients	CE-2®
Casein	19.3%	Water	8.9%
d,l-methionine	0.3%	Crude protein	25.4%
Sucrose	48.5%	Crude fat	4.4%
Corn starch	14.5%	Crude fiber	4.1%
Alphacel, Nonnutritive bulk	4.8%	Crude ash	6.9%
Choline bitartate	0.2%	Nitrogen-free extract	50.3%
Mineral mix	3.4%
Vitamin mix	1.0%
Fat1	8.0%

¹Fat used was beef tallow, fish oil, or safflower oil.

Table 2 Approximate fatty acid profile (percent of total fat)

	Beef tallow	Fish oil	Safflower oil
Myristic (14:0)	3
Palmitic acid (16:0)	26	25.1	7.1
Stearic acid (18:0)	14	4.4	2.5
Oleic acid (18:1)	47	12.9	13.3
Palmitoleic acid (16:1)	3	14.9
Linoleic acid (18:2)	3	2.4	76.0
Linolenic acid (18:3)	1	1.2	0.3
Eicosapentaenoic acid (20:5)		15.6
Docosahexaenoic acid (22:6)		8.8
Others	3	1.5	0.8
Omega-3/omega-6 ratio	1:3	10.6:1	1:255

Dietary fat administration was commenced 1 wk prior to IND administration. Each fat-containing diet consisted of a fat-free AIN76 (Clea Japan, Tokyo) diet and 3 different types of 8% w/w fatty acids. Fatty acid profiles in the fat rich diet were Beef tallow, Fish oil and Safflower oil. CE-2 was given as a reference diet (R).

Table 3 Effect of dietary fat treatment on the histological score induced by indomethacin¹

Lipid	Diet
	R	BT	FO	SO
Without IND (grade)	0.20 ± 0.08	0.30 ± 0.11	0.20 ± 0.07	0.20 ± 0.08
With IND (grade)	3.24 ± 0.31	3.71 ± 0.42ab	3.65 ± 0.31ab	2.64 ± 0.51

¹Values are represented as mean ± SEM, n = 8-12;

^aP < 0.05 vs IND,

^bP < 0.05 vs IND + SO. Grade 0, normal villi structure; grade 1, development of a small subepithelial space at the villous apex; grade 2, enlarged subepithelial space, but no change in villous length and width; grade 3, few shortened villi and presence of cells in the lumen; grade 4, most villi are shortened and widened with crypt hyperplasia and cells in the lumen; and grade 5, blunting of all villi with elongated crypts and a high number of cells in the lumen. IND: Indomethacin; R: Reference diet (CE-2); BT: Beef tallow; FO: Fish oil; SO: Safflower oil.

Table 4 Effect of dietary fat treatment on the area of small intestinal lesions induced by indomethacin¹

Lipid	Diet
	R	BT	FO	SO
Without IND (mm2)	0.80 ± 0.11	0.9 ± 0.13	0.7 ± 0.11	0.70 ± 0.14
With IND (mm2)	21.8 ± 2.3	32.1 ± 3.2ab	41.6 ± 3.1ab	19.1 ± 1.70

¹Values are represented as mean ± SEM, n = 8-12;

^aP < 0.05 vs IND,

^bP < 0.05 vs IND + SO. IND: Indomethacin; R: Reference diet (CE-2); BT: Beef tallow; FO: Fish oil; SO: Safflower oil.

Table 5 Effect of dietary fat treatment on infiltrating cell score¹

Lipid	Diet
	R	BT	FO	SO
Without IND (mm2)	1	1	1	1
With IND (mm2)	2.0 ± 0.22	2.9 ± 0.23ab	2.7 ± 0.24ab	1.9 ± 0.14

¹Values are represented as mean ± SEM; n = 8-12;

^aP < 0.05 vs IND;

^bP < 0.05 vs IND + SO. The number of infiltrating cells was calculated as the number of cells per millimeter of muscularis mucosa and graded as follows: grade 1, less than 30 cells/mm; grade 2, 30-59 cells/mm; grade 3, 60-89 cells/mm; and grade 4, over 90 cells/mm. FO: Fish oil; SO: Seed oil; BT: Beef tallow; IND: Indomethacin; R: Reference diet (CE-2).