Volume 125, Issue 3, Pages 775-785 (September 2003) Dietary glycine prevents chemical-induced experimental colitis in the rat  Isao Tsune, Kenichi Ikejima, Miyoko Hirose, Mutsuko Yoshikawa, Nobuyuki Enomoto, Yoshiyuki Takei, Nobuhiro Sato  Gastroenterology  Volume 125, Issue 3, Pages 775-785 (September 2003) DOI: 10.1016/S0016-5085(03)01067-9

Figure 1 Macroscopic changes of the colon after TNBS treatment. Rats fed a diet containing 5% glycine or casein as controls for 3 days were given a single intracolonic injection of TNBS (50 mg in 50% ethanol/rat) as described in detail in the Materials and Methods section. The gross appearance of (A) the colon and macroscopic changes of the (B) luminal side of the distal colon were observed 5 days after TNBS treatment. Bars indicate 5-cm and 1-cm lengths in A and B, respectively. The wet weight of distal 8-cm portions of the colon were measured (C, n = 10; ∗P < 0.05 vs. control-diet/saline group; #P < 0.05 vs. control-diet/TNBS group). The average levels of macroscopic score 5 days after TNBS treatment are plotted (D, ∗n = 10; P < 0.05 vs. control-diet/TNBS group). Gastroenterology 2003 125, 775-785DOI: (10.1016/S0016-5085(03)01067-9)

Figure 2 Histopathologic changes and tissue MPO activities in the colon after TNBS treatment. Experimental design as in Figure 1. Representative microphotographs of the colonic tissue from the (A) control-diet group without TNBS, and 5 days after TNBS treatment with (B, C) control diet and (D, E) glycine diet are shown (H&E staining original magnification: B, D, 40×; C, E, 400×). The average levels of histologic scoring at day 5 of TNBS treatment are plotted (F, n = 10; means ± SEM; ∗P < 0.05 vs. control-diet/TNBS). MPO activities in the colonic tissue 2 days after TNBS treatment were determined by a standard enzymatic procedure as described in the Materials and Methods section (G, n = 5; means ± SEM; ∗P ≤ 0.05 vs. control-diet/saline; #P ≤ 0.05 vs. control-diet/TNBS). Gastroenterology 2003 125, 775-785DOI: (10.1016/S0016-5085(03)01067-9)

Figure 3 Expression of IL-1β and TNF-α mRNA and protein levels in the colon after TNBS treatment. IL-1β and TNF-α mRNA levels in the colonic tissue 2 days after TNBS treatment were measured by RT-PCR. (A) Representative photographs of the specific bands for IL-1β, TNF-α, and β-actin are shown. Data of densitometric analysis for (B) IL-1β and (C) TNF-α are plotted (n = 5; ∗P < 0.05 vs. control-diet/saline; #P < 0.05 vs. control-diet/TNBS). IL-1β and TNF-α protein levels in the colonic tissue 2 days after TNBS treatment were measured by ELISA. Mean values for (D) IL-1β and (E) TNF-α are plotted (n = 5; ∗P < 0.05 vs. control-diet/saline; #P < 0.05 vs. control-diet/TNBS). Gastroenterology 2003 125, 775-785DOI: (10.1016/S0016-5085(03)01067-9)

Figure 4 Expression of CINC and MIP-2 mRNA and protein levels in the colon after TNBS treatment. Experimental design as in Figure 4 except that CINC and MIP-2 mRNA levels were measured by RT-PCR. (A) Representative photographs of the specific bands for CINC, MIP-2, and β-actin are shown. Data of densitometric analysis for (B) CINC and (C) MIP-2 are plotted (n = 5; ∗P < 0.05 vs. control-diet/saline; #P < 0.05 vs. control-diet/TNBS). CINC and MIP-2 protein levels in the colonic tissue 2 days after TNBS treatment were measured by ELISA. Mean values for (D) CINC and (E) MIP-2 are plotted (n = 5; ∗P ≤ 0.05 vs. control-diet/saline; #P ≤ 0.05 vs. control-diet/TNBS). Gastroenterology 2003 125, 775-785DOI: (10.1016/S0016-5085(03)01067-9)

Figure 5 Effect of dietary glycine on a chronic model of TNBS colitis. Experimental design as in Figure 1 except that the severity of colonic damage was evaluated 14 days after a single TNBS administration. Dietary treatment was continued throughout the period. The representative macroscopic photographs of chronic ulceration caused by TNBS in the (A) control-diet group and the (B) glycine-diet group are shown (bars = 1 cm). Representative microphotographs of TNBS-induced chronic ulceration in the colon in the (C) control diet— and (D) glycine diet—fed rats are shown (H&E staining original magnification: 40×). The average levels of (E) macroscopic score and (F) histologic score 14 days after TNBS treatment are plotted (n = 5; ∗P < 0.05 vs. control-diet/saline group; #P < 0.05 vs. control-diet/TNBS group). Gastroenterology 2003 125, 775-785DOI: (10.1016/S0016-5085(03)01067-9)

Figure 6 Effect of dietary glycine on established TNBS colitis. Dietary treatment with/without glycine was started 48 hours after a single TNBS enema, and the severity of colonic damage was evaluated 5 days later (7 days after TNBS treatment). The representative macroscopic photographs of 8-cm portions of the distal colon in the control- and glycine-diet groups given TNBS are shown (A, bars = 1 cm). Representative microphotographs of TNBS-induced ulceration in the colon in the (B) control diet— and (C) glycine diet—fed rats are shown (H&E staining original magnification: 40×). The average levels of (D) macroscopic score and (E) histologic score are plotted (n = 10; ∗P ≤ 0.05 vs. control-diet/saline group; #P ≤ 0.05 vs. control-diet/TNBS group). Gastroenterology 2003 125, 775-785DOI: (10.1016/S0016-5085(03)01067-9)

Figure 7 Macroscopic changes of the colon and hematocrit values after DSS administration. Rats were pretreated with control or glycine diet for 3 days, and subsequently they were given 3% DSS orally in drinking water ad libitum for 5 days. (A) The gross appearance of colon was observed 5 days later. Bars indicate 5-cm lengths. The average values of the (B) total colon lengths and (C) hematocrit are plotted (n = 10; ∗P ≤ 0.05 vs. control-diet/water alone group; #P ≤ 0.05 vs. control-diet/DSS group). Gastroenterology 2003 125, 775-785DOI: (10.1016/S0016-5085(03)01067-9)

Figure 8 Histopathologic changes and tissue MPO activities in the colon after DSS treatment. Experimental design as in Figure 7. Representative microphotographs of the colonic tissue from the (A) control-diet group without DSS, (B) the glycine-diet group without DSS, (C) 5 days after DSS treatment with control diet, and (D) glycine diet are shown (H&E staining original magnification: 200×). The (E) average levels of histologic scoring and the (F) average tissue MPO activities in the colon at day 5 of DSS treatment are plotted (n = 10; means ± SEM; ∗P ≤ 0.05 vs. control-diet/water alone; #P ≤ 0.05 vs. control-diet/DSS). Gastroenterology 2003 125, 775-785DOI: (10.1016/S0016-5085(03)01067-9)