Figure 5
Eugenol treatment reduces C. rodentium burden in the colon.
(a), Enumeration of C. rodentium in the colon and feces at day 3 and day 6 p.i., respectively. Each data point represents one individual. Results are pooled from two separate infections, n = 10–13 per group. Significance determined using the Mann-Whitney U-test and expressed as the median. U = untreated mice. (**p = 0.0048; *p = 0.0431). (b), Both luminal (fecal matter) and adherent (extensively washed colons) bacterial colonization is reduced in eugenol treated mice at day 3 p.i. Results are pooled from two separate experiments, n = 9 per group. Significance determined using the Mann-Whitney U-test and expressed as the median. (*p = 0.05; ***p < 0.0008) U = untreated mice. Dashed line represents detection limit. U = untreated. (c), Representative immunostaining for the C. rodentium-specific effector Tir (green) in colon, with DAPI (blue) as a counter stain at 3 days p.i.. Tir staining present at day 3 p.i. in untreated mice which is absent in eugenol treated mice. Original magnification = 100×. (d), H&E stained distal colon sections from untreated and eugenol treated mice at day 3 p.i. Minor inflammation is evident in untreated and eugenol treated mice (top panel original magnification = 50×; bottom panel original magnification = 400×). (e), Cytokine and chemokine production, TNFα and MCP-1, in the colon and spleen in response to C. rodentium infection 6 days p.i. Results shown as pg of cytokine produced per gram of organ, n = 9–12 mice per group. (**p = 0.0092; TNFα *p = 0.0172; MCP-1 *p = 0.0351) Significance determined using two-tailed Student's t-test and expressed as the mean ± SEM. (f), C. rodentium was grown with or without eugenol at 13.3 ug/mL (denoted 1×) and growth was determined using optical density measurements every hour for 20 hours at 600 nm.
