Inflammatory bowel disease is a chronic intestinal inflammatory condition, the pathogenesis of which is complex and not fully understood. It includes mainly two diseases, namely, ulcerative colitis and Crohn’s disease, that still need effective and lasting therapy without major side effects.
Available evidence suggests that an abnormal immune response against the microorganisms of the intestinal flora is responsible for the disease in genetically susceptible individuals [
Strontium salts are used in routine clinical practice for treatment of osteoporosis, sensitive teeth, and bone pain related to bone metastasis [
The present study was approved by the Animal Ethics Committee of Cumhuriyet University in accordance with the Standards for the Care and Use of Laboratory Animals.
Thirty female Wistar albino rats each weighing about 180–200 grams were included in the study. They were maintained under standard conditions (12 h light/dark cycle; 25 ± 3°C, 45–65% humidity) and had free access to standard rat feed and water
Serum levels of neopterin (Rat Neopterin ELISA- Cusabio,), TNF-
Experimental ulceration in colon tissue was done according to the method described by Mousavizadeh et al [
Seven days after the induction of colitis, rats in all groups including groups 1–5 were sacrificed by cervical subluxation, blood was obtained by retroorbital puncture for biochemical estimation, and the colon was removed and postfixed. Sections of the colon were stained for hematoxylin-eosin and evaluated microscopically and scored for inflammation.
After sacrificing animals, the colon was carefully dissected from anus till rectum and placed in saline. The colon was opened longitudinally over the mesenteric border and washed gently in saline. It was placed on a rubber mat with the mucosal side up and evaluated macroscopically. Macroscopic changes in colonic mucosa were scored from 0 to 3 with score 0 referred to preserved mucosa with normal appearance, score 1 to edema and congestion, score 2 to ulceration and hemorrhage, and finally score 3 to abundant multiple ulcers and thinned bowel wall.
After macroscopic evaluation, the colon was then placed with the serosal side up and dissected. Serial sections of 6 mm were obtained and fixed with %10 buffered formaldehyde. They were embedded in paraffin blocks. Sections of 5 µm were prepared from these blocks and stained with hematoxylin and eosin and scored for inflammation. Severity and abundance of edema, necrosis, inflammatory infiltration, apoptosis, thrombosis-vascular congestion, and shedding of epithelial cells were considered during microscopic scoring. Histopathological evaluation of the slides was performed by one pathologist who was blinded about the groups. Microscopic changes were scored from 0 to 3 with score 0 referred to no swelling in epithelial cells, normal crypt appearance, sporadic monocyte infiltration, either sporadic or none neutrophilic infiltration; score 1 to moderate blurred swelling in epithelial cells, sporadic polymorphonuclear leukocyte infiltration in crypts, mild monocyte, and neutrophil infiltration in submucosa; score 2 to shedding of epithelial cells and flatness of mucosa, shedding of crypt epithelium, moderate monocytic-neutrophilic infiltration of submucosa; and score 3 to marked epithelial ulcers, crypt abscesses, and marked monocytic and neutrophilic infiltration of submucosa.
Data were analyzed by using SPSS 15.0 package software. As the assumptions of parametric tests could not be fulfilled, Kruskal Wallis, Mann-Whitney U test, and Chi-square tests were used for statistical evaluation. A
We compared the mean serum neopterin, TNF-
The neopterin, TNF-
Comparison of neopterin levels among groups. The horizontal lines in the middle of each box indicate the median, while the top and bottom borders of the box mark the 25th and 75th percentiles, respectively. The whiskers above and below the box mark the maximum and minimum neopterin levels. Open circles indicate outliers. Asterisks represent extreme cases.
Comparison of TNF-alpha levels among groups. The horizontal lines in the middle of each box indicate the median, while the top and bottom borders of the box mark the 25th and 75th percentiles, respectively. The whiskers above and below the box mark the maximum and minimum TNF-alpha levels.
Comparison of IFN-gamma levels among groups. The horizontal lines in the middle of each box indicate the median, while the top and bottom borders of the box mark the 25th and 75th percentiles, respectively. The whiskers above and below the box mark the maximum and minimum IFN-gamma levels.
There was a significant difference by means of both macroscopic and microscopic scores between group 2 (The colitis group) and other four groups (
Macroscopic and microscopic scores of the each 6 rats in the five groups.
Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | |
---|---|---|---|---|---|
Macroscopic* scores | 0 | 3 | 2 | 1 | 1 |
0 | 3 | 1 | 1 | 2 | |
0 | 3 | 2 | 2 | 1 | |
0 | 3 | 0 | 2 | 2 | |
0 | 3 | 2 | 2 | 2 | |
0 | 3 | 0 | 1 | 2 | |
Median ± SEM | 0 | 3 | 1.50 ± 0.40 | 1.50 ± 0.22 | 2.00 ± 0.21 |
|
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Microscopic* scores | 0 | 3 | 1 | 2 | 1 |
0 | 3 | 1 | 1 | 2 | |
0 | 3 | 2 | 2 | 1 | |
0 | 2 | 1 | 1 | 1 | |
0 | 3 | 1 | 1 | 0 | |
0 | 3 | 0 | 2 | 2 | |
Median ± SEM | 0 | 3 | 1.00 ± 0.25 | 1.50 ± 0.22 | 1.00 ± 0.30 |
Histopathological changes in the colon of experimental rats. (a) Normal intact mucosa from normal colon
We have found in our study for the first time in the literature that strontium chloride had comparable therapeutic efficiency when compared with prednisolone in a rat ulcerative colitis model. We investigated the effect of strontium at two doses, 40 mg/kg and 160 mg/kg, but did not find a difference between these two doses by means of histological and biochemical healing.
The immune system plays a dominant role in inflammatory bowel disease. During active inflammation, Th0 cells differentiate into T helper cell type (Th)1, Th17, and/or Th2 cells, upon the action of interleukin- (IL-) 12/IL-18, IL-6/TGF-
Neopterin, a pyrazino[2,3-d]-pyrimidine compound, is a metabolite of cyclic guanosine monophosphate that is released by activated dendritic cells and macrophages after induction by
Strontium salts may also directly act on nonneuronal cells such as keratinocytes or immunoregulatory inflammatory cells. Recent reports demonstrate that strontium salts can suppress keratinocyte derived tumor necrosis factor-alpha (TNF-
Strontium has been used to treat patients with osteoporosis or other disorders of bone mineralization. Treatment has involved administration of “low doses” of strontium salts (usually the lactate, gluconate, carbonate, or ranelate) over several years. No adverse side-effects were reported in studies on osteoporosis patients [
In conclusion, we have found in our study that strontium chloride has comparable therapeutic efficiency with prednisolone in a rat ulcerative colitis model. We have found the dose of 40 mg/kg to be effective in suppressing inflammation in rats; however, new studies investigating the efficiency of lower doses can be planned. Our findings have important implications in that a new way to an alternative therapy for nonresponder patients is opened and a hope for osteoporotic ulcerative colitis patients emerged with one medication for two diseases. However, further studies in different phases are needed to confirm our results.
The authors declare that there is no conflict of interests regarding the publication of this paper.