Immunohistochemical Study of the Effect of Calendula Officinalis of ß-catenin Protein Expression in Experimental Colon Cancer

Abstract

Background: Colorectal adenocarcinoma is one of the most prevalent and treatable malignancies of the gastrointestinal tract. Recent in vitro studies have demonstrated the anticancer effect of Calendula officinalis extract on a tumor cell line derived from colorectal cancers. The inhibitory effect of this extract ranges from 70- 100% and an in vitro study has demonstrated that Calendula officinalis extract inhibits expression of nuclear ß-catenin protein on dysplastic colonic aberrant cryptal cells. The aim of present study was to evaluate in vivo the effect of Calendula officinalis extract on the expression of  ß-catenin protein in dysplastic colonic aberrant cryptal.

Materials and Methods: In this study 20 male Wistar rats with an approximate age of 12 weeks that weighed 200-300g were assigned to two equal groups (treatment and control). For the induction of colorectal carcinoma these two groups were given two subcutaneous injections of 1,2-dimethylhydrazine (40mg/kg) twice a week for eight weeks. Thereafter, the treatment group received Calendula officinalis extract (200mg/kg) daily for ten weeks through gavage. The control group received normal saline by the same manner. After ten weeks of treatment with Calendula officinalis extract, distal parts of colonic tissue were sampled in both groups. Expression of ß-catenin was assessed semi-quantitatively by four scales through immunohistochemical analysis. Significant difference between the groups was determined by the Mann-Whitney U test. Statistical significance was considered at p‹0.05.

Results: Immunohistochemical studies revealed that the expression of nuclear ß-catenin protein in dysplastic colonic aberrant cryptal cells was lower in the treatment group compared to the control group. The mean difference between the treatment and control groups was significant (p ‹0.01).

Conclusion: The results of this in vivo study indicated that Calendula officinalis extract has an inhibitory potential on the expression of nuclear ß-catenin protein in dysplastic colonic aberrant cryptal cells in experimental colorectal carcinoma of rats.