Antiproliferative potential of methanolic extracts of Ageratum conyzoides linnaeus via downregulation of ki-67 and upregulation of p53 protein expression in hepatic tissue of rats

Abstract

Background: Hepatic tissue is susceptible to toxicity induced by hepatotoxins, leading to lesions, necrosis, fibrosis, tumor, or carcinoma. However, it is self-regenerating which can actively proliferate to recover lost segments. During tissue proliferation, molecular markers such as Ki-67 and p53 proteins usually play opposing roles. In this study, we aimed at assessing the antiproliferative potential of methanolic extracts of Ageratum conyzoides Linn using the expression of these markers of proliferation in hepatic tissues of adult male Wistar rats. Materials and Methods: Twenty animals used for this study were divided equally into four groups (1–4) as follows: Group 1 represented control, whereas Groups 2–4 were, respectively, treated with extracts at dosage of 100, 300, and 500 mg/kg (body weight) orally for 28 days. Afterward, the animals were sacrificed; their hepatic tissues were harvested, were processed into tissue sections, were histologically stained using hematoxylin and eosin technique, and were immunostained for Ki-67 and p53 proteins using horseradish peroxidase-3, 3-Diaminobenzidine technique (with monoclonal anti-Ki67 and anti-p53 antibodies). Stained sections were examined and quantified using Image-J software. Data obtained were statistically analyzed using IBM-SPSS (version 20) and compared using t- test. Results: The tissue histology showed densely packed hepatocytes in treated groups. The immunostaining revealed statistically significant (P < 0.05) upregulation of the Ki-67 expression only among the treated Group 4 animals, whereas the p53 protein expression was statistically significantly (P < 0.05) upregulated in all the treated groups. Conclusions: The findings of this study implied that only higher dose of extracts could trigger increase in the rate of hepatic cell proliferation even the inhibitory signal of proliferation becomes activated. Hence, the exposure of methanolic leaf extracts of A. conyzoides L. may cause dose-dependent antiproliferative activity.