The Role of Aloe vera in Inhibiting the P53 Protein Expression and Enhancing the HT29 Colon Cancer Cells Proliferation

Background: Aloe vera is one of the most widely recognized herbs considered a valid treatment option for its wound healing and anti-inflammatory properties. However, there is insufficient evidence regarding the effectiveness of its anti-tumor activity on colon cancer. Objectives: In this study, therefore, we investigated the effect of Aloe vera on the proliferation and survival of the HT29 colon cancer cell line. Methods: The effect of processed Aloe vera gel (PAG) on colon carcinogenesis was examined using low glucose Dulbecco’s modified Eagle’s medium (DMEM) with 10% serum and 1% penicillin-streptomycin in the HT29 cells. Then, we obtained the expression levels of P53 and BCL2 using the immunocytochemical (ICC) method. To determine the viability of the HT29 cells, we also performed the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: The MTT assay showed that the HT29 cells were viable in 5%, 10%, 15%, and 20% of Aloe vera gel (AVG). However, these cells had a more obvious proliferation in the 10% Aloe vera group than in the control group. In the 10% concentration group, mitotic cells were evident in the center of the colonies. The P53 protein expression decreased, but the BCL2 protein expression remained unchanged in the 10% group compared to the control group. Conclusions: The results, therefore, indicated that in the 10% Aloe vera concentration, the expression levels of P53, known as a tumor suppressor protein in colon cancer, decreased in HT29. Our results also showed that the application of Aloe vera for its anti-tumor activity in colon cancer should be further evaluated.