Vitexin's Role in Colon Cancer Apoptosis: AMPK/mTOR Pathway Modulation Explored Through Experimental and Computational Approaches.

Abstract

Background: Colorectal cancer is a significant global public health challenge, contributing substantially to cancer-related mortality worldwide. Vitexin has been shown to promote the polarization of macrophages towards the M1 phenotype, a process dependent on the Vitamin D receptor. This polarization is crucial in the tumor microenvironment, as it helps mitigate the progression from chronic colitis to colorectal cancer. Despite its potential, the mechanisms of vitexin's action and its impact on colon cancer remain unclear.

Objective: This study aims to evaluate the inhibitory effects of vitexin on cell proliferation and apoptosis in the Caco-2 colon cancer cell line, with a specific focus on its modulation of antioxidant enzyme activities, pro-apoptotic factors, and key signaling pathways involved in cell survival and proliferation.

Methods: The IC50 of vitexin against Caco-2 cells was determined. Cell viability and necrosis rates were assessed after 48 hours of incubation with vitexin at concentrations of 19.01, 38.01, and 76.02 μg/mL. Additionally, levels of superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), P53, Bax, TSC2, Sestrin 2, and PUMA, as well as the expression of AMPK, PI3K, Akt, and mTOR genes and proteins, were measured using q-PCR and Western blotting techniques in Caco-2 cells post-incubation.

Results: Vitexin exhibited an IC50 of 38.01 ± 0.64 μg/mL against Caco-2 cells. Treatment with vitexin at the specified concentrations for 48 hours resulted in a significant decrease in cell viability by 28.40%, with inhibitory rates reaching 71.6%. Apoptosis rates increased to 93.81%, 171.41%, and 294.12%, respectively, with a corresponding rise in necrosis rates by 194.19%, 400.22%, and 811.44%. Pharmacological analysis revealed that vitexin significantly inhibited SOD and CAT activities while enhancing MDA production. Furthermore, vitexin treatment upregulated the expression of key apoptotic markers (P53, Bax, TSC2, Sestrin 2, and PUMA) and the expression of AMPK, PI3K, and Akt, while downregulating mTOR genes and proteins, implicating various signaling pathways.

Conclusion: This study demonstrates that vitexin induces apoptosis in Caco-2 colon cancer cells through multiple mechanisms, including modulation of antioxidant enzymes, upregulation of pro-apoptotic factors, and regulation of key signaling pathways involved in cell survival and proliferation. These findings suggest that vitexin's mechanisms of action involve complex interactions with various cellular pathways, making it a promising candidate for further research and potential therapeutic applications in colorectal cancer.