Colorectal cancer is one of the leading causes of cancer deaths worldwide. Currently, chemotherapy is the primary way for colorectal cancer, but with severe side effects. Therefore, it is urgent to find safer and more effective adjuvant treatment methods. At present, natural active substances are promising alternatives, as numerous studies have demonstrated possible synergistic anticancer effects in plant‐active polyphenols. In the present study, the combined effect of procyanidins (PC) (from peanut skin) and resveratrol (RES) (from peanut buds) on the synergistic anticancer potential was investigated. CACO‐2 and HCT‐8 cells were served as colorectal cancer models, and HEPG‐2 and HUH‐7 cells were served as liver cancer models to observe the effects of PC and RES alone or in combination on the growth and proliferation of these four types of cancer cells. The results revealed that both PC and RES could inhibit the cells’ proliferation in a manner with concentration‐dependent, but they exerted synergistic anticancer effects only on CACO‐2 cells. PC and RES could synergistically inhibit CACO‐2 cell clone formation, inducing apoptosis of CACO‐2 cells and blocking their cell cycle in G0/G1 phase. Additionally, as observed by the results of Western blot assay, the combined effect of PC and RES also inhibited the phosphorylation of Thr308, Ser473, and ERK and promoted the phosphorylation of IKBα and NF‐κB in CACO‐2 cells. These findings collectively indicate that PC combined with RES might exert synergistic anticancer effects by regulating AKT, ERK, and NF‐κB signaling pathways.

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Alpha gliadin peptide induces damage and apoptosis of intestinal cells and aggravates pathology of celiac disease (CD) by inducing oxidative stress. Therefore, inhibition or alleviation of oxidative stress in CD may be an effective approach to the adjunctive treatment of CD. Black soybean peptides (BSPs) have been shown to inhibit oxidative stress and inflammation. The effect of BSPs on CD remains unknown. In this paper, the effect and mechanism of BSPs on the α-gliadin peptide (p31-43)-induced Caco-2 cytotoxicity were studied. We identified BSPs that alleviated the cytotoxicity of p31-43 in the CD cell model: Caco-2 cells were pre-treated with bioactive peptides for 3 hours before the addition of p31-43 for treatment for 24 hours, and then cells were collected for subsequent experiments. Our results show that p31-43 can significantly increase the ROS and MDA levels of Caco-2 cells, disrupt the glutathione redox cycle, reduce the activity of the antioxidant enzyme, and inhibit the activation of antioxidant signaling pathways. BSPs pretreatment can inhibit the increase of Keap1 protein induced by p31-43, activate antioxidant genes through Nrf2 protein, improve the activity of the antioxidant enzyme, alleviates glutathione redox cycle imbalance, promote the expression of GCLC or GCLM, and reduce oxidative damage.