Anti-cervical carcinoma effect of Portulaca oleracea L. polysaccharides by oral administration on intestinal dendritic cells

Abstract

Background Cervical cancer is the second most prevalent cancer worldwide. Portulaca oleracea L. polysaccharide (POL-P3b) has been found to have enhancing immune and anti-cervical cancer activity by oral administration. Dendritic cells (DC) play a key roles in regulating intestinal immune homeostasis. In this study, we analyzed the inhibition apoptosis effects of POL-P3b on intestinal DC and relevant mechanisms. Methods Intestinal DC was isolated from U14-bearing mice treated with POL-P3b (50 mg/kg, 100 mg/kg and 200 mg/kg, respectively). The effects of POL-P3b on proliferation and inhibiting apoptosis in intestinal DC were evaluated by MTT assay, Hoechst 33342 and Annexin V-FITC/PI staining. Mitochondrial Ca 2+ was analyzed using flow cytometry instrument. The potential mechanisms underlying POL-P3b-induced protection of intestinal DC from cervical cancer-induced apoptosis were detected with Western blotting evaluation of expression levels of TLR4 and relevant proteins for apoptotic signaling pathway. Results We found that a large number of intestinal DC were apoptosis in U14-bearing mice. Treatment with POL-P3b in U14-bearing mice at different doses for 12 d resulted in a significant increase in intestinal DC survival, and the mechanisms were related to inhibiting DC apoptosis. Conclusion Our results suggested that POL-P3b-induced protection against tumor-induced intestinal DC apoptosis through stimulating the TLR4-PI3K/AKT-NF-κB signaling pathway. This study enhanced understanding of the oral administration with POL-P3b exerted on anti-tumor activity and its action mechanism.

Potential Functional Food Products and Molecular Mechanisms of Portulaca Oleracea L. on Anticancer Activity: A Review

“…Oxidative Medicine and Cellular Longevity in rat ovarian and gastric cancer and mouse cervical cancer and sarcomas, as shown Table 2 [19][20][21][22]62]. Another bioactivity from P. oleracea is portulacacerebrosie A, a cerebroside compound that suppresses the invasion and metastasis of liver cancer HCCLM3 cells and acts in leucocythemia treatment are show in Table 2 [24,63].…”

“…Polysaccharides from P. oleracea act on free radicals through the antioxidant mechanism, modulating the immune system, which may be preventive and therapeutic in rat ovarian and gastric cancer and mouse cervical cancer and sarcomas, as shown Table 2 [ 19 – 22 , 62 ].…”

“…In gastric cancer, interleukins (IL-2 and IL-4) and TNF- α were enhanced by polysaccharides that also provide dose-dependent protection against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induced oxidative injury by enhancing Superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH-Px) [ 22 ]. In addition to acting against ovarian, gastric, and cervical cancer, polysaccharides also work against intestinal cancer by stimulating the TLR4-PI3K/AKT-NF- κ B signaling pathway and Anti-NF- κ B activity along with two upstream ROS and NO mechanisms [ 18 , 62 ], showing the importance of studying these molecules in P. oleracea matrices.…”

Natural products and their derivatives: Promising modulators of tumor immunotherapy

“…For example, Portulaca oleracea L . polysaccharides (POL‐P3b), derived from the monodentate plant, demonstrated tumor growth inhibition and immunoregulation, and can be used for treating cervical cancer and for enhancing immunity 83,105 . As a biologic response regulator, polysaccharides promote cellular humoral and immune responses to inhibit and eliminate tumor cells.…”

“…Additionally, POL‐P3b can also induce apoptosis of intestinal DC by stimulating the TLR4‐PI3K/AKT‐NF‐κB signaling pathway. In vivo studies have shown that POL‐P3b possess a significant inhibitory effect on cervical cancer xenografts 105 . Xie's group reported the immunoregulatory activity of the polysaccharide from Gganoderma atrum (PGA) in CT26 and S180 tumor‐burdened mouse models, as evidenced by the activation of macrophage phagocytosis and inhibition of tumor growth by PGA through the inhibition of the MAPK signal pathway, induced by TLR4 101,102 .…”