Portulaca oleracea L. polysaccharides enhance the immune efficacy of dendritic cell vaccine for breast cancer.

Previous studies have reported that Portulaca oleracea L. polysaccharides (POL-P3b) is an immunoregulatory agent. However, few studies exist on POL-P3b as a novel immune adjuvant in combination with the DC vaccine for breast cancer treatment. In this work, a DC vaccine loaded with mouse 4T1 tumor cell antigen was prepared to evaluate the properties of POL-P3b in inducing the maturation and function of DC derived from mouse bone marrow, and then to investigate the effect of the DC vaccine combined with POL-P3b on breast cancer in vivo and in vitro. Morphological changes of DC were observed using scanning electron microscopy. Phenotypic and functional analyses of DC were detected by flow cytometry and allogeneic lymphocyte reaction. Cytokine levels in the DC culture supernatant were detected by ELISA. Western blotting analysis was used for the protein expression of TLR4, MyD88 and NF-κB. Apoptosis detection and protein expression of the tumor tissue were analyzed by TUNEL staining and immunohistochemistry, respectively. The security of POL-P3b was evaluated by the detection of hematological and blood biochemical indicators and pathological analysis for tissues. POL-P3b can induce DC activation and maturation, which is attributed to increasing the specific anti-tumor immune response, and the mechanism of action involved in the TLR4/MyD88/NF-κB signaling pathway. Experimental results in vivo further suggested that the administration of POL-P3b-treated antigen-primed DC achieved remarkable tumor growth inhibition through inducing apoptosis and enhancing immune responses. Moreover, the POL-P3b-treated DC vaccine was able to inhibit lung metastases. The results proved the feasibility of POL-P3b as an edible adjuvant of the DC vaccine for anti-breast cancer therapy.

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

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 Ca2+ 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.

Improving the activity of Lycium barbarum polysaccharide on sub-health mice.

Sub-health has been described as a chronic condition of unexplained deteriorated physiological function, which falls between health and illness and includes fatigue as one of its principal manifestations. Mitochondrial dysfunctions have been discovered in fatigue-type sub-health such as impaired oxidative phosphorylation and mitochondrial damage. In the present study, we evaluated the effects of Lycium barbarum polysaccharide (LBP-4a), a polysaccharide fraction purified from Lycium barbarum, on anti-fatigue in sub-health mice, and the relevant mechanisms were studied. Forty mice were divided into control, model, LBP-4a(L) and LBP-4a(H) groups. Model mice were prepared through compound factors, including forced swim tests, sleep deprivation and wrapping restraint stress tests. After LBP-4a treatment for 4 weeks, the gastrocnemius muscles were obtained for morphological observation and the activities of SOD, GSH-Px and MDA content were detected. Furthermore, mitochondrial membrane potential and Ca(2+) content were measured in isolated skeletal muscle mitochondria. The results showed that LBP-4a could reduce skeletal muscle damage and MDA levels and enhance of SOD and GSH-Px activities compared with the model group. The levels of mitochondrial membrane potential and Ca(2+) were increased in LBP-4a-treated skeletal muscle mitochondria; moreover, the high-dosage group was better than that of the low dosage. In conclusion, LBP-4a exhibited anti-fatigue activity on sub-health mice, and the mechanism was closely correlated with a reduction in lipid peroxidation levels and an increase in antioxidant enzyme activities in skeletal muscle tissue, improving the intracellular calcium homeostasis imbalance and increasing mitochondrial membrane potential. These observations provided the background for the further development of LBP-4a as a type of anti-fatigue therapy used in sub-health treatment.

Antitumor activity of Portulaca oleracea L. polysaccharides against cervical carcinoma in vitro and in vivo.

Portulaca oleracea L. has been used as folk medicine in different countries to treat different ailments in humans. P. oleracea L. polysaccharide (POL-P), extracted from P. oleracea L., is found to have bioactivities such as hypoglycemic and hypolipidemic activities, antioxidant and antitumor activities. In our study, a water-soluble polysaccharide (POL-P3b) was successfully purified from Galium verum L. by DEAE cellulose and Sephadex G-200 column chromatography. To evaluate the anticancer efficacy and associated mechanisms of POL-P3b on cervical cancer in vitro and in vivo, we showed that treatment of HeLa cell with POL-P3b inhibited cell proliferation. In addition, POL-P3b significantly inhibited tumor growth in U14-bearing mice. Further analysis indicated that POL-P3b possesses the activity of inhibiting cervical cancer cell growth in vitro and in vivo at a concentration- and time-dependent manner, and the mechanisms were associated with Sub-G1 phase cell cycle arrest, triggering DNA damage and inducing apoptosis.

Protective effects of diosmetin extracted from Galium verum L. on the thymus of U14-bearing mice.

Diosmetin (DGVL) extracted from the traditional Chinese herb Galium verum L. has been found to have anticancer activity. In this study, the effects of DGVL on the thymus of U14-bearing mice were investigated. Using flow cytometry, peripheral blood lymphocytes were characterized based on the expression of surface markers for T helper cells (CD4(+)) and T suppressor cells (CD8(+)). Serum levels of tumor necrosis factor α (TNF-α), interleukin-2 (IL-2), IL-10, and transforming growth factor ß1 (TGF-ß1) and a cell proliferation assay were determined with an enzyme-linked immunosorbent assay. The expression of Fas and Fas ligand (FasL) on the thymus was determined by Western blotting. Our results showed that DGVL inhibited tumor growth and significantly increased the thymus weight compared with the control. Also, DGVL elevated serum levels of IL-2 and significantly reduced levels of TNF-α, TGF-ß1, and IL-10 in a dose-dependent manner. Histological study and terminal dUTP nick end labeling staining results showed that DGVL protected thymus tissue against the onslaught of tumor growth by inhibiting thymus lymphocyte apoptosis. The cell proliferation assay revealed that DGVL might promote more thymus lymphocytes towards proliferation. Furthermore, the ratio of CD4(+)/CD8(+) T lymphocytes was significantly increased from 0.69 to 2.29 by treatment with DGVL. Immunoblotting analyses revealed that the expression of Fas and FasL on the thymus was lower in mice in the DGVL treatment group than in the control mice. In conclusion, DGVL can inhibit tumor growth and protect tumor-induced apoptosis of the thymus, and the mechanism is closely associated with reduced cell death in the thymus and a Fas-FasL-dependent pathway.