AIM OF THE STUDY: The present study aimed to characterize the chemical properties of a purified polysaccharide extracted from the aerial part of Tetrastigma hemsleyanum (SYQP) and investigate its antipyretic and antitumor effects in mice models.
MATERIALS AND METHODS: Water-soluble crude polysaccharides from the aerial parts of Tetrastigma hemsleyanum were extracted and fractionated by DEAE and gel permeation chromatography. Homogeneity, molecular weight, monosaccharide composition, and FTIR analysis were performed to characterize the SYQP. Antipyretic effect of SYQP was examined using Brewer's yeast induced hyperthermia test. Antitumor effect was investigated using H22 tumor bearing mice. The serum cytokines were determined to evaluated the biological activities of SYQP.
RESULTS: SYQP was composed of galacturonic acid (GalA), glucose (Glc), mannose (Man), arabinose (Ara), galactose (Gal), and rhamnose (Rha) with a molar ratio of 11.3:7.1:2.5:1.0:0.9:0.5 and it had an average molecular weight of 66.2 kDa. The oral administration of SYQP at 200 and 400 mg/kg could markedly suppress the hyperthermia of mice induced by Brewer's yeast and decrease the production of cytokines especially prostaglandin E2 (PGE2) in the serum of mice. SYQP inhibited the growth of H22 tumor in mice with inhibitory rate of 39.9% at the administration dose of 200 mg/kg and increased the production of cytokines such as tumor necrosis factor-alpha (TNF-a) and interferon γ (IFN-γ). Experimental results showed that the preventive administration of SYQP before lipopolysaccharide (LPS) reduced the high cytokine levels such as IL-6, IL-10 and IFN-γ, indicating that SYQP might act as a competitor with LPS to interact with toll like receptor 4 (TLR4), which further regulated the secretion of cytokines.
CONCLUSION: The anti-inflammatory and antitumor activities of SYQP might be related to its regulation of host immune function by controlling the secretion of cytokines.
AIM OF THE STUDY: To evaluate the immune stimulatory effects of F3 from S. crispus in NMU-induced rat mammary tumor model.
MATERIALS AND METHODS: Immunohistochemistry analysis of cellular immune parameters (CD4+ or CD8+ T cells, CIITA, MHC-II and CD68) was performed on NMU-induced rat mammary tumor nodules, followed by evaluation of the serum level of 34 cytokines using the cytokine antibody array.
RESULTS: Significant increase in MHC-II, CD4+ and CD8+ T cell and CIITA expression by tumor cells was observed in F3-treated rats compared to the tumor control group. F3-treated rats also displayed a significant decrease in the serum level of CCL2 and CD68+ infiltrating macrophages. Serum IFN-γ level in this group was increased by 1.7-fold suggesting enhanced infiltration of T cells, and upregulation of CIITA and MHC-II expression in the tumor cells might be triggered by F3-induced production of IFN-γ.
CONCLUSION: Our findings demonstrated for the first time that a subfraction from S. crispus, F3, is capable of activating the immune system in rats-bearing NMU-induced mammary tumor, which may contribute to the anticancer effects of F3, and additionally support the traditional use of S. crispus leaves to boost the immune system.
METHODS: The effect of P. amarus-generated TLY on DCs maturation was evaluated by determination of MHC class I, II and CD 11c expression as well as the co-stimulatory molecules CD 83 and 86 by using flow cytometry. The phagocytic capacity of TLY-pulsed DCs was investigated through FITC-dextran uptake by using flow cytometry. The effect on the cytokines release including IL-12, IL-6 and IL-10 was elucidated by using ELISA. The migration capacity and T cell proliferation activity of pulsed DCs were measured. The relative gene expression levels of cytokines were determined by using qRT-PCR. The major constituents of P. amarus extract were qualitatively and quantitatively analyzed by using validated reversed-phase high performance liquid chromatography (HPLC) methods.
RESULTS: P. amarus-generated TLY significantly up-regulated the expression levels of MHC class I, CD 11 c, CD 83 and 86 in pulsed DCs. The release of interleukin IL-12 and IL-6 was enhanced by TLY-DCs at a ratio of 1 DC: 3 tumor apoptotic bodies (APO), however, the release of IL-10 was suppressed. The migration ability as well as allogeneic T-cell proliferation activities of loaded DCs were significantly enhanced, but their phagocytic capacity was highly attenuated. The gene expression profiles for IL-12 and IL-6 of DCs showed increase in their mRNA gene expression in TLY pulsed DCs versus unloaded and LPS-treated only DCs.
CONCLUSION: The effect of P. amarus-generated TLY on the immune effector mechanisms of DCs verified its potential to induce an in vitro anti-tumor immune response against the recognized tumor antigen.