Polysaccharides from green sweet pepper increase the antineoplastic effect of methotrexate on mammary tumor cells

Polysaccharides extracted from tucum-do-cerrado fruits (Bactris setosa Mart) have antineoplastic effects in mice while preserving hepatic gluconeogenesis

This study investigated the antitumoral, anti-inflammatory and oxidative effects of polysaccharides from tucum (Bactris setosa, TUC) using the Ehrlich carcinoma as a tumor model. Additionally, the glycogen content, cytochrome P levels, and gluconeogenesis from lactate were assessed in the liver of healthy animals. Tumor-bearing female mice were orally treated with 50 and 100 mg.kg-1 of TUC or vehicle, once a day, or with 1.5 mg.kg-1 methotrexate via i.p., every 3 days, along 21 days. Both doses of TUC reduced the tumor weight and volume. In the tumor tissue, it decreased GSH and IL-1β levels, and increased LPO, NAG, NO and TNF-α levels. The tumor histology showed necrosis and leukocytes infiltration. The metabolic effects of TUC were investigated by measurement of total cytochrome P (CYP) and glycogen in tumor-bearing mice, and by ex vivo liver perfusion on non-bearing tumor male mice, using lactate as gluconeogenic precursor. Metabolically, the hepatic glucose and pyruvate productions, oxygen uptake, and the total CYP concentration were not modified by TUC. Thus, tucum-do-cerrado polysaccharides have antitumor effects through the modulation of oxidative stress and inflammation, without impairing glucose production from lactate in the liver, the main organ responsible for the metabolism of organic and xenobiotic compounds.

The ameliorative effect on chemotherapy-induced injury and tumor immunosuppressive microenvironment of the polysaccharide from the rhizome of Menispermum dauricum DC

Combined medication has attracted increasing attention as an important treatment option for tumors due to the serious adverse effects of chemotherapy. In this study, as a new therapy strategy, a combination treatment of MDP (a polysaccharide from the rhizome of Menispermum dauricum DC.) with cyclophosphamide (CTX) was investigated. The results showed that combination treatment with MDP and CTX exerted a significantly synergistic anti-tumor effect in Lewis tumor-bearing mice, improved CTX-induced emaciation and hair loss, as well as increased the number of leukocytes, erythrocytes, hemoglobin, and platelets in the peripheral blood. In addition, compared with CTX alone, the thymus index and spleen index of the MDP + CTX group were increased, the number of CD3 + T cells, CD8 + T cells, white blood cells and B cells in spleen also increased significantly. MDP could also ameliorate the increase in liver and kidney index caused by CTX. In the Lewis lung cancer model, MDP showed a certain degree of anti-tumor effects, which may be related to its promotion of tumor-associated macrophages (TAMs) to M1 phenotype polarisation, enhancement of the number of T cells in tumor tissues and promotion of Th cells in tumor tissues to Th1 phenotype polarisation, thus alleviating the immunosuppressive microenvironment in tumor tissues. This study laid the foundation for the development of MDP as a polysaccharide drug for the treatment or adjuvant therapy of tumors and has important significance for the further clinical application of polysaccharides.

Research Progress on the Anticancer Activity of Plant Polysaccharides

Tumor is a serious threat to human health, with extremely high morbidity and mortality rates. However, tumor treatment is challenging, and the development of antitumor drugs has always been a significant research focus. Plant polysaccharides are known to possess various biological activities. They have many pharmacological properties such as immunomodulation, antitumor, antiviral, antioxidative, antithrombotic, and antiradiation effects, reduction of blood pressure and blood sugar levels, and protection from liver injury. Among these effects, the antitumor effect of plant polysaccharides has been widely studied. Plant polysaccharides can inhibit tumor proliferation and growth by inhibiting tumor cell invasion and metastasis, inducing cell apoptosis, affecting the cell cycle, and regulating the tumor microenvironment. They also have the characteristics of safety, high efficiency, and low toxicity, which can alleviate, to a certain extent, the adverse reactions caused by traditional tumor treatment methods such as surgery, radiotherapy, and chemotherapy. Therefore, this paper systematically summarizes the direct antitumor effects of plant polysaccharides, their regulatory effects on the tumor microenvironment, and intervening many common high-incidence tumors in other ways. It also provides data support for the administration of plant polysaccharides in modern tumor drug therapy, enabling the identification of new targets and development of new drugs for tumor therapy.

MG-Pe: A Novel Galectin-3 Ligand with Antimelanoma Properties and Adjuvant Effects to Dacarbazine

Melanoma is a highly metastatic and rapidly progressing cancer, a leading cause of mortality among skin cancers. The melanoma microenvironment, formed from the activity of malignant cells on the extracellular matrix and the recruitment of immune cells, plays an active role in the development of drug resistance and tumor recurrence, which are clinical challenges in cancer treatment. These tumoral metabolic processes are affected by proteins, including Galectin-3 (Gal-3), which is extensively involved in cancer development. Previously, we characterized a partially methylated mannogalactan (MG-Pe) with antimelanoma activities. In vivo models of melanoma were used to observe MG-Pe effects in survival, spontaneous, and experimental metastases and in tissue oxidative stress. Analytical assays for the molecular interaction of MG-Pe and Gal-3 were performed using a quartz crystal microbalance, atomic force microscopy, and contact angle tensiometer. MG-Pe exhibits an additive effect when administered together with the chemotherapeutic agent dacarbazine, leading to increased survival of treated mice, metastases reduction, and the modulation of oxidative stress. MG-Pe binds to galectin-3. Furthermore, MG-Pe antitumor effects were substantially reduced in Gal-3/KO mice. Our results showed that the novel Gal-3 ligand, MG-Pe, has both antitumor and antimetastatic effects, alone or in combination with chemotherapy.

Sitagliptin Potentiates the Anti-Neoplastic Activity of Doxorubicin in Experimentally-Induced Mammary Adenocarcinoma in Mice: Implication of Oxidative Stress, Inflammation, Angiogenesis, and Apoptosis

Sitagliptin (STG) is a highly selective dipeptidyl peptidase-4 inhibitor recently used in the treatment of type 2 diabetes. The current study aimed to investigate the anti-neoplastic effect of STG alone and in combination with Doxorubicin (Dox), a known chemotherapeutic agent but with ominous side effects. After intramuscular inoculation of 2 × 106 Ehrlich tumor cells, Female Swiss mice were divided into tumor-bearing control, STG-treated, Dox-treated, and a combination of STG and Dox-treated groups. The results showed a significant reduction in the tumor growth of the treated animals in comparison with those of the positive control group with a more prominent effect in the co-treated group. Where, the anti-proliferative and apoptotic effect of STG, and its chemo-sensitizing ability, when used in combination with Dox, was mediated by modulation of oxidative stress (MDA and GSH), attenuation of tumor inflammation (IL-6 and IL-1β), and angiogenesis (VEGF), suppressing proliferation (β-catenin and cyclin-D1) and enhancement of apoptosis (survivin, p53, caspase 3). Thus, in conclusion, STG as adjunctive therapy for Dox could be a strategy for the treatment of breast cancer patients, by their ability in hindering cell proliferation and minimizing the associated oxidative and inflammatory adverse reactions.