Strongylocentrotus nudos Egg Polysaccharide induces autophagy and apoptosis in leukaemia cells by regulating mitochondrial function

Enzymatic degraded polysaccharides from Enteromorpha prolifera inhibit the growth of THP-1 cells and induce apoptosis via the mitochondrial pathway

Polysaccharides from Enteromorpha prolifera (EP) is a kind of sulfated polysaccharides with complex structure. Several reports have showed that EP play roles in antioxidant and anti-inflammatory, while, whose function in anti-leukemia is still poorly understood. In this work, EPH were the hydrolysis products of EP by ulvan lyase EPL15085, which displayed lower molecular weight and enhanced sulfate groups than EP. Importantly, EPH exhibited effective inhibitory effect on the human leukemia monocyte cell line, THP-1 cells, however, the EP treated group showed no significant change. Results of JC-1 staining and ROS assay showed mitochondrial dysfunction after EPH treatment, and the increased rate of Bax/Bcl ultimately activated Caspase family proteins to induce apoptosis, indicating the mitochondrial pathway was involved. This study demonstrates the enzymatic products of EP showed enhanced effect on anti-leukemia, which would provide insights for approaches to uncover novel physiological functions of marine polysaccharides and potential therapy for acute myeloid leukemia patients.

Effect of levan polysaccharide on chronological aging in the yeast Saccharomyces cerevisiae

Levan is a fructose-based biopolymer with diverse applications in the medicinal, pharmaceutical, and food industries. However, despite its extensive biological and pharmacological actions, including antioxidant, anti-inflammatory, and antidiabetic properties, research on its anti-aging potential is limited. This study explored levan's impact on the chronological lifespan (CLS) of yeast Saccharomyces cerevisiae for the first time. The results show that levan treatment significantly extended the CLS of wild-type (WT) yeast by preventing the accumulation of oxidative stress markers (reactive oxygen species, malondialdehyde, and protein carbonyl content) and ameliorating apoptotic features such as reduced mitochondrial membrane potential, loss of plasma membrane integrity, and externalization of phosphatidylserine. By day 40 of the CLS, a significant increase in yeast viability of 6.8 % (p < 0.01), 11.9 % (p < 0.01), and 20.8 % (p < 0.01) was observed at 0.25, 0.5, and 1 mg/mL of levan concentrations, respectively, compared to control (0 %). This study's results indicate that levan treatment substantially modulates the expression of genes involved in the TORC1/Sch9 pathway. Moreover, levan treatment significantly extended the CLS of yeast antioxidant-deficient mutant sod2Δ and antiapoptotic gene-deficient mutant pep4Δ. Levan also extended the CLS of signaling pathway gene-deficient mutants such as pkh2Δ, rim15Δ, atg1, and ras2Δ, while not affecting the CLS of tor1Δ and sch9Δ.

Antitumor immunostimulatory activity of the traditional Chinese medicine polysaccharide on hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent malignancy, often associated with compromised immune function in affected patients. This can be attributed to the secretion of specific factors by liver cancer cells, which hinder the immune response and lead to a state of immune suppression. Polysaccharides derived from traditional Chinese medicine (TCM) are valuable constituents known for their immunomodulatory properties. This review aims to look into the immunomodulatory effects of TCM polysaccharides on HCC. The immunomodulatory effects of TCM polysaccharides are primarily manifested through the activation of effector T lymphocytes, dendritic cells, NK cells, and macrophages against hepatocellular carcinoma (HCC) both in vivo and in vitro settings. Furthermore, TCM polysaccharides have demonstrated remarkable adjuvant antitumor immunomodulatory effects on HCC in clinical settings. Therefore, the utilization of TCM polysaccharides holds promising potential for the development of novel therapeutic agents or adjuvants with advantageous immunomodulatory properties for HCC.

Pharmacokinetic study of Strongylocentrotus nudus egg polysaccharide in rats and beagles using a 3H-labeling method

Strongylocentrotus nudus egg polysaccharide (SEP) extracted from sea urchins has potential anticancer activity. However, little is known about its pharmacokinetic properties. To investigate the pharmacokinetics of SEP, it was radiolabeled with tritium. Furthermore, a sensitive, selective, and rapid liquid scintillation counter (LSC) method for quantifying ³H-SEP in biological matrix was validated. The lower quantification limit of the method was 4 Bq. The relative standard deviations (RSDs) of the intra- and inter-day precision were <3.0% and <3.9%, respectively. ³H-SEP was successfully applied to investigate the pharmacokinetics of SEP after intravenous administration of 20, 40, and 80 mg/kg (40 μCi/kg) in rats and 5, 10, and 20 mg/kg (6 μCi/kg) in beagles. The AUC_(0-t) of SEP at three different doses was 487.81 ± 39.99 mg/L*h, 1,003.10 ± 95.94 mg/L*h, and 2,188.84 ± 137.73 mg/L*h in rats and 144.12 ± 3.78 mg/L*h, 322.62 ± 28.03 mg/L*h, and 754.17 ± 37.79 mg/L*h in beagles. The terminal elimination half-life (t_1/2) of SEP was longer in beagles (204.29 ± 139.34 h) than in rats (35.48 ± 6.04 h). The concentration of SEP in plasma declined rapidly in both rats and beagles. All the study results provide detailed pharmacokinetic profiles of SEP in two kinds of animals, which will be helpful for further development.

The dual role of autophagy in acute myeloid leukemia

Acute myeloid leukemia (AML) is a severe hematologic malignancy prevalent in older patients, and the identification of potential therapeutic targets for AML is problematic. Autophagy is a lysosome-dependent catabolic pathway involved in the tumorigenesis and/or treatment of various cancers. Mounting evidence has suggested that autophagy plays a critical role in the initiation and progression of AML and anticancer responses. In this review, we describe recent updates on the multifaceted functions of autophagy linking to genetic alterations of AML. We also summarize the latest evidence for autophagy-related genes as potential prognostic predictors and drivers of AML tumorigenesis. We then discuss the crosstalk between autophagy and tumor cell metabolism into the impact on both AML progression and anti-leukemic treatment. Moreover, a series of autophagy regulators, i.e., the inhibitors and activators, are described as potential therapeutics for AML. Finally, we describe the translation of autophagy-modulating therapeutics into clinical practice. Autophagy in AML is a double-edged sword, necessitating a deeper understanding of how autophagy influences dual functions in AML tumorigenesis and anti-leukemic responses.

Strongylocentrotus nudos Egg Polysaccharide induces autophagy and apoptosis in leukaemia cells by regulating mitochondrial function

In this study, we investigated the ability of the Polysaccharide from the Eggs of Strongylocentrotus nudus (SEP) to regulate cellular autophagy and apoptosis in leukaemia cells. Human acute myeloid leukaemia (AML) cells (HL60) and murine AML cells (L1210) treated with SEP were used to assess viability using Cell Counting Kit‐8, cytotoxicity by measuring lactate dehydrogenase release, the generation of reactive oxygen species (ROS) by DCFH‐DA staining. In addition, we utilized a mouse model of leukaemia in which L1210 cells were injected into DBA/2 mice by sub‐axillary injection. Treatment with SEP decreased cell viability, increased in cytotoxicity and increased the release of ROS in a dose‐dependent manner. SEP treatment was also associated with the activation of pro‐apoptotic proteins cleaved caspase‐3, cleaved caspase‐9 and cleaved poly (ADP‐ribose) polymerase (PARP). Activation of the apoptotic pathway led to the release of cytochrome C (CytoC) into the cytosol of the cell resulting in decreased membrane potential. The effect of SEP treatment was depended on the activation of the nuclear factor kappa‐B (NF‐κB) signalling pathway as SEP treatment led to an increase in NF‐κB phosphorylation, and inhibition of NF‐κB signalling using PDTC blocked SEP‐mediated activation of apoptosis. Treatment with SEP also prolonged survival time in our leukaemia mouse model and was associated with diminished tumour volume, increased leucocyte and lymphocyte proliferation, promoted pro‐inflammatory factor release in serum and enhanced immune function. Taken together, these data suggest that SEP inhibits the progression of leukaemia by initiating mitochondrial dysfunction, autophagy, and apoptosis via the NF‐κB signalling pathway.