This study aimed to investigate the inhibitory effect and mechanism of lotus seedpod polysaccharides (LSP) on cervical cancer HeLa cells using commercial kits, flow cytometry, cell scratch wound healing assay, and Transwell cell migration and invasion assays. Transcriptomics, proteomics, and Western blot were integrated to explore the potential mechanism by which LSP inhibit HeLa cells. The results indicated that LSP significantly reduced HeLa cell viability, affected cell morphology, induced apoptosis and mitochondrial membrane potential collapse, increased reactive oxygen species (ROS) production, and inhibited cell migration and invasion. Transcriptomic analysis revealed that 120 μg/mL LSP significantly regulated the expression of 12347 genes (5550 upregulated, 6797 downregulated) in HeLa cells, altering biological processes, molecular functions, and cellular components, and modulating metabolic pathways, oxidative phosphorylation, chemical carcinogenesis-ROS, and the cell cycle. Proteomic analysis showed that 120 μg/mL LSP significantly regulated the expression of 1143 proteins (379 upregulated, 764 downregulated) in HeLa cells, altering biological processes, molecular functions, and cellular components, and modulating several pathways including the pentose phosphate pathway, purine metabolism, glycolysis/gluconeogenesis, and nucleotide metabolism. Integrated transcriptomic and proteomic analysis revealed 1041 overlapping differentially expressed proteins and genes, which were significantly enriched in glycolysis/gluconeogenesis, amino sugar and nucleotide sugar metabolism, the pentose phosphate pathway, glutathione metabolism. Further investigation focusing on the glycolysis/gluconeogenesis pathway revealed that LSP significantly decreased adenosine triphosphate (ATP) content, glucose consumption, and lactate production in HeLa cells, inhibited the activities of hexokinase (HK), phosphofructokinase (PFK), and pyruvate kinase (PK), and downregulated the protein expression levels of glycolytic enzymes, including glucose-6-phosphate isomerase (GPI), phosphofructokinase platelet-type (PFKP), phosphofructokinase muscle-type (PFKM), fructose-bisphosphate aldolase A (ALDOA), triosephosphate isomerase 1 (TPI1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate kinase 1 (PGK1), phosphoglycerate mutase 1 (PGAM1), enolase 1 (ENO1), enolase 2 (ENO2), enolase 3 (ENO3), pyruvate kinase M (PKM), lactate dehydrogenase A (LDHA), and lactate dehydrogenase B (LDHB). In conclusion, LSP have a significant inhibitory effect on HeLa cells, which may be related to their significant suppression of the glycolysis pathway. These findings provide a theoretical basis for the functional development and high-value utilization of LSP for the prevention and treatment of cervical cancer.

In our previous study, a pectin NOP from Gannan navel orange (Citrus sinensis Osbeck cv. Newhall) peels has been gained. This study sequentially determines its structure using methylation analysis and NMR spectroscopy, and evaluates its gastroprotective activity against alcohol-induced gastric mucosal lesions (AGML) in rats. Meanwhile, the mechanism was explored by RNA-seq, western blot, 16S rRNA and untargeted metabolomics analyses along with correlation analyses and molecular docking. Results showed that NOP consisted of HG domain, RG-I domain and β-1,6-D-glucan structure. The side chains of RG-I domain were composed of →5)-α-L-Araf-(1→, β-D-Galp-(1→, →4)-β-D-Galp-(1→ and →3,6)-β-D-Galp-(1→ residues. NOP ameliorated gastric lesion, decreased inflammatory responses and protein expressions of inflammatory signaling pathways-related hub targets (Ccl2, Cxcl1, Icam1, Il6, Jun and Lif), changed gene expressions and metabolism of gastric tissues, and regulated gut microbiota in AGML rats. Moreover, gut microbiota biomarkers, biochemical indexes and differential metabolites affected by NOP showed significantly positive and negative correlations. Furthermore, the representative metabolites like hypoxanthine and the inflammatory signaling pathways-related hub targets exhibited good binding activities. It can be concluded that NOP is a candidate for alleviating AGML, exerting gastroprotection through inflammatory signaling pathways, gut microbiota and metabolites in AGML rats. This study provides theoretical basis for the exploitation and utilization of NOP in preventing AGML, and the future mechanism investigation.

In this study, we aimed to purify a fraction (LSP2) from a previously obtained refined lotus seedpod polysaccharide, characterize its structure, and evaluate its anti-diabetic effect in streptozotocin-induced rats. Its mechanism of action was investigated using multi-omics approaches. Results showed that LSP2 was a pectin with a molecular weight of 14.619 kDa, primarily composed of galacturonic acid (GalA, 73.49%). LSP2 was identified as a high-ester HG-type pectin, with a backbone consisting of →4)-α-D-GalpA-6-OMe-(1→ and →4)-α-D-GalpA-(1→ residues in an approximate molar ratio of 2:1. LSP2 exhibited scavenging activities on 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 1,1-diphenyl-2-picryl-hydrazyl (DPPH), and hydroxyl (OH) radicals, along with α-glucosidase activity inhibitory effect (half-maximal inhibitory concentration: 0.193 mg/mL). LSP2 alleviated hyperglycemia and dyslipidemia, and enhanced insulin secretion and antioxidant levels in diabetic rats. Transcriptomic and western blot analyses showed that LSP2 altered gene expressions of liver tissues, notably downregulating the forkhead box O (FoxO) signaling pathway, as evidenced by marked reductions in protein expressions of hub targets FOXO1, phosphoenolpyruvate carboxykinase 1 (PCK1), and glucose-6-phosphatase catalytic subunit (G6PC). Metabolomic profiling revealed that LSP2 altered liver and fecal metabolisms, with eight and eleven metabolic biomarkers, respectively (e.g., 1-stearoyl-2-hydroxy-sn-glycero-3-phosphocholine, SOPC, phosphorylcholine; glutamic acid, L-glutamine, tryptophan), and significantly modulated four and six metabolic pathways respectively (e.g., choline metabolism in cancer, biosynthesis of unsaturated fatty acids, linoleic acid metabolism; protein digestion and absorption, glutathione metabolism, glutamatergic synapse). 16S rRNA sequencing showed that LSP2 regulated fecal gut microbiota in, particularly affecting ten differential genera bacteria (Muribaculaceae, Streptococcus, Lactobacillus, etc.). Significant correlations were observed among differential metabolites, differential gut microbiota and biochemical indexes (FBG, TG, HDL-C, liver SOD, liver MDA, FOXO1, PCK1, and G6PC) affected by LSP2. These findings suggest that LSP2 exerts an anti-diabetic effect in streptozotocin-induced rats, potentially through regulation of the gut-liver axis. This study supports the potential of LSP2 in diabetes mellitus intervention.

Lotus (Nelumbo nucifera Gaertn.) is an abundant edible and medical resource, and the utilizable parts of lotus include leaves, roots, seeds, plumule, seed skins, flowers and seed pots, which contain many bioactive components including polysaccharides, and possess high nutritional value and many pharmacological activities. As an important component in different parts of lotus, polysaccharides have a variety of biological activities, such as antioxidatnt, anti-saccharification, hypoglycemic, immunoregulatory, antibacterial and anti-osteoporosis activities. At present, only scattered information is available on polysaccharides in different parts of lotus, so this paper reviews recent progress in research on the extraction, purification, structural features and biological activity of polysaccharides from different parts of lotus, aim at providing a reference for the comprehensive exploitation and utilization of polysaccharides in different parts of lotus to promote the application of lotus by-products.