Numerous polysaccharides have been isolated from plants and used as a source of biological response modifiers in therapeutic agents. We previously found a novel acidic polysaccharide from Plantago asiatic L. seeds, named PLP, having strong antioxidant abilities in vitro. To further elucidate the role of PLP as a biological response modifier, the immunomodulating activities of PLP in macrophage cells were explored in the current study. We confirmed that stimulation of murine macrophage cells with PLP resulted in cell proliferation. PLP could directly bind to macrophage with saturable and reversible character and required TLR2 and TLR4 participation. PLP interaction with TLR2 and TLR4 led to the activation of intracellular p38, ERK and JNK. Furthermore, specific inhibitors of p38, ERK and JNK could weaken the ability of PLP to induce macrophage cell proliferation. Overall, this study indicated for the first time the immunostimulating properties of PLP on macrophage cells through a receptor-mediated mechanism, which involves TLR2 and TLR4 MAPK signaling pathways, and highlighted the role of PLP as an efficacious biological modifier in oncologic immunotherapy.

A new chromogenic and fluorescent “turn-on” chemodosimeter 3 was designed and synthesized by using a fluoride-sensitive self-immolative linker, in combination with the fluorescent dyes 7-hydroxy-4-trifluoromethyl coumarin. The chemodosimeter exhibited high selectivity and sensitivity toward fluoride anions through “turn-on” chromogenic and fluorogenic dual modes.A novel fluorescent chemosensor containing 7-hydroxy-4-trifluoromethyl coumarin was developed for sensing of fluoride based on F−-sensitive self-immolative linker.

A novel polysaccharide (GPP-S), with a molecular mass of 1.2 × 106 Da, was isolated from the tetraploid Gynostemma pentaphyllum Makino by alkali extraction followed by purifications using DEAE and Sephacryl S-400 column chromatographies. The monosaccharide composition of GPP-S was determined as rhamnose, arabinose, glucose, and galactose with a molar ratio of 1.00:3.72:19.49:7.82. The structural analysis suggested that the backbone of GPP-S is (1→4)-linked-glucose and (1→6)-linked-galactose with a (1→4,6)-linked-glucose branch every six monosaccharide residues. The terminals were 1-)-α-arabinose, glucuronic acid, and other monosaccharides. GPP-S exhibited scavenging capacities against hydroxyl, peroxyl, and DPPH• radicals in vitro. GPP-S also had inhibitory activities on IL-1β, IL-6, and COX-2 gene expressions in RAW 264.7 mouse macrophage cells. These results suggested that GPP-S could be developed as a bioactive ingredient for functional foods and dietary supplements.