Pseuderanthemum carruthersii (Seem.) Guillaumin is a native tree in Vietnam. The water extract of the leaves from this tree gives a highly viscous product that has been used to heal wounds and treat inflammations. Our previous studies showed that the leaves of P. carruthersii have a high content of polysaccharides. In this study, the structure and influence of the neutral polysaccharide from Pseuderanthemum carruthersii (PCA1) on lipopolysaccharide (LPS)-stimulated RAW264.7 cells were investigated. The PCA1 isolated from P. carruthersii is a galactan-type polysaccharide, containing galactose (77.0%), 3-O-methyl galactose (20.0%), and arabinose (3.0%). Linkage analysis of PCA1 showed that both the 3-O-methyl galactose and galactose were 1,4-linked. The presence of 3-O-methyl galactose units as part of the polysaccharide is important and can be used as a chemotaxonomic marker. The molecular weight of the PCA1 was 170 kDa. A PCA1 concentration of 30–40 μg/mL strongly inhibited TNFα, IL-1β, and IL-6 inflammatory cytokine production, and reactive oxygen species (ROS) release. PCA1 had inhibitory activities on pro-inflammatory cytokine and ROS release in LPS-stimulated mouse macrophages in vitro through MAPK signaling.

Pseuderanthemum carruthersii (Seem.) Guill. var. atropurpureum (Bull.) Fosb is a tree native of Vietnam, this medicinal leaf has a high viscosity that has been used to heal wounds, heal the sores, stop bleeding... Polysaccharide has attracted great attentions for its benefits to human health. Polysaccharide from natural sources have diverse anti-inflammatory, anticoagulant and wound healing activities. Polysaccharide is not only valuable in medicine, also widely used in foodstuffs such as gel thickening or emulsifying agents, emulsifiers, fillers. The polysaccharide content in P. carruthersii var atropurpureum leaves was (11.63 ± 0.375)% in dry weight. The appropriate polysaccharide extraction conditions were determined: water, material/solvent ratio (1g/25ml), extracted temperature of 60°C, extraction time 15 hours. The polysaccharide composition was purified by TCA 10%, with a purity of (71.47 ± 0.94)%.

Pseuderanthemum palatiferum (Ness) Radlk is a tree native of Vietnam with various use in traditional medicine. It has been used for the treatment of many diseases including wound, colitis, stomach-aches, trauma, high blood pressure, nephritis, diarrhoea. However, the research on effective constituents from P. palatiferum has mainly been focused on small-molecular compounds. Some compounds: flavonoids, phytol, palmitic acid, ß-sitosterol, triterpenoid saponin, stigmasterol and salicylic acid have been detected in leaves. Polysaccharides have attracted great attentions for its benefits to human health. Polysaccharides from natural sources have diverse anti-inflammatory, anticoagulant and wound healing activities. In this study, we extracted and determined the polysaccharide content from the leaves of P. palatiferum plant. The polysaccharide content in P. palatiferum leaves was 8.2% (± 0.65) in dry weight. The appropriate polysaccharide extraction conditions were determined as: 25% ethanol, material/solvent ratio (1g/10ml), extracted temperature of 70°C, extraction time 12 hours. The polysaccharide composition was purified by TCA 10%, with a purity of 77.8% (± 1.19). The immunostimulatory activities of polysaccharide XH were also examined in cyclophosphamide (CY)-induced immunosuppressed mice. Mice treated with polysaccharide XH exhibited increased white blood cell counts (p < 0.05) compared with immunosuppressed mice. These results indicate that polysaccharide XH from P. palatiferum can enhance immune function in CY-induced immunosuppressed mice.

Streptococcus mutans is the primary etiological agent of human dental caries. The well-known extraordinary ability of S. mutans to adapt and survive the environment of human mouth is highly acidogenicity and strong exopolysaccharide (EPS) production, a skeleton of dental plaque (biofilm). In this research, the total biofilm biomass, as well as the contents of protein, intracellular polysaccharide (IPS), alkaline soluble polysaccharide (ASP), water soluble polysaccharide (WSP) in the biofilm treated with 150 M α-mangostin was reduced ca. 40% compared to those of the control in ethanol as the vehicle. Two important glycosyltranferases B and C, responsible for biofilm formation by S. mutans, showed to be very sensitive to α-mangostin. Under the treatment condition, biofilm structure was clearly changed. Non-uniform and bigger microcolonies were found in the treated biofilms. Effects of α-mangostin on expression of the virulent genes and the detailed changes in biofilm structure are now under examination. The results showed that the -mangostin is a new and potential anti-biofilm agent of S. mutans UA159.