A naturally occurring acidic lacquer polysaccharide with glucuronic acid at the terminals of the complex branches has specific biological activities including promotion of blood coagulation and antitumor activities. The polysaccharide has two molecular weight fractions M¯n=10×10(4) and M¯n=3.0×10(4). In the present work, two pure fractions were isolated for the first time by Sephadex G-100 column chromatography. Then, each fraction was treated with diluted alkaline solution to decrease the molecular weights to M¯n=3.0×10(4) and M¯n=1.4×10(4), respectively. The NMR and IR spectra and specific rotations of the fractionated and original lacquer polysaccharides were almost identical, suggesting that the lacquer polysaccharides are an associated structure with several low molecular weight polysaccharides of M¯n=1.4×10(4). Interactions between each lacquer polysaccharide and poly-L-lysine, a model compound of proteins and peptides with positively-charged amino groups, were investigated by surface plasmon resonance (SPR) to elucidate the biological mechanism. The apparent dissociation-rate (kd), association-rate (ka), and dissociation constant (KD) obtained by SPR indicate that the lacquer polysaccharides had weaker interactions with poly-L-lysine than sulfated polysaccharides and that the interaction depended on the molecular weight. These SPR results suggest that the specific biological activities of lacquer polysaccharides originate from electrostatic interaction.

Lamiaceae plants produce essential oils (EOs) with diverse chemical compositions and biological activities. This study investigated the volatile composition and multiple biological activities of EOs from 13 Lamiaceae species. EOs were obtained by hydrodistillation and characterized by gas chromatography–mass spectrometry (GC-MS), followed by hierarchical clustering and principal component analysis. Antioxidant, antibacterial, cytotoxic, and anti-inflammatory activities were evaluated using in vitro and murine models. GC-MS analysis revealed substantial interspecific variation in volatile composition, with Origanum vulgare characterized by carvacrol and limonene, Thymus spp. by thymol, Rosmarinus officinalis by eucalyptol and α-pinene, Mentha canadensis by L-menthol, and Perilla frutescens by perillaldehyde. Scutellaria baicalensis, Elsholtzia ciliata, Phlomis mongolica, and Schizonepeta tenuifolia showed distinctive profiles associated with limonene and isopulegone, nepetalactone, pulegone, and anethole and anisaldehyde, respectively. Multivariate analysis further separated the 13 oils into three chemotype groups: a carvacrol-rich Origanum group, a Scutellaria and Thymus group enriched in sesquiterpenes or thymol, and a group comprising the remaining six genera dominated by shared monoterpene hydrocarbons. Most EOs exhibited substantial 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, with Rosmarinus officinalis and Perilla frutescens showing the strongest activity, with IC₅₀ values of 2.14 and 2.08 μg/mL, respectively. Origanum vulgare, Thymus citriodorus, Thymus vulgaris, and Thymus mongolicus displayed strong antibacterial activity against five pathogens, with minimum inhibitory concentration (MIC) values ranging from 2 to 8 μg/mL. Cytotoxicity assays showed potent activity against HepG2 and LNCaP cells, with IC₅₀ values ranging from 0.31 to 0.95 μg/mL. Elsholtzia ciliata and Perilla frutescens exhibited particularly strong potency, with IC₅₀ values ranging from 0.31 to 0.40 μg/mL. In a murine skin inflammation model, selected EOs significantly reduced inflammation-related markers, including COX-2, TNF-α, NF-κB, IKK, Akt, and PKC. Correlation analysis identified significant associations of carvacrol, thymol, and β-linalool with antibacterial activity, whereas no significant associations were observed between individual major constituents and antioxidant or cytotoxic activity after false discovery rate (FDR) correction. Overall, the 13 Lamiaceae EOs displayed distinct chemical profiles and activity patterns, providing a basis for further investigation of their bioactive constituents and potential applications.

Naturally occurring prostaglandin E₂ (PGE₂) influences cytokine production regulation in bovine neutrophils exposed to Staphylococcus aureus Rosenbach. Here, we employed bovine neutrophils as the primary experimental system, and administered specific inhibitors targeting various receptors, which were subsequently exposed to S. aureus. Cytokine expression levels in dairy cow neutrophils induced by S. aureus via the endogenous PGE₂-EP2/4 receptor pathway were investigated, and its effects on P38, extracellular signal-regulated kinase (ERK), P65 activation, and phagocytic function in Staphylococcus aureus Rosenbach-induced dairy cow neutrophils, were examined. Blocking cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) enzymes substantially decreased PGE₂ production and release in S. aureus-exposed bovine neutrophils. Cytokine output showed significant reduction compared to that in SA113-infected controls. Phosphorylation of P38, ERK, and P65 signaling molecules was depressed in the infected group. Pharmacological interference with EP2/EP4 receptors similarly diminished cytokine secretion and phosphorylation patterns of P38, ERK, and P65, with preserved cellular phagocytic function. During S. aureus infection of bovine neutrophils, COX-2 and mPGES-1 participated in controlling PGE₂ biosynthesis, and internally produced PGE₂ molecules triggered NF-κB and MAPK inflammatory pathways via EP2/EP4 receptor activation, later adjusting the equilibrium between cytokine types that promote or suppress inflammation. This signaling mechanism coordinated inflammatory phases through receptor-mediated processes.