To evaluate the anti-inflammatory mechanism of Dendrobium officinale polysaccharides (DOP) as well as their acute and long-term toxicity, thereby providing a scientific basis for clinical application within a safe dosage range.

The anti-inflammatory mechanism of DOP was comprehensively investigated through in vitro cell experiments and in vivo animal studies. In the cell experiment, a mouse macrophage RAW264.7 inflammation model was established using lipopolysaccharide (LPS) stimulation. Different concentrations of DOP (50, 100, 200 μg/mL) were added, and the expression levels of inflammatory cytokines (TNF-α, IL-6, IL-1β) were measured. In the animal experiment, a xylene-induced ear edema model was used to observe the anti-inflammatory effect of DOP, and serum inflammatory cytokine levels were detected by ELISA. Additionally, acute toxicity tests and long-term toxicity tests were conducted to monitor mouse survival rate, body weight changes, biochemical indicators (ALT, AST, BUN, Cr), and to assess the risk of immune-allergic reactions.

Cell experiment results showed that DOP significantly downregulated the expression levels of the inflammatory cytokines TNF-α, IL-6, and IL-1β in a dose-dependent manner (P<0.05). In animal experiments, DOP significantly reduced xylene-induced ear thickness and serum inflammatory cytokine levels in mice, demonstrating significant anti-inflammatory activity. In toxicity experiments, a high dose of DOP (5 000 mg/kg) reduced mouse survival rate to 40% and significantly inhibited body weight gain (P<0.05), while low to medium doses (50, 100, 200 mg/kg) showed no obvious acute toxicity. Long-term toxicity tests indicated that a high dose of DOP (200 mg/kg) significantly elevated liver and kidney function indicators ALT, AST, BUN, and Cr (P<0.05), suggesting that high doses may induce liver and kidney injury.

DOP exhibits significant anti-inflammatory effects with low toxicity within low to medium dosage ranges. However, potential acute toxicity and risk of liver and kidney injury exist at high doses. while also suggesting that long-term use requires caution and close monitoring of toxic reactions.