This study aimed to explore the antipyretic and anti-inflammatory effects of rectal administration of Reduning injection in feverish rats induced by lipopolysaccharide (LPS), and observe the temperature changes and inflammatory indexes. The selected rats were randomly divided into 6 groups, with 10 rats in each group, named as normal empty group, model group, intravenous group (2 mL/kg), low-dose enema group (1 mL/kg), middle-dose enema group (2 mL/kg), and high-dose enema group (4 mL/kg). The hourly temperature variations in rats injected with LPS in the abdomen were recorded. Five hours later, blood samples from the abdominal aorta were collected to monitor immunoglobulin M (IgM), immunoglobulin A (IgA), interleukin (IL)-6, and tumor necrosis factor (TNF)-α. At 5 hours, the fever peak induced by LPS appeared, and obvious antipyretic effects were observed; the effect was optimal in the medium dose enema group at 4 hours (p < 0.05); the IgM value in the enema groups, the intravenous group, and normal empty group was significantly lower than that in the model group; the IgA value in each group was higher than that in the model group, but there was no statistical significance (p > 0.05); values of IL-6 and TNF-α in each group were lower than those in the model group, and the difference was statistically significant except for the high-dose enema group (p > 0.05). Low-dose and medium-dose rectal administration of Reduning injection have inhibitory effects on IL-6, TNF-α, and IgM in feverish rats induced by LPS, but there is no obvious difference compared to intravenous administration and it could achieve an anti-inflammatory effect. There is a possibility of enhancing IgA immunity with rectal administration, but there is no obvious difference compared to intravenous administration, and rectal administration has no significant effect on mucosal immunity.
Keywords: Reduning injection; antipyretic and anti-inflammatory effect; immunoglobulin; inflammatory factor; rats; rectal administration.