Abstract: 【Objective】 This study was aimed to investigate the effect of compound Shuanghuanglian preparation on the phagocytosis and secretion function of macrophages, and provide scientific basis for the in-depth development of compound Shuanghuanglian and the rational selection of drugs for poultry and livestock.【Method】 Lonicera japonica, Scutellaria baicalensis, Forsythia suspense and Andrographis paniculata were dried and crushed to prepare extracts, and Shuanghuanglian oral solution (Lonicera japonica:Scutellaria baicalensis:Forsythia suspense=1:1:2), compound Shuanghuanglian oral solution (Lonicera japonica:Scutellaria baicalensis:Forsythia suspense:Andrographis paniculata=1:1:2:2), and Andrographis paniculata oral solution were prepared in the proportions of the three drugs, and adjusted to a pH of 7.0, with a concentration of 1 g/mL.Three drugs were applied to the monocyte-macrophage cells in the mice.RAW264.7 cell viability was determined using CCK-8 method to establish the safe concentration of three drugs.The maximum permissible concentration of the drugs was diluted into three concentrations using a two-fold dilution method.Lipopolysaccharide (LPS) and hydrocortisone succinate sodium (HCSS) were employed to simulate the states of inflammation and immunosuppression in the body.The three drugs were used to treat cells in the two aforementioned states, as well as normal cells.The macrophage Fc/C3b receptor activity and phagocytosis capacity were measured using YC and EA rosette method as well as neutral red phagocytosis.Additionally, the macrophage secretion capacity was evaluated via ELISA.【Result】 The safe concentration range of compound Shuanghuanglian, Shuanghuanglian and Andrographis paniculata were 0.625-2.5, 3.125-12.5 and 0.625-2.5 mg/mL, respectively.Different concentrations of compound Shuanghuanglian, Shuanghuanglian and Andrographis paniculata acted on macrophages, and the cell phagocytic ability was significantly higher than that of blank control group (P<0.05).Compound Shuanghuanglian had the ability to reduce the active phagocytosis of LPS macrophage RAW264.7 and enhance the low phagocytosis of HCSS macrophages RAW264.7.Different concentrations of compound Shuanghuanglian could decrease the Fc/C3b receptor activity of activated macrophages and enhance the Fc/C3b receptor activity of low.Different concentrations of compound Shuanghuanglian had the ability to promote macrophages to secrete nitric oxide (NO), tumor necrosis factor-α (TNF-α), γ-interferon (IFN-γ) and lysozyme (LZM), and inhibit the secretion of NO, TNF-α, IFN-γ and interleukin 6 (IL-6) by LPS macrophages.【Conclusion】 Compound Shuanghuanglian could enhance the immunity and anti-inflammatory ability of the body by activating the Fc/C3b receptor activity of macrophages, while inhibiting the secretion function of activated macrophages to reduce the damage caused by hyperimmune function.The results provided a reference basis for the in-depth development of the traditional Chinese veterinary medicine compound Shuanghuanglian.

Key words: compound Shuanghuanglian; macrophage Fc/C3b receptor; phagocytosis; secretory function