Immunostimulatory Effects of Aqueous Extract of Heracleum persicum Desf. on Mouse Peritoneal Macrophages

Background: The immune system provides protection against infectious diseases that are caused by various microorganisms, in particular pathogenic fungi. Utilization of herbal immunostimulants is one solution to improve the immunity of humans and to decrease their susceptibility to infectious diseases. Objectives: The current study aimed to investigate the immunostimulatory effects of the aqueous extract of Heracleum persicum on mouse peritoneal macrophages. Materials and Methods: The present in vitro study investigated the effect of the aqueous extract of H. perscium on the viability of macrophages and nitric oxide (NO) production using microculture tetrazolium (MTT) assay and Griess method, respectively. The effects on fungicidal activity and reactive oxygen species (ROS) production of stimulated peritoneal macrophages were also studied using killing method and nitroblue tetrazolium (NBT) assay, respectively. Results: The aqueous extract of H. persicum (Hp-W) at concentration of 10 mg/mL resulted in a significant increase in NO production (8.17 nmol) by macrophages (P < 0.05). Moreover, H. persicum had a stimulatory effect on the level of ROS (P < 0.05) and a strong candidacidal activity in macrophages treated with 20 mg/mL of the extract (P < 0.05). Conclusions: The aqueous extract of H. persicum showed a significant immunostimulatory activity on macrophages. To clarify the exact mechanisms of this activity, more studies should be done with purified immunostimulatory components of H. persicum in future.