Velvet antler, a traditional Chinese medicine, is believed to have body-strengthening, immunomodulatory and anti-aging effects.
It has been used in Chinese commercial functional foods and nutraceuticals. This study aimed to investigate the immunomodulatory
effects of aqueous extract of velvet antler (AEVA) from Cervus elaphus Linnaeus and its simulated gastrointestinal digests (SGDs) in vitro. Experiments were carried out by measuring the effects of AEVA and SGDs on splenocyte proliferation, neutral red pinocytosis and nitric oxide (NO) production by macrophages. AEVA (10-400 μg/mL) showed inhibitory effects on concanavalin A (ConA)-stimulated splenocyte proliferation while no difference was observed when lipopolisaccharide (LPS) was used as stimulus.
An inhibitory effect was also observed in neutral red pinocytosis by AEVA treated macrophages. During simulated gastrointestinal digestion, AEVA kept and strengthened its inhibitory effect on ConA-stimulated splenocyte proliferation. However, digestion of AEVA counteracted the inhibitory effect on pinocytosis. In addition, AEVA alone had no effect on NO production by macrophages while some SGDs (200 μg/mL) increased NO production by LPS-stimulated macrophages. The results indicated that AEVA could keep its inhibitory effect on T-cells by oral administration. In contrast, the effect of AEVA on macrophage function was changed
during digestion.