Chinese tonic herbs are often used as remedies for the treatment of cancer or immunity related diseases. Cytokine regulation is one of the pathways that modulates the immune system. In the present study, we investigated the effects of commonly used Chinese herbs on cytokine regulation in human peripheral blood mononuclear cells (PBMC) and human acute monocytic leukemia cell line, THP-1. Among the 15 selected Chinese herbs, Paeonia lactiflora exhibited inhibitory effect on phytohemagglutinin (PHA)-activated PBMC proliferation and induced IFN-γ production. We also used a multiplexed flow cytometric bead-based assay to analyze the release of 17 cytokines and reverse transcription polymerase chain reaction (RT-PCR)/quantitative real-time PCR (qRT-PCR) to
evaluate gene expression. Cuscuta chinensis induced both interleukin-8 and MIP-1β release in THP-1 cells and influenced mRNA transcription. Dioscorea opposita, Cinnamomum osmophloeum, and Glycyrrhiza uralensis enhanced secretion of granulocytemacrophage colony-stimulating factor (GM-CSF) and influenced GM-CSF gene expression. As such, different Chinese tonic herbs may regulate immunomodulatory functions in human cells via diverse processes such as the modulation of different cytokines and
may be used as adjuvant immunity-boosting drugs. The present study is the first to use high-throughput multiplexed flow cytometric method to analyze cytokine regulatory effects of herbal extracts.