Panax ginseng abuse exhibits a pro-inflammatory effect by activating the NF-κB pathway

P. ginseng (Panax ginseng C. A. Meyer) is a well-known traditional medicine that has been used for thousands of years to treat diseases. However, "ginseng abuse syndrome" (GAS) often occurs due to an inappropriate use such as high-dose or long-term usage of ginseng; information about what causes GAS and how GAS occurs is still lacking. In this study, the critical components that potentially caused GAS were screened through a step-by-step separation strategy, the pro-inflammatory effects of different extracts on messenger RNA (mRNA) or protein expression levels were evaluated in RAW 264.7 macrophages through quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot, respectively. It was found that high-molecular water-soluble substances (HWSS) significantly increased the expression of cytokines (cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and interleukin 6 (IL-6)) and cyclooxygenase 2 (COX-2) protein; gel filtration chromatography fraction 1 (GFC-F1) further purified from HWSS showed prominent pro-inflammatory effects by increasing the transcription of cytokines (COX-2, iNOS, tumor necrosis factor alpha (TNF-α), and interleukin 1β (IL-1β)) as well as the expression of COX-2 and iNOS protein. Moreover, GFC-F1 activated nuclear factor-kappa B (NF-кB) (p65 and inhibitor of nuclear factor-kappa B alpha (IκB-α)) and the p38/MAPK (mitogen-activated protein kinase) signaling pathways. On the other hand, the inhibitor of the NF-κB pathway (pyrrolidine dithiocarbamate (PDTC)) reduced GFC-F1-induced nitric oxide (NO) production, while the inhibitors of the MAPK pathways did not. Taken together, GFC-F1 is the potential composition that caused GAS through the production of inflammatory cytokines by activating the NF-кB pathway.