## 1 Introduction  
_Panax ginseng_ C.A. Meyer (\(P\). _ginseng_) is a perennial herb that has been used as a traditional Chinese medicine in Asian countries including Korea, China, and Japan for thousands of years. _P. ginseng_ has been shown to have anti-inflammatory [1], anti-oxidant [2], anti-cancer [3, 4], anti-stress [5], cognitive function enhancement [6], anti-fatigue [7], and anti-wrinkle [8, 9] activities. It is composed of ginseng, phenolic compounds, polysaccharides, peptides, polyacetylenes, fatty acids, and other ingredients [10].  
In previous studies, red ginseng, which results from the heat processing of white ginseng, exhibits beneficial effects in the human body from the chaining of ginseng [11, 12]. It is known that during heat processing, the natural ginsengides, Rg1, Re, Rb1, Rc, and Rd gradually decrease, whereas the content of effective active substances, such as ginseng Rg3, Rg2, and Rh1, increases [13, 14].  
In addition to ginessels, the active ingredients in ginseng include ginseng polysaccharides. Presently, a significant amount of research has been done on ginseng, however, few studies have been conducted on the polysaccharides in red ginseng. Recently, pharmacological activity of plant polysaccharides has been reported including anti-oxidant [15, 16], anti-cancer [17, 18], and immunity regulatory [19] effects. Thus, research on polysaccharides has grown significantly in recent years. Previous reports showed that Korean red ginseng (KRG) polysaccharides regulate the immune system by effectively reducing cytotoxicity caused by ginsengides and promoting anti-inflammatory activity [20, 21], regulating intestinal homeostasis [22], macrophage activation [23], and preventing influenza [24]. Thus, red ginseng polysaccharides play an important role in regulating the immune system.  
The innate immune system represents the first defense mechanism against invading foreign pathogens or harmful substances. In addition to the physical defense of the skin, innate immunity also consists of immune cells such as the complement system, phagocytes, and NK cells [25]. Of these, macrophages in phagocytes can non-specifically recognize foreign bodies and bind to surface receptors to activate phagocytosis and produce nitric oxide (NO) and reactive oxygen species to kill foreign bodies [24; 26]. In addition, cytokines (i.e., IL-6, TNF-\(\alpha\), and IL-1) secreted by activated macrophages induce and regulate the inflammatory response and transmit signals to the acquired immune system consisting of T lymphocytes. [PERSON] [23] reported that plant polysaccharides or glycoproteins can activate macrophages by recognizing and binding to receptors, such as toll-like receptor 4 (TLR4), cluster of differentiation 14 (CD14), complement receptor 3 (CR3), scavenger receptor, dectin-1, or the mannose receptor. This triggers a cascade of intracellular signaling molecules in the activated macrophages, which are transmitted to the nucleus through the MAPK (ERK, JNK p38) and NF-\(\kappa\)B signaling pathways, thereby upregulating gene transcription and secreting inflammatory cytokines (i.e., IL-6, TNF-\(\alpha\), IL-1, and IFN-\(\gamma\)) and NO [27].  
Although previous papers have shown that red ginseng has various effects, the specific active ingredients in KRG have not been fully elucidated [1; 2; 3; 4; 5; 6; 7; 8; 9; 10]. To the best of our knowledge, ginseng is one of the active ingredients responsible for the pharmacological effects of ginseng; however, not all the biological activities of ginseng are attributable to ginseng. Therefore, in this study, we isolated the polysaccharide component (KRG-P) from KRG extracts and analyzed its chemical properties and evaluated its immune-enhancing effects and mechanism.