Ginseng root extract enhances autophagy level of macrophages RAW264.7 and improves their proliferation and phagocytic ability
Macrophages are one of the important innate immune cells in the body, with various functions such as phagocytosis, antigen presentation, immune defense, and inflammation regulation. Macrophages mainly recognize receptors and pathogens through their expressed patterns and activate related molecules, thereby engulfing pathogens.

Autophagy is a process that maintains the homeostasis of the body. It can engulf cytoplasmic proteins or organelles and encapsulate them into vesicles, which then fuse with lysosomes to form autolysosomes. These lysosomes degrade the contents they contain, thereby fulfilling the metabolic needs of the cell and the renewal of certain organelles. Autophagy plays an important role in macrophage phagocytosis, antigen presentation, regulation of immune response, and inflammatory response. The decline in autophagy function of macrophages can affect their phagocytic function. Ginseng has the effect of enhancing immunity, which is reflected in various aspects such as specific antibody formation, lymphocyte proliferation, and increased phagocytic ability of macrophages. This article uses ginseng root extract to act on macrophages RAW264.7, exploring its effects on the autophagy level, proliferation ability, and phagocytic ability of macrophages, providing a theoretical basis for further research on ginseng root extract.

Proliferation is the prerequisite and basis for immune cells to differentiate into multiple functional phenotypes and play corresponding roles in immune response, while phagocytosis is an important means for macrophages and other phagocytic cells to eliminate exogenous pathogenic microorganisms and endogenous aging and dead cells. In this study, a certain concentration of ginseng root extract can significantly promote macrophage proliferation and enhance their phagocytic ability, indicating that ginseng root extract can achieve immune regulation by promoting macrophage proliferation and improving macrophage phagocytic ability.

Autophagy is a conserved cellular degradation pathway. Autophagy utilizes lysosomes to degrade damaged organelles and large molecular substances, and the amino acids and small molecular substances produced are reused, thereby achieving intracellular material circulation and environmental balance. When autophagy is formed, cytoplasmic LC3 hydrolyzes a small peptide to form LC3-I. LC3-I binds to PE to form an autophagosome membrane (i.e. LC3-II). Therefore, the size of the LC3-II/I ratio can estimate the level of autophagy. When mammalian cells undergo autophagy, the content of LC3 in the cell and the conversion of LC3-I to LC3-II are significantly enhanced. Autophagy related protein 7 (Atg7) can promote the formation of autophagic lysosomes and the breakdown of damaged mitochondria during autophagy.

AMPK/mTOR and Akt/mTOR are two classic autophagy signaling pathways. Adenosine activated protein kinase (AMPK) is a serine/threonine kinase that, upon activation (phosphorylation), can inhibit mTOR activity and enhance cellular autophagy levels. Protein kinase B (Akt or PKB) is also a type of serine/threonine protein kinase that can synergize with phosphatidylinositol dependent protein kinase 1/2 to promote the binding of phosphatidylinositol triphosphate to itself. Akt is transferred from the cytoplasm to the plasma membrane and becomes active (phosphorylated). After activation, Akt can activate downstream protein mTOR (phosphorylated), thereby inhibiting the process of autophagy.

The research results showed that the expression levels of Atg7 and LC3 proteins in RAW264.7 macrophages increased, while the expression of p-AKT and p-mTOR decreased, and the phosphorylation level of AMPK increased. The differences compared with the control group were statistically significant. Ginseng root extract participates in mediating the autophagy response of macrophages RAW264.7 through multiple pathways. Autophagy plays an important role in the functioning of macrophages. By regulating autophagy levels through autophagy regulators, the effect of ginseng root extract on macrophage RAW264.7 function can be enhanced or neutralized.

In summary, ginseng root extract can promote the proliferation of macrophages RAW264.7, enhance its phagocytic function, and increase the autophagy level of macrophages RAW264.7 through AMPK/mTOR and AKT/mTOR signaling pathways, which are correlated. This study provides a theoretical basis for the application of ginseng root extract in cellular autophagy and immune regulation, but the molecular mechanism of its action still needs to be further studied.