Discussion on the relationship between ginseng active ingredients and human health

As we all know, ginseng plays a very important role in human health. Ginseng has the effects of anti-aging, lowering blood sugar, lowering blood lipids, promoting digestion, etc., and also has a certain protective effect on cardiovascular and liver function. Therefore, analyzing the relationship between the active ingredients in ginseng and human health is conducive to exploring the dose-effect relationship between ginseng and human health, and then improving human health and ginseng utilization.

Research progress

01 Ginsenoside Rg1 reduces lipopolysaccharide-induced chronic liver injury by activating the Nrf2 signaling pathway and inhibiting hepatocyte inflammasomes

Abstract:

Ginseng is a precious traditional Chinese medicine with multiple pharmacological effects. Ginsenoside Rg1 is the main active ingredient extracted from ginseng, which has anti-aging and antioxidant effects.

Research purpose: Chronic inflammatory damage to hepatocytes is an important pathological basis for many liver diseases. However, its pathogenesis is still unclear, and the therapeutic strategy to prevent its development needs to be further explored. The mouse chronic liver injury model was established by intraperitoneal injection of LPS (200 μg/kg) for 21 days. Serum liver function indexes and IL-1β, IL-6, and TNF-α levels were detected using corresponding kits. Hematoxylin and eosin (H&E), periodic acid-Schiff (PAS), and Masson staining showed pathological damage, glycogen deposition, and liver fibrosis in the liver. IF was used to detect the nuclear import of p-Nrf2 and the generation of Col4 in the liver, and IHC was used to detect the expression of NLRP3 and AIM2 in the liver. Western blot and q-PCR were used to detect the expression of proteins and mRNA related to liver fibrosis and apoptosis in mice, as well as the expression of inflammasome-related proteins such as Keap1, p-Nrf2, NLRP3, NLRP1, and AIM2. Cell Counting Kit-8 was used to detect the cell viability of human hepatocellular carcinoma cells (HepG2) to select the action concentration of LPS, and the kit was used to detect the generation of intracellular ROS. Western blot was used to detect the expression of Nrf2, HO-1, NQO1, and NLRP3, NLRP1, and AIM2 inflammasome-related proteins in the nucleus of HepG2 cells. Finally, the feasibility of molecular interconnection between Rg1 and Nrf2 was verified by molecular docking.

Results: Rg1 treatment for 21 days reduced the levels of serum ALT and AST and the levels of inflammatory factors IL-1β, IL-6, and TNF-α in LPS-induced mice. Rg1 significantly reduced hepatocyte injury, apoptosis, inflammatory cell infiltration, and liver fibrosis in LPS-stimulated mice. Rg1 promoted LPS-induced liver Keap1 degradation, enhanced p-Nrf2 and HO-1 expression, and reduced NLRP1, NLRP3, AIM2, cleaved caspase-1, IL-1β, and IL-6 levels. In addition, Rg1 effectively inhibited the increase of ROS in HepG2 cells induced by LPS, while inhibition of Nrf2 reversed the role of Rg1 in the generation of ROS and the expression of NLRP3, NLRP1, and AIM2 in LPS-induced HepG2 cells. Finally, molecular docking showed that Rg1 had a strong affinity for Nrf2.

Conclusions:

LPS mediates oxidative stress injury and inflammasome activation, significantly increasing liver ROS accumulation and fibrosis, thereby promoting chronic liver injury. In contrast, Rg1 significantly improved chronic liver injury by reducing Keap1 expression, increasing p-Nrf2 levels, and inhibiting NLRP3, NLRP1, and AIM2 inflammasomes. This suggests that Rg1 may protect mice from LPS-induced chronic liver injury by promoting the separation of Nrf2 from Keap1, thereby activating the Nrf2 pathway and inhibiting the inflammatory response. However, due to the particularity of liver tissue, ROS levels in liver tissue could not be detected by dihydroethylene (DHE) staining, which has been successfully applied to kidneys. In addition, other effects of Rg1 on liver injury and its exact mechanism of coordinating Nrf2/HO-1 need to be further explored.

02 Ginsenoside Rg1 regulates Tfh cell subset homeostasis and improves experimental colitis by inhibiting TLR/MyD88 pathway

Abstract:

Imbalance of follicular helper T (Tfh) cell subsets is closely related to the occurrence of inflammatory bowel disease (IBD). Ginsenoside Rg1 (G-Rg1), the main component of ginseng, has good immunomodulatory and anti-inflammatory effects. Dextran sodium sulfate was used to induce colitis in mice, and G-Rg1 (200 mg/kg·d) was gavaged for 14 days. The results showed that G-Rg1 could significantly alleviate the symptoms of colitis in mice, regulate the balance of Tfh cell subsets, promote the secretion of IL-4 and IL-10, and inhibit the expression of IFNγ, IL-17A, and IL-21. Molecular docking analysis showed that G-Rg1 had good binding activity with the target genes of the TLR/MyD88 signaling pathway and could reduce the expression levels of proteins such as TLR2, MyD88, IRAK4, TRAF6, and TAK1. It suggests that G-Rg1 can effectively regulate the balance of Tfh cell subsets, and its mechanism may be related to the inhibition of TLR/MyD88 signaling pathway.

Conclusions:

In this study, mice treated with DSS for 3 days developed typical UC symptoms. After continuous administration for 14 days, the body weight of UC mice was significantly improved, the DAI score was reduced, the body weight and colonic edema were restored, and the inflammatory cell infiltration in the submucosal layer of the colon was alleviated. G-Rg1 significantly downregulated the expression of IFN-γ, IL-17A, and IL-21, and significantly upregulated the expression of IL-4 and IL-10, suggesting that G-Rg1 can effectively alleviate the DSS-induced mouse UC model.

Flow cytometric analysis showed that the Tfh cell subsets in the spleen of DSS-induced colitis mice were unbalanced during the onset of the disease. This imbalance was corrected after 14 days of G-Rg1 treatment. Compared with the model group, the number of Tfh1, Tfh17, and Tfh21 cells in the G-Rg1-treated mice was significantly reduced, and the number of Tfr and Tfh10 cells was significantly increased. This evidence suggests that G-Rg1 has a certain therapeutic effect on the experimental UC model, and its reduction of pathological damage may be achieved by regulating the balance of Tfh cell subsets.

Representative target genes in the TLR-MyD88 signaling pathway were selected for molecular docking analysis with G-Rg1. The results showed that G-Rg1 had good binding activity with TLR2, MyD88, IRAK4, TRAF6, and TAK1 genes. When the inflammatory Tfh cell subsets are unbalanced, the TLR/MyD88 signaling pathway in the colon mucosal tissue will also be abnormally activated. By Western Blotting verification, the expression of TLR2, TLR4, MyD88, Rac1, IRAK4, IRAK1, TRAF6, TAK1, TAB1, MKK3, CREB, and p38mapk-related proteins increased. During DSS-induced colitis in mice, activation of the TLR/MyD88 signaling pathway coexists with activation of DSS-induced Tfh cells and the occurrence of colonic mucosal damage. These two processes may interact with each other, and G-Rg1 can inhibit the activation of this signaling pathway, which is manifested by inhibiting the expression of TLRs and their downstream proteins.

This study showed that G-Rg1 can effectively restore DSS-induced colonic pathological damage. This may be achieved by inhibiting the TLR/MyD88 signaling pathway and regulating the balance of Tfh cell subsets. G-Rg1 can act as an inhibitor of the TLR/MyD88 signaling pathway, thereby reducing the level of proinflammatory cytokines in colon tissue, restoring the balance of Tfh cell subsets, and ultimately alleviating intestinal inflammatory symptoms. The experimental results are consistent with the predictions of network pharmacology.

03 Panaxydol extracted from ginseng inhibits NLRP3 inflammasome activation and improves NASH-induced liver injury

Abstract:

In nonalcoholic steatohepatitis (NASH), activation of NOD-like receptor protein 3 (NLRP3) inflammasome exacerbates liver inflammation and fibrosis, indicating that the development of inflammasome inhibitors can become a major candidate drug for improving NASH. Ginseng is rich in natural active ingredients with anti-inflammatory effects. In this study, polar and non-polar components of ginseng were separated to detect the regulatory effects of NLRP3 inflammasomes and identify pure components of inflammasome inhibitors that improve diet-induced NASH. Non-polar components of ginseng extracted with ethyl acetate solvent can reduce the secretion of IL-1β and the expression of active caspase-1. The study found that panaxydol (PND) is a pure component that inhibits NLRP3 inflammasome activation. PND blocks inflammasome cytokine release, pyroptosis, caspase-1 activation, and inflammasome complex spotting. The inhibitory effect of PND on NLRP3-dependent pathways was specific through potential interactions with the NLRP3 ATP-binding motif. In addition, in vivo studies showed that PND reduced tissue inflammation and ameliorated the development of NASH by disrupting the NLRP3 inflammasome. These results provide new insights into the natural product panaxynol as an inhibitor of NLRP3 inflammasome and may provide a potential therapeutic candidate for alleviating NASH.

Conclusions:

In this study, non-saponin panaxynol was identified as a key inhibitor of NLRP3 inflammasome activation in mouse and human macrophages. It was also found that PND specifically inhibited NLRP3-mediated inflammasomes without affecting AIM2 and NLRC4-dependent pathways. Screening experiments were performed to reveal the anti-inflammatory effects of ginseng isolated parts. Unexpectedly, the polar parts (H2O and BuOH) containing a large number of saponin types (ginsenosides) did not alter IL-1β secretion. It was also found that PND did not inhibit NLRP3 inflammation by inhibiting the LPS-priming step. This study reports that ginseng extract panaxol selectively inhibits NLRP3 inflammasome, thereby improving NASH-induced liver inflammation and fibrosis. Therefore, PND may be a potential therapeutic option for delaying liver inflammation when liver bioavailability and side effects of human use are confirmed in the near future.

04 Saponin Rb1 prevents age-related endothelial cell senescence by regulating SIRT1/caveolin-1/enos signaling pathway

Abstract:

Ginsenoside Rb1 (g-Rb1) is one of the main bioactive components of ginseng and has been scientifically considered to have anti-aging effects. The vascular pharmacological activity and potential clinical application value of g-Rb1 need further study. Human umbilical vein endothelial cells (HUVECs) were used to establish a replicative aging model, and the effects of g-Rb1 on the SIRT1/caveolin-1/eNOS axis were detected by real-time RT-PCR, western blotting, small interfering RNA (siRNA), and immunoprecipitation.

Results: g-Rb1 increased the production of NO in HUVECs and alleviated the replicative senescence of HUVECs. The application of g-Rb1 increased the mRNA and protein abundance of SIRT1 and eNOS, while inhibiting the expression of caveolin-1. siRNA inhibited SIRT1 and eNOS, thus inhibiting the anti-aging function of g-Rb1, while caveolin-1 siRNA enhanced its anti-aging function. g-Rb1 reduced the acetylation level of caveolin-1, increased the production of NO, and was inhibited by SIRT1 siRNA, indicating that both g-Rb1 and caveolin-1 siRNA can reduce the acetylation level of eNOS and increase NO production.

Conclusion: G-Rb1 inhibits age-related endothelial cell senescence by regulating the SIRT1/caveolin-1/eNOS signaling pathway.

Conclusions:

This study showed that g-Rb1 alleviated the replicative senescence of HUVECs by upregulating SIRT1/caveolin-1/eNOS, reducing the acetylation levels of caveolin-1 and eNOS, and increasing the expression of NO. It was also found for the first time that g-Rb1 regulated the activity of eNOS by regulating the expression and acetylation of caveolin-1, and this finding was related to the upregulation of SIRT1. The experimental results can provide a new theoretical basis for g-Rb1 to delay endothelial cell senescence. However, the clinical application of g-Rb1 requires further experimental research.

05 Ginseng polysaccharides prevent the occurrence of non-alcoholic fatty liver disease by regulating mouse liver metabolism and intestinal microorganisms

Abstract:

Ginseng polysaccharides prevent the occurrence of non-alcoholic fatty liver disease by regulating mouse liver metabolism and intestinal microorganisms. A new polysaccharide (PSPJ) with specific molecular weight and monosaccharide composition was isolated and purified from ginseng water extract. The efficacy of PSPJ in avoiding nonalcoholic fatty liver disease (NAFLD) was evaluated by 16S rRNA analysis and non-targeted metabolomics analysis. This study suggests that PSPJ can significantly reduce liver fat accumulation, elevated blood lipids and ALT caused by HFD, suggesting that PSPJ can prevent NAFLD. Cell experiments proved that PSPJ does not directly affect hepatocytes. 16S rRNA analysis showed that PSPJ can improve intestinal flora disorders and changes in short-chain fatty acids (SCFAs) caused by high-fat diet (HFD). In particular, the addition of PSPJ reduced the abundance of Turicibacter, Dubosiella and Staphylococcus, and increased the abundance of Bacteroides, Blautia and Lactobacillus. Non-targeted metabolomics analysis showed that PSPJ improved liver metabolic disorders by regulating arachidonic acid metabolism, carbohydrate digestion and absorption, fatty acid biosynthesis, fatty acid metabolism and retinol metabolism. The results of this study indicate that PSPJ has the potential to regulate liver metabolism by changing the composition of intestinal bacteria, thereby preventing NAFLD.

Conclusions:

This study showed that in the HFD-induced NAFLD mouse model, the addition of PSPJ inhibited lipid accumulation in the liver, regulated intestinal microbial flora dysbiosis, improved liver metabolism, and affected intestinal SCFAs levels. It is worth noting that PSPJ does not directly act on hepatocytes to exert its effects. The relationship between the specific structure of PSPJ and the therapeutic effect of NAFLD will be further explored. In addition, the impact of intestinal flora will be further studied through flora transplantation to ensure effectiveness. Combining intestinal metabolomics, serum metabolomics, and liver metabolomics will help to discover specific differential metabolites regulated by the microbiota and clarify the specific mechanism of action of PSPJ.