Mechanism of 6-gingerol in improving glucose and lipid metabolism disorders in L6 myoblasts based on network pharmacology research
Dysregulation of glucose and lipid metabolism, as an important characteristic of metabolic diseases, seriously endangers human health. With the rapid increase of high-fat or high-sugar diet, obesity, diabetes, hypertension, dyslipidemia, nonalcoholic fatty liver, atherosclerosis and other diseases related to glucose and lipid metabolism have attracted more and more attention. Insulin resistance (IR) is one of the main core pathologies of glucose and lipid metabolism, commonly present in patients with abnormal glucose and lipid metabolism. Skeletal muscle is an important site for energy metabolism in the body and the main organ for glucose consumption. About 80% of glucose uptake and fatty acid consumption caused by insulin stimulation are completed by skeletal muscle. Therefore, skeletal muscle tissue plays an important role in insulin resistance and is a key peripheral tissue for regulating glucose and lipid metabolism. Studies have shown that muscle mitochondrial energy supply disorder, increased fatty acid intake and reduced oxidation are closely related to disorders of glucose and lipid metabolism such as lipid deposition, IR, type 2 diabetes (T2DM). The establishment of a glucose and lipid metabolism disorder model by stimulating L6 rat myoblasts with free fatty acids has been applied in the evaluation of various potential hypoglycemic and lipid-lowering drugs. However, due to the complex regulatory mechanism of glucose and lipid metabolism, the single target of drug therapy, and the risk of adverse reactions, finding safe, effective, and comprehensive drugs to improve glucose and lipid metabolism disorders has always been a difficult problem for clinical physicians to solve. Traditional Chinese medicine has obvious characteristics and advantages in preventing and treating glucose and lipid metabolism disorders, with features such as multi-target, multi pathway, synergistic enhancement, and synergistic interaction.

Traditional Chinese Medicine believes that diseases related to glucose and lipid metabolism disorders belong to the categories of quenching thirst, spleen itching, phlegm turbidity, fatigue, symptom scars, and accumulation. They are a group of syndromes caused by organ dysfunction and loss of body fluids due to transfusion. Blood lipids and blood sugar are like nourishing blood and body fluids, which are refined substances produced by the transformation of water and grains. Under physiological conditions, the organs function well, and the essence of water and grains permeates the blood vessels, warming the skin and nourishing the organs and bones. Overeating fat, sweet and mellow wine, sitting for a long time and lying down for a long time can damage the temper, the spleen does not dissipate essence, the essence cannot go up to the lungs and go to the hundred veins, the essence of water and grain remains unchanged, the soil is blocked and the wood is stagnant, the stagnation turns to heat, the gas consumption hurts the body fluid, the clear gas does not rise, the turbid yin does not fall, the accumulation of dampness generates phlegm, and the retention of phlegm causes fatigue. The turbid phlegm and addiction lead to increased blood sugar and lipid due to the inhibition of the meridians and viscera, which is the basic cause and pathogenesis of diseases related to the disorder of glucose and lipid metabolism. Ginger is the rhizome of Zingiber officinale Rosc, a plant in the ginger family. Ginger is one of the most commonly used seasonings in the world and also one of the most commonly used herbs in traditional medicine. Traditional Chinese medicine believes that ginger has a pungent taste and can disperse phlegm, regulate the spleen, stomach, and lung meridians, warm the middle and dispel cold, dry dampness and eliminate phlegm. It is widely used in regulating the spleen and stomach and treating phlegm and dampness. Ginger can improve lipid metabolism and has a good lipid-lowering effect. The 6-gingerol in ginger has high biological activity in lipid-lowering. Our previous research has shown that 6-gingerol can significantly improve fatty liver, lipid deposition, mitochondrial function, hypertriglyceridemia, and insulin sensitivity in rats induced by high fructose and aging. Pournaderi et al. found that 6-gingerol, as the main active ingredient in ginger, has significant anti-inflammatory and antioxidant effects. Algandaby et al. pointed out that the anti-inflammatory effect of 6-gingerol can prevent and treat liver fibrosis in rats. Saravanan et al. found that 6-gingerol reduces obesity induced by a high-fat diet by regulating lipid distribution and adjusting the levels of insulin, leptin, amylase, and lipase.

Although there have been numerous literature reports indicating that 6-gingerol can improve glucose and lipid metabolism disorders, its specific targets and mechanisms of action are still unclear. With the development of bioinformatics, exploring drug targets based on network pharmacology has become an emerging research hotspot. This study combines network pharmacology with in vitro experiments to investigate the target and mechanism of 6-gingerol in treating glucose and lipid metabolism disorders in L6 rat myoblasts induced by high fructose and high oleic acid.

The disorder of glucose and lipid metabolism is a disease involving heredity, environment, spirit, diet and other factors. Its mechanism mainly involves neuroendocrine immune disorder, insulin resistance, oxidative stress, inflammatory reaction, intestinal flora imbalance, etc. The main clinical manifestations are hyperglycemia, dyslipidemia, fatty liver, overweight, hypertension, atherosclerosis, etc. This study constructed a gene regulatory network for 6-gingerol glucose and lipid metabolism disorders and found that the PI3K-AKT signaling pathway is closely related to the target of 6-gingerol. Further gene mapping revealed that the PI3KAKT pathway, mTOR, ERK, and NF – κ B-p65 may be important targets for the action of 6-gingerol.

The PI3K-AKT signaling pathway is the main signaling pathway activated by insulin. After insulin activates this pathway, it induces downstream protein cascade reactions and participates in glucose and lipid metabolism. PI3K activates AKT, which phosphorylates downstream substrates involved in regulating various cellular functions, including apoptosis, metabolism, and cell cycle progression. When the body is in an IR state, the transduction of this signaling pathway is also affected, and the related functional transduction pathways are weakened or blocked. The phosphorylation levels of insulin receptor substrates (IRS), PI3K, and AKT proteins in the pathway are downregulated. The impaired PI3K-AKT pathway is associated with the development of obesity and disturbances in glucose and lipid metabolism. The results of this study showed that compared with the control group, the AKT gene level and protein phosphorylation were downregulated in the model group; Compared with the model group, the AKT gene level and protein phosphorylation level were upregulated in the treatment group; There was no significant difference in the PI3K gene among the groups, and compared with the model group, the PI3K protein level was significantly upregulated in the treatment group. This suggests that 6-gingerol may overcome damage to the insulin signaling pathway and improve glucose and lipid metabolism disorders by regulating the PI3K-AKT pathway. MTOR is a 289kD serine/threonine kinase, a downstream pathway of PI3K-AKT, and an important molecular link between essential nutrients and metabolic processes for cell growth. Research has shown that in a high-fat environment, the phosphorylation level of mTOR increases. Inhibiting mTOR phosphorylation can promote the activation of autophagy signaling pathways and improve insulin resistance, thereby improving glucose and lipid metabolism disorders. Yu et al. demonstrated that 6-gingerol inhibits the expression of p-mTOR. The results of this study showed that compared with the control group, the model group had upregulated pmTOR; Compared with the model group, the administration of p-mTOR was downregulated, suggesting that 6-gingerol may inhibit mTOR phosphorylation to improve glucose and lipid metabolism disorders.

Nishi et al. found that long-term lipid metabolism imbalance can lead to ectopic fat distribution (lipotoxicity) in peripheral organs, including the kidneys, heart, and skeletal muscles, thereby accelerating peripheral inflammation and disease. Research has shown that ectopic deposition of lipids in skeletal muscle can promote the occurrence of inflammation. In recent years, more and more evidence shows that there is a potential relationship between chronic low-grade inflammation and disorders of glucose and lipid metabolism (such as insulin resistance, apparent obesity and type 2 diabetes), which are related to abnormal production of inflammatory factors. Elevated levels of inflammatory cytokines can affect insulin and lipid signaling molecules, leading to disturbances in glucose and lipid metabolism. Longo et al. also found that glucose and lipid metabolism disorders can be improved by improving inflammation and insulin sensitivity in tissues. Research has shown that gene transcription and expression of inflammatory cytokines require activation of nuclear transcription factor kappa B (NF – κ B), with NF – κ B activation being associated with mitogen activated protein kinase (MAPK). NF – κ B is a eukaryotic transcription factor associated with oxidative stress, and p65 is an important subunit involved in NF – κ B activation. Activated NF – κ B enters the nucleus and induces the expression of many genes involved in innate and adaptive immune regulation, cell adhesion, inflammatory response, and anti apoptotic mechanisms. The MAPK pathway plays an important role in the inflammatory response, including the cascade reaction mediated by p38 MAPK and ERK. The activation of this signaling pathway is related to the increased release of inflammatory factors such as TNF – α caused by the activation of the NF – κ B pathway, thereby exacerbating the inflammatory response. At present, multiple in vitro and in vivo experiments have shown that the active ingredients of ginger exert strong anti-inflammatory effects by inhibiting NF – κ B and MAPK phosphorylation. NF – κ B can mediate the regulation of various inflammatory mediators, including TNF – α, IL-1 β, IL-6, IL-8, etc. Research has also shown that 6-gingerol extracted from edible ginger has anti-inflammatory effects. This study found that compared with the control group, the protein levels of IL-1 β, TNF – α, p-ERK, and p-NF – κ Bp65 were upregulated in the model group; After administration, this situation was reversed, indicating that 6-gingerol may improve glucose and lipid metabolism disorders by regulating the post-translational levels of ERK and NF – κ B-p65, blocking pro-inflammatory factors IL-1 β and TNF – α, and reducing inflammation.

In summary, 6-gingerol can inhibit the phosphorylation of ERK and NF – κ B-p65 proteins, thereby reducing inflammatory responses and improving insulin resistance by regulating the PI3K/AKT/mTOR axis. This study elucidated the potential targets of 6-gingerol in treating glucose and lipid metabolism disorders, providing a theoretical basis for the clinical application of 6-gingerol.