Research on the conversion pattern of 6-gingerol in stir-fried ginger and the protective activity mechanism of its conversion products on HUVECs

Gingerol compounds are the main active and spicy components in ginger, among which 6-gingerol has the highest content. Gingerol compounds have an unstable structure due to multiple phenolic hydroxyl groups. During drying, heating, and processing, the gingerol component can be decomposed and converted, which is a primary factor contributing to the varied pharmacological effects of processed ginger products. However, the specific conversion pattern and activity changes of gingerol components before and after conversion are still unclear. This study aims to observe the conversion mechanism of 6-gingerol during the processing of dried ginger into stir-fried ginger, using 6-gingerol as a representative compound. Furthermore, by investigating its mechanism of protecting vascular endothelial cells, this study provides experimental evidence for the changes in the pharmacological effects of 6-gingerol and ginger during processing. Traditionally, the sand-frying method was used to process dried ginger, and it was verified that 6-gingerol could be converted into 6-shogaol and zingerone during the processing. Subsequently, the use of 6-gingerol monomer to simulate the changes in stir-fried ginger further confirmed the conversion of its components. On the other hand, network pharmacology methods were used to predict the mechanisms by which 6-shogaol, zingerone, and 6-gingerol protect human umbilical vein endothelial cells (HUVECs). The LPS-induced HUVECs injury model experiment was used to verify the differential protective effects of 6-shogaol, zingerone, and 6-gingerol on HUVEC injury. The results showed that with the extension of frying time and the increase of temperature, the content of 6-shogaol and zingerone in stir-fried ginger gradually increased, while the content of 6-gingerol decreased with time. The simulated processing experiment of 6-gingerol monomer also confirmed that during the oil bath heating process, a portion of 6-gingerol is converted into 6-shogaol and zingerone. Network pharmacology and cell experiments have shown that 6-shogaol, zingerone, and 6-gingerol improve inflammation and oxidative stress responses in HUVECs, reduce the expression of genes and proteins related to ferroptosis and apoptosis, and their effects are related to the activation of the PI3K-AKT-NRF2 pathway. The conclusion of the study is that when dried ginger is processed into stir-fried ginger, 6-gingerol is partially converted into 6-shogaol and zingerone, and all three components have a protective effect on the LPS-induced HUVECs injury model, with 6-shogaol having stronger activity.