Ganoderma lucidum aqueous extract inducing PHGPx to inhibite membrane lipid hydroperoxides and regulate oxidative stress based on single-cell animal transcriptome

In this study, the single-cell eukaryotic model organism Tetrahymena thermophila was used as an experimental material to reveal the anti-aging mechanism of Ganoderma lucidum aqueous extract. After treatment with the G. lucidum aqueous extract, the logarithmic phase was extended, and the maximum density of T. thermophila increased to 5.5 × 10⁴ cells/mL. The aqueous extract was more effective than the main active monomers of G. lucidum. The membrane integrity in the cell including mitochondria and nucleus appeared improvement after treatment with the G. lucidum aqueous extract, which observed by ammonia silver staining and transmission electron microscopy. Gene Ontology (GO) functional enrichment of the differentially expressed genes in transcriptome showed that the G. lucidum aqueous extract promoted the biological metabolic process of membrane components. According to Kyoto Encyclopedia of Genes and Genomes (KEGG), the glutathione metabolism process was enhanced in both growth phases. Protein–protein interaction (PPI) network analysis illustrated that phospholipid hydroperoxide glutathione peroxidase (PHGPx) played a key role in the anti-aging mechanism. The results suggested that G. lucidum aqueous extract improved the GPX activity as well as reduced the malondialdehyde content and cell damage. More importantly, the expression of PHGPx was promoted to reduce the oxidation degree of the membrane lipids and enhance the integrity of the membrane to achieve anti-aging effects.