Abstract: BACKGROUND: Luteolin has a variety of pharmacological activities such as antibacterial, anti-inflammatory, antioxidant, etc., which can inhibit the release of cellular inflammatory factors, promote cell proliferation, and improve the cellular microenvironment.
OBJECTIVE: To explore the potential roles and mechanisms of luteolin in promoting diabetic chronic wound healing using network pharmacology and in vivo experiments.
METHODS: Potential targets of luteolin were screened using multiple databases, systemic pharmacology of Chinese medicines database, PubChem and UniProt databases. Genes related to wound healing were identified through the GeneCards database. A protein-protein interaction network was constructed to screen core targets, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to explore the biological pathways that luteolin may affect. In vivo experiments in mice were conducted to observe the effects of luteolin on wound healing. Eighteen C57BL/6 mice were randomly divided into three groups. A 1 cm diameter full skin defect wound was made on the back of the control group (n=6), and a 1 cm diameter full skin defect wound was made on the back of the model group (n=6) and the treatment group (n=6) after the establishment of the diabetes model. The treatment group was given 200 mg/kg luteolin by gavage once a day for 9 consecutive days after the operation, and the wound healing was observed. At the end of drug administration, the samples were taken for hematoxylin-eosin and Masson staining. qRT-PCR was used to detect the mRNA expression of interleukin 6 and tumor necrosis factor α, and western blot was used to detect the protein expression of phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway.
RESULTS AND CONCLUSION: (1) Network pharmacological analysis identified 56 potential target genes associated with luteolin for the treatment of chronic wounds, of which the AKT gene was most closely linked to other target genes. Gene Ontology analysis indicated that luteolin could have antioxidant and anti-stress effects and have the potential to act as a multi-targeted drug. Kyoto Encyclopedia of Genes and Genomes analysis indicated that the target genes of luteolin were mainly enriched in the PI3K/AKT signaling pathway. (2) On the 9th day of drug administration, the remaining wound area of mice in the control and treatment groups was smaller than that of the model group (P < 0.05). Hematoxylin-eosin and Masson staining results showed that compared with the model group, the number of trabecular granulation tissues and collagen deposition were increased in the treatment group, and the degree of epithelialization was higher and close to that of the control group. The mRNA expression of interleukin 6 and tumor necrosis factor α on the wound surface was lower in the treatment group than the model group (P < 0.05), while the protein expression of p-PI3K and p-AKT was higher in the treatment group than the model group (P < 0.05). To conclude, luteolin inhibits wound inflammatory response and promotes healing of diabetic wounds by modulating the PI3K/AKT signaling pathway.

Key words: luteolin, chronic wound healing, diabetes, PI3K/AKT signaling pathway, network pharmacology, inflammatory response, tissue repair, gene enrichment analysis, engineered tissue construction