Kaempferol Inhibits The Growth Of Hypertrophic Scar By Inhibiting The Phosphorylation Of Akt

Objective: To explore whether kaempferol inhibits the growth of hypertrophic scar by inhibiting the phosphorylation of protein kinase B(Akt).It provides a new idea and method for the clinical inhibition of scar formation by Chinese herbal extracts.Methods: The experiment was mainly divided into two parts.The first part was cell experiment.The hypertrophic scar tissues were collected from 15 patients who received cicatrictomy in the Burn and Plastic Department of the General Hospital of Northern Theater Command from October,2021,to August,2022.Fibroblasts from hypertrophic scar were obtained and divided into control group and kaempferol groups with different concentrations.The proliferation,life cycle,apoptosis,and migration of scar tissue fibroblasts were analyzed at various concentrations of kaempferol by MTT assay,flow cytometry,Hoechst 33258 assay,Transwell laboratory assay,and scar assay.The effects of various kaempferol doses on the expression of associated proteins in HSFB were investigated using Western blot.The Akt si-RNA-transfected cells were split into four groups: DMSO+si-NC,DMSO+si-Akt,kaempferol+NC,and kaempferol+si-Akt.By the MTT assay,flow cytometry,Hoechst 33258 assay,Transwell assay,and scratch assays,the biological function of the cells was investigated.By the Western-blot assay,the Akt and p-Akt proteins were identified.In the second part,a scar model of the rabbit ear was created.The model was observed generally.The HE staining,Masson staining,Western-blot test,and immunohistochemistry were used to confirm if kaempferol reduced the formation and growth of scar by reducing Akt and p-Akt.Results: According to the MTT assay,flow cytometry,Hoechst 33258 assay,Transwell assay,and scratch assay results,kaempferol inhibits the fibroblast life cycle,speeds up apoptosis and the rate of cell death,and decreased the proliferation rate and migration ability of fibroblasts in the kaempferol group with the increase of kaempferol concentration and the extension of action time.Western blot showed that kaempferol group could down-regulate the expression of p-Akt.After silencing Akt,according to the MTT assay,flow cytometry,Hoechst 33258 assay,Transwell assay,and scratch assay results,it was found that kaempferol could inhibit the biological function of fibroblasts by inhibiting the phosphorylation of Akt.Although Akt was silenced,the addition of kaempferol had no appreciable impact on fibroblast migration,cell cycle,or proliferation,and it had no positive effect on apoptosis.General observation showed that after 1 week of administration,scars in the experimental group were smaller in area,lighter in color,flatter in surface and slightly softer than those in the control group.The HE and Masson staining results of the rabbit ear scar model experiment showed that Compared with the experimental group,the epidermis and dermis of the control group were thicker,with a large number of vascular hyperplasia,disordered collagen fiber arrangement and excessive accumulation.The collagen fibers in the experimental group were thinner and more orderly than those in the control group.Immunohistochemical experiments results showed that the positive expression of brown granules was more obvious in the control group than in the group smeared with kaempferol,and kaempferol down-regulated the expression of p-Akt in HS tissue.The expression of p-Akt was down-regulated in the kaempferol coated group compared with the control group.Conclusions:1.Kaempferol can inhibit the proliferation and migration of HSFB,arrest the cell cycle and promote apoptosis by down-regulating the expression of p-Akt.2.Kaempferol can inhibit the formation and development of HS by down-regulating the expression of p-Akt.3.HS could not be inhibited by adding more kaempferol after Akt was silenced.