Phenytoin sodium‐ameliorated gingival fibroblast aging is associated with autophagy

Abstract Background and Objective Human gingival fibrolasts aging is an important cause of periodontal disease. Phenytoin sodium (phenytoin) has a side effect of gingival hyperplasia and an effect on the autophagy progress. This study investigated whether the effect of phenytoin on aging gingival fibroblast is related to the autophagy pathway. Material and Methods The aging model of gingival fibroblast cell line HGF‐1 was induced by hydrogen peroxide (H 2 O 2 ), and the treatment of phenytoin and 3‐methyladenine (3‐MA) was performed simultaneously. Cell viability, cell cycle, and intracellular calcium ion were measured by flow cytometry. Changes in expression of basic fibroblast growth factor ( bFGF ), P16 INK4A , P21 cip1 , and bFGF, P16 INK4A , P21 cip1 , LC3II, p62, and Beclin were tested by using reverse transcription polymerase chain reaction, western blot, and immunofluorescence staining. Results The results showed that aging HGF‐1 proliferation was inhibited by H 2 O 2 , gene, protein expression of bFGF, P16 INK4A , and P21 cip1 were decreased, autophagy‐related proteins LC3II, p62, and Becline were decreased, and the proportion of G0/G1 phase and intracellular calcium ion of cell cycle was increased. Phenytoin treatment could recovery above changes, but the effect of phenytoin could be blocked by 3‐MA. Conclusion We propose that phenytoin alleviates the aging of gingival fibroblasts induced by H 2 O 2 . This condition is related to the enhancement of autophagy pathway.