ABSTRACT
<p><b>OBJECTIVE</b>To observe the effects of Cinnamyl aldehyde (CA) on NIH3T3 cell cycle and explore the possible mechanism further.</p><p><b>METHOD</b>Flowcytometry was used for observing cell cycle distribution. Expressions of proliferation cell nuclear antigen (PCNA) and Cyclin D1 protein in NIH3T3 cells were assessed by immunocytochemistry.</p><p><b>RESULT</b>After culture with CA for 24 hours, the percentage of populations of S phase was enhanced by 3% (P < 0.05) and cell proliferation index (PrI, S + G2/M) was increased by 3.5% (P < 0.01) , but G2/M phase had no obvious changes. The expressions of Cyclin D1 and PCNA proteins were improved markly by CA compared with controlgroup (P < 0.01).</p><p><b>CONCLUSION</b>CA could promote more cells in G0/G1 phase into S phase, which may be related to the regulation of the expressions of PCNA and Cyclin D1.</p>