Background and purpose: Today medicinal plants have received much attention in treatment of many cancers. Juglans regia has phenolic compounds and is used in cytotoxicity studies.  This study investigated the effects of hydroalcoholic extract of Juglans regia on the growth of human cervical and liver cancer cells.

Materials and methods: The hydroalcoholic extract of the fruit of Juglans regia was prepared by percolation method. The HeLa and HepG₂ cancer cells were cultivated and further incubated with different concentrations of the extract.  After 72 hours, cell growth inhibition was examined using MTT assay. The results were statistically analyzed in Prism ver.3 applying ANOVA and post-test.

Results: The inhibitory concentration 50 (IC50) of the plant extract on human HepG₂ and HeLa cancer cells were 449.1 ± 18.26 μg/ml and 222.4 ± 2.66 μg/ml, respectively. The IC50of Cisplatin on these cancer cells were found to be 15.96±1.117 and 15.79±1.147 μg/ml, respectively. 

Conclusion: The IC50of Juglans regia on HeLa and HepG₂ was more than that in Cisplatin. Accordingly, further investigations are needed on other cancer cell lines. Moreover, due to the fact that the extract was total, future studies should aim at identifying its active substances.