Abstract

In this study, the effect of Gelam honey against radiation-induced DNA damage and cell survival rate of human diploid fibroblasts (HDFs) was evaluated. The degree of damaged DNA was determined by Comet assay while Clonogenic assay was used to evaluate cell survival rate. Irradiated Gelam honey at the concentration of 6 mg/ml was used to treat HDFs pre-, during- and post-exposure to 1 Gy of gamma-rays to evaluate its radioprotectant properties. Comet assay showed that exposure to gamma-rays caused a significant increase in total DNA damage in a dose dependent manner (p<0.05). Pre-treatment with Gelam honey at 6 mg/ml decreased the degree of damaged DNA significantly (p<0.05) which was not observed when Gelam honey treatment was given during- and post-irradiation. Clonogenic assay showed the percentage of survival fraction of HDFs decreased significantly with increasing dose of gamma-rays exposure (p<0.05). Cell survival rate however was significantly increased when HDFs were treated with Gelam honey pre- and during-irradiation. These findings indicated that pre-treatment with Gelam honey protected against radiation-induced DNA damage and enhanced cell survival rate. In conclusion, Gelam honey may acts as a radioprotectant agent in gamma-irradiated human diploid fibroblasts.

Key words: Gelam honey, radioprotectant, human diploid fibroblasts (HDFs), DNA damage, cells survival.