To investigate the protective effects of Portulaca oleracea
seed extract (POA) against
cytotoxicity, oxidative stress and reactive oxygen species (ROS) generation induced by hydrogen
) in human liver cells (HepG2).
The extract (POA) was obtained by ethanol extraction of P. oleracea
seeds. Cytotoxicity in
HepG2 cells was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT)
assay, neutral red uptake (NRU) assay and morphological changes. The cells were pre-exposed to noncytotoxic
concentrations (5 - 25 μg/mL) of POA for 24 h, and then cytotoxic (0.25 mM) concentration of
. After 24 h of exposure, MTT and NRU assays were used to evaluate cell viability, while
morphological changes were assessed using phase contrast inverted microscopy. The effect of POA on
reduced glutathione (GSH) level, lipid peroxidation (LPO), and ROS generation induced by H2
The results showed that pre-exposure to POA (25 μg/mL) significantly (p <0.01) attenuated
the loss of cell viability by up to 38 % against H2
-induced oxidative stress and ROS generation. In
addition, POA (25 μg/mL) significantly (p <0.01) increased GSH level (31 %), but decreased the levels
of LPO (37 %) and ROS generation (49 %).
This study demonstrates that POA has the capacity to protect HepG2 cells against H2
induced cell death by inhibiting oxidative stress and ROS generation.