Objective: To investigate the protective effect of Pollen Pini on oxidative damage of HepG2 cells induced by H2O2. Method: HepG2 cells were divided into normal control group

H2O2 model group and intervention group. HepG2 cells of the intervention group were pretreated with different concentrations of Pollen Pini for 12 h. Then

to produce oxidative stress

the H2O2 model group and the intervention group were treated with 400 μmol·L-1 H2O2 to damage cells for 2 h. Cell viability was measured by methylthiazolyl tetrazolium (MTT) assay. To evaluate the protective effect of Pini Pollen on HepG2 cells

cell viability

intracellular reactive oxygen species (ROS)

superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities

lactate dehydrogenase (LDH) and malondialdehyde (MDA) contents were detected. In addition

the expressions of key genes nuclear factor-E2-related factor 2 (Nrf2)

Kelch-like epichlorohydrin-associated protein 1 (Keap 1)

heme oxygenase-1 (HO-1)

glutamate-cysteine ligase (GCL) in antioxidant pathway were determined by western blot. Result: MTT results showed that

compared with normal control group

the cytotoxicity of Pollen Pini groups (80

40

20

10

5 mg·L-1) were non-toxic. The contents of ROS

LDH and MDA in the H2O2 model group were significantly increased (P<0.01)

while the activities of SOD and GSH-Px were significantly depressed (P<0.01). Compared with the H2O2 model group

the contents of ROS

LDH and MDA in the intervention group were significantly reduced (P<0.05

P<0.01)

whereas the activities of SOD and GSH-Px were significantly increased (P<0.05

P<0.01). Western blot results indicated that pollen pini up-regulated protein expressions of Nrf2

HO-1 and GCL

but down-regulated the expression of Keap1 protein. Conclusion: The 5-20 mg·L-1 of Pollen Pini can effectively protect 400 μmol·L-1 H2O2-induced oxidative stress damage in HepG2 cells. The mechanism may be related to regulation of the activity of SOD

GSH-Px activity

ROS

LDH and MDA levels

and protein expressions of key genes Nrf2

Keap 1

HO-1

and GCL in the antioxidant pathway.