Fig 3. Effects
of AS-IV on influenza virus in A549 cells. (A) A549 cells infected with
IAV were treated with 50,75, and 100μM AS-IV, and the infection rate of
IAV in A549 cells in each group was observed after 16h, with a scale
bar, of 100 μ m. (B, C) Western blot detected NP protein expression in
A549 cells treated with AS-IV after influenza virus infection. (D)100μM
AS-IV treated A549 cells infected with IAV, and immunofluorescence was
performed at different time points (2h, 4h, 6h, 8h, 10h, 12h) to observe
the effect of AS-IV on nuclear membrane shuttle transport of IAV NP
protein in A549 cells, with scale bar,20 μ
m. The values are expressed as
the mean ± SD. of three independent experiments. ns, no significant
difference. * P < 0.05, ** P < 0.01.
3.2. AS-IV down-regulates
ROS induced by influenza virus infection
To detect the antioxidant effects of AS-IV, intracellular TAC, SOD, GPX,
CAT, MDA, and ROS levels were measured. We confirmed that the levels of
intracellular TAC, SOD, GPX, and CAT were significantly reduced after
influenza virus infection, while AS-IV treatment restored the inhibition
of TAC, SOD, GPX, and CAT by influenza virus infection
(Fig. 4A-D). The results of MDA
detection showed that MDA concentration in the IAV group was increased
compared with the NC group, while MDA level in AS-IV-treated cells was
down-regulated compared with the IAV group
(Fig. 4E). As shown in flow cytometry
analysis, the ROS levels were dramatically elevated after influenza
virus infection, while the levels of ROS for AS-IV groups were rescued
after treatment (Fig. 4F).