CMS Alleviated Oxidative Stress, Inflammation and Apoptosis in
the Retina of DR Rats
Further, we examined oxidative stress and inflammation in STZ rats. It
was shown that compared with the sham-operated rats, the reactive oxygen
species (ROS) and 3,4-methylenedioxyamphetamine (MDA) levels were
significantly increased, while superoxide dismutase (SOD) level was
decreased in the retinal tissue of rats injected with STZ, which could
be blocked by co-treatment of CMS in a dose-dependent manner (Table 2).
In addition, the results of RT-qPCR and western blot analysis suggested
that compared with sham-operated rats, the expression of iNOS was
notably increased in rats injected with STZ, which was inhibited by CMS
in a dose-dependent manner (Figure 2A - B). Nitrite test showed that
compared with sham-operated rats, the expression of NO was notably
increased in rats injected with STZ, which was blocked by CMS in a
dose-dependent manner (Figure 2C). According to the result of ELISA,
compared with sham-operated rats, rats injected with STZ presented
notably increased expression of interleukin-6 (IL-6), tumor necrosis
factor α (TNF-α), and C-reactive protein (CRP). And compared with rats
injected with STZ, rats injected with CMS + STZ presented a
significantly decreased expression of IL-6, TNF-α, and CRP, and the
effect of CMS was dose-dependent (Figure 2D - F). Then cell apoptosis
was detected by TUNEL, which found that apoptosis in rats injected with
STZ notably increased when compared with sham-operated rats. And
compared with rats injected with STZ, apoptosis in rats injected with
CMS + STZ obviously reduced, and the effect of CMS was dose-dependent
(Figure 2G). Besides, western blot analysis showed that the expression
of apoptotic factors (Cyt-C and Caspase-3) in rats injected with STZ was
higher than that in sham-operated rats. And compared with rats injected
with STZ, rats injected with CMS + STZ showed a reduced expression of
apoptotic factors (Cyt-C and Caspase-3), and the effect of CMS was
dose-dependent (Figure 2H). Taken together, it was concluded that CMS
was beneficial to alleviate the increased oxidative stress, inflammation
and apoptosis in retina in the STZ rat model induced by DR.