Research Article: Ginsenoside Rb1 attenuates diabetic retinopathy in streptozotocin-induced diabetic rats1

Date Published: February 28, 2019

Publisher: Sociedade Brasileira para o Desenvolvimento da Pesquisa em
Cirurgia

Author(s): Changxia Dong, Peng Liu, Huaizhou Wang, Mei Dong, Guangxin Li, Yuanbin Li.

http://doi.org/10.1590/s0102-8650201900201

Abstract

To investigated the effects of ginsenoside Rb1 on diabetic retinopathy in
streptozotocin-induced diabetic rats.

Diabetes was induced by a single intraperitoneal injection of streptozotocin
(80 mg/kg) in male Wistar rats. Ginsenoside Rb1 (20, 40 mg/kg) was injected
(i.p.) once a day for 4 weeks. Then, using fundus photography, the diameter
and vascular permeability of retinal vessels were investigated. Retinal
histopathology was undertaken. Contents of malondialdehyde (MDA) and
glutathione (GSH) in retinas were assayed. Levels of nuclear factor
erythroid 2-related factor 2 (Nrf2), glutathione cysteine ligase catalytic
subunit (GCLC), and glutathione cysteine ligase modulatory subunit (GCLM)
were measured.

Treatment with ginsenoside Rb1 attenuated the diabetes-induced increase in
the diameter of retinal blood vessels. Ginsenoside Rb1 reduced extravasation
of Evans Blue dye from retinal blood vessels. Ginsenoside Rb1 partially
inhibited the increase in MDA content and decrease in GSH level in rat
retinas. Nrf2 levels in the nuclei of retinal cells and expression of GCLC
and GCLM were increased significantly in rats treated with ginsenoside Rb1.

These findings suggest that ginsenoside Rb1 can attenuate diabetic
retinopathy by regulating the antioxidative function in rat retinas.

Partial Text

Diabetes mellitus is a metabolic disease that affects more than 170 million people
worldwide. Despite a new generation of medications and advances in clinical
treatments, the prevalence of diabetes mellitus has risen dramatically in recent
decades.

There are studies which indicated a protective role for alcoholic
ginseng root extract and Korean red ginseng
powder agonist DR16,17. However, the alcoholic extract and power of ginseng
contain many compounds. Therefore, it is still unclear which compound of
ginseng has the property of preventing DR. The present findings
suggest that ginsenoside Rb1 abrogated (at least in part) the diabetes-induced
increase in the diameter of and histopathologic changes in retinal vessels.
Ginsenoside Rb1 also reduced the permeability of retinal blood vessels in diabetic
rats. Ginsenoside Rb1 augmented levels of Nrf2 and GSH and, therefore, attenuated
oxidative-stress injury to the retina. Thus, this work constitutes the first study
demonstrating that ginsenoside Rb1 can attenuate DR by regulating the antioxidative
function in STZ-induced diabetic rats.

In the present study, we observed that treatment with ginsenoside Rb1 resulted in an
increase in nuclear translocation of Nrf2 in the retinas of STZ-induced diabetic
rats. Moreover, our data showed that expression of GCLC and GCLM was enhanced after
treatment with ginsenoside Rb1. In accordance with these findings, ginsenoside Rb1
also led to an increase in GSH content followed by the decrease in the MDA level.
These results suggest that the protective effects of ginsenoside Rb1 can be
attributed (at least in part) to anti-oxidative properties due to augmentation of
Nrf2-induced expression of GCLC and GCLM. The current study suggests that
ginsenoside Rb1 can attenuate DR by regulating the antioxidative function in rat
retinas.

 

Source:

http://doi.org/10.1590/s0102-8650201900201

 

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