Puerarin inhibited oxidative stress and alleviated cerebral ischemia-reperfusion injury through PI3K/Akt/Nrf2 signaling pathway

Qianqian Zhang; Min Yao; Jiajia Qi; Rui Song; Lei Wang; Jiacheng Li; Xian Zhou; Dennis Chang; Qi Huang; Lili Li; Ning Wang

doi:10.3389/fphar.2023.1134380

Puerarin inhibited oxidative stress and alleviated cerebral ischemia-reperfusion injury through PI3K/Akt/Nrf2 signaling pathway

Front Pharmacol. 2023 May 22:14:1134380. doi: 10.3389/fphar.2023.1134380. eCollection 2023.

Authors

Qianqian Zhang^{1

2

3}, Min Yao^{1

2

3}, Jiajia Qi^{1

2

3}, Rui Song¹, Lei Wang^{1

2

3}, Jiacheng Li^{1

2

3}, Xian Zhou⁴, Dennis Chang⁴, Qi Huang^{1

2

5}, Lili Li^{1

2

3

6}, Ning Wang^{1

2

3

6}

Affiliations

¹ Department of Pharmacy, Anhui University of Chinese Medicine, Hefei, China.
² Anhui Province Key Laboratory of Research & Development of Chinese Medicine, Anhui University of Chinese Medicine, Hefei, China.
³ Anhui Province Key Laboratory of Chinese Medicinal Formula, Anhui University of Chinese Medicine, Hefei, China.
⁴ National Institute of Complementary Medicine, Western Sydney University, Westmead, NSW, Australia.
⁵ Anhui Province Key Laboratory of Pharmaceutical Preparation Technology and Application, Anhui University of Chinese Medicine, Hefei, China.
⁶ Institute for Pharmacodynamics and Safety Evaluation of Chinese Medicine, Anhui Academy of Traditional Chinese Medicine, Hefei, China.

Abstract

Introduction: Puerarin (PUE) is a natural compound isolated from Puerariae Lobatae Radix, which has a neuroprotective effect on IS. We explored the therapeutic effect and underlying mechanism of PUE on cerebral I/R injury by inhibiting oxidative stress related to the PI3K/Akt/Nrf2 pathway in vitro and in vivo. Methods: The middle cerebral artery occlusion and reperfusion (MCAO/R) rats and oxygen-glucose deprivation and reperfusion (OGD/R) were selected as the models, respectively. The therapeutic effect of PUE was observed using triphenyl tetrazolium and hematoxylin-eosin staining. Tunel-NeuN staining and Nissl staining to quantify hippocampal apoptosis. The reactive oxygen species (ROS) level was detected by flow cytometry and immunofluorescence. Biochemical method to detect oxidative stress levels. The protein expression related to PI3K/Akt/Nrf2 pathway was detected by using Western blotting. Finally, co-immunoprecipitation was used to study the molecular interaction between Keap1 and Nrf2. Results: In vivo and vitro studies showed that PUE improved neurological deficits in rats, as well as decreased oxidative stress. Immunofluorescence and flow cytometry indicated that the release of ROS can be inhibited by PUE. In addition, the Western blotting results showed that PUE promoted the phosphorylation of PI3K and Akt, and enabled Nrf2 to enter the nucleus, which further activated the expression of downstream antioxidant enzymes such as HO-1. The combination of PUE with PI3K inhibitor LY294002 reversed these results. Finally, co-immunoprecipitation results showed that PUE promoted Nrf2-Keap1 complex dissociation. Discussion: Taken together, PUE can activate Nrf2 via PI3K/Akt and promote downstream antioxidant enzyme expression, which could further ameliorate oxidative stress, against I/R-induced Neuron injury.

Keywords: PI3K/Akt/Nrf2 pathway; cerebral ischemia reperfusion injury (CIRI); hippocampal neurons; oxidative stress; puerarin.

Grants and funding

The study was supported by “Basic Research on the Application of Chinese Medicinal Formula in the Prevention and Treatment of Encephalopathy” of Excellent Research and Innovation Team of Universities in Anhui Province (Department of Education of Anhui Province, No.2022AH010034) and Anhui Province 13th batch 115 industrial innovation team “Innovative team for prevention and treatment of encephalopathy with acupuncture and medicine” project (Anhui talent Office [2020] No.4) and Academic assistance program for the top-notch innovative talents from universities in 2017 provided by Anhui Province Office of Education (gxbjZD15).