Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Curcumin protects trabecular meshwork cells against hydrogen peroxide-induced oxidative stress and apoptosis via Nrf2-keap1 pathway

Yi Luo^1,2, Hongtao Ding³, Dujun Li⁴, Jihong Luo⁴

¹Department of OphthalmologyA292;Wuhan Forth Hospital; ²Department of Ophthalmology, Wuhan Puai Hospital, Tongji Medical College, Huazhong University of Science and Technology; ³Department of Internal Medicine, Wuhan No. 1 Hospital, Wuhan 430022; ⁴Department of Ophthalmology, Hubei Provincial Hospital of Traditional Chinese Medicine, Hubei Provincial Academy of Traditional Chinese Medicine, Hubei Provincial University of Traditional Chinese Medicine, Hubei 430065, China.

For correspondence:- Hongtao Ding Email:

Accepted: 24 October 2018 Published: 30 November 2018

Citation: Luo Y, Ding H, Li D, Luo J. Curcumin protects trabecular meshwork cells against hydrogen peroxide-induced oxidative stress and apoptosis via Nrf2-keap1 pathway. Trop J Pharm Res 2018; 17(11):2169-2176 doi: 10.4314/tjpr.v17i11.9

© 2018 The authors.
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Abstract

Purpose: To explore the effects and molecular mechanism of action of curcumin on trabecular meshwork cells (TMCs).

Methods: TMCs were isolated from pig eyes and NF-E2-related factor 2 (Nrf2) was knocked down by siRNA transfection. The effect of curcumin on intracellular reactive oxygen species (ROS) was measured by a ROS-specific dye. Annexin V-FITC/propidium iodide (PI) double labeling was applied to determine apoptosis. The expressions of apoptosis-associated proteins and Nrf2-Kelch-like ECH-associated protein 1 (Keap 1) pathway activation were assessed by western blotting, while target gene transcription was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR).

Results: Curcumin reduced the levels of intracellular ROS and apoptosis induced by H₂O₂, upregulated B-cell lymphoma-2 (Bcl-2), downregulated Bcl2-associated X (Bax), and activated caspase-3 and nine other proteins (p < 0.05). Curcumin reduced the expressions of Nrf2, HO-1, and NQO1, and increased Keap1 in H₂O₂-induced TMCs (p < 0.05). Moreover, Nrf2 knockdown partly reversed the effect of curcumin on ROS and apoptosis in TMCs induced by H₂O₂ (p < 0.05).

Conclusion: Curcumin inhibited oxidative stress and apoptosis by Nrf2-Keap1 activation in TMCs. Curcumin is therefore a potential therapeutic agent for the management of glaucoma.

Keywords: Curcumin, Oxidative stress, Apoptosis, Glaucoma, Nrf2-Keap1