Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Arbutin mitigates chronic hypertension-induced optic nerve damage in rats via regulation of inflammatory cytokine levels and oxidative stress

Zongshan Fan, Fengqiong Zhao, Hai Huang, Xuewen Huang

Department of Ophthalmology, Nanchong Central Hospital, The Second Clinical College of North Sichuan Medical College, Nanchong, Sichuan 637000, China;

For correspondence:- Xuewen Huang Email: gxrjrx@163.com Tel:+8618281701631

Accepted: 2 December 2021 Published: 30 December 2021

Citation: Fan Z, Zhao F, Huang H, Huang X. Arbutin mitigates chronic hypertension-induced optic nerve damage in rats via regulation of inflammatory cytokine levels and oxidative stress. Trop J Pharm Res 2021; 20(12):2489-2495 doi: 10.4314/tjpr.v20i12.5

© 2021 The authors.
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Abstract

Purpose: To investigate the effect of arbutin on chronic hypertension-induced optic nerve damage in rats, and the mechanism(s) of action involved.

Methods: Adult Sprague Dawley rats (n = 32) of both sexes weighing 200 - 230 g (mean weight = 215 ± 15 g) were randomly assigned to 4 groups (8 rats/group): control group, chronic hypertension glaucoma (CHG) group, 50 mg arbutin/kg body weight group, and 100 mg arbutin/kg group. Intraocular hypertension was produced in the right eye of each rat via ischemia/reperfusion. Intraocular pressure (IOP), retinal ganglion cell (RGC) survival and histopathological changes were determined. The levels of interleukin (IL)-1β, IL-6, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and nitric oxide (NO) were assayed using their respective kits. Messenger RNA (mRNA) and protein expressions of pro- and anti-apoptotic factors in retinal tissue were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting, respectively.

Results: Intraocular pressure (IOP) was significantly higher in CHG group than in control group, but was significantly and time-dependently reduced by arbutin (p < 0.05). Arbutin treatment significantly enhanced the survival of RGCs in retinal tissues of CHG rats (p < 0.05. It significantly and dose-dependently lowered the levels of circulating IL-1β, IL-6, NF-kB and NO (p < 0.05). Moreover, arbutin significantly and dose-dependently downregulated the mRNA expressions of caspase-3 and caspase-8, and bax and Akt, but upregulated bcl-2 mRNA expression (p < 0.05). Similarly, it significantly and dose-dependently downregulated the protein expressions of caspase-3, bax, p-NF-kB, inducible nitric oxide synthase (iNOS) and Akt, while it upregulated bcl-2 protein expression (p < 0.05).

Conclusion: These results show that arbutin mitigates chronic hypertension-induced optic nerve damage in rats via the regulation of inflammatory cytokine levels and oxidative stress, and therefore can potentially be used for the management of glaucoma.

Keywords: Apoptosis, Arbutin, Glaucoma, Intraocular pressure, Neuroprotection