Amlodipine Attenuates Carrageenan-induced Oxidative Stress Targeting Transsynaptic Neuronal Damage by Promoting Survival of Retinal Ganglion Cells in Adult Zebrafish (Danio rerio)

Sep 30, 2026

Uploaded by Jiven

Transsynaptic degeneration of retinal ganglion cells (RGCs) is implicated in progressive vision loss in glaucoma, yet carrageenan (Carr)-induced inflammation and oxidative stress have not been fully evaluated. This study tests whether amlodipine (AML) administration reduces Carr-driven oxidative stress that can trigger free radical–mediated neurodegeneration and behavioral changes in zebrafish. Behavioral outcomes are assessed via NTDT and LDPT, while oxidative markers and histopathology evaluate antioxidant defense and RGC/neuronal survival.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages10

Reading Time25 min

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Abstract

Background

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Introduction

Amlodipine Attenuates Carrageenan-induced Oxidative Stress Targeting Transsynaptic Neuronal Damage by Promoting Survival of Retinal Ganglion Cells in Adult Zebrafish (Danio rerio) Annals of Neurosciences 1–10 © The Author(s) 2024 Article reuse guidelines: [in.sagepub.com/journals-permissions-india](in.sagepub.com/journals-permissions-india)[ ](in.sagepub.com/journals-permissions-india)DOI: 10. 1177/09727531241246671 [journals.sagepub.com/home/aon](journals.sagepub.com/home/aon) Ashirbad Nanda 1,2, Sai Aparna 1,3, Rudra Narayan Sahoo4 and Manorama Patri 1,5 Abstract Background: Transsynaptic degeneration of retinal ganglion cells (RGCs) likely plays a role in progressive loss of vision in glaucoma. Carrageenan (Carr), obtained from seaweed (Rhodophyceae), a sulphated polysaccharide extracted from a species of red algae (Chondrus crispus), is a reversible gel mostly used in eye-drop preparation due to its hydrocolloid nature. But Carr-induced inflammation causing oxidative stress in animals has not yet been evaluated. It was reported that amlodipine (AML) can inhibit inflammatory cytokines by lowering intracellular calcium concentration and increasing antioxidant defences. Purpose: In this study, we examined the impact of AML administration on Carr-induced oxidative stress, causing free radial– mediated neurodegeneration and behavioural alteration in zebrafish. Methods: We aimed to evaluate the behavioural alteration in zebrafish using the novel tank diving test (NTDT) and the light-dark preference test (LDPT) as invaluable tools for analysing visual functions. To understand the role of the antioxidant defence system, oxidative stress biomarkers such as lipid peroxidation and CAT activity were analysed. RGCs of the retina of the eye and neurons of the optical tectum (TeO) in the brain were investigated by histopathological studies. Results: Carr-treated groups swam in random patterns and showed an increased number of transitions and spent more time in alter zones, whereas controls prefer perceived motion. AML significantly attenuates the increased lipid peroxidation level and decreased CAT activity with Carr administration. Histopathological analysis showed an increase in the percentage of pyknotic cell counts after Carr treatment, whereas AML supplementation significantly reduced the pyknotic RGC cell count in the retina and TeO of the brain. Conclusion: Findings showed the effectiveness of AML as an antioxidant and neuroprotective agent by reducing pyckonsis in developmental RGCs and possible repair mechanisms against Carr-induced oxidative stress. This study may be useful to know the underlying mechanisms of weakening and eliminating central neurons for synaptic connections in the visual system of zebrafish. Keywords Amlodipine, carrageenan, glaucoma, retinal ganglionic cells, zebrafish Received 03 November 2023; accepted 06 March 2024 Introduction Glaucoma causes characteristic damage in retinal ganglion cells (RGCs), causing vision loss and blindness by damaging the optic nerves. RGCs are the binding neurons connecting the retina with the visual processing centre within the central nervous system (CNS) with restricted regeneration capacity. 1,2 Moreover, the RGC axon extends from the retina to the brain and is most vulnerable to free radicals. An increase in free radical generation contributes to DNA and protein damage, leading to apoptosis. Free radicals attack neural cells and contribute to an increase in wall pressure in the eye cup that may trigger the degeneration of RGCs.3,4 RGCs and their trans-synaptic neuronal protection have become an emerging topic in the control of glaucoma.5,6 Axonal degeneration of RGCs in glaucoma contributes to progressive damage to the 1 Neurobiology Laboratory, Department of Zoology, School of Life Sciences, Ravenshaw University, Cuttack, Odisha, India 2School of Pharmacy and Life Sciences, Centurion University of Technology and Management, Bhubaneswar, Odisha

FAQs

What research question does the study address?

The study examines how amlodipine administration affects carrageenan-induced oxidative stress and its downstream transsynaptic neuronal damage in adult zebrafish.

How were behavioral changes in zebrafish measured?

Behavioral alteration was evaluated using the novel tank diving test (NTDT) and the light-dark preference test (LDPT) to analyze visual-related functions.

What key biological effects did amlodipine show against carrageenan?

Amlodipine significantly attenuated increased lipid peroxidation and reduced CAT activity changes caused by carrageenan, and it lowered the pyknotic RGC cell count in both retina and the optical tectum.

Sep 30, 2026

Uploaded by Jiven