Investigation
of the neuroprotective effects of squid ink extract to mitigate the reactive oxidative
species in stress-induced neuroblastoma cell line
Elangovan Sujatha and Arumugam Sivakumar
Res. J. Biotech.; Vol. 21(2); 105-116;
doi: https://doi.org/10.25303/212rjbt1050116; (2026)
Abstract
Neurodegeneration due to exposure to oxidants has severe effects on neuronal loss
when exposed for a prolonged period, causing them to loss neurons. The degeneration
of neurons in the substantia nigra decreases the production of dopamine in the brain,
which can further act as an initiator for the early onset of Parkinson’s disease
(PD). Carbidopa-levodopa is the standard drug used in the treatment of PD, but it
comes with a drawback of drug side effects in the long run. Marine compounds exhibit
potential for drug discovery and are rising to overcome these shortcomings in the
existing drugs. We assessed and optimised the half maximum inhibitory concentration
(IC50) of stress-induced models for hydrogen peroxide and acrylamide, as well as
the standard drug levodopa (LD) and squid ink (SI) extract using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium
bromide (MTT) assay and evaluated their cytotoxic effects. Reactive oxygen species
(ROS), cell apoptosis, colony formation, DNA fragmentation, cell migration and gene
expression studies were evaluated through 2',7'-dichlorofluorescein diacetate (DCFH-DA),
flow cytometry, proliferation assay, 4′,6-diamidino-2-phenylindole (DAPI), scratch
test assay and real-time quantitative polymerase chain reaction (RT-qPCR) respectively.
The cell viability assay exhibited IC50 values of 77±0.14, 79±0.17 and 82±0.21 μg/ml
concentrations for control, hydrogen peroxide and acrylamide groups respectively.
The ROS assay showed significant antioxidant activity in the stress-induced groups
compared to the LD-treated group. Likewise, DAPI staining showed lesser DNA fragmentation
in stress-induced cells in SI-treated groups. Similarly, the flow cytometry exhibited
increased cell viability in SI-treated stress-induced cells. The gene expression
studies in SI-treated revealed the downregulation of pro-apoptotic genes. SI-extract
exhibited potential antioxidant properties. Further, we recommend performing extensive
screening of these marine compounds to obtain potential therapeutics to overcome
neurodegenerative diseases caused due to oxidative stress.
