Eleganolone, a diterpene isolated from seaweed Bifurcaria bifurcata (Phaeophyceae, Fucales), protects neuronal cells from oxidative stress-induced damage

The brown seaweed Bifurcaria bifurcata has gained particular interest in recent years due to its abundance in bioactive linear diterpenes with potential high-value applications. Evidences suggests that oxidative stress is an important mediator of neurodegenerative disorders. In this research study, the aim was to evaluate the potential protective effect of eleganolone, diterpene isolated from the brown seaweed B. bifurcata, on oxidative stressed human neuroblastoma SH-SY5Y cells by tert-butyl hydroperoxide (tert-BOOH). The protective effects of eleganolone on the oxidative stressed SH-SY5Y cells were measured by cell viability, cytotoxicity, oxidative stress biomarkers and antioxidative enzyme activity assays, as well as associated intracellular signaling pathways. The mRNA expression of apoptosis, inflammation, oxidative stress and neuronal development signaling pathway-related genes was analyzed by real-time RT-PCR. Eleganolone prevented the elevation of oxidative stress markers, such as reactive oxygen species, malondialdehyde, nitric oxide and caspase 3/7 activity, as well as induced an increase in reduced glutathione and antioxidant enzyme activities in a dose-dependent manner on oxidative stressed SH-SY5Y cells. Additionally, our data showed that eleganolone downregulated the expression of genes associated with apoptosis (BAX, BNIP3, p53, p38, APAF1), inflammation (NFKB1, TNF-α, IL-6, IL-1β), oxidative stress (HO-1) and neuronal development (CAMK2A, WNT5A, WNT7A) pathways in SH-SY5Y cells exposed to oxidative stressor tert-BOOH. These findings suggest that eleganolone offers neuroprotective potential in ameliorating diverse pathological aspects associated with oxidative stress.