Neuroprotective effect of water lily (Nymphaea pubescens Willd) seed ethanolic extract against trimethyltin-induced cognitive impairment and neurodegeneration in mice

Cognitive impairments are profound outcomes of neurodegenerative disease, a global health issue. Water lily (Nymphaea pubescens, Nymphaeaceae) extracts have been reported to counteract oxidative stress. However, their protective effects against neurodegenerative disease remain to be fully investigated. The current study aimed to determine the neuroprotective effect of water lily seed ethanolic extract on trimethyltin (TMT)-induced cognitive impairment and neurodegeneration in a mouse model.

A single dose of TMT (0.6 mg/kg BW) was intraperitoneally injected to young adult male mice followed by daily oral treatments with different doses of water lily seed extract (0, 100, 200, and 400 mg/kg BW) for 28 days. Thereafter, cognitive behaviors were assessed, malondialdehyde (MDA) levels and catalase (CAT) activities were determined, followed by histopathological examination of the brain.

The results revealed that, compared to the non-treated group, the water lily extract at doses of 100–400 mg/kg BW was effective in counteracting the decline in memory and spatial cognition of TMT-induced impairment (P < 0.05). Moreover, the extract, particularly at doses of 200 and 400 mg/kg BW, substantially lowered the MDA level while elevating the CAT activity level (P < 0.05). Water lily seed extract also significantly reduced TMT-induced pyramidal cell degeneration in the hippocampus and cerebral cortex (P < 0.05).

Our findings demonstrated that ethanolic extract from water lily seeds could effectively reduce TMT-induced cognitive impairment and MDA levels and enhance CAT activity thereby precluding neurodegeneration in the hippocampus and cerebral cortex. Thus, water lily seed extract is a potent candidate for a natural anti-neurodegenerative supplement.