Isolation and characterization of components responsible for neuroprotective effects of Allium cepa outer scale extract against ischemia reperfusion induced cerebral injury in mice

Abstract

The antioxidant‐mediated neuroprotective effect of Allium cepa outer scale extract (ACE) in mice with cerebral ischemia‐reperfusion (I‐R) injury was demonstrated in our earlier work. The current investigation aimed at establishing the bioactive component(s) responsible for this activity. Thus ACE was fractionated into ethyl acetate (EF) and aqueous (AF) fractions. These fractions were evaluated against cerebral I‐R injury in mice. I‐R injury in mice was induced by bilateral common carotid artery occlusion followed by 24 hr reperfusion. Memory, sensorimotor functions, cerebral infarct size, and oxidative stress were measured to address the neuroprotective mechanism of test substances. EF showed marked improvement of memory and sensorimotor functions by reducing brain oxidative stress and infarct size in mice after I‐R injury. The bioactive EF was subjected to chromatographic (HPLC‐PDA, HPLC‐MS, preparative HPLC) and spectroscopic studies to isolate and identify the neuroprotective compounds. This lead to separation of three components, namely quercetin, quercetin 4′‐O‐glucoside, and the remaining fraction, from EF. The separated components were biologically evaluated. These components showed improvement in mice with I‐R injury. But, EF displayed more marked neuroprotective effects as compared to the isolated components. The distinct neuroprotective outcome of EF may be credited to the synergistic action of compounds present in EF. Further studies such as evaluation of neurotoxic effects and other possible neuroprotective mechanisms are required to develop EF as a neuroprotective drug.

Recent Advances in Bioactive Compounds, Health Functions, and Safety Concerns of Onion (Allium cepa L.)

“…The neuroprotective effect of onion on learning and memory abilities was assessed in STZ-induced diabetic rats, and it was found that red onion ethanolic extract treatment could improve the learning and memory impairments in diabetic rats with reduced escape latency and traveled distance in Morris water maze test and increased step-through latency in passive avoidance test (105). The neuroprotective effect of onion on cerebral injury was evaluated in a cerebral ischemia/reperfusion mouse model, which was established by bilateral common carotid artery occlusion followed by reperfusion (108). It was revealed that the outer scale extract of onion could improve the memory and sensorimotor functions in cerebral injury mice by reducing cerebral infarct size and oxidative stress.…”

Combination of paeoniflorin and calycosin-7-glucoside alleviates ischaemic stroke injury via the PI3K/AKT signalling pathway

“…In our study, the mNSS was assessed 24 h after reperfusion in accordance with previous studies (Singh et al. 2018a , 2020 ).…”

Quercetin: A Bioactive Compound Imparting Cardiovascular and Neuroprotective Benefits: Scope for Exploring Fresh Produce, Their Wastes, and By-Products

“…The quercetin extractives from different extracts showed different neuroprotective effects. It was suggested that further evaluation for neurotoxic effects and appropriate neuroprotective mechanisms should be continued to explore [82]. The neurotoxic damage induced by Bisphenol-A (BPA) in zebrafish (Danio rerio) and the effect of quercetin supplement treatment was carried out by Sahoo et al [83].…”