β-Amyrin Rich Bombax ceiba Leaf Extract with Potential Neuroprotective Activity against Scopolamine-Induced Memory Impairment in Rats

The neuroprotective potential of Bombax ceiba L. (Malvaceae) leaves extract (BCLE) was evaluated herein for the first time. Memory impairment was induced in rats by scopolamine (SC) administration for seven days (1.5 mg/kg/day, i.p.). BCLE (200 mg/kg) or donepezil (1mg/kg) was administered orally a week before and then concomitantly with SC for another week. BCLE improved the rats’ behaviors estimated by Morris water maze and passive avoidance tests, where the rats showed prolongation in time spent in platform quadrant and step-through latency, respectively, compared to administration of SC alone. BCLE also ameliorated the antioxidant parameters (Catalase with malondialdehyde (MDA), and the SC-induced elevation of acetylcholinesterase (AChE) in rats’ brain tissues. Histopathological studies supported the above results. BCLE phytochemical study resulted in isolation and structural elucidation of β-sitosterol linoleate (first to be isolated from the genus) and β-amyrin. Twenty-seven compounds ( 93 .35%) were identified in BCLE by gas chromatography / mass spectrometry (GC/MS) . The major components were triterpenoids (69.82%), composing mainly of β-amyrin (45.28%), lupeol (15.03%) and olean-12-en-3-one (6.27%), in addition to fatty acid esters (13.37%) and steroids ( 7.75%), which were rich in methyl palmitate (9.87%) and stigmasterol acetate (4.91%), respectively. These compounds may be responsible for ameliorating the SC-induced oxidative stress and cholinergic dysfunction.