Isolation of bioactive components from Corallocarpus epigaeus tuber and inhibitory potential against various molecular forms of acetylcholinesterase

Abstract

AbstractBackgroundIn human, acetylcholinesterase (AChE) is involved in cholinergic neurotransmission. AChE exhibits as different globular form such as G4 (tetramer), G2 (dimer) and G1 (monomer). For the most part of the adult brain G4 forms is present. Nevertheless, under dementia such as Alzheimer’s disease (AD) conditions, the ratio between G1 and G4 form is increased which is involved in disease progression. Inhibition of AChE is considered important therapeutic intervention to overcome the AD. Corallocarpus epigaeus comes under the family of Cucurbitacea has known for the biological properties such as anti‐snake venom, analgesic, anthelminthic properties and antidiabetic activity. Identifying natural compounds with AChE inhibition is considered important for AD treatment. In the present study, bioactive fraction extracted from tuber of C. epigaeus was investigated for its inhibition against different molecular forms of AChE in in vitro.MethodDried tuber powder of C. epigaeus was extracted using various solvents sequentially by increasing polarity in Soxhlet apparatus. Methanol extract was further purified by silica column chromatography. The partially purified fraction was studied for the inhibition against different molecular forms of AChE. Kinetic analysis was carried out to determine the type of inhibition and inhibitor constant. The active compounds in partially purified fraction were determined using gas chromatography mass spectrum analysis (GCMS).ResultPartially purified fraction of methanolic extract of C. epigaeus tuber inhibited all the molecular forms (G1, G2 and G4) of AChE at microgram per milliliter concentration. Kinetic analysis revealed the mixed type non‐competitive mode of inhibition with low Ki value. GCMS analysis 4H‐pyran‐4‐one, 2,3‐dihydro‐3,5‐dihydroxy‐6‐methyl and alpha‐linolenic acid as major constituents in the extract.ConclusionThe bioactive components in tuber of C. epigaeus inhibited AChE in in vitro. This is the first report on the inhibitory effect of C. epigaeus tuber extract against AChE. Further in vivo studies are necessary to understand the anti‐dementia effect of C. epigaeus.