Antioxidant, anti-diabetic, acetylcholinesterase inhibitory potential and estimation of alkaloids (lycorine and galanthamine) from Crinum species: An important source of anticancer and anti-Alzheimer drug

Abstract

Crinum L. (Amaryllidaceae J.St. Hil.) is a bulbous monocot well known for its ornamental value and medicinal properties. Aqueous and methanolic leaf extracts of twelve Crinum genotypes were evaluated for their phytochemicals, antioxidants, in vitro anti-diabetic and acetyl cholinesterase (AChE) inhibitory activities. Maximum total phenolic content (TPC) (86.18 ± 0.61 mg TAE g−1 extract) was exhibited by C. asiaticum form 2 whereas maximum total alkaloid content (TAC) (10.81 ± 0.22 mg CoE g−1 extract), total flavonoid content (TFC) (145.06 ± 3.95 mg CE g−1 extract) and TTC (436.55 ± 3.70 mg CE g−1 extract) content were recorded for C. x powelii. The antioxidant activities were determined by 2, 2′-azinobis 3-ethylbenzthiazoline]-6-sulfonic acid (ABTS), 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP) and phosphomolybdenum assays. Methanol extract of C. asiaticum form 2 had the highest FRAP (462.81 ± 1.98 mg Fe II g−1 extract), phosphomolybdenum (116.03 ± 3.80 mg AAE g−1 extract) and DPPH radical scavenging activities (111.54 ± 2.03 mg TE g−1 extract). ABTS radical scavenging activity was greatest in aqueous extract of C. latifolium (39.65 ± 0.91 mg TE g−1 extract). RP-HPLC analysis revealed the highest phenolics in C. asiaticum form 1. Amaryllidaceae alkaloids, galanthamine (GAL) and lycorine (LY) were recorded the highest in C. latifolium (721.3 ± 4.96 μg g−1 dry weight and C. solapurense (3717.0 ± 9.40 μg g−1 DW), respectively. C. jagus revealed the highest inhibition of α-amylase (60.30%) and α-glucosidase (94.04%). AChE inhibition was maximum (76.52%) in the methanol extract of C. latifolium. This study constitutes the first comparative account of antioxidants, phenolic profiling, anti-diabetic potential and simultaneous quantification of anti-Alzheimer and anticancer drugs, viz. GAL and LY, respectively from Crinum genotypes.