Polyphenolic Glycosides from the Fruits Extract of Lycium ruthenicum Murr and Their Monoamine Oxidase B Inhibitory and Neuroprotective Activities

Abstract

The fruits ofLycium ruthenicum Murr have long been consumed as health food and used in folk medicine in China. Apart from the well-known polysaccharides, the active small molecular constituents in this fruit have not been fully studied. In this work, a systematic phytochemical study was carried out to investigate the small molecules and their potential health benefits. Nine new polyphenolic glycosides, lyciumserin A−I (1−9), together with 16 known compounds (10−25), were isolated and elucidated by high-resolution electrospray ionization mass spectrometry and comprehensive NMR analyses in combination with chemical hydrolysis. Compounds 1, 2, and 16 exhibited moderate inhibitory activity of monoamine oxidase B (MAO-B), while compounds 1 (50 μM) and 2 (100 μM) displayed significant neuroprotective effects (69.22 and 72.38% of cell viability, respectively) in the 6hydroxydopamine-induced injury of the PC12 cell model (54.41%), comparable to the positive drug rasagiline (70.45%). The neuroprotective effect of 1 and 2 was further evidenced by the observation of the morphological change and fluorescein diacetate/ propidium iodide staining. In addition, the levels of the major active compounds (1, 3, 5/6, and 16−18) vary from 21.5 to 892.3 μg/ g. This is the first report on phenolic glycosides from the fruits ofL. ruthenicum Murr that possess both significant MAO-B inhibitory and neuroprotective effects, indicating the promising potential of the fruits for the development of health care products and even therapeutic agents for the treatment of Parkinson's disease and other neurodegenerative diseases.

Screening of Monoamine Oxidase B Inhibitors from Fragaria nubicola by Ligand Fishing and Their Neuroprotective Effects

“…Compounds 1 and 2 were evaluated for their neuroprotective activities against 6-OHDA-induced cell damage in PC12 cells using the CCK-8 assay in vitro . The 6-OHDA induces cytotoxicity in PC12 cells, which provides a suitable model for studying the drug candidates for treatment of PD. , In this work, we used the 300 μM 6-OHDA to treat PC12 cells and reduce the cell viability to about 50%, which are good for the following experiments. , As shown in Figure , the survival rates of the PC12 cells were improved when the cells were preincubated with different concentrations of 1 or 2 for 2 h before being exposed to 6-OHDA. Especially, at a concentration of 100 μM, 1 and 2 could increase the survival rates from 51.74 to 65.76 and 62.97%, respectively, compared to 69.34% of the positive control rasagiline.…”

“…Curcumin was bought from Sichuan Must Biological Co., Ltd. (Chengdu, China). Methyl 2- O - β - d -glucopyranosyl-4,6-dihydroxyphenylacetate and 2- O -(3-methoxyl-4,5-dihydroxybenzoyl)-4-hydroxy-6- O - β - d -glucopyranosyl-phenylacetic acid were prepared in-house according to previous work . All chemicals and solvents were purchased from Kelong Chemical Reagent Factory (Chengdu, China).…”

Ligand fishing of monoamine oxidase B inhibitors from Platycodon grandiflorus (Jacq.) A.DC. roots by the enzyme functionalised magnetic nanoparticles

“…The PC12 cells were cultured in DMEM high glucose medium with 10% FBS and 1% double antibody (streptomycin/penicillin) at 37°C in a 5% carbon dioxide (CO 2 ) atmosphere. The CCK‐8 assay was used to determine cell viability as described previously 28 . Briefly, 1 × 10 4 PC12 cells were seeded on 96‐well cell culture plates and cultured overnight.…”

Protective effect and mechanism of Lycium ruthenicum polyphenols against acrylamide-induced neurotoxicity

“…[21][22][23] L. ruthenicum Murr. is a common perennial plant, mainly found in northwestern China, 24 rich in polyphenols with antioxidant and anti-aging 25,26 protective effects. Polyphenols can be up to 28.52 mg g −1 in L. ruthenicum Murr.…”