Simultaneous Quantification of Four Marker Compounds in Bauhinia coccinea Extract and Their Potential Inhibitory Effects on Alzheimer’s Disease Biomarkers

Abstract

Bauhinia coccinea is a tropical woody plant widely distributed in Vietnam and Unnan in southern China. Although many studies have shown the biological activities of extracts from various other species in the genus, no studies have investigated the effects of B. coccinea extracts on biological systems. In the present study, a quantitative analysis of four marker compounds of ethanol extracts of B. coccinea branches (EEBC) was performed using the high performance liquid chromatography (HPLC)-photodiode array (PDA) method. Among gallic acid, (+)-catechin, ellagic acid, and quercitrin contained in EEBC, the most abundant compound was (+)-catechin (18.736 mg/g). In addition, we investigated the EEBC on neuroprotection, antioxidation, and Alzheimer’s disease (AD) marker molecules, acetylcholinesterase (AChE), and amyloid-β (Aβ). EEBC significantly inhibited hydrogen peroxide (H2O2)-induced cell death in a HT22 neuronal cell line and increased 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl scavenging activity markedly. EEBC also inhibited AChE and Aβ aggregation. Among the four compounds, gallic acid exhibited strong inhibitory effects against AChE activation. In the Aβ aggregation assay, the four marker compounds exhibited inhibitory effects lower than 30%. According to the results, EEBC could exert anti-AChE activation and Aβ aggregation activities based on the interactive effects of the marker compounds. Our findings suggest that EEBC are sources of therapeutic candidates for application in the development of AD medication based on AChE and Aβ dual targeting.

Plant-Derived Bioactive Compounds in the Management of Neurodegenerative Disorders: Challenges, Future Directions and Molecular Mechanisms Involved in Neuroprotection

“…One such in vivo study showed that juice from the leaves of Morus alba had significant protective effects against arsenic-induced neurotoxicity by reducing AChE and BChE level and improved hepatic functioning by restoring normal levels of GSH, SOD, alanine transferase (ALT), aspartate transferase (AST), and alkaline phosphatase (ALP) in Swiss albino mice [ 27 ]. The high-performance liquid chromatography (HPLC)–photodiode array (PDA) method revealed the presence of gallic acid, catechin, ellagic acid, and quercitrin in Bauhinia coccinea , and its ethanolic extract demonstrated neuroprotection through antioxidant activities, as evidenced by the significant inhibition of amyloid-β (Aβ) aggregation and AChE and suppression of hydrogen peroxide (H 2 O 2 )-induced cell death in HT22 neuronal cells in AD [ 28 ]. Among many extracts tested for anti-AD activities, chloroform extract from Enhydra fluctuans was reported to possess the best inhibitory activities, with IC50 values of 83.90 μg/mL and 48.14 μg/mL against AChE and BchE, respectively, and free-radical-scavenging activity was also observed at an IC50 value of 113.27 μg/mL by DPPH radical-scavenging assay, owing to the presence of 19.16 mg gallic acid equivalent/g extract of phenolics and 41.84 mg catechin equivalent/g extract of flavonoids in the extract [ 29 ].…”