Coconut (Cocos nucifera) Ethanolic Leaf Extract Reduces Amyloid-β (1-42) Aggregation and Paralysis Prevalence in Transgenic Caenorhabditis elegans Independently of Free Radical Scavenging and Acetylcholinesterase Inhibition

Abstract

Virgin coconut oil (VCO) has been the subject of several studies which have aimed to alleviate Alzheimer’s disease (AD) pathology, focusing on in vitro antioxidant and acetylcholinesterase (AChE) inhibitory activities. Here, we studied an underutilized and lesser-valued part of the coconut tree, specifically the leaves, using in vitro and in vivo approaches. Coconut leaf extract (CLE) was screened for antioxidant and AChE inhibitory properties in vitro and therapeutic effects in two strains of transgenic Caenorhabditis elegans expressing amyloid-β1–42 (Aβ1-42) in muscle cells. CLE demonstrated free radical scavenging activity with an EC50 that is 79-fold less compared to ascorbic acid, and an AChE inhibitory activity that is 131-fold less compared to Rivastigmine. Surprisingly, in spite of its low antioxidant activity and AChE inhibition, CLE reduced Aβ deposits by 30.31% in CL2006 in a dose-independent manner, and reduced the percentage of paralyzed nematodes at the lowest concentration of CLE (159.38 μg/mL), compared to dH2O/vehicle (control). Phytochemical analysis detected glycosides, anthocyanins, and hydrolyzable tannins in CLE, some of which are known to be anti-amyloidogenic. Taken together, these findings suggest that CLE metabolites alternatively decrease AB1–42 aggregation and paralysis prevalence independently of free radical scavenging and AChE inhibition, and this warrants further investigation on the bioactive compounds of CLE.

Acorenone B: AChE and BChE Inhibitor as a Major Compound of the Essential Oil Distilled from the Ecuadorian Species Niphogeton dissecta (Benth.) J.F. Macbr

“…AD is a prevalent disease that affects more than 26 million people globally, and is the most common neurodegenerative disease worldwide [ 7 ]. AChE inhibitors (AChEIs) have medical applications and are particularly important for the symptomatic treatment of Alzheimer’s disease [ 8 ].…”

Antiplasmodial activity of Cocos nucifera leaves in Plasmodium berghei-infected mice

“…Different products from the coconut plant have been studied extensively for their medicinal properties (Roopan 2016). Research has demonstrated the presence of metabolites such as polyphenols, glycosides, steroids, alkaloids, terpenoids, and others which could be responsible for those activities (Renjith et al 2013;Manalo et al 2017;Oliveira et al 2009;Singla et al 2011;Soumya et al 2014). More specifically, the husk extracts of C. nucifera have shown to have antimalarial properties when tested in vitro and in vivo (Adebayo et al 2012;Adebayo et al 2013;Balogun et al 2014;Angeles et al 2005).…”

“…Several studies have described the traditional use of C. nucifera husk, water and inflorescence on mice and rats to address several pathologies (Naskar et al 2011;Rinaldi et al 2009;Renjith et al 2013;Alviano et al 2004;Omoboyowa et al 2016). One study describes the use of C. nucifera leaf extracts as reducing amyloid-b aggregation in transgenic Caenorhabditis elegans (Manalo et al 2017). Another study describes the safety of C. nucifera leaf extracts in mice, however, it does not evaluate the effectiveness of these extracts on any pathology (Paul et al 2012).…”

Analysis of the antiparasitic and anticancer activity of the coconut palm (Cocos nucifera L. ARECACEAE) from the natural reserve of Punta Patiño, Darién

“…It has traditionally been used in countries of South Asia, Africa, and America, for treating arthritis, diarrhea, fevers, inflammation, skin infections, miscarriage prevention, asthma, female sterility and as a diuretic, among others[2]. A leaf extract from the coconut plant decreases amyloid-β 1–42 aggregation and paralysis[3]. Catechins and epicatechins were responsible for the antiparasitic activity from the husk of Cocos nucifera against Leishmania parasites[4].…”