GC-MS analysis, cholinesterase inhibitory and antioxidant potentials of Zapoteca portoricensis (Jacq.) H.M. Hern (Fabaceae) root extracts

Abstract

The age-related neurodegenerative illness known as Alzheimer's disease (AD) is typified by the unavoidable decline in cognitive function.  Existing drugs has limitations, therefore there is an urgent need for new neurotherapeutic agents. There has been a lot of excitement in recent years about finding therapeutic herbs that can restore cognitive impairment due to their lower side effects. The aim of the study is  to evaluate the cholinesterase inhibitory and antioxidant potentials of Zapoteca portoricensis (Jacq.) H.M. Hern root extracts and also identify the bioactive molecules present. Ellman colorimetric assay was used to evaluate the cholinesterase inhibitory potentials of  various extracts at 1 mg/mL. The antioxidant potentials of extracts were evaluated using in-vitro chemical analysis. GC-MS was used to  identify bioactive molecules from most active extract. One-way ANOVA at α0.05 was adopted. Ethyl acetate extract showed the highest  acetylcholinesterase (IC₅₀ = 0.149±0.00 mg/mL) and butyrylcholinesterase (IC₅₀ = 0.393±0.02 mg/mL) inhibitory potential as compared to  eserine for AChE (IC₅₀ = 0.051±0.01 mg/mL) and for BuChE (IC₅₀ = 0.049±0.00 mg/mL). Ethyl acetate extract also demonstrated its  potential to chelate metals (IC₅₀ = 0.106±0.02 mg/mL) as compared to EDTA (IC₅₀ = 0.086±0.00 mg/mL). The DPPH radical scavenging  potential was higher in ethyl acetate extract (IC₅₀ = 0.082±0.05 mg/mL) when compared to vitamin C (IC₅₀ = 0.008±0.00 mg/mL). The total  antioxidant capacity of extracts revealed that ethyl acetate extract also has the highest concentration (125.5±14.3 mg/g AAE/g of  extract (R²=0.9276)). The GC-MS analysis of ethyl acetate extract revealed the presence of 62 compounds which includes n-Hexadecanoic  acid (RT 14.81, Area % 10.03), 9,12- Octadecadienoic acid (Z,Z)- (RT 15.97, Area % 10.03), cis-9-Hexadecenal (RT 16.01, Area % 8.36). The  ethyl acetate extract from the root of Zapoteca portoricensis has the aptitude to prolong the half-life of acetylcholine by its ability to inhibit  cholinesterase enzyme.