Quantification of Major Bioactive Constituents, Antioxidant Activity, and Enzyme Inhibitory Effects of Whole Coffee Cherries (Coffea arabica) and Their Extracts

Abstract

Coffee cherry is a rich source of chlorogenic acids (CGAs) and caffeine. In this study we examined the potential antioxidant activity and enzyme inhibitory effects of whole coffee cherries (WCC) and their two extracts on α-amylase, α-glucosidase and acetylcholinesterase (AChE) activities, which are targets for the control of diabetes and Alzheimer’s diseases. Whole coffee cherry extract 40% (WCCE1) is rich in chlorogenic acid compounds, consisting of a minimum of 40% major isomers, namely 3-caffeoylquinic acids, 4-caffeoylquinic acids, 5-caffeoylquinic acids, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, 4-feruloylquinc acid, and 5-feruloylquinc acid. Whole coffee cherry extract 70% (WCCE2) is rich in caffeine, with a minimum of 70%. WCCE1 inhibited the activities of digestive enzymes α-amylase and α-glucosidase, and WCCE2 inhibited acetylcholinesterase activities with their IC50 values of 1.74, 2.42, and 0.09 mg/mL, respectively. Multiple antioxidant assays—including DPPH, ABTS, FRAP, ORAC, HORAC, NORAC, and SORAC—demonstrated that WCCE1 has strong antioxidant activity.

Ethnopharmacological study of the genus Coffea and compounds of biological importance

“…in vitro studies were used to assess the inhibition of α-glucosidase and α-amylase using an extract of the coffee cherry (C. arabica), CGA and acarbose, a drug used in diabetic patients. The treatments inhibited both enzymes, presenting mean inhibitory concentrations (IC 50 ) in the α-glucosidase test of 33 mg/mL, 2.1 mg/mL and 1.25 mg/mL for the extract, CGA, and acarbose, respectively; in the tests of α-amylase, the IC 50 values were 15 mg/mL for the extract, 2.8 mg/mL for CGA and 0.008 mg/mL for acarbose (Nemzer et al, 2021). Caffeine (1,3,7trimethylxanthine) is a heterocyclic alkaloid that has a purine base known as xanthine (Figure 5d).…”

“…The main biological properties reported for coffee infusions are associated with antioxidant, anti-inflammatory, antidiabetic, antibacterial, and anticancer activities, among others (Jeszka-Skowron et al, 2016;Khochapong et al, 2021). Oxidative stress is a trigger for chronic degenerative diseases such as diabetes, cancer, aging, inflammatory diseases and cardiovascular diseases (Nemzer et al, 2021).…”

“…The antioxidative properties of coffee infusions have been studied using classical and widely used in vitro techniques; these properties are mainly attributed to CGA and caffeine, although other compounds that influence antioxidative properties, such as epicatechin, catechin and anthocyanins, have also been reported (Hutachok et al, 2020;Nemzer et al, 2021). The anti-hyperglucemic effect of coffee cherry extract and roasted bean waste of C. arabica has been attributed to the inhibitory activity of the enzymes α-glucosidase and α-amylase (Nemzer et al, 2021;Vázquez-Sánchez et al, 2018). Likewise, glucose regulation by CGA is mediated by the inhibition of glucose-6-phosphatase activity to reduce glucose production in the liver.…”

“…It has been determined that the antioxidative properties of caffeine are related to increased levels of reduced glutathione (GSH) due to greater absorption of cysteine in the presence of caffeine and its ability to eliminate reactive oxygen species (ROS), particularly the hydroxyl radical (-OH), it is the main target being the adenosine receptors involved in the regulation of ROS production (Stefanello et al, 2019). In in vivo tests, antioxidant activity has been determined based on the actions of regulatory enzymes that protect against oxidative damage, such as SOD and GHS reductase (Al-Megrin et al, 2020;Choi et al, 2018;Kwak et al, 2018;Nemzer et al, 2021). Other functions associated with CGA are anti-inflammatory activity and the regulation of glucose and lipid metabolism (Bhandarkar et al, 2019).…”

Bioinspired 5-caffeoylquinic acid capped silver nanoparticles using Coffee arabica leaf extract for high-sensitive cysteine detection

“…A recent study by Cangeloni et al showed a quantitative estimation of 5-CQA, caffeine, mangiferin and trigonelline, the four major phytochemicals present in CAE with a mass content in the order of 16.27 ± 1.66, 7.94 ± 0.42, 4.47 ± 0.13, 4.43 ± 0.14 g/Kg DW of coffee leaves 11 . As the number of hydroxyls group is an important factor which determines the antioxidant activity of a molecule, the reduction mechanism of Ag + ions to Ag 0 can be controlled by the dominant bioactive molecule having a higher number of hydroxyl groups in it 27 . The most abundant phytochemicals in CAE; CGAs are esters formed with quinic acid and trans-cinnamic acids like caffeic acid and ferulic acid in which the hydroxyl part from phenolic acid donates a hydrogen atom to free radicals that accounts for its strong hydroxyl and superoxide scavenging action.…”