Chemical Analysis, Toxicity Study, and Free-Radical Scavenging and Iron-Binding Assays Involving Coffee (Coffea arabica) Extracts

Abstract

We aimed to analyze the chemical compositions in Arabica coffee bean extracts, assess the relevant antioxidant and iron-chelating activities in coffee extracts and instant coffee, and evaluate the toxicity in roasted coffee. Coffee beans were extracted using boiling, drip-filtered and espresso brewing methods. Certain phenolics were investigated including trigonelline, caffeic acid and their derivatives, gallic acid, epicatechin, chlorogenic acid (CGA) and their derivatives, p-coumaroylquinic acid, p-coumaroyl glucoside, the rutin and syringic acid that exist in green and roasted coffee extracts, along with dimethoxycinnamic acid, caffeoylarbutin and cymaroside that may be present in green coffee bean extracts. Different phytochemicals were also detected in all of the coffee extracts. Roasted coffee extracts and instant coffees exhibited free-radical scavenging properties in a dose-dependent manner, for which drip coffee was observed to be the most effective (p < 0.05). All coffee extracts, instant coffee varieties and CGA could effectively bind ferric ion in a concentration-dependent manner resulting in an iron-bound complex. Roasted coffee extracts were neither toxic to normal mononuclear cells nor breast cancer cells. The findings indicate that phenolics, particularly CGA, could effectively contribute to the iron-chelating and free-radical scavenging properties observed in coffee brews. Thus, coffee may possess high pharmacological value and could be utilized as a health beverage.

Antibacterial, Antiradical and Antiproliferative Potential of Green, Roasted, and Spent Coffee Extracts

“…In C33A cells, aqueous GB or ethanolic SCG extracts seemed to increase cell viability; however, this does not necessarily indicate an increase in cell proliferation. Similar results have been described, as some metabolites contained in GB or SCG coffee extracts can increase enzymatic-mitochondrial activity, specifically a phytochemicals such as kahweol and cafestol, and CGAs can increase and potentiate mitochondrial-reducing enzymes and increased formazan products, which can result in higher percentages of cell viability [39]. Notably, the ethanolic extract from SCG diminished A549 cell viability only at 12.5 µg•mL −1 , the lowest concentration evaluated.…”

Deferiprone–resveratrol hybrid attenuates iron accumulation, oxidative stress, and antioxidant defenses in iron-loaded human Huh7 hepatic cells

“…This study uses the method of Hutachok et al, and the method description partly reproduces their wording ( Hutachok et al, 2021 ). Venous blood (10 mL) was drawn from blood donors, collected in sodium heparin (158 USP units)-coated tubes, and diluted with sterile PBS at a 1:1 (v/v) ratio.…”

“…This study uses the MTT method of Hutachok et al, and the method description partly reproduces their wording ( Hutachok et al, 2021 ). In other words, the assay is based on the ability of the mitochondrial reductase system in live cells to change the yellow-colored MTT dye to a blue-colored formazan product.…”

Consumption of Green Tea Extract Tablets Improved Anticoagulant Proteins and Reduced Platelet Aggregation in Transfusion-Dependent β-Thalassemia Patients

“…resveratrol) obtained from red wine and catechins obtained from green tea (Camellia sinensis) 21 . Importantly, we have recently demonstrated that chlorogenic acid (CGA)-abundant coffee (Coffea arabica) extracts have exhibited ROS−scavenging and anti−cyclooxygenase (COX) activities, while inhibiting the aggregation of platelets in platelet−rich plasma (PRP) induced by ADP, collagen, epinephrine and arachidonic acid in a concentration−dependent manner 22,23 .…”