In vitro studies on the interactions of blood lipid level‐related biological molecules with gallic acid and tannic acid

Abstract

BACKGROUND To provide the scientific evidence for a possible new mechanism of hypolipidemic effects of gallic acid (GA) and tannic acid (TA), the binding capacity of GA and TA with blood lipid level‐related biological molecules, including fat, cholesterol and cholates, were investigated in vitro. Additionally, we attempted to study the interactions of cholates with GA and TA by spectroscopic methods, high‐performance liquid chromatography electrospray‐ionization mass spectrometry (HPLC‐ESI‐MS) analysis and molecular modeling studies. RESULTS Our results demonstrated that both GA and TA were capable of binding with the blood lipid level‐related biological molecules in vitro. The fat‐binding capacity of TA was 122.1% that of GA when the addition of polyphenol was 90 mg. The inhibitory effects of GA and TA on the cholesterol solubility in mixed micelles and liquid egg yolk exhibited a dose‐dependent relationship (0.5–2.0 mg mL−1). In cholate‐binding tests, TA showed higher affinity for sodium cholate than GA at a concentration of 2.0 mg mL−1, while no significant difference in the affinity for sodium deoxycholate was found between GA and TA. Moreover, the data of spectroscopic methods, HPLC‐ESI‐MS analysis and molecular modeling studies indicated that GA and TA might precipitate cholates through hydrophobic interactions and intermolecular hydrogen bonds rather than covalent bonds. CONCLUSION The findings of the present study suggested that the binding capacity of GA and TA with blood lipid level‐related biological molecules might play a crucial role in their hypolipidemic effects in animals. © 2019 Society of Chemical Industry

Hypolipidemic, anti‐inflammatory, and anti‐atherosclerotic effects of tea before and after microbial fermentation

“…Pu‐erh tea effectively lowers lipids, as evidenced by epidemiology, in vitro experiments, and clinical investigation (Huang et al., 2019; Sun et al., 2019). Furthermore, theabrownins, tea polysaccharides, tea polyphenols, GA, caffeine, and lovastatin can lower lipids (Gong et al., 2010; Nakamura et al., 2017; Sugiura et al., 2020; Xiong, Cao et al., 2019; Zeng et al., 2019; Zhong et al., 2020). In this study, sun‐dried green tea was inoculated with Monascus purpureus and fermented to obtain fermented pu‐erh tea.…”

Cinnamomum burmannii (Nees & T. Nees) Blume and Eleutherine palmifolia (L.) Merr. extract combination ameliorate lipid profile and heart oxidative stress in hyperlipidemic mice

“…Quercetin from C. burmannii can inhibit cholesterol synthesis by inhibiting the activity of HMG-CoA reductase [ 37 ]. Moreover, tannic acid and gallic acid have a high affinity for cholesterol [ 38 ]. In addition, the inhibitory effects on digestion and absorption of cholesterol in the gastrointestinal tract were induced by catechin, epicatechin, and epicatechin gallate from E. palmifolia [ 39 ].…”

Biomedical applications of tannic acid

“…TA binds to lipids in blood and decreases cholesterol solubility. 149 TA forms large lipid complexes through hydrogen bonding and hydrophobic interactions that are not able to be absorbed by cells. [149][150][151] TA also disrupts the lipids of the cell and nuclear membranes altering membrane permeability leading to apoptosis.…”

“…149 TA forms large lipid complexes through hydrogen bonding and hydrophobic interactions that are not able to be absorbed by cells. [149][150][151] TA also disrupts the lipids of the cell and nuclear membranes altering membrane permeability leading to apoptosis. 95,143 Polyphenols in combination with other chemotherapeutic drugs, may increase the anticancer potential and make more effective drug therapies against multiple drug resistant strains of cancer.…”