Antidiabetic Micro-/Nanoaggregates from Ge-Gen-Qin-Lian-Tang Decoction Increase Absorption of Baicalin and Cellular Antioxidant Activity In Vitro

Abstract

The antidiabetic effects of Ge-Gen-Qin-Lian-Tang decoction (GQD) have been proven clinically. In a pharmacological study conducted on STZ-induced diabetic rats, the constitutive aggregates/sediments of Ge-Gen-Qin-Lian-Tang decoction exhibited stronger hypoglycemic and antioxidant activities compared to the soluble compositions. This study aims to demonstrate the pharmacological properties of aggregates derived from GQD by measuring permeability of the active monomer phytochemicals (e.g., baicalin) in a Caco-2 cell monolayer and determine the cellular viability, intracellular redox status (MDA and SOD), and insulin secretion of pancreatic β-cell line, INS-1, following STZ-induced oxidative stress. The aggregates were separated into three fractions, namely, “MA (microaggregates),” “400 g supernatant,” and “MNA (micro-/nanoaggregates),” by centrifugation at 400 ×g and 15000 ×g, respectively. Aggregates in the sediment increased baicalin absorption, showed little toxicity to β-cells, elevated intracellular SOD levels, and significantly suppressed oxidative damage effects on cellular viability and functions. The “MA” fraction had a larger particle size and provided higher antioxidant cellular protection than “MNA” in vitro, implying that the sediments may be the active components in the herbal decoction. The actions of these micro-/nanoaggregates may provide a new perspective for understanding the antidiabetic effects of herbal decoctions and aid in interpretation of synergistic actions between the multiple components.

Constituents, Pharmacokinetics, and Pharmacology of Gegen-Qinlian Decoction

“…The interactions between the constituents of TCMs may change the existing form of these compounds. For example, GQD contains micro-and nano-scale aggregates that improve the bioavailability of baicalin, which is responsible for the synergistic actions between the multiple constituents (Lin et al, 2017). However, how these aggregates are formed is still unclear.…”

MERTK+/hi M2c Macrophages Induced by Baicalin Alleviate Non-Alcoholic Fatty Liver Disease

“…Baicalin (7-glucuronic acid, 5, 6-dihydroxyflavone), a major bioactive flavonoid compound found in the dried root of Scutellaria baicalensis Georgi (SBG), has been used and studied intensively in traditional Chinese medicine for its therapeutic potentials and broad pharmacological properties, including anti-inflammation, antioxidant, antiviral, and anticancer properties [ 16 , 17 , 18 , 19 ]. A recent study has shown that baicalin is capable of repolarizing LPS-induced M1 macrophages into the M2 phenotype characterized by the downregulation of IRF5 , TNFα , and IL-23 in vitro [ 20 ].…”

Study on Supramolecules in Traditional Chinese Medicine Decoction

“…High absorption rates of baicalin indicated that the supramolecules changes pharmacokinetics of Gegen Qinlian decoction and improves the bioavailability of insoluble phytochemicals, like baicalin, may be essential for the synergistic actions in the herbal decoction. It showed that the supramolecules in the Gegen Qinlian decoction had a better medicinal effect [ 20 ]. When investigating the protein self-assembly behavior during the Gegen Qinlian decoction, Lin separated Pueraria protein and Coptis protein and found that the two proteins could form supramolecules under simulated decoction conditions.…”