Compositions, Formation Mechanism, and Neuroprotective Effect of Compound Precipitation from the Traditional Chinese Prescription Huang-Lian-Jie-Du-Tang

Abstract

Abstract:Compounds in the form of precipitation (CFP) are universally formed during the decocting of Chinese prescriptions, such as Huang-Lian-Jie-Du-Tang (HLJDT). The formation rate of HLJDT CFP even reached 2.63% ± 0.20%. The identification by liquid chromatography mass spectrometry (LC-MS n ) proved that the main chemical substances of HLJDT CFP are baicalin and berberine, which is coincident with the theory that the CFP might derive from interaction between acidic and basic compounds. To investigate the formation mechanism of HLJDT CFP, baicalin and berberine were selected to synthesize a simulated precipitation and then the baicalin-berberine complex was obtained. Results indicated that the melting point of the complex interposed between baicalin and berberine, and the UV absorption, was different from the mother material. In addition, 1 H-NMR integral and high-resolution mass spectroscopy (HR-MS) can validate that the binding ratio was 1:1. Compared with baicalin, the chemical shifts of H and C on glucuronide had undergone significant changes by 1 H-, 13 C-NMR, which proved that electron transfer occurred between the carboxylic proton and the lone pair of electrons on the N atom. Both HLJDT CFP and the baicalin-berberine complex showed protective effects against cobalt chloride-induced neurotoxicity in differentiated PC12 cells. It is a novel idea, studying the material foundation of CFP in Chinese prescriptions.

Origin and Formation Mechanism Investigation of Compound Precipitation from the Traditional Chinese Prescription Huang-Lian-Jie-Du-Tang by Isothermal Titration Calorimetry

“…As shown in Table 2 , five constituents were characterized and determined based on their retention behaviors and MS data. The result showed that the main ingredients of SB-CC CFP were baicalin (2) and berberine (4), which was consistent with the results of previous studies on the chemical substances of HLJDT CFP [ 15 ], proving the interactions between Scutellaria baicalensis and Coptis chinensis to be the main source of HLJDT CFP.…”

“…However, as the absolute value of Δ G was not very high, this reaction was not very violent. As shown in Table 4 , the estimated stoichiometric ratio (n) was 1.002, indicating the binding ratio of baicalin and berberine was 1:1, which conformed to the result of baicalin-berberine complex 1 H-NMR and 13 C-NMR test [ 15 ]. Δ H = −371.6 kJ/mol, −TΔ S = 336.027 kJ/mol, which indicated that most of the binding energy was enthalpy, as the entropy change (Δ S ) of binding contributed unfavorably [ 16 , 24 ].…”

“…In previous studies, we concentrated on the formation rate, compositions, and neuroprotective effects of HLJDT CFP, the results of which proved that the HLJDT CFP was both stable and controllable. The formation rate of HLJDT CFP even reached 2.63 ± 0.21% during the process of decoction [ 15 ]. Compared with the supernatant, the CFP showed better neuroprotective effects on PC12 cells injured by CoCl 2 .…”

“…We first selected and mixed every two herbal medicines in a non-woven bag (pore diameter < 30 µm) respectively, and then decocted the mixtures. Later on, the compositions of SB-CC CFP were identified by HPLC-MS n and proved to be almost the same as that of HLJDT CFP [ 15 ], thus confirming SB-CC CFP as the main source of HLJDT CFP.…”

Synergistic Effect of Berberine-Based Chinese Medicine Assembled Nanostructures on Diarrhea-Predominant Irritable Bowel Syndrome In Vivo

“…This result might provide an idea to explain the combination of Scutellaria baicalensis Georgi and Coptis chinensis Franch rhizome to treat diarrhea by TCM. Finally, BA-BBR NPs showed better therapeutic effect on IBS-D than BA/BBR mixture, suggesting that the synergistic effect of BBR and BA is achieved due to the formation of self-assemblies rather than the simple mixing, which is consistent with the results of our research in vitro ( Zhang et al, 2016 ; Wang et al, 2017 ; Huang et al, 2020 ).…”