Some peculiarities of taxifolin electrooxidation in the aqueous media: The dimers formation as a key to the mechanism understanding

Mechanism of Action of Dihydroquercetin in the Prevention and Therapy of Experimental Liver Injury

Liver disease is a global health problem that affects the well-being of tens of thousands of people. Dihydroquercetin (DHQ) is a flavonoid compound derived from various plants. Furthermore, DHQ has shown excellent activity in the prevention and treatment of liver injury, such as the inhibition of hepatocellular carcinoma cell proliferation after administration, the normalization of oxidative indices (like SOD, GSH) in this tissue, and the down-regulation of pro-inflammatory molecules (such as IL-6 and TNF-α). DHQ also exerts its therapeutic effects by affecting molecular pathways such as NF-κB and Nrf2. This paper discusses the latest research progress of DHQ in the treatment of various liver diseases (including viral liver injury, drug liver injury, alcoholic liver injury, non-alcoholic liver injury, fatty liver injury, and immune liver injury). It explores how to optimize the application of DHQ to improve its effectiveness in treating liver diseases, which is valuable for preparing potential therapeutic drugs for human liver diseases in conjunction with DHQ.

Taxifolin stability: In silico prediction and in vitro degradation with HPLC-UV/UPLC-ESI-MS monitoring

Taxifolin has a plethora of therapeutic activities and is currently isolated from the stem bark of the tree Larix gmelinni (Dahurian larch). It is a flavonoid of high commercial interest for its use in supplements or in antioxidant-rich functional foods. However, its poor stability and low bioavailability hinder the use of flavonoid in nutritional or pharmaceutical formulations. In this work, taxifolin isolated from the seeds of Mimusops balata, was evaluated by in silico stability prediction studies and in vitro forced degradation studies (acid and alkaline hydrolysis, oxidation, visible/UV radiation, dry/humid heating) monitored by high performance liquid chromatography with ultraviolet detection (HPLC-UV) and ultrahigh performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS). The in silico stability prediction studies indicated the most susceptible regions in the molecule to nucleophilic and electrophilic attacks, as well as the sites susceptible to oxidation. The in vitro forced degradation tests were in agreement with the in silico stability prediction, indicating that taxifolin is extremely unstable (class 1) under alkaline hydrolysis. In addition, taxifolin thermal degradation was increased by humidity. On the other hand, with respect to photosensitivity, taxifolin can be classified as class 4 (stable). Moreover, the alkaline degradation products were characterized by UPLC-ESI-MS/MS as dimers of taxifolin. These results enabled an understanding of the intrinsic lability of taxifolin, contributing to the development of stability-indicating methods, and of appropriate drug release systems, with the aims of preserving its stability and improving its bioavailability.

Investigation of the spectroelectrochemical behavior of quercetin isolated from Zanthoxylum bungeanum

Flavonoids are common bioactive components in plants. Quercetin is the most abundant flavonoid in the human diet, accounting for more than half of the total daily consumption of flavonoids. In this study, adsorption and electrocatalytic activities of quercetin isolated from Zanthoxylum bungeanum on an electrode was studied via homemade electrodes. An in situ UV-Visible thin-layer spectroelectrochemical method was used to study the electrochemical behavior of quercetin in detail and to explore its electrochemical reaction mechanism. This experiment proves that UV-Vis thin-layer spectroelectrochemistry is a feasible way for studying the electrochemical reaction mechanism of flavonoids in plants.

Molybdenum sulfide-based electrochemical platform for high sensitive detection of taxifolin in Chinese medicine

MoS₂ and nitrogen doped active carbon composite (MoS₂/ANC) is fabricated to detect taxifolin and exhibits superior redox current response and decreased redox potential difference. Further investigation reveals that the kinetic process of the redox reaction of taxifolin on MoS₂/ANC electrode is controlled by both adsorption and diffusion process. Under the optimum conditions, the redox peak currents linearly relate with the concentration of taxifolin in the range of 1 × 10^-9-1 × 10^-6 mol L^-1, accompanied by the low detection limit (3 × 10^-10 mol L^-1). Meanwhile, outstanding selectivity, stability and repeatability are also obtained at MoS₂/ANC electrode. At last, the proposed method is applied to quantitatively detect taxifolin in fructus polygoni orientalis and satisfactory results have been achieved.