Gastric floating pill enhances the bioavailability and drug efficacy of dihydromyricetin in vivo

Pharmacological and therapeutic effects of natural products on liver regeneration-a comprehensive research

Liver regeneration (LR) refers to the physiological process by which hepatocytes undergo cellular proliferation to restore the structure and function of the liver following significant hepatocyte loss due to injury or partial hepatectomy (PH). While the liver possesses a remarkable regenerative capacity, this process is tightly regulated to ensure appropriate cessation once homeostasis is reestablished. Various strategies, including technological interventions and pharmacological agents, have been explored to enhance LR. Among these, natural products have emerged as promising candidates for promoting LR. For instance, quercetin, a natural compound, has been shown to enhance LR following PH by maintaining redox homeostasis and stimulating hepatocyte proliferation. However, natural products present certain limitations, such as poor solubility and low bioavailability, which may hinder their clinical application. Modifications in the formulation and mode of administration have demonstrated potential in overcoming these challenges and optimizing their pharmacological effects. Recent advancements in research have further highlighted the growing relevance of natural products, including traditional Chinese medicine (TCM), in the context of LR. Despite this progress, a comprehensive and systematic review of their roles, mechanisms, and therapeutic potential remains lacking. This review aims to bridge this gap by summarizing natural products with demonstrated potential to promote LR. Drawing on data from PubMed, Web of Science, and CNKI databases, it elucidates their pharmacological effects and regulatory mechanisms, providing a valuable reference for future research and clinical application in the field of LR.

Metabolic mechanisms of Dihydromyricetin and strategies for enhancing its bioavailability: A recent review

Dihydromyricetin, a flavonoid primarily found in vine tea, offers a range of health-promoting benefits, making it a promising functional food ingredient for improving nutrition and preventing diseases. However, its limited solubility, unstable physicochemical properties, short half-life, and rapid metabolism contribute to poor bioavailability, which restricts its broader application in food, pharmaceutical, and related industries. To overcome these challenges, extensive research has focused on strategies to enhance the bioavailability of dihydromyricetin. This paper reviews the digestion, absorption, tissue distribution, and metabolic mechanisms of dihydromyricetin in the human body. It examines the key factors influencing its bioavailability and highlights the design and construction of various bio-based delivery systems aimed at improving its bioavailability. Furthermore, the paper explores the potential applications of these delivery systems. The development of such systems can significantly enhance the stability and bioavailability of dihydromyricetin, providing a solid theoretical foundation for advancing its use in food and medicine.

Chitosan-based dihydromyricetin composite hydrogel demonstrating sustained release and exceptional antibacterial activity

Plant-derived antibacterial agents are increasingly pivotal in mitigating the escalating threat posed by pathogenic microorganisms. Dihydromyricetin (DMY), a plant bioactive compound prevalent in Ampelopsis grossedentata, exhibits remarkable antibacterial properties. However, its poor solubility in water significantly hinders its application in antibacterial therapies, necessitating the exploration of suitable carriers for the loading and sustained release of DMY. In this study, a chitosan-based hydrogel was rapidly synthesized at 25 °C using carboxymethyl chitosan and sodium alginate as precursors, and then utilized for the encapsulation of DMY. The as-prepared hydrogel was characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis, indicating its favorable swelling properties, injectability, transparency, and self-healing capabilities. Antibacterial assays demonstrated that both surface and internal of the hydrogel exhibited over 99 % inhibition against both Pseudomonas aeruginosa and Staphylococcus aureus when the DMY loading concentration reached 0.4 mg/mL. Furthermore, drug release studies demonstrated that the hydrogel effectively sustained the release of DMY for up to 130 h, irrespective of the acidic or alkaline aqueous solutions, as well as in phosphate-buffered saline. These findings provide novel insights and references for the synergistic antibacterial application of plant-derived agents in conjunction with hydrogels.

Enzymatic modification of dihydromyricetin by glucosylation and acylation, and its effect on the solubility and antioxidant activity

Although dihydromyricetin exhibits strong potential for pharmaceutical applications, its limited aqueous solubility, permeability and stability restrict its use. In this work, we have synthesized a series of glucosides and acyl-glucosides of dihydromyricetin that could increase the bioavailability of this molecule. First, the R134A variant of sucrose phosphorylase from Thermoanaerobacterium thermosaccharolyticum catalyzed the formation of three monoglucosides, and the major one was identified as dihydromyricetin 4'-O-α-D-glucopyranoside (>75% conversion yield). The molecular features that define this specificity for the 4'-OH phenolic group were investigated through induced-fit docking analysis of each potential derivative. Furthermore, the acylation of the 4'-monoglucoside with fatty acid vinyl esters (C8, C12, and C16) was performed with high efficiency using the lipase from Thermomyces lanuginosus. Three novel acyl derivatives of dihydromyricetin were characterized. Furthermore, the water solubility and antioxidant activity (ABTS, DPPH) of the synthesized compounds were measured, concluding that the location of the glucosyl moiety may affect their physicochemical properties and, as a result, their bioactivity.

Nanocochleates as novel delivery vehicles for enhancement of water solubility, stability and controlled release of dihydromyricetin in gastrointestinal tract

Dihydromyricetin (DHM) possesses impressive antioxidant and anti-inflammatory properties; however, its effectiveness is limited by poor bioavailability. Liposomes improve the solubility and stability of insoluble bioactives but encounter challenges in gastrointestinal fluids after oral administration. Consequently, DHM-loaded nanocochleates were fabricated to enhance the solubility, stability, and release behavior of DHM. The nanoliposomes exhibited an entrapment efficiency (EE) ranging from 85.64 % to 88.79 %, a particle size between 136.20 and 150.70 nm, a polydispersity index (PDI) of 0.36 to 0.43, and a zeta potential of -6.82 to -11.13 mV. In contrast, the cylindrical-shaped nanocochleates demonstrated an EE ranging from 74.94 % to 84.64 %, a particle size between 239.07 and 571.43 nm, a PDI from 0.16 to 0.61, and a zeta potential ranging from -21.97 to -27.10 mV. The nanocochleates exhibited improved water solubility (64.75 %) and retained antioxidant activity (41.38 %) compared to free DHM. Additionally, they demonstrated enhanced stability of DHM compared to nanoliposomes during 30 days of storage. Fourier transform infrared spectroscopy and differential scanning calorimetry confirmed that DHM was encapsulated within nanocochleate structures via ionic and chemical interactions. X-ray diffraction revealed a distinct organization of the nanocochleates in comparison to the nanoliposomes. The release of DHM from nanocochleates demonstrated a prolonged and controlled release in simulated gastrointestinal medium, unlike the burst release observed with nanoliposomes. This study hightlighted the potential of nanocochleates as novel delivery vehicles for enhancing the stability and bioavailability of DHM. It also offered a unique perspective on developing functional food formulations that utilize nanocochleates as promising nanocarriers for bioactives.

A double-layered gastric floating tablet for zero-order controlled release of dihydromyricetin: Design, development, and in vitro/in vivo evaluation

Dihydromyricetin (DHM) is an important natural flavonoid. However, most of DHM preparations have shown shortcomings such as low drug loading, poor drug stability, and/or large fluctuations in blood concentration. This study aimed to develop a gastric floating tablet with a double-layered structure for zero-order controlled release of DHM (DHM@GF-DLT). The final product DHM@GF-DLT showed a high average cumulative drug release at 24 h that best fit the zero-order model, and had a good floating ability in the stomach of the rabbit with a gastric retention time of over 24 h. The FTIR, DSC, and XRPD analyses indicated the good compatibility among the drug and the excipients in DHM@GF-DLT. The pharmacokinetic study revealed that DHM@GF-DLT could prolong the retention time of DHM, reduce the fluctuation of blood drug concentration, and enhance the bioavailability of DHM. The pharmacodynamic studies demonstrated that DHM@GF-DLT had a potent and long-term therapeutic effect on systemic inflammation in rabbits. Therefore, DHM@GF-DLT had the potential to serve as a promising anti-inflammatory agent and may develop into a once-a-day preparation, which was favorable to maintain a steady blood drug concentration and a long-term drug efficacy. Our research provided a promising development strategy for DHM and other natural products with a similar structure to DHM for improving their bioavailability and therapeutic effect.

Polymeric Excipients in the Technology of Floating Drug Delivery Systems

The combination of targeted transport and improvement of the release profile of the active pharmaceutical ingredient (API) is a current trend in the development of oral medicinal products (MP). A well-known way to implement this concept is to obtain floating gastroretentive delivery systems that provide a long stay of the dosage form (DF) on the surface of the stomach contents. The nomenclature of excipients (Es) of a polymeric nature used in the technology of obtaining floating drug delivery systems (FDDS) is discussed. Based on the data presented in research papers, the most widely used groups of polymers, their properties, and their purpose in various technological approaches to achieving buoyancy have been determined. In addition, ways to modify the release of APIs in these systems and the Es used for this are described. The current trends in the use of polymers in the technology of floating dosage forms (FDF) and generalized conclusions about the prospects of this direction are outlined.

Strategic developments in the drug delivery of natural product dihydromyricetin: applications, prospects, and challenges

Dihydromyricetin (DHM) is an important natural flavonoid that has attracted much attention because of its various functions such as protecting the cardiovascular system and liver, treating cancer and neurodegenerative diseases, and anti-inflammation effect, etc. Despite its great development potential in pharmacy, DHM has some problems in pharmaceutical applications such as low solubility, permeability, and stability. To settle these issues, extensive research has been carried out on its physicochemical properties and dosage forms to produce all kinds of DHM preparations in the past ten years. In addition, the combined use of DHM with other drugs is a promising strategy to expand the application of DHM. However, although invention patents for DHM preparations have been issued in several countries, the current transformation of DHM research results into market products is insufficient. To date, there is still a lack of deep research into the pharmacokinetics, pharmacodynamics, toxicology, and action mechanism of DHM preparations. Besides, preparations for combined therapy of DHM with other drugs are scarcely reported, which necessitates the development of dosage forms for this application. Apart from medicine, the development of DHM in the food industry is also of great potential. Due to its multiple effects and excellent safety, DHM preparations can be developed for functional drinks and foods. Through this review, we hope to draw more attention to the development potential of DHM and the above challenges and provide valuable references for the research and development of other natural products with a similar structure-activity relationship to this drug.

Cyclic RGD-Decorated Liposomal Gossypol AT-101 Targeting for Enhanced Antitumor Effect

Introduction

(-)-Gossypol (AT-101), the (-)-enantiomer of the natural compound gossypol, has shown significant inhibitory effects on various types of cancers such as osteosarcoma, myeloma, glioma, lung cancer, and prostate cancer. However, the clinical application of (-)-gossypol was often hindered by its evident side effects and the low bioavailability via oral administration, which necessitated the development of suitable (-)-gossypol preparations to settle the problems. In this study, injectable cyclic RGD (cRGD)-decorated liposome (cRGD-LP) was prepared for tumor-targeted delivery of (-)-gossypol.

Methods

The cRGD-LP was prepared based on cRGD-modified lipids. For comparison, a non-cRGD-containing liposome (LP) with a similar chemical composition to cRGD-LP was specially designed. The physicochemical properties of (-)-gossypol-loaded cRGD-LP (Gos/cRGD-LP) were investigated in terms of the drug loading efficiency, particle size, morphology, drug release, and so on. The inhibitory effect of Gos/cRGD-LP on the proliferation of tumor cells in vitro was evaluated using different cell lines. The biodistribution of cRGD-LP in vivo was investigated via the near-infrared (NIR) fluorescence imaging technique. The antitumor effect of Gos/cRGD-LP in vivo was evaluated in PC-3 tumor-bearing nude mice.

Results

Gos/cRGD-LP had an average particle size of about 62 nm with a narrow size distribution, drug loading efficiency of over 90%, and sustained drug release for over 96 h. The results of NIR fluorescence imaging demonstrated the enhanced tumor targeting of cRGD-LP in vivo. Moreover, Gos/cRGD-LP showed a significantly enhanced inhibitory effect on PC-3 tumors in mice, with a tumor inhibition rate of over 74% and good biocompatibility.

Conclusion

The incorporation of cRGD could significantly enhance the tumor-targeting effect of the liposomes and improve the antitumor effect of the liposomal (-)-gossypol in vivo, which indicated the potential of Gos/cRGD-LP that warrants further investigation for clinical applications of this single-isomer drug.

A multifaceted review on dihydromyricetin resources, extraction, bioavailability, biotransformation, bioactivities, and food applications with future perspectives to maximize its value

Natural bioactive compounds present a better alternative to prevent and treat chronic diseases owing to their lower toxicity and abundant resources. (+)-Dihydromyricetin (DMY) is a flavanonol, possessing numerous interesting bioactivities with abundant resources. This review provides a comprehensive overview of the recent advances in DMY natural resources, stereoisomerism, physicochemical properties, extraction, biosynthesis, pharmacokinetics, and biotransformation. Stereoisomerism of DMY should be considered for better indication of its efficacy. Biotechnological approach presents a potential tool for the production of DMY using microbial cell factories. DMY high instability is related to its powerful antioxidant capacity due to pyrogallol moiety in ring B, and whether preparation of other analogues could demonstrate improved properties. DMY demonstrates poor bioavailability based on its low solubility and permeability with several attempts to improve its pharmacokinetics and efficacy. DMY possesses various pharmacological effects, which have been proven by many in vitro and in vivo experiments, while clinical trials are rather scarce, with underlying action mechanisms remaining unclear. Consequently, to maximize the usefulness of DMY in nutraceuticals, improvement in bioavailability, and better understanding of its actions mechanisms and drug interactions ought to be examined in the future along with more clinical evidence.