Metal organic frameworks (MOFs) are formed by self-assembly of metal ions and organic ligands. A special type of MOF called ZIF-8, which is formed by self-assembly of zinc ions and 2-methylimidazole, shows excellent stability in aqueous solutions and disintegrates under acidic conditions. These properties make ZIF-8 a suitable carrier material for pH-stimulated drug delivery systems. Glabridin is an isoflavane compound that is widely present in the roots of licorice. Because of its outstanding skin whitening properties, glabridin is widely used as a whitener in the cosmetics industry. In this study, ZIF-8 was employed to encapsulate glabridin. Glabridin-loaded ZIF-8 was successfully prepared with a drug encapsulation efficiency of 98.67%. The prepared sample showed a fusiform or cruciate flower-like structure, and its size was about 3 μm. ZIF-8 enabled pH-controlled release of glabridin. Moreover, ZIF-8 encapsulation significantly enhanced the intracellular anti-oxidant activity and melanogenesis inhibitory activity of glabridin. This study provides a new approach that shows great potential to improve the biological application of glabridin.

(1) Background: Many studies have shown that microgravity experienced by astronauts or long-term bedridden patients results in increased oxidative stress and bone loss. Low-molecular-weight chondroitin sulfates (LMWCSs) prepared from intact chondroitin sulfate (CS) have been demonstrated to possess good antioxidant and osteogenic activities in vitro. This study aimed to assess the antioxidant activity of the LMWCSs in vivo and evaluate their potential in preventing microgravity-induced bone loss. (2) Methods: we used hind limb suspension (HLS) mice to simulate microgravity in vivo. We investigated the effects of LMWCSs against oxidative stress damage and bone loss in HLS mice and compared the findings with those of CS and a non-treatment group. (3) Results: LMWCSs reduced the HLS-induced oxidative stress level, prevented HLS-induced alterations in bone microstructure and mechanical strength, and reversed changes in bone metabolism indicators in HLS mice. Additionally, LMWCSs downregulated the mRNA expression levels of antioxidant enzyme- and osteogenic-related genes in HLS mice. The results showed that overall effect of LMWCSs was better than that of CS. (4) Conclusions: LMWCSs protect against the bone loss caused by simulated microgravity, which may be related to their ability to reduce oxidative stress. LMWCSs can be envisaged as potential antioxidants and bone loss protective agents in microgravity.

Cannabidiol (CBD) is the major functional component in hemp and has a broad range of pharmacological applications, such as analgesic, anti-epileptic, anti-anxiety, etc. Currently, CBD is widely used in pharmaceuticals, cosmetics, and food. To ensure the quality and safety of the products containing CBD, more and more related sample testing is being conducted, and the demand for CBD-certified reference material (CRM) has also sharply increased. However, there is currently a lack of relevant reference materials. In this paper, a simple method for preparing CBD CRM was established based on preparative liquid chromatography using crude hemp extract as a raw material. A qualitative analysis of CBD was performed using techniques such as ultraviolet absorption spectroscopy (UV), infrared spectroscopy (IR), mass spectrometry (MS), nuclear magnetic resonance spectroscopy (NMR), and differential scanning calorimetry (DSC). High-performance liquid chromatography (HPLC) was used for the homogeneity and stability tests, and the data were analyzed using an F-test and a T-test, respectively. Then, eight qualified laboratories were chosen for the determination of a certified value using HPLC. The results show that the CBD CRM had excellent homogeneity and good stability for 18 months. The certified value was 99.57%, with an expanded uncertainty of 0.24% (p = 0.95, k = 2). The developed CBD CRM can be used for the detection and quality control of cannabidiol products.