An Integrated NMR, LC-DAD-MS, LC-QTOF Metabolomic Characterization of Sartoria hedysaroides: Correlation of Antioxidant and Enzyme Inhibitory Activity with Chemical Composition by Multivariate Data Analysis

Fe3O4@MXene@PEI aerogel immobilized acetylcholinesterase for inhibitor screening from herbal plants

Screening of acetylcholinesterase (AChE) inhibitors is a common strategy in drug discovery for treating Alzheimer's disease. Herein, AChE was immobilized onto magnetic polyethyleneimine-based MXene aerogels through both electrostatic interactions and covalent bonds, enabling its application in AChE activity assays and inhibitor screening of herbal plants. The composite was analyzed using a range of techniques, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Zeta potential analysis, to gain insight into its chemical and physical properties. The proposed Fe3O4@MXene@PEI-AChE composite exhibited enhanced temperature and pH stability, as evaluated by Ellman's method, along with good reusability. The Michaelis Menten constant (Km) of the immobilized AChE was calculated to be 0.68 mmol/L. Additionally, an inhibition kinetic study was conducted to verify the feasibility of utilizing the immobilized enzyme to screen for inhibitors, with huperzine A employed as a model inhibitor. The proposed strategy was employed to compare the AChE inhibitory activity of 18 commonly used herbal medicines for treating AD, revealing both the aqueous and alcoholic extracts of Coptis chinensis as exhibiting the highest AChE inhibitory activity. Finally, the screening of AChE inhibitors in Coptis chinensis extracts were conducted by combining the proposed strategy with UPLC-Q-Orbitrap high resolution mass spectrometry. This study presents a feasible strategy for monitoring AChE activity and holds considerable potential for further exploration of AChE-inhibiting active ingredients in herbal medicines.

Plant Extracts as Skin Care and Therapeutic Agents

Natural ingredients have been used for centuries for skin treatment and care. Interest in the health effects of plants has recently increased due to their safety and applicability in the formulation of pharmaceuticals and cosmetics. Long-known plant materials as well as newly discovered ones are increasingly being used in natural products of plant origin. This review highlights the beneficial effects of plants and plant constituents on the skin, including moisturizing (e.g., Cannabis sativa, Hydrangea serrata, Pradosia mutisii and Carthamus tinctorius), anti-aging (e.g., Aegopodium podagraria, Euphorbia characias, Premna odorata and Warburgia salutaris), antimicrobial (e.g., Betula pendula and Epilobium angustifolium), antioxidant (e.g., Kadsura coccinea, Rosmarinus officinalis, Rubus idaeus and Spatholobus suberectus), anti-inflammatory (e.g., Antidesma thwaitesianum, Helianthus annuus, Oenanthe javanica, Penthorum chinense, Ranunculus bulumei and Zanthoxylum bungeanum), regenerative (e.g., Aloe vera, Angelica polymorpha, Digitaria ciliaris, Glycyrrihza glabra and Marantodes pumilum), wound healing (e.g., Agrimonia eupatoria, Astragalus floccosus, Bursera morelensis, Jatropha neopauciflora and Sapindus mukorossi), photoprotective (e.g., Astragalus gombiformis, Calea fruticose, Euphorbia characias and Posoqueria latifolia) and anti-tyrosinase activity (e.g., Aerva lanata, Bruguiera gymnorhiza, Dodonaea viscosa, Lonicera japonica and Schisandra chinensis), as well as their role as excipients in cosmetics (coloring (e.g., Beta vulgaris, Centaurea cyanus, Hibiscus sabdariffa and Rubia tinctiorum), protective and aromatic agents (e.g., Hyssopus officinalis, Melaleuca alternifolia, Pelargonium graveolens and Verbena officinalis)).

Synergistic Inhibiting Effect of Phytochemicals in Rheum palmatum on Tyrosinase Based on Metabolomics and Isobologram Analyses

Tyrosinase (TYR) plays a key role in the enzymatic reaction that is responsible for a range of unwanted discoloration effects, such as food browning and skin hyperpigmentation. TYR inhibitors could, therefore, be candidates for skin care products that aim to repair pigmentation problems. In this study, we used a metabolomics approach combined with the isobologram analysis to identify anti-TYR compounds within natural resources, and evaluate their possible synergism with each other. Rheum palmatum was determined to be a model plant for observing the effect, of which seven extracts with diverse phytochemicals were prepared by way of pressurized solvent extraction. Each Rheum palmatum extract (RPE) was profiled using nuclear magnetic resonance spectroscopy and its activity of tyrosinase inhibition was evaluated. According to the orthogonal partial least square analysis used to correlate phytochemicals in RPE with the corresponding activity, the goodness of fit of the model (R₂ = 0.838) and its predictive ability (Q₂ = 0.711) were high. Gallic acid and catechin were identified as the active compounds most relevant to the anti-TYR effect of RPE. Subsequently, the activity of gallic acid and catechin were evaluated individually, and when combined in various ratios by using isobologram analysis. The results showed that gallic acid and catechin in the molar ratios of 9:5 and 9:1 exhibited a synergistic inhibition on TYR, with a combination index lower than 0.77, suggesting that certain combinations of these compounds may prove effective for use in cosmetic, pharmaceutical, and food industries.