Astragali radix is a traditional medicinal herb with a long history and wide application. It is frequently used in prescriptions with other medicinal materials to replenish Qi. According to the classics of traditional Chinese medicine, Astragali radix is attributed with properties such as Qi replenishing and surface solidifying, sore healing and muscle generating, and inducing diuresis to reduce edema. Modern pharmacological studies have demonstrated that some extracts and active ingredients in Astragali radix function as antioxidants. The polysaccharides, saponins, and flavonoids in Astragali radix offer beneficial effects in preventing and controlling diseases caused by oxidative stress. However, there is still a lack of comprehensive research on the effective components and molecular mechanisms through which Astragali radix exerts antioxidant activity. In this paper, we review the active components with antioxidant effects in Astragali radix; summarize the content, bioavailability, and antioxidant mechanisms; and offer a reference for the clinical application of Astragalus and the future development of novel antioxidants.

Oxidation of methionine residues to methionine sulfoxide (MetSO) may cause changes in protein structure and function, and may eventually lead to cell damage. Methionine sulfoxide reductases (Msrs) are the only known enzymes that catalyze the reduction of MetSO back to methionine by taking reducing equivalents from the thioredoxin system, and thus protect cells from oxidative damage. Nonetheless, a lack of convenient assays for the enzymes hampers the exploration of their functions. We report the discovery of Msr-blue, the first turn-on fluorescent probe for Msr with a >100-fold fluorescence increment from screening a rationally-designed small library. Intensive studies demonstrated the specific reduction of Msr-blue by the enzymes. Msr-blue is ready to determine Msr activity in biological samples and live cells. Importantly, we disclosed a decline of Msr activity in a Parkinson's model, thus providing a mechanistic linkage between the loss of function of Msrs and the development of neurodegeneration. The strategy for the discovery of Msr-blue would also provide guidance for developing novel probes with longer excitation/emission wavelengths and specific probes for Msr isoforms.

Astragali Radix (AR), a traditional Chinese herbal medicine, is derived from the dried roots of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao (A. membranaceus var. mongholicus, AMM) or Astragalus membranaceus (Fisch.) Bge (A. membranaceus, AM). According to traditional Chinese medicine (TCM) theory, AR is believed to tonify qi, elevate yang, consolidate the body’s surface to reduce sweating, promote diuresis and reduce swelling, generate body fluids, and nourish the blood. It has been widely used to treat general weakness and chronic illnesses and to improve overall vitality. Extensive research has identified various medicinal properties of AR, including anti-tumor, antioxidant, cardiovascular-protective, immunomodulatory, anti-inflammatory, anti-diabetic, and neuroprotective effects. With advancements in technology, methods such as computer-aided drug design (CADD) and artificial intelligence (AI) are increasingly being applied to the development of TCM. This review summarizes the progress of research on AR over the past decades, providing a comprehensive overview of its traditional efficacy, botanical characteristics, drug design and distribution, chemical constituents, and phytochemistry. This review aims to enhance researchers’ understanding of AR and its pharmaceutical potential, thereby facilitating further development and utilization.

Caffeic acid (CA) is a prevalent polyphenolic compound commonly found in various plant-derived foods. Due to its diverse pharmacological properties, including antioxidant activity, cardiovascular protection, and immune regulation, CA has garnered significant attention. Ionizing radiation (IR) is extensively utilized across industrial sectors, agriculture, defense applications, scientific research, and clinical medicine; however, the detrimental effects of radiation on human health cannot be ignored. IR can directly damage the DNA, proteins, and lipids within macromolecules or ionize water molecules to generate substantial quantities of free radicals that indirectly harm cells, especially those in the brain which are highly susceptible to radiation exposure. Consequently, effective strategies for preventing and treating IR-induced neurological damage represent an urgent medical challenge that necessitates resolution. Our study aims to investigate the protective effects of CA against IR-induced neuronal cell damage along with elucidating its potential mechanisms of action. The results indicate that CA can covalently modify active cysteine residues on Keap1 protein altering its conformation; this modification disrupts the interaction between Keap1 and Nrf2 while facilitating Nrf2's translocation into the nucleus where it activates downstream expression of cellular protective factors such as heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase 1 (NQO1), Thioredoxin Reductase-1 (TrxR1) and other cellular protective factors to play a role in countering radiation-induced neurological damage. In conclusion, CA emerges as an effective radioprotective agent capable of exerting antiradiation effects. Our findings provide valuable insights for developing novel therapeutic agents aimed at preventing and treating IR-induced neurological impairment.