Introduction/Overview
In the vast field where traditional medicine and modern pharmacology intersect, natural products have always been an important source of new drug discovery and development due to their structural diversity and rich biological activity. As a class of secondary metabolites widely present in the plant kingdom, iridoid glycosides have attracted much attention due to their significant pharmacological activities such as anti-inflammatory, neuroprotective, and antioxidant effects. Cornuside, as a representative iridoid glycoside, has become a hot topic in natural product pharmacology research since its discovery due to its outstanding performance in anti allergic, anti-inflammatory, and neuroprotective effects. Its CAS number is 131189-57-6, mainly derived from the traditional Chinese medicine Cornus officinalis（Cornus officinalis The fruit of Sieb. et Zucc. Modern pharmacological studies have shown that Cornus officinalis glycoside effectively inhibits allergic reactions and inflammatory cascades by regulating key signaling pathways such as p38 MAPK, JNK, NF - κ B; At the same time, it demonstrates the potential to improve cognitive impairment by affecting the cholinergic system and antioxidant defense system. This article aims to systematically review the chemical structure, plant origin, pharmacological activity, mechanism of action, medicinal properties, and clinical application prospects of the new glycoside from Cornus officinalis, in order to provide comprehensive scientific references for the in-depth research and future development of this compound.
Chemical structure and physicochemical properties
Cornus officinalis glycoside is a cyclic terpenoid glycoside compound. Its molecular formula is C24H30O14 and its molecular weight is 542.4900. Structurally, it is composed of a cyclohexene ether terpene mother nucleus (usually a split cyclohexene ether terpene or its derivative) connected to a sugar group (mostly glucose) through glycosidic bonds. This specific structure is the material basis for its biological activity. The ene bonds, epoxy or hemiacetal structures on the parent nucleus of cyclohexene ether terpenes make them easy to participate in redox reactions and interact with biomolecules, while the sugar moiety has a significant impact on their water solubility and bioavailability.
In terms of physicochemical properties, the new glycoside of Cornus officinalis exhibits typical characteristics of glycoside compounds. The calculated lipid water partition coefficient (LogP) is -0.2149, indicating that the compound has good hydrophilicity. The topologically polar surface area (TPSA) is as high as 221.9000 Å ², which is mainly attributed to the numerous hydroxyl and glycosyl oxygen atoms in the molecule, further confirming its strong polarity. The predicted value of its water solubility is 16.7576 mg/mL, which belongs to the soluble range, which is beneficial for its development in water-based formulations. However, its high polarity and TPSA also pose challenges to its transmembrane absorption, especially its blood-brain barrier permeability is predicted to be "low", suggesting that it may need to improve brain delivery through pharmaceutical means or structural modifications in the treatment of central nervous system diseases. In addition, preliminary pharmacological risk assessment showed that Cornus officinalis glycoside had no inhibition on hERG potassium channels (hERG inhibition: No), and the Ames test result was 0.0, indicating a low potential mutagenic risk and providing preliminary positive signals for its safety evaluation.
Plant sources and extraction methods
The new glycoside of Cornus officinalis is mainly derived from the Cornus officinalis plant in the family Cornaceae（Cornus officinalis Sieb. et Zucc.'s dried and ripe fruit pulp, also known as the traditional Chinese medicine "Cornus officinalis". Cornus officinalis is a traditional Chinese medicine that nourishes the liver and kidneys, astringents the essence, solidifies and removes impurities. It is listed as a medium grade in the "Shennong Bencao Jing". Modern research has confirmed that it contains various active ingredients such as iridoid glycosides, triterpenes, polysaccharides, organic acids, etc. Among them, iridoid glycosides are considered one of its important pharmacological substances.
Extracting new saponins from Cornus officinalis fruit usually follows the conventional process of natural product chemistry. Firstly, crush the dried Cornus officinalis pulp and extract it using an appropriate solvent. Common extraction solvents include methanol, ethanol, or ethanol water mixed solutions of different concentrations. Reflux extraction, ultrasound assisted extraction, or microwave-assisted extraction techniques are used to improve extraction efficiency. After obtaining the crude extract, preliminary separation was carried out through systematic solvent extraction (such as petroleum ether, ethyl acetate, n-butanol, etc.), and the new glycoside of Cornus officinalis was mainly enriched in n-butanol or water layer due to its high polarity. Further purification relies on various chromatographic techniques, such as silica gel column chromatography, macroporous adsorption resin column chromatography (such as D101, AB-8 type), reverse phase silica gel column chromatography (such as ODS-C18), and high-performance liquid chromatography (HPLC) preparative chromatography. By comparing the physicochemical properties of compounds (such as thin-layer chromatography behavior, HPLC retention time) and spectral data (nuclear magnetic resonance hydrogen spectrum, carbon spectrum, mass spectrometry) with literature reports, high-purity Cornus officinalis glycoside monomers can be ultimately identified and obtained. Optimizing the extraction and purification process to improve yield and purity is a prerequisite for ensuring its subsequent pharmacological research and application.
Pharmacological activity research
A large number of pharmacological experiments in vitro and in vivo have confirmed that the new glycoside of Cornus officinalis has various biological activities, mainly focused on anti allergic, anti-inflammatory, neuroprotective, and antioxidant fields.
1. Anti allergic activity:
The new glycoside of Cornus officinalis exhibits significant anti allergic effects. In the classic IgE mediated mast cell activation model, Cornus officinalis glycoside can effectively inhibit mast cell degranulation and histamine release. Histamine is a key inflammatory mediator in allergic reactions, and its release is inhibited, directly alleviating allergic symptoms such as vasodilation and smooth muscle contraction. This activity suggests that Cornus officinalis glycoside has potential value in the treatment of type I hypersensitivity diseases such as allergic rhinitis, asthma, and urticaria.
2. Anti inflammatory activity:
The anti-inflammatory effect of Cornus officinalis glycoside has been widely studied. In the lipopolysaccharide (LPS) - induced macrophage (such as RAW 264.7 cells) inflammation model, icariin can dose dependently inhibit the production and expression of a series of inflammatory mediators. These mediators include inducible nitric oxide synthase (iNOS) and its product nitric oxide (NO), cyclooxygenase-2 (COX-2) and its product prostaglandin E2 (PGE2), as well as key pro-inflammatory cytokines such as tumor necrosis factor - α (TNF - α), interleukin-6 (IL-6), and interleukin-1 β (IL-1 β). These factors play a central role in the process of acute and chronic inflammation, and their inhibition indicates that Cornus officinalis glycoside has broad-spectrum anti-inflammatory potential.
3. Neuroprotection and improvement of cognitive function activity:
Cornus officinalis glycoside exhibits a protective effect in a neurological disease model. In Alzheimer's disease (AD) related models, it has been demonstrated that icariin can improve cognitive impairment in mice. Its function is closely related to regulating the cholinergic system: on the one hand, it can inhibit the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) (with stronger inhibitory activity on BuChE, IC50 of 55.84 μ g/mL), reducing the breakdown of neurotransmitter acetylcholine (ACh); On the other hand, it can enhance the activity of choline acetyltransferase (ChAT) and promote the synthesis of ACh. This dual effect of "opening up sources and throttling" helps to increase the ACh level in synaptic cleft, thereby improving learning and memory function. In addition, its protective effect in the oxidative stress model indirectly supports its neuroprotective effect.
4. Antioxidant activity:
Although not elaborated in detail in the provided compound information, according to its related disease targets, the antioxidant damage activity of Cornus officinalis glycoside involves regulating a series of key factors in the endogenous antioxidant defense system. These targets include the transcription factor NFE2L2 (NRF2) and its downstream antioxidant proteins, such as superoxide dismutase 1/2 (SOD1/SOD2), catalase (CAT), glutathione peroxidase 1 (GPX1), and heme oxygenase 1 (HMOX1). By activating the NRF2 signaling pathway, Cornus officinalis glycoside may enhance cells' ability to resist oxidative stress, clear excess reactive oxygen species (ROS), and protect cells from oxidative damage, providing important molecular basis for its anti-inflammatory and neuroprotective activities.
Mechanism of action and molecular targets
The multiple pharmacological activities of Cornus officinalis glycoside stem from its precise regulation of multiple key signaling pathways within cells.
1. The core mechanism of anti allergy and anti-inflammatory: inhibition of MAPKs/NF - κ B signaling pathway
This is the core mechanism by which the new glycoside of Cornus officinalis exerts anti-inflammatory and anti allergic effects. When cells are stimulated by LPS, allergens, etc., members of the mitogen activated protein kinase (MAPKs) family, p38 and c-Jun N-terminal kinase (JNK), are rapidly phosphorylated and activated. At the same time, the nuclear factor kappa B (NF - κ B) pathway is also activated, and its inhibitory protein I κ B undergoes phosphorylation and degradation, allowing NF - κ B (usually p65/p50 dimer) to enter the nucleus and initiate transcription of numerous downstream inflammatory mediator genes. Research has shown that Cornus officinalis glycoside can effectively inhibit the phosphorylation of p38 MAPK and JNK, while preventing the degradation of I κ B and nuclear translocation of NF - κ B p65 subunit. Through this dual inhibition, Cornus officinalis glycoside comprehensively blocks the excessive production of inflammatory mediators such as iNOS, COX-2, TNF - α, IL-6 from both upstream signaling and downstream gene transcription levels, thereby exerting strong anti-inflammatory and anti allergic effects.
2. Mechanisms of neuroprotection and cognitive improvement: regulating cholinergic system and antioxidant defense
In terms of neuroprotection, the direct molecular targets of Cornus officinalis glycoside are acetylcholinesterase (AChE and BuChE). By reversibly or competitively inhibiting the active centers of these enzymes, the hydrolysis of ACh is slowed down. Meanwhile, it upregulates ChAT activity through mechanisms that are yet to be fully elucidated. This series of effects collectively enhance the efficiency of cholinergic neurotransmission, which is the main pathway for improving cognitive function. In addition, its antioxidant activity is closely related to the activation of the NRF2/ARE pathway. NRF2 is the central regulator of cellular antioxidant response. At rest, NRF2 binds to Keap1 and is degraded by ubiquitination. The new glycoside of Cornus officinalis may promote the dissociation of NRF2 and Keap1 by modifying cysteine residues on Keap1 or affecting related kinases, and then translocate to the nucleus, bind with antioxidant response elements (ARE), initiate the gene expression of a series of phase II detoxifying enzymes and antioxidant proteins such as SOD, CAT, GPX1, HMOX1, etc., and construct a strong cellular defense system to combat oxidative stress damage commonly seen in neurodegenerative diseases.
Evaluation of drug properties and pharmacokinetics
The pharmacological evaluation based on calculations and preliminary experimental data shows that the new glycoside of Cornus officinalis has both advantages and challenges as a drug lead compound.
Advantages: Its good water solubility (16.7576 mg/mL) is beneficial for formulation development; The preliminary safety warning is good, with no hERG inhibition or Ames mutagenicity, reducing the risk of cardiac toxicity and genetic toxicity; The molecular weight is moderate (542.49), meeting the requirements for molecular weight in the five rules of generic drugs (<500 Da slightly exceeds, but many natural product drugs have molecular weights in this range).
Challenge aspect: Its high polarity (LogP=-0.2149) and huge topological polarity surface area (TPSA=221.9 Å ²) are the main unfavorable factors affecting its oral absorption and bioavailability. High TPSA is often associated with poor cell membrane permeability, which is consistent with its predicted "low" blood-brain barrier permeability, limiting the direct effect of its prototype drug on the central nervous system. In addition, as a glycoside compound, it may be easily hydrolyzed by glycosidases in gut microbiota or epithelial cells in the gastrointestinal tract to generate aglycones, and its pharmacokinetic behavior may undergo significant changes.
At present, there are relatively limited research reports on the pharmacokinetics of the new glycoside system in Cornus officinalis. Limited animal experiments suggest that its oral absorption may be moderate or poor, with a wide distribution in the body but limited entry into brain tissue. In terms of metabolism, it may undergo phase I and phase II metabolic reactions such as hydrolysis (deglycosylation), oxidation, and binding (such as glucuronidation and sulfation). Its excretion pathway may mainly be through the kidneys and bile. To overcome its drug defects, future research can focus on: 1) developing novel drug delivery systems, such as nanoparticles, liposomes, microemulsions, etc., to improve their oral bioavailability and brain targeting; 2) Reasonable structural modifications can be made, such as preparing prodrugs to improve their lipid solubility and membrane permeability while maintaining their activity; 3) Conduct systematic ADME (absorption, distribution, metabolism, excretion) research to clarify its in vivo fate and provide a basis for dosage form design and clinical dosing regimens.
Clinical application prospects and prospects
The multi-target and multi pathway action characteristics of Cornus officinalis glycosides have demonstrated broad application prospects in the prevention and treatment of various diseases.
1. Allergic and inflammatory diseases: Based on its strong anti allergic and anti-inflammatory effects, Cornus officinalis glycoside is expected to be developed as a new drug or functional food additive for the treatment of allergic rhinitis, bronchial asthma, atopic dermatitis, allergic conjunctivitis and other diseases. It may have a more comprehensive therapeutic effect than single antihistamines or local hormones by inhibiting mast cell degranulation and downregulating multiple inflammatory mediators.
2. Neurodegenerative diseases and cognitive impairment: For cognitive disorders such as Alzheimer's disease and vascular dementia, Cornus officinalis glycoside exerts its effects through dual or multiple mechanisms of "cholinesterase inhibition" and "potential antioxidant/anti-inflammatory", which may be more advantageous compared to existing single mechanism drugs such as donepezil. Although its blood-brain barrier permeability is a major challenge, breaking through this barrier through technologies such as nano targeted delivery will significantly enhance its neuroprotective value.
3. Other chronic inflammation related diseases: Its inhibition of NF - κ B pathway may also have therapeutic potential in atherosclerosis, rheumatoid arthritis, inflammatory bowel disease and other diseases closely related to chronic low-grade inflammation.
Looking ahead to the future, the research and development of new glycosides from Cornus officinalis need to be further explored in the following directions:
- In depth mechanism exploration: By utilizing techniques such as proteomics, metabolomics, and chemical proteomics, more unknown direct targets and signal networks can be discovered.
- Structural optimization and derivative development: Using it as the parent nucleus, conduct systematic structure-activity relationship studies and synthesize a series of derivatives in order to obtain candidate compounds with stronger activity and better drug properties.
- Technological innovation in formulation: Vigorously developing new drug delivery systems suitable for improving the bioavailability and brain targeting of water-soluble natural products.
- Preclinical and clinical research advancement: Complete the toxicological evaluation of the system and conduct standardized clinical trials to verify its safety and effectiveness in humans.
- Multi component collaborative research: As one of the main active ingredients of Cornus officinalis, this study aims to investigate its synergistic effects with other components in Cornus officinalis, such as mononucleoside, loganin, polysaccharides, etc., and elucidate the material basis of the overall action of traditional Chinese medicine formulas.
Conclusion
As a cyclic ether terpenoid glycoside isolated from the traditional Chinese medicine Cornus officinalis, the new glycoside of Cornus officinalis has become a promising research object in the field of natural product pharmacology due to its significant multiple pharmacological activities such as anti allergic, anti-inflammatory, neuroprotective, and antioxidant effects. Its mechanism of action focuses on regulating the MAPKs/NF - κ B inflammatory signaling pathway and NRF2 antioxidant pathway, and directly acts on targets such as cholinesterase, reflecting the characteristics of multi-target intervention. Despite facing challenges in terms of oral absorption and blood-brain barrier penetration in terms of drug properties, its good safety and water solubility have laid a solid foundation for its further development. With the continuous development of modern medicinal chemistry, pharmacy, and pharmacology technologies, through in-depth structural optimization, formulation innovation, and systematic evaluation of the new glycoside of Cornus officinalis, it is expected to be developed into a new type of drug for treating allergic inflammatory diseases and neurodegenerative diseases, thus better inheriting and developing the treasure trove of traditional Chinese medicine and benefiting human health.
