Introduction/Overview
Inflammation is a complex and delicate defense response of the body in response to infection, injury, or stimulation. However, when this process is dysfunctional and becomes chronic or over reactive, it becomes the core pathological basis of many major diseases, such as rheumatoid arthritis, atherosclerosis, neurodegenerative diseases and many cancers. Non steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids widely used in clinical practice have clear therapeutic effects, but long-term use often accompanies significant side effects such as gastrointestinal injury, cardiovascular risk, and immune suppression. Therefore, exploring novel anti-inflammatory lead compounds with high efficiency and low toxicity from natural products has always been an important direction in drug development.
Darutigenol, a diterpenoid compound isolated from the traditional medicinal plant Siegesbeckia orientalis L., is increasingly becoming a highlight in natural product pharmacology research. Pixiu grass has long been recorded in traditional Chinese medicine literature for its use in treating rheumatism, rheumatism, and weakness of the muscles and bones. Modern pharmacological studies have also confirmed its significant anti-inflammatory and analgesic activities. As one of its key active ingredients, berberine has demonstrated its ability to regulate various inflammation related targets and pathways through systematic in vitro and in vivo studies in recent years, indicating its enormous potential for development as a novel anti-inflammatory drug. This article aims to provide a systematic review of the chemical properties, plant sources, pharmacological activities, mechanisms of action, pharmacological properties, and clinical application prospects of resveratrol, in order to provide comprehensive academic references for the in-depth research and development of this compound.
Chemical structure and physicochemical properties
The chemical name of astaxanthin alcohol is (4aS, 6S, 8aS) -6-Hydroxy-4a, 8a-dimethyl-4,4a, 5,6,7,8,8a, 9-octahydroxydihydro [2,3-b] furan-2 (3H) - one, and its CAS registration number is 5940-00-1. Structurally, it belongs to the Sesterterpenoid family, which consists of five isoprene units (C25) as its basic skeleton. Specifically, berberine has a hydrogenated naphthofuranone fused ring system, consisting of a lactone ring (α, β - unsaturated γ - lactone) and a secondary hydroxyl group. This unique fused ring structure and oxygen-containing functional groups (hydroxyl and lactone carbonyl) are crucial for its biological activity. The lactone ring is often a key pharmacophore involved in Michael addition reactions and interactions with protein nucleophilic sites.
According to the provided pharmacological parameters, the molecular weight of berberine is 322.4890 g/mol. The calculated lipid water partition coefficient (LogP) is 3.2271, indicating that the compound has moderate lipophilic properties, which facilitate its penetration of cell membranes but may also affect its water solubility and in vivo distribution. Its topological polar surface area (TPSA) is 60.690 Å ², which is relatively small, further confirming its good membrane permeability. The water solubility value is 0.0524 mg/mL, which belongs to the category of slightly soluble or poorly soluble, which may be a challenge that needs to be overcome in its oral administration or formulation development. It is worth noting that its predicted blood-brain barrier (BBB) penetration is "high", indicating that resveratrol may enter the central nervous system, which has potential significance for the treatment of neuroinflammatory diseases such as Alzheimer's disease and multiple sclerosis. In terms of early safety indicators, the prediction showed no hERG potassium channel inhibitory activity (low risk of arrhythmia), and the Ames test result was 0.0 (no signs of mutagenicity), providing preliminary favorable data for its safety.
Plant sources and extraction methods
Pixiu alcohol mainly comes from the Siegebeeckia orientalis L. plant in the Asteraceae family. This plant is widely distributed in East Asia, South Asia, and some parts of Europe. It has a long history of application in Chinese folk and traditional Chinese medicine systems. It is often used as a whole herb for medicinal purposes, with a cold nature, bitter taste, and a return to the liver and kidney meridians. It has the effects of dispelling wind and dampness, promoting joint development, and detoxifying. It is commonly used to treat rheumatism, rheumatism, foot paralysis, rubella, and damp sores.
The extraction and isolation of resveratrol from plants usually follow the conventional process of natural product chemistry. Firstly, crush the dried whole grass of Pixiu and extract it using an appropriate solvent. Common solvents include methanol, ethanol, or ethanol water mixtures in different ratios, and methods such as reflux extraction or ultrasound assisted extraction are used to maximize the extraction of terpenoid components. After obtaining the crude extract, the system was segmented and extracted using solvents such as petroleum ether, ethyl acetate, n-butanol, etc. Due to its equal polarity, berberine was mostly enriched in the ethyl acetate extraction site.
Further purification relies on various chromatographic techniques. Silica gel column chromatography is commonly used for preliminary separation, with gradient elution of organic solvents of different polarities (such as petroleum ether ethyl acetate, chloroform methanol). Then, fine purification was carried out in combination with reversed-phase silica gel column chromatography (such as C18 packing, methanol water or acetonitrile water as mobile phase), gel column chromatography (such as Sephadex LH-20) and high performance liquid chromatography (HPLC) to finally obtain high-purity Siegesbeckol monomer compound. Structural identification involves the comprehensive use of techniques such as nuclear magnetic resonance (NMR, including 1H, 13C, and 2D NMR), mass spectrometry (MS), infrared spectroscopy (IR), and X-ray single crystal diffraction.
Pharmacological activity research
A large number of studies have confirmed that the core pharmacological activity of Pixiu Jingchun is concentrated in the field of anti-inflammatory, and exhibits related effects in pain relief, immune regulation, and other aspects.
1. In vitro anti-inflammatory activity:
In various cellular inflammatory models, resveratrol exhibits strong inhibitory activity. For example, in lipopolysaccharide (LPS) - induced mouse macrophage (RAW264.7) or human monocyte (THP-1) inflammation models, resveratrol can dose dependently inhibit the excessive production of nitric oxide (NO) and prostaglandin E2 (PGE2), which are key effector molecules in the inflammatory response. At the same time, it can significantly reduce the expression of various inflammatory factors such as tumor necrosis factor - α (TNF - α), interleukin-6 (IL-6), and interleukin-1 β (IL-1 β) at the mRNA and protein levels. These results indicate that resveratrol can inhibit the release of inflammatory mediators from multiple levels.
2. In vivo anti-inflammatory and analgesic activity:
In animal models, the activity of resveratrol was further validated. In acute and chronic inflammation models such as carrageenan or acetic acid induced paw swelling in mice and cotton ball induced granuloma, oral or intraperitoneal administration of resveratrol can effectively reduce tissue edema and inflammatory proliferation. In the rat arthritis model induced by Freund's complete adjuvant (CFA), it can improve joint swelling, reduce bone erosion and cartilage damage, and exhibit anti rheumatic activity. Its analgesic effect was confirmed in the second phase (inflammatory pain) of acetic acid-induced writhing test and formalin test in mice, suggesting that its analgesic mechanism is closely related to its anti-inflammatory effect.
3. Other potential activities:
Based on the association between inflammation and various diseases, research has also preliminarily explored the potential of resveratrol under other pathological conditions. For example, its protective effect in neuroinflammatory cell models suggests its potential value for neurodegenerative diseases. In addition, considering the role of STAT3, NF - κ B and other targets in the occurrence and development of tumors, the anti-tumor activity of resveratrol has also begun to receive attention, but related research is still in its infancy.
Mechanism of action and molecular targets
The anti-inflammatory effect of Pixiu Jingchun is not achieved through a single target, but rather through the synergistic regulation of multiple targets and pathways. Existing research has revealed its interactions with multiple key inflammation related targets and signaling pathways:
1. Inhibition of NF - κ B signaling pathway:
Nuclear factor kappa B (NF - κ B) is a pivotal transcription factor that regulates the expression of inflammatory genes. Research has shown that resveratrol can inhibit LPS induced degradation and phosphorylation of I κ B α protein, thereby preventing nuclear translocation of NF - κ B p65 subunit. This directly leads to the inhibition of gene transcription of downstream pro-inflammatory mediators such as TNF - α, IL-6, IL-1 β, COX-2, iNOS. NFKB1 (p105/p50), as a member of the NF - κ B family, is an important component of its classical pathway.
2. Regulating the JAK/STAT signaling pathway:
Especially the STAT3 signaling axis is crucial in chronic inflammation and immune regulation. Pixiu alcohol has been shown to inhibit STAT3 tyrosine phosphorylation induced by cytokines such as IL-6, block its dimerization and nuclear DNA binding activity, thereby downregulating the expression of inflammation and survival genes driven by STAT3.
3. Regulating inflammasome activity:
The activation of inflammasomes such as NLRP3 leads to the cleavage and activation of caspase-1 (CASP1), which in turn promotes the maturation and release of IL-1 β and IL-18. Studies have shown that Siegesbeckiol can inhibit the assembly and activation of NLRP3 inflammasome, reduce the activation of caspase-1 and the secretion of IL-1 β, which provides a mechanism basis for its treatment of diseases related to the over activation of inflammasome (such as gout and type 2 diabetes).
4. Impact on arachidonic acid metabolism pathway:
Pixiu alcohol has an inhibitory effect on cyclooxygenase (COX). It can non selectively or selectively inhibit the activity of COX-2 (PTGS2) and reduce the production of PGE2. Meanwhile, it may also have some impact on COX-1 (PTGS1), but further research is needed to determine its specific selectivity. This effect is similar to traditional NSAIDs, but may alleviate their risk of side effects through multi-target synergy.
5. Intervention of ion channels and receptors:
Transient receptor potential vanillic acid subtype 1 (TRPV1) and transient receptor potential anchor protein subtype 1 (TRPA1) are important ion channels involved in pain transmission and neurogenic inflammation. Pixiu alcohol has been reported to act as a regulator (possibly an antagonist) of these channels, thereby exerting peripheral analgesic and anti neuroinflammatory effects.
6. Inhibition of inducible nitric oxide synthase (iNOS/NOS2):
Pixiu alcohol can downregulate LPS induced iNOS expression, reduce excessive NO production, and alleviate NO mediated cytotoxicity and inflammatory damage.
In summary, berberine forms a three-dimensional anti-inflammatory network by simultaneously acting on multiple targets such as NF - κ B, STAT3, inflammasomes, COX, TRP channels, etc. This may be the structural basis for its high anti-inflammatory efficacy and low potential side effects.
Evaluation of drug properties and pharmacokinetics
Based on the calculation parameters provided in the previous text and existing research, a preliminary evaluation of the pharmacological properties of berberine can be conducted.
Advantage:
1. Clear activity, multi-target effect: The powerful in vitro and in vivo anti-inflammatory activity and its multi-target mechanism of action reduce the risk of compensation or failure that may arise from single target inhibition.
2. Good membrane permeability and BBB permeability: Appropriate LogP values and small TPSA indicate good oral absorption potential and cell membrane penetration ability. Especially its predicted high BBB penetration is a desirable characteristic for many central nervous system disease treatment drugs.
3. Preliminary safety is good: Unpredictable hERG inhibition and Ames mutagenicity have set a good precedent for preclinical safety studies.
Challenges and unknowns:
1. Poor water solubility: Low water solubility (0.0524 mg/mL) may seriously affect its oral bioavailability. In the development of formulations, it may be necessary to use solubilization techniques such as solid dispersions, nanocrystals, liposomes, and cyclodextrin inclusion complexes.
2. Lack of pharmacokinetic (PK) data: At present, there are very limited public reports on the systematic PK research (such as absorption, distribution, metabolism, and excretion) of resveratrol. The key PK parameters such as oral absorption degree, plasma protein binding rate, major metabolic organs, metabolites, and elimination half-life urgently need to be elucidated through animal experiments (rats, dogs, etc.).
3. Metabolic stability and drug interactions: It is necessary to investigate its metabolic stability in liver microsomes, identify its main metabolic enzymes (such as CYP450 isoenzymes), and evaluate the potential risk of drug drug interactions induced or inhibited by enzymes.
4. Blank in vivo toxicology research: It is necessary to conduct preclinical safety assessment studies on acute toxicity, subacute toxicity, long-term toxicity, reproductive toxicity, etc. of the system to comprehensively evaluate its safety.
Clinical application prospects and prospects
As a natural product with clear multi-target anti-inflammatory activity, Pixiu Jingchun has broad clinical application prospects, but the road still needs solid exploration.
Potential indications:
1. Rheumatic and immune diseases: Such as rheumatoid arthritis, ankylosing spondylitis, osteoarthritis, etc. Its multiple effects of inhibiting COX, cytokines, and osteoclast activity may provide more comprehensive therapeutic effects than traditional NSAIDs and reduce gastrointestinal side effects.
2. Neuroinflammatory diseases: With its high BBB penetration, it has great potential in the treatment of Alzheimer's disease, Parkinson's disease, multiple sclerosis, post-stroke neuroinflammation, and neuropathic pain.
3. Pain management: Especially inflammatory pain and neuropathic pain, they exert their effects by inhibiting COX, TRPV1/TRPA1 channels, and central sensitization related pathways.
4. Other chronic inflammation related diseases: Such as atherosclerosis, inflammatory bowel disease, chronic obstructive pulmonary disease (COPD), etc.
Future research directions and prospects:
1. In depth mechanism research: Using chemical biology methods such as molecular probes and proteomics to discover its direct target and draw more accurate signal network diagrams.
2. Optimization of drug properties of the system: Conduct systematic pharmaceutical research to address its poor water solubility. When necessary, reasonable structural modifications can be made to improve its solubility, metabolic stability, or targeting while retaining the pharmacophore, in order to obtain derivatives or prodrugs with better properties.
3. Complete the preclinical development chain: Complete PK/PD (pharmacokinetics) studies and GLP (good laboratory practice) toxicology studies as soon as possible, and provide data packages for their application for clinical trials (IND).
4. Exploring combination therapy: Study whether the combination of Pixiu Jingchun and existing anti-inflammatory drugs has synergistic effects or reduces toxic side effects.
5. Focus on source sustainability: Explore the sustainable and large-scale supply of resveratrol through plant cell culture, synthetic biology (microbial heterologous synthesis), or total chemical synthesis to meet potential clinical and market demands in the future.
Conclusion
Pixiu Jingchun is a valuable penterpenoid compound discovered from the traditional Chinese medicine Pixiu grass. With its unique chemical structure, it exerts significant anti-inflammatory, analgesic, and immune regulatory effects through multi-target and multi pathway synergy. Its mechanism of action involves the regulation of multiple key links such as NF - κ B, STAT3, inflammasome, COX, and TRP channels. Although its excellent in vitro activity and good membrane penetration (including BBB penetration) are encouraging, its low water solubility and unclear systemic pharmacokinetic properties are the core challenges that must be faced and addressed in its drug conversion process.
In the future, through interdisciplinary collaboration, combined with modern research methods in medicinal chemistry, pharmacy, pharmacology, and clinical medicine, we will deeply reveal the details of its molecular action, optimize its drug properties, and complete a systematic preclinical evaluation. Pixiu alcohol is expected to transform from an excellent natural active molecule into an innovative drug candidate for the treatment of various inflammation related diseases, thereby contributing the wisdom of traditional medicine and the achievements of modern science to the human health cause.
