Introduction/Overview
Natural products have always been an important source of innovative drug discovery, among which triterpenoid saponins have attracted much attention due to their structural diversity and wide range of biological activities. Raddeanin A is an oleanane type pentacyclic triterpenoid saponin isolated from the rhizomes of Anemone raddeana Regel, a plant in the Ranunculaceae family. Its CAS number is 89412-79-3. Since its discovery, numerous studies have revealed its excellent oral activity and multi-target, multi pathway anti-tumor properties, as well as its ability to regulate inflammation, bone metabolism, and immune microenvironment. Its pharmacological effects are not limited to direct cytotoxic effects, but also involve reshaping the tumor microenvironment and regulating the immune system, demonstrating a paradigm shift in natural product research from traditional "fighting poison with poison" to modern "multidimensional regulation". This article aims to systematically review the chemical properties, plant sources, pharmacological activities, molecular mechanisms, medicinal properties, and application prospects of Zhujie Xiangfu Su A in various diseases, especially in the field of cancer, in order to provide comprehensive scientific references for the in-depth research and clinical translation of this compound.
Chemical structure and physicochemical properties
The molecular formula of Zhujie Xiangfu Su A is C ₄₇ H ₇₆ O ₁₇, with a molecular weight of 897.1090. Its core structure is the oleanol-12-en-28-oic acid (oleanolic acid) skeleton, which belongs to the oleanane type triterpenoid saponins. This structure is connected to a linear trisaccharide chain consisting of glucuronic acid, glucose, and xylose at position C-3, and a glucose unit at position C-28, forming a disaccharide chain structure. This specific glycosylation pattern has a decisive impact on its biological activity and water solubility.
From the analysis of physical and chemical properties, its calculated lipid water partition coefficient (LogP) is 2.9455, indicating that it has a certain degree of lipophilicity, but not highly hydrophobic. Its topological polar surface area (TPSA) is as high as 254.5200 Å ², mainly attributed to the abundant hydroxyl and glycosidic oxygen atoms in the molecule, indicating that it has more hydrogen bond donor and acceptor sites. The water solubility parameter is 0.0847, belonging to the category of slightly soluble to poorly soluble, which is consistent with its larger molecular weight and glycoside structure, and is also a common challenge faced by most saponin compounds. Preliminary pharmacological predictions indicate that its blood-brain barrier permeability is low, suggesting that its direct effects on central nervous system diseases may be limited, but it may also reduce the risk of central neurotoxicity. In addition, its hERG inhibition risk prediction is negative, and the Ames test prediction result is 0.0 (negative), suggesting that it may have lower risks of cardiac toxicity and genetic toxicity, but further experimental verification is needed.
Plant sources and extraction methods
Zhujie Xiangfu A mainly comes from the dried rhizomes of Anemone raddeana Regel, a plant in the Ranunculaceae family. This medicinal herb is called "Zhujie Xiangfu" or "Two Headed Tip" in traditional Chinese medicine and is commonly used to treat rheumatism, rheumatism, swelling, and other diseases. Its extraction and separation usually follow the conventional process of natural product chemistry.
Firstly, the dried Zhujie Xiangfu medicinal material is crushed and subjected to reflux extraction or ultrasound assisted extraction using alcohol solvents (such as methanol, ethanol) or a mixture of alcohol and water to fully extract saponin components. Subsequently, the extract was obtained by vacuum concentration. After dispersing the extract in water, gradient extraction was carried out using organic solvents such as petroleum ether, ethyl acetate, and n-butanol in sequence. Zhujiexiangsu A was mainly enriched in the n-butanol extraction site. Further purification relies on column chromatography techniques, often using methods such as silica gel column chromatography, reverse phase silica gel (such as ODS) column chromatography, macroporous adsorption resin (such as D101, AB-8) chromatography, and high performance liquid chromatography (HPLC) for separation and purification. Modern technology has also explored efficient separation techniques such as high-speed countercurrent chromatography (HSCCC). The optimization of extraction process usually focuses on factors such as solvent concentration, solid-liquid ratio, extraction time, and temperature to improve the yield and purity of the target compound.
Pharmacological activity research
Zhujie Xiangfu Su A exhibits extensive and powerful pharmacological activities, and its research has expanded from the initial anti-inflammatory and analgesic effects to multiple cutting-edge fields such as anti-tumor, anti osteolysis, neuroprotection, and immune regulation.
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Antitumor activity This is the core activity of Zhujie Xiangfu Su A that has received the most attention. Studies have shown that it can significantly inhibit the proliferation of a variety of malignant tumor cells, including but not limited to breast cancer, colorectal cancer, glioblastoma, non-small cell lung cancer, castration resistant prostate cancer, multiple myeloma, cholangiocarcinoma and melanoma. Its function is not only to inhibit cell growth, but also to effectively suppress the migration, invasion, and angiogenesis of cancer cells (anti angiogenesis), and reverse the epithelial mesenchymal transition (EMT) process, thereby blocking tumor metastasis and spread. In addition, it can significantly induce apoptosis and cell cycle arrest in tumor cells (mostly in the G2/M phase), and promote the production of reactive oxygen species (ROS), leading to oxidative stress damage.
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Anti osteolytic and bone protective activity: In the model of osteolytic disease caused by bone metastasis of breast cancer and multiple myeloma, Rhizoma Cyperi A can effectively inhibit the differentiation and formation of osteoclasts and their bone absorption function, reduce bone damage, and show the potential to treat cancerous bone pain and pathological fracture.
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Anti inflammatory and immune regulatory activity Zhujie Xiangfu Su A is an effective inhibitor of NLRP3 inflammasome, which can alleviate various inflammatory reactions. Of particular importance, it can induce immunogenic cell death (ICD) in tumor cells, release damage associated molecular patterns (DAMPs), and promote the maturation of dendritic cells (DCs), thereby activating tumor specific T cell immune responses. In addition, it can regulate the tumor immune microenvironment and exhibit significant synergistic effects with immune checkpoint inhibitors such as anti-PD-1 antibodies.
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Neuroprotective potential In Alzheimer's disease related research, Zhujie Xiangfu Su A has shown certain improvement effects, and its mechanism may be related to anti-inflammatory, antioxidant, and regulation of related signaling pathways.
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Retinal protective effect The study also found that Phyllostachys A can improve the blood retinal barrier function, which has potential therapeutic value for vascular eye diseases such as diabetes retinopathy.
Mechanism of action and molecular targets
The multiple pharmacological effects of Zhujie Xiangfu Su A stem from its extensive intervention in multiple key signaling pathways within cells and regulation of multiple molecular targets, reflecting the characteristic of "multi-target" action.
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Core signaling pathway inhibition：
- PI3K/AKT/mTOR pathway This pathway is the core regulator of cell survival, proliferation, and metabolism. Zhujie Xiangfu Su A can significantly downregulate the expression of phosphorylated PI3K (p-PI3K) and AKT (p-AKT) proteins, and inhibit mTOR activity, thereby strongly blocking this pro cancer signaling axis, inducing cell apoptosis and autophagy.
- MAPK/ERK pathway By inhibiting MAPK/ERK signaling, Zhujie Xiangfu extract A interferes with cell proliferation and differentiation signals.
- SRC kinase and VEGFR2 Inhibition of SRC family kinases and vascular endothelial growth factor receptor 2 (VEGFR2) directly weakens the migration, invasion, and angiogenesis abilities of tumor cells.
- Wnt/β - catenin pathway Inhibiting this pathway helps to prevent the EMT process and maintain the characteristics of tumor stem cells.
- JNK signaling pathway Its regulation of JNK is involved in mediating apoptosis and stress response.
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Key target protein regulation：
- Apoptosis related targets By downregulating the expression of anti apoptotic proteins Bcl-2 and Mcl-1, and possibly affecting the transcriptional activity of STAT3, mitochondrial pathway apoptosis can be promoted.
- Cell cycle targets Inhibiting Wee1 kinase, disrupting cell cycle checkpoints, leading to cycle arrest.
- Androgen receptor (AR)In castration resistant prostate cancer, it can inhibit the activity of full-length AR (AR-FL) and splicing variants (AR Vs), overcoming hormone therapy resistance.
- Inflammatory core components Directly inhibit the assembly and activation of NLRP3 inflammasomes.
- Other related targets The study also suggests that it may affect matrix metalloproteinase MMP-2, hypoxia inducible factor HIF-1 α, topoisomerase TOP1/TOP2A, estrogen receptor ESR1, and aromatase CYP19A1, which together form a complex network of anti-tumor, anti-inflammatory, and anti metastatic effects.
Evaluation of drug properties and pharmacokinetics
Although Zhujie Xiangfu Su A has shown great potential in preclinical studies, its medicinal properties still face some challenges, and related research is gradually deepening.
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Absorption, distribution, metabolism, excretion (ADME)As a saponin compound, its larger molecular weight and higher polarity may lead to suboptimal oral bioavailability. Existing research has confirmed its oral activity, but specific absolute bioavailability data still needs to be clarified. The prediction of low blood-brain barrier permeability seems to contradict some central activity, which may suggest that its neuroprotective effect is mainly achieved through peripheral anti-inflammatory or indirect mechanisms, or there may be limited entry into the brain mediated by specific transporters. There are still few research reports on its metabolic pathways (such as hydrolysis, deglycosylation), major metabolites, and excretion modes (bile or kidney) in the body, which will be the focus of future pharmacokinetic studies.
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Formulation and delivery strategy To improve its water solubility and bioavailability, researchers are exploring various advanced drug delivery systems. For example, preparing it into nanoparticles, liposomes, micelles, or phospholipid complexes can enhance its stability, promote intestinal absorption, and achieve targeted enrichment at the tumor site (using EPR effect or active target modification), thereby reducing systemic toxicity while improving therapeutic efficacy.
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Preliminary evaluation of safety Based on its multi-target effects, a comprehensive evaluation of its potential toxicity is required. Although it is predicted that there will be no inhibition of the hERG channel and the Ames test is negative, systematic preclinical toxicology studies are still needed, including acute toxicity, long-term repeated administration toxicity, and assessment of the potential autoimmune risks associated with sustained activation of the immune system.
Clinical application prospects and prospects
The diverse biological activities of Zhujie Xiangfu Su A have brought broad application prospects in the treatment of various difficult to treat diseases.
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Tumor treatment field：
- Single or combination therapy: It can be used as a single drug for tumor types that are not sensitive to or resistant to traditional chemotherapy, such as castration resistant prostate cancer, triple negative breast cancer, etc.
- Synergistic effect When used in combination with conventional chemotherapy drugs such as paclitaxel and cisplatin, targeted drugs, or immune checkpoint inhibitors (anti-PD-1/PD-L1 antibodies), it exhibits significant synergistic effects and is expected to overcome drug resistance and improve efficacy.
- Anti metastasis and anti osteolysis Has unique advantages in preventing and treating tumor bone metastasis and related osteolytic destruction.
- Immunotherapy sensitizer Its ability to induce ICD and activate anti-tumor immunity makes it a highly promising immunotherapy sensitizer or combination therapy partner.
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Non tumor disease field：
- Inflammatory diseases: It can be used to treat chronic inflammatory diseases related to NLRP3, such as gout, atherosclerosis, type 2 diabetes, etc.
- Bone and joint diseases It has therapeutic potential for diseases such as rheumatoid arthritis and osteoporosis with abnormal activation of osteoclasts.
- Neurodegenerative diseases The activity in models such as Alzheimer's disease and Parkinson's disease deserves further exploration.
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Challenges and Future Directions：
- In depth mechanism research Further use of chemical biology methods (such as affinity fishing and proteomics) is needed to identify its direct target and draw a more accurate "compound target pathway phenotype" network map.
- structural optimization By using medicinal chemical methods to modify its structure and improve its pharmacokinetic properties (such as increasing solubility and metabolic stability) while maintaining its activity.
- Clinical translational research Accelerate toxicology, efficacy, and pharmacokinetic studies that comply with Good Clinical Practice (GLP) for non clinical drug research, and provide solid data for their application for clinical trials.
- Personalized healthcare Explore the relationship between its activity and specific biomarkers (such as pathway activation status, AR variant expression) to achieve precise medication.
Conclusion
Zhujie Xiangfu Su A, as a triterpenoid saponin derived from traditional Chinese medicine, has demonstrated remarkable comprehensive pharmacological activities in anti-tumor, anti-inflammatory, bone protection, and immune regulation due to its multi-target and multi pathway properties. It not only directly kills tumor cells by intervening in classic oncogenic pathways such as PI3K/AKT, MAPK, Wnt, but also cleverly combines direct killing with immune activation by regulating NLRP3 inflammasome and inducing immunogenic cell death, representing a new approach to natural product anti-cancer research. Although it faces challenges in terms of solubility and bioavailability, modern drug delivery technologies and structural optimization strategies provide feasible solutions for this. With the in-depth study of its molecular mechanism and pharmacokinetic properties, Zhujie Xiangfu Su A is expected to gradually move from an excellent preclinical candidate molecule to clinical development, providing new weapons for the treatment of cancer and related major diseases, and also providing an important paradigm for the development of innovative drugs based on natural products.
