Storage conditions：Short-term storage at 2~8℃, long-term storage at -20 ~ -80℃
Cinnamaldehyde (CAS number: 104-55-2) is the main volatile aromatic component in plants of the cinnamon genus, and belongs to the parent structure of cinnamaldehyde compounds. Its chemical name is (E) -3-phenylpropan-2-enal. As a natural product, cinnamaldehyde has attracted widespread attention in pharmacology, food industry, and agriculture in recent years due to its unique aromatic odor and diverse biological activities. It has multiple pharmacological effects such as antibacterial, antifungal, hypoglycemic, vasodilator, and sensitizer, and is widely used in seasonings and food preservatives. With the in-depth study of the pharmacological mechanisms of natural products, cinnamaldehyde, as a compound with good safety and potential for drug development, has gradually revealed its molecular targets and mechanisms of action, showing promising applications in fields such as anti infection, metabolic diseases, and cardiovascular diseases.
This article will systematically review the chemical structure and physicochemical properties, plant sources and extraction methods, pharmacological activity and mechanism of action, drug evaluation and pharmacokinetic characteristics of cinnamaldehyde. Combined with the latest research progress, it will explore its clinical application prospects and future development directions, providing theoretical references for natural product pharmacology research and new drug development.
Cinnamaldehyde has the chemical formula C9H8O, a molecular weight of 132.16, and is characterized by an α, β - unsaturated aldehyde compound with a phenyl group attached to the acrolein skeleton. Its (E) - isomer, trans cinnamaldehyde, is the main form found in nature and has high stability and biological activity. The molecular structure contains a conjugated aromatic ring and α, β - unsaturated aldehyde groups, which give it strong electrophilic properties and reactivity, allowing it to covalently bind with functional groups such as thiol and amino groups in biomolecules.
In terms of physical and chemical properties, cinnamaldehyde appears as a colorless to pale yellow liquid with a characteristic cinnamon aroma. Its LogP value is about 1.92, indicating moderate lipid solubility, which is beneficial for membrane penetration. The polar surface area (TPSA) is 17.07 Å ², and the number of hydrogen bond acceptors is 1, indicating that its molecular polarity is low and easy to be absorbed by organisms. Cinnamaldehyde can penetrate the blood-brain barrier (BBB) well, indicating its potential application value in central nervous system diseases. Toxicological evaluation shows that the LD50 is about 2220 mg/kg, with low toxicity and no significant hepatotoxicity, cardiotoxicity, or hERG channel inhibition. The Ames mutagenicity test result is negative, indicating high safety.
Cinnamaldehyde is mainly present in the bark, leaves, and fruits of Cinnamomum spp., with the highest content found in cinnamon bark. The content of natural cinnamaldehyde is greatly affected by plant species, geographical environment, harvesting time, and processing methods. Common cinnamon varieties include Chinese cinnamon (Cinnamomum cassia), Ceylon cinnamon (Cinnamomum verum), etc.
There are various methods for extracting cinnamaldehyde, including distillation, solvent extraction, and supercritical CO2 extraction. The traditional distillation method uses steam distillation to extract volatile oils, followed by distillation to obtain cinnamaldehyde. The solvent extraction method commonly uses organic solvents such as ethanol and ether, which are suitable for extracting non-volatile and partially volatile components. Supercritical CO2 extraction method has been widely studied and applied in recent years due to its strong selectivity, solvent-free residue, and environmental friendliness. The improvement of extraction purity and yield lays the foundation for the large-scale production and application of cinnamaldehyde.
Cinnamaldehyde exhibits broad-spectrum antibacterial and antifungal activity, and has inhibitory effects on various Gram positive bacteria, Gram negative bacteria, and fungi. Its antibacterial targets involve key enzymes such as bacterial DNA gyrase (GYRA), cell wall synthase (FABI), and dihydrofolate reductase (DHFR), which can interfere with bacterial DNA replication, cell wall synthesis, and metabolic processes. In addition, cinnamaldehyde has an inhibitory effect on fungal ERG11 (CYP51A1) enzyme, blocking the synthesis of fungal cell membrane sterols and exerting antifungal effects. Its antibacterial mechanism includes disrupting cell membrane integrity, inhibiting enzyme activity, and inducing oxidative stress, exhibiting a low risk of drug resistance.
Cinnamaldehyde exhibits significant activity in regulating glucose metabolism, improving insulin sensitivity, promoting glucose uptake, and lowering blood sugar levels. Its mechanism of action is partially attributed to the inhibition of phenylalanine ammonia lyase (EC 4.3.1.24), which affects amino acid metabolism and gluconeogenesis processes. In addition, cinnamaldehyde can activate AMPK signaling pathway, regulate lipid metabolism, and reduce insulin resistance, showing the potential to treat type 2 diabetes and metabolic syndrome.
Cinnamaldehyde has vasodilatory effects, which can promote NO production, reduce vascular tension, and improve hemodynamics by regulating endothelial nitric oxide synthase (eNOS) activity. Its antioxidant and anti-inflammatory properties help to reduce vascular endothelial damage and prevent atherosclerosis and hypertension related cardiovascular diseases. Animal experiments have shown that cinnamaldehyde can lower blood pressure, improve myocardial ischemia-reperfusion injury, and has good cardiovascular protective effects.
Cinnamaldehyde can inhibit various pro-inflammatory factors such as TNF - α, IL-6, and NF - κ B signaling pathways, reducing inflammatory responses. Its antioxidant activity is mainly achieved by clearing free radicals and enhancing endogenous antioxidant enzyme activity (such as SOD, CAT), protecting cells from oxidative damage. This characteristic makes cinnamaldehyde potentially valuable in the prevention and treatment of chronic inflammatory and neurodegenerative diseases.
Cinnamaldehyde also exhibits a sensitizing effect, which can enhance the efficacy of certain drugs or treatments. In addition, it is widely used as a seasoning in the food industry, with both safety and functionality.
The multi-target mechanism of action of cinnamaldehyde is the basis for its various pharmacological effects. Its key targets include:
Bacterial targets Cinnamaldehyde inhibits the activity of enzymes such as GYRA (DNA gyrase A), FABI (fatty acid synthase), DHFR (dihydrofolate reductase), FTSZ (cell division protein), MECA (cell membrane protein), PENA (penicillin binding protein), CDR1 (fungal multidrug resistance protein), and blocks the growth and reproduction of bacteria and fungi.
metabolic enzyme Phenylalanine aminotransferase (EC 4.3.1.24) is a target of cinnamaldehyde that regulates amino acid and sugar metabolism, affecting gluconeogenesis and energy metabolism.
signaling pathway The regulation of signaling pathways such as AMPK, NF - κ B, and eNOS is the molecular basis for its hypoglycemic, anti-inflammatory, and vasodilatory effects.
Oxidative stress-related targets Cinnamaldehyde enhances antioxidant enzyme expression and reduces oxidative damage by regulating the Nrf2/ARE pathway.
In addition, the alpha, beta unsaturated aldehyde structure of cinnamaldehyde enables it to form covalent addition with protein thiol groups, regulate protein function, and further enrich its mechanism of action.
The pharmacological evaluation of cinnamaldehyde shows that it has good potential for drug development. Moderate molecular weight, moderate lipid solubility, low polarity, and easy oral absorption. Its high blood-brain barrier penetration ability suggests that it can be used for the treatment of central nervous system related diseases. Toxicological data shows that cinnamaldehyde has high safety, no significant hepatotoxicity, cardiotoxicity, or mutagenicity, and is suitable for long-term use.
Pharmacokinetic studies have shown that cinnamaldehyde is rapidly absorbed and widely distributed after oral administration, mainly metabolized through the liver. The metabolites are mainly cinnamic acid and its complexes. Its half-life is moderate and its clearance rate in the body is good. Due to its volatility and chemical activity, the improvement of formulation stability and bioavailability will be the focus of future research.
Cinnamaldehyde, as a multifunctional natural product, has shown broad prospects in clinical applications. Its antibacterial and antifungal effects provide new ideas for the development of anti infective drugs, especially in the context of increasingly severe drug-resistant bacteria. Its hypoglycemic and metabolic regulating effects make it a potential candidate for adjuvant treatment of diabetes and metabolic syndrome. The vasodilation and cardiovascular protective effects provide natural drug options for the prevention and treatment of cardiovascular diseases.
In the future, based on the structural optimization of cinnamaldehyde and the application of drug carrier technology, it is expected to improve its bioavailability and targeting, and expand its clinical indications. In addition, in-depth analysis of its molecular mechanism and safety evaluation will provide a solid foundation for its clinical translation. By combining modern medicinal chemistry, molecular biology, and pharmacological techniques, cinnamaldehyde is expected to become an important model for the development of natural product drugs.
Cinnamaldehyde, as a natural product with a wide range of sources, simple structure, and rich biological activity, has demonstrated good pharmacological properties and clinical application potential due to its multi-target and multi mechanism pharmacological characteristics. Its research in antibacterial, hypoglycemic, vasodilatory, and anti-inflammatory fields continues to deepen, promoting the development of natural product pharmacology. In the future, through systematic pharmacokinetic studies, structural optimization, and clinical trial verification, cinnamaldehyde is expected to become a safe and effective natural medicine, contributing new strength to human health.
