Bioavailability of caffeic acid in rats and its absorption properties in the Caco-2 cell model

Screening of the Anti-Neurodegenerative Activity of Caffeic Acid after Introduction into Inorganic Metal Delivery Systems to Increase Its Solubility as the Result of a Mechanosynthetic Approach

The proven anti-neurodegenerative properties of caffeic acid in vivo are limited due to its poor solubility, which limits bioavailability. Therefore, caffeic acid delivery systems have been developed to improve caffeic acid solubility. Solid dispersions of caffeic acid and magnesium aluminometasilicate (Neusilin US2-Neu) were prepared using the ball milling and freeze-drying techniques. The solid dispersions of caffeic acid:Neu obtained by ball milling in a 1:1 mass ratio turned out to be the most effective. The identity of the studied system in comparison to the physical mixture was confirmed using the X-Ray Powder Diffractionand Fourier-transform infrared spectroscopy techniques. For caffeic acid with improved solubility, screening tests were carried out to assess its anti-neurodegenerative effect. The obtained results on the inhibition of acetylcholinesterase, butyrylcholinesterase, tyrosinase, and antioxidant potential provide evidence for improvement of caffeic acid's anti-neurodegenerative activity. As a result of in silico studies, we estimated which caffeic acid domains were involved in interactions with enzymes showing expression relevant to the neuroprotective activity. Importantly, the confirmed improvement in permeability of the soluble version of caffeic acid through membranes simulating the walls of the gastrointestinal tract and blood-brain barrier further strengthen the credibility of the results of in vivo anti-neurodegenerative screening tests.

Optimization of Delivery and Bioavailability of Encapsulated Caffeic Acid

Caffeic acid is a widely distributed phenolic acid. It is described in the scientific literature that caffeic acid has poor solubility. The aim of this study was to improve the solubility of caffeic acid for better dissolution kinetics when administered orally. During the study, oral capsules of different compositions were modeled. The results of the disintegration test revealed that the excipients affected the disintegration time of the capsules. The excipient hypromellose prolonged the disintegration time and dissolution time of caffeic acid. The dissolution kinetics of caffeic acid from capsules depend on the chosen excipients. P407 was more effective compared to other excipients and positively affected the dissolution kinetics of caffeic acid compared to other excipients. When the capsule contained 25 mg of β-cyclodextrin, 85% of the caffeic acid was released after 60 min. When the capsule contained 25-50 mg poloxamer 407, more than 85.0% of the caffeic acid was released from capsules after 30 min. The research results showed that in order to improve the dissolution kinetics of caffeic acid, one of the important steps is to improve its solubility.

Modulatory effect of caffeic acid in alleviating diabetes and associated complications

Diabetes mellitus (DM) is one of the most common metabolic disorders characterized by elevated blood glucose levels. Prolonged uncontrolled hyperglycemia often leads to multi-organ damage including diabetic neuropathy, nephropathy, retinopathy, cardiovascular disorders, and diabetic foot ulcers. Excess production of free radicals causing oxidative stress in tissues is often considered to be the primary cause of onset and progression of DM and associated complications. Natural polyphenols can be used to induce or inhibit the expression of antioxidant enzymes such as glutathione peroxidase, heme oxygenase-1, superoxide dismutase, and catalase that are essential in maintaining redox balance, and ameliorate oxidative stress. Caffeic acid (CA) is a polyphenolderived from hydroxycinnamic acid and possesses numerous physiological properties includ-ing antioxidant, anti-inflammatory, anti-atherosclerotic, immune-stimulatory, cardioprotective, antiproliferative, and hepatoprotective activities. CA acts as a regulatory compound affecting numerous biochemical pathways and multiple targets. These include various transcription factors such as nuclear factor-B, tumor necrosis factor-α, interleukin-6, cyclooxygenase-2, and nuclear factor erythroid 2-related factor 2. Therefore, this review summarizes the pharmacological properties, molecular mechanisms, and pharmacokinetic profile of CA in mitigating the adverse effects of DM and associated complications. The bioavailability, drug delivery, and clinical trials of CA have also been discussed.

Bioactive compounds and functional foods as coadjuvant therapy for thrombosis

Cardiovascular diseases (CVDs) are the leading cause of death. The most common cardiovascular pathologies are thromboembolic diseases. Antithrombotic therapy prevents thrombus formation or dissolves that previously constituted. However, it presents a high rate of accidents such as gastric bleeding and cerebrovascular embolism. Plant foods and their secondary metabolites have been reported to regulate blood hemostasis. This review article aims to propose plant foods and their metabolites as adjuvant therapy for the management of thromboembolic diseases. Various databases were consulted, using antiplatelet, anticoagulant, and fibrinolytic as key terms. In total, 35 foods and 24 secondary metabolites, via in vitro, in vivo, and clinical studies, have been reported to regulate platelet aggregation, blood coagulation, and fibrinolysis. According to the studies presented in this review, plant foods with effects at concentrations less than 50 μg mL^-1 and secondary metabolites with IC₅₀ less than 100 μM can be considered agents with high antithrombotic potential. This review suggests that plant foods and their secondary metabolites should be used to develop foods, ingredients and nutraceuticals with functional properties. The evidence presented in this review shows that plant foods and their bioactive compounds could be used as adjuvants for the treatment and prevention of thrombotic complications. However, further in vivo and clinical trials are required to establish effective and safe doses.

Oral Pharmacokinetics of Hydroxycinnamic Acids: An Updated Review

Hydroxycinnamic acids (HCAs) such as caffeic acid (CA), chlorogenic acid (CGA), coumaric acid (COA) isomers, ferulic acid (FA) and rosmarinic acid (RA) are natural phenolic acids with widespread distribution in vegetal foods and well-documented pharmacological activities. However, the low bioavailability of HCAs impairs their administration by the oral route. The present review addresses new findings and important factors/obstacles for their oral administration, which were unexplored in the reviews published a decade ago concerning the bioavailability of phenolic acids. Based on this, the article aims to perform an updated review of the water solubility and gastrointestinal stability of HCAs, as well as describe their oral absorption, distribution, metabolism and excretion (ADME) processes by in vitro, ex vivo, in situ and in vivo methods.

D-DOPA Is a Potent, Orally Bioavailable, Allosteric Inhibitor of Glutamate Carboxypeptidase II

Glutamate carboxypeptidase-II (GCPII) is a zinc-dependent metalloenzyme implicated in numerous neurological disorders. The pharmacophoric requirements of active-site GCPII inhibitors makes them highly charged, manifesting poor pharmacokinetic (PK) properties. Herein, we describe the discovery and characterization of catechol-based inhibitors including L-DOPA, D-DOPA, and caffeic acid, with sub-micromolar potencies. Of these, D-DOPA emerged as the most promising compound, with good metabolic stability, and excellent PK properties. Orally administered D-DOPA yielded high plasma exposures (AUCplasma = 72.7 nmol·h/mL) and an absolute oral bioavailability of 47.7%. Unfortunately, D-DOPA brain exposures were low with AUCbrain = 2.42 nmol/g and AUCbrain/plasma ratio of 0.03. Given reports of isomeric inversion of D-DOPA to L-DOPA via D-amino acid oxidase (DAAO), we evaluated D-DOPA PK in combination with the DAAO inhibitor sodium benzoate and observed a >200% enhancement in both plasma and brain exposures (AUCplasma = 185 nmol·h/mL; AUCbrain = 5.48 nmol·h/g). Further, we demonstrated GCPII target engagement; orally administered D-DOPA with or without sodium benzoate caused significant inhibition of GCPII activity. Lastly, mode of inhibition studies revealed D-DOPA to be a noncompetitive, allosteric inhibitor of GCPII. To our knowledge, this is the first report of D-DOPA as a distinct scaffold for GCPII inhibition, laying the groundwork for future optimization to obtain clinically viable candidates.

Dietary Polyphenols Alleviate Autoimmune Liver Disease by Mediating the Intestinal Microenvironment: Challenges and Hopes

Autoimmune liver disease is a chronic liver disease caused by an overactive immune response in the liver that imposes a significant health and economic cost on society. Due to the side effects of existing medicinal medications, there is a trend toward seeking natural bioactive compounds as dietary supplements. Currently, dietary polyphenols have been proven to have the ability to mediate gut-liver immunity and control autoimmune liver disease through modulating the intestinal microenvironment. Based on the preceding, this Review covers the many forms of autoimmune liver illnesses, their pathophysiology, and the modulatory effects of polyphenols on immune disorders. Finally, we focus on how polyphenols interact with the intestinal milieu to improve autoimmune liver disease. In conclusion, we suggest that dietary polyphenols have the potential as gut-targeted modulators for the prevention and treatment of autoimmune liver disease and highlight new perspectives and critical issues for future pharmacological applications.

Mitochondria-targeted anti-oxidant AntiOxCIN4 improved liver steatosis in Western diet-fed mice by preventing lipid accumulation due to upregulation of fatty acid oxidation, quality control mechanism and antioxidant defense systems

Non-alcoholic fatty liver disease (NAFLD) is a health concern affecting 24% of the population worldwide. Although the pathophysiologic mechanisms underlying disease are not fully clarified, mitochondrial dysfunction and oxidative stress are key players in disease progression. Consequently, efforts to develop more efficient pharmacologic strategies targeting mitochondria for NAFLD prevention/treatment are underway. The conjugation of caffeic acid anti-oxidant moiety with an alkyl linker and a triphenylphosphonium cation (TPP+), guided by structure-activity relationships, led to the development of a mitochondria-targeted anti-oxidant (AntiOxCIN4) with remarkable anti-oxidant properties. Recently, we described that AntiOxCIN4 improved mitochondrial function, upregulated anti-oxidant defense systems, and cellular quality control mechanisms (mitophagy/autophagy) via activation of the Nrf2/Keap1 pathway, preventing fatty acid-induced cell damage. Despite the data obtained, AntiOxCIN4 effects on cellular and mitochondrial energy metabolism in vivo were not studied. In the present work, we proposed that AntiOxCIN4 (2.5 mg/day/animal) may prevent non-alcoholic fatty liver (NAFL) phenotype development in a C57BL/6J mice fed with 30% high-fat, 30% high-sucrose diet for 16 weeks. HepG2 cells treated with AntiOxCIN4 (100 μM, 48 h) before the exposure to supraphysiologic free fatty acids (FFAs) (250 μM, 24 h) were used for complementary studies. AntiOxCIN4 decreased body (by 43%), liver weight (by 39%), and plasma hepatocyte damage markers in WD-fed mice. Hepatic-related parameters associated with a reduction of fat liver accumulation (by 600%) and the remodeling of fatty acyl chain composition compared with the WD-fed group were improved. Data from human HepG2 cells confirmed that a reduction of lipid droplets size and number can be a result from AntiOxCIN4-induced stimulation of fatty acid oxidation and mitochondrial OXPHOS remodeling. In WD-fed mice, AntiOxCIN4 also induced a hepatic metabolism remodeling by upregulating mitochondrial OXPHOS, anti-oxidant defense system and phospholipid membrane composition, which is mediated by the PGC-1α-SIRT3 axis. AntiOxCIN4 prevented lipid accumulation-driven autophagic flux impairment, by increasing lysosomal proteolytic capacity. AntiOxCIN4 improved NAFL phenotype of WD-fed mice, via three main mechanisms: a) increase mitochondrial function (fatty acid oxidation); b) stimulation anti-oxidant defense system (enzymatic and non-enzymatic) and; c) prevent the impairment in autophagy. Together, the findings support the potential use of AntiOxCIN4 in the prevention/treatment of NAFLD.

Phytochemicals, Nutrition, Metabolism, Bioavailability, and Health Benefits in Lettuce-A Comprehensive Review

Lettuce is one of the most famous leafy vegetables worldwide with lots of applications from food to other specific uses. There are different types in the lettuce group for consumers to choose from. Additionally, lettuce is an excellent source of bioactive compounds such as polyphenols, carotenoids, and chlorophyll with related health benefits. At the same time, nutrient composition and antioxidant compounds are different between lettuce varieties, especially for green and red lettuce types. The benefit of lettuce consumption depends on its composition, particularly antioxidants, which can function as nutrients. The health benefits rely on their biochemical effect when reaching the bloodstream. Some components can be released from the food matrix and altered in the digestive system. Indeed, the bioaccessibility of lettuce is measuring the quantity of these compounds released from the food matrix during digestion, which is important for health-promoting features. Extraction of bioactive compounds is one of the new trends observed in lettuce and is necessarily used for several application fields. Therefore, this review aims to demonstrate the nutritional value of lettuce and its pharmacological properties. Due to their bioaccessibility and bioavailability, the consumer will be able to comprehensively understand choosing a healthier lettuce diet. The common utilization pattern of lettuce extracted nutrients will also be summarized for further direction.

Soybean oil and coconut oil enhance the absorption of chlorogenic acid in humans

The effect of a mainly polyunsaturated oil (soybean oil) and a mainly medium chain triglyceride oil (coconut oil) on the absorption of the phenolic antioxidant chlorogenic acid (5-caffeoylquinic acid) was investigated using 90 healthy volunteers. Serum concentrations and the absorbed percentages of chlorogenic acid of volunteers who received chlorogenic acid without oils (0.006 ± 0.001 mg/ml, 5.7 ± 0.2%), chlorogenic acid with soybean oil (0.012 ± 0.001 mg/ml, 11.8 ± 1.3%), and chlorogenic acid with coconut oil (0.067 ± 0.014 mg/ml, 65.6 ± 18.1%) were significantly different from each other (p < .05). There was a strong positive correlation between the increase in serum and plasma antioxidant capacity and the absorption of chlorogenic acid. The major fatty acid of each of soybean oil and coconut oil also improved the permeability of chlorogenic acid in Caco-2 cell monolayers. The results suggest that the tested edible oils may improve the nutritional value of chlorogenic acid-containing foods by improving the absorption of chlorogenic acid. PRACTICAL APPLICATIONS: Small polar antioxidants such as phenolic acids and flavonoids are poorly absorbed through the intestinal epithelium. Chlorogenic acid was used in the present study as a model for small polar phenolic antioxidants. According to the present study, soybean oil with mainly polyunsaturated fatty acids and coconut oil with mainly medium chain fatty acids improve the absorption of these antioxidants. These findings suggest that proper planning of diets or food supplements containing phenolic antioxidants with medium chain or polyunsaturated fatty acid-rich edible oils may enhance the nutritional benefits expected from phenolic antioxidants.

Detection and Comparison of Bioactive Compounds in Different Extracts of Two Hazelnut Skin Varieties, Tonda Gentile Romana and Tonda Di Giffoni, Using a Metabolomics Approach

Agro-wastes are one of the major sources for nutritional and therapeutic benefits along with other beneficial properties. Dark brown pellicular pericarp (skin or testa), covering the hazelnut seed, is removed before consumption after the roasting of a kernel. Defatted skins of both hazelnut varieties, Tonda Gentile Romana and Tonda di Giffoni, were profiled by a metabolomics-based approach and this was used to discriminate between these two different hazelnut cultivars. In particular, an untargeted metabolomic extract from hazelnut by-products was investigated by UHPLC-Mass spectrometry followed by multivariate statistics analysis, and significant qualitative and quantitative metabolic differences were observed between them. Samples were also assessed for their total phenolic and antioxidant capacity using two different assays. Although no significant differences were found in total phenolic contents and antioxidant capacity, the Flavone, Flavonol, Flavonoid, and Phenylpropanoid Biosynthesis pathway was significantly higher in the Romana rather than in the Giffoni variety, whereas Myricetin and Syringetin compounds were more representative in Giffoni cultivars. These results indicated that hazelnut skin, especially from the Romana variety, could potentially be used as an ingredient in healthy food. Healthy food is a new food category with an expanding demand from future generations.

Biochemometric Analysis of Fatty Acid Amide Hydrolase Inhibition by Echinacea Root Extracts

Recent research demonstrates that Echinacea possesses cannabimimetic activity with potential applications beyond common contemporary uses for relief of cold and flu symptoms. In this study, we investigated the in vitro inhibitory effect of root extracts of Echinacea purpurea and Echinacea angustifolia on fatty acid amide hydrolase, the main enzyme that degrades the endocannabinoid anandamide. The objective was to relate variation in bioactivity between commercial Echinacea genotypes to their phytochemical profiles and to identify determinants of activity using biochemometric analysis. Forty root extracts of each of species were tested for inhibition of fatty acid amide hydrolase and analyzed by HPLC-DAD/MS to identify and quantitate alkylamides and caffeic acid derivatives. Fatty acid amide hydrolase inhibition ranged from 34 - 80% among E. angustifolia genotypes and from 33 - 87% among E. purpurea genotypes. Simple linear regression revealed the caffeic acid derivatives caftaric acid and cichoric acid, and the alkylamide dodeca-2E,4Z-diene-8,10-diynioc acid 2-methylbutylamide, as the strongest determinants of inhibition in E. purpurea (r* = 0.53, 0.45, and 0.20, respectively) while in E. angustifolia, only CADs were significantly associated with activity, most notably echinacoside (r* = 0.26). Regression analysis using compound groups generated by hierarchical clustering similarly indicated that caffeic acid derivatives contributed more than alkylamides to in vitro activity. Testing pure compounds identified as determinants of activity revealed cichoric acid (IC₅₀ = 45 ± 4 µM) and dodeca-2E,4E,8Z,10E-tetraenoic acid isobutylamide (IC₅₀ = 54 ± 2 µM) as the most active. The results suggest that several phytochemicals may contribute to Echinacea's cannabimimetic activity and that ample variation in genotypes exists for selection of high-activity germplasm in breeding programs.

Phytophospholipid Complex of Caffeic Acid: Development, In vitro Characterization, and In Vivo Investigation of Antihyperlipidemic and Hepatoprotective Action in Rats

Caffeic acid (CA), a hydroxycinnamic acid possessing a variety of pharmacological activities, has caused a growing interest for the treatment of hyperlipidemia and associated conditions. This work endeavored to develop a novel formulation of CA-Phospholipon® 90H complex (CA-PC) using a solvent evaporation method. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectrophotometry (FTIR), and powder X-ray powder diffraction (PXRD) was carried to confirm the formation of CA-PC. The CA-PC was functionally evaluated in terms of solubility, in vitro and ex vivo drug release, and in vivo bioavailability and efficacy studies. SEM, DSC, FTIR, and XRD studies indicated the physical interaction of CA with Phospholipon® 90H to form a complex. Dynamic light scattering (DLS) studies described particle size of 168 ± 3.9 nm with a monodisperse distribution (PDI 0.17) and a negative zeta-potential of - 16.6 ± 2.1 mV. The phospholipid complex significantly improved (4.2-fold) the solubility of CA. In vitro and ex vivo dissolution studies of the formulated CA-PC revealed a significantly higher release compared with the pure CA. The pharmacokinetic study of CA-PC in rats demonstrated a significant increase (4.79-fold) in oral bioavailability when compared with pure CA as well. Additionally, a significant improvement in serum lipid profile, serum liver biomarker enzyme levels and, restoration of hepatic tissue architecture to normal, in high-fat diet (HFD) induced hyperlipidemic model was obtained upon CA-PC administration when compared with pure CA. These findings indicated that CA-PC would serve as an effective and promising formulation for CA delivery with improved antihyperlipidemic and hepatoprotective activity.Graphical abstract.

Simultaneous Determination of Phenolic Compounds in Plasma by LC-ESI-MS/MS and Their Bioavailability after the Ingestion of Table Olives

The role attributed to polyphenols on human health needs to be correlated with their plasmatic concentrations after food consumption. Then, a method based on liquid-liquid extraction followed by highly sensitive LC-ESI-MS/MS analysis was developed to determinate 16 phenolic compounds in plasma. Validation gave appropriate recovery, matrix effect (80%-120%), linear correlation (R² > 0.995), precision (<15%), LOQ (0.04-2.51 nM), and short chromatographic run. The method was verified after the administration of Arbequina table olives to rats. A single dose of destoned olives was given by gavage, and plasmatic concentrations of polyphenols were analyzed at 30 min. Interestingly, the profile found in plasma greatly differed from that of the olives. Plasmatic concentrations, from highest to lowest, were salidroside, p-coumaric acid, hydroxytyrosol, verbascoside, tyrosol, luteolin, and luteolin-7-O-glucoside. In conclusion, a simple and robust method was developed, enabling the identification and quantification of unaltered polyphenols in plasma after olives consumption, thus demonstrating its suitability for pharmacokinetics studies.

Natural Sources, Pharmacokinetics, Biological Activities and Health Benefits of Hydroxycinnamic Acids and Their Metabolites

Hydroxycinnamic acids (HCAs) are important natural phenolic compounds present in high concentrations in fruits, vegetables, cereals, coffee, tea and wine. Many health beneficial effects have been acknowledged in food products rich in HCAs; however, food processing, dietary intake, bioaccessibility and pharmacokinetics have a high impact on HCAs to reach the target tissue in order to exert their biological activities. In particular, metabolism is of high importance since HCAs' metabolites could either lose the activity or be even more potent compared to the parent compounds. In this review, natural sources and pharmacokinetic properties of HCAs and their esters are presented and discussed. The main focus is on their metabolism along with biological activities and health benefits. Special emphasis is given on specific effects of HCAs' metabolites in comparison with their parent compounds.

Effects of steam explosion pretreatment on the composition and biological activities of tartary buckwheat bran phenolics

Steam explosion (SE) is an efficient technology to disrupt materials for improving their quality. In this study, SE was applied to release phenolics and improve the roughening of tartary buckwheat bran. The results showed that SE promoted the dissolution of phenolics, particularly, the content of the bound fraction was nearly increased by two times (0.36 vs. 0.99 mg GAE per g DW). The analysis of the phenolic composition showed that SE improved the liberation of bound pyrogallic acid, protocatechuic acid and caffeic acid. The biological activity tests indicated that SE effectively enhanced the oxygen radical absorbance capacity (ORAC) in vitro of the extract of bound phenolics by 270%. It also improved the cellular antioxidant activity (CAA) in vitro of the extract of free phenolics by 215%. Furthermore, SE showed potential in improving the antiproliferative activity of the total phenolic extract against Caco-2 cells as well as the bound phenolic extract against HepG2 cells in vitro.

Phenolic Compounds Exerting Lipid-Regulatory, Anti-Inflammatory and Epigenetic Effects as Complementary Treatments in Cardiovascular Diseases

Atherosclerosis is the main process behind cardiovascular diseases (CVD), maladies which continue to be responsible for up to 70% of death worldwide. Despite the ongoing development of new and potent drugs, their incomplete efficacy, partial intolerance and numerous side effects make the search for new alternatives worthwhile. The focus of the scientific world turned to the potential of natural active compounds to prevent and treat CVD. Essential for effective prevention or treatment based on phytochemicals is to know their mechanisms of action according to their bioavailability and dosage. The present review is focused on the latest data about phenolic compounds and aims to collect and correlate the reliable existing knowledge concerning their molecular mechanisms of action to counteract important risk factors that contribute to the initiation and development of atherosclerosis: dyslipidemia, and oxidative and inflammatory-stress. The selection of phenolic compounds was made to prove their multiple benefic effects and endorse them as CVD remedies, complementary to allopathic drugs. The review also highlights some aspects that still need clear scientific explanations and draws up some new molecular approaches to validate phenolic compounds for CVD complementary therapy in the near future.

Charting the structural and thermodynamic determinants in phenolic acid natural product - cyclodextrin encapsulations

Cyclodextrins are pliable platforms that have served to optimize the pharmaceutic profile of numerous compounds and to enhance the stability of natural food additives. Caffeic and rosmarinic acid are natural products with proven health benefits, though their full therapeutic potential has not been exploited. To enhance their pharmaceutic profile, we developed cyclodextrin-based formulates and unveiled their thermodynamic and structural principles. The complexes' stoichiometry was determined by ESI-MS. Solid-state and liquid NMR spectroscopy revealed the interactions and the topographical location of the caffeic and rosmarinic acid inside the cyclodextrin cavity. The theoretically analyzed HP-β-CD's degree of substitution (DS) of caffeic and rosmarinic acids can explain the intensities obtained by 2D NOESY experiments. The thermodynamics and the affinity of the complexes were evaluated through isothermal titration calorimetry. In addition, the rosmarinic and caffeic acids as, also, their complexes showed considerable antimicrobial activity against common food spoilage and pathogenic bacteria. The generated data could provide the basis to understand the structural and thermodynamic determinants implicated in natural products - CD recognition and to develop platforms for the optimization of their pharmaceutical and stability profiles in order to be utilized as safe and stable natural antimicrobial food additives.Communicated by Ramaswamy H. Sarma.

Red Beetroot and Betalains as Cancer Chemopreventative Agents

Carcinogenesis is the process whereby a normal cell is transformed into a neoplastic cell. This action involves several steps starting with initiation and followed by promotion and progression. Driving these stages are oxidative stress and inflammation, which in turn encompasses a myriad of aberrant gene expressions, both within the transforming cell population and the cells within the surrounding lesion. Chemoprevention of cancer with bioreactive foods or their extracted/purified components occurs via normalizing these inappropriate gene activities. Various foods/agents have been shown to affect different gene expressions. In this review, we discuss whereby the chemoprevention activities of the red beetroot itself may disrupt carcinogenesis and the activities of the water-soluble betalains extracted from the plant.

Pharmacokinetic profile and metabolite identification of bornyl caffeate and caffeic acid in rats by high performance liquid chromatography coupled with mass spectrometry

Bornyl caffeate was initially discovered as a bioactive compound in medicinal plants. Despite the promising pharmacological activities including anti-tumor and antibacterial activities, the pharmacokinetics of the compound remain open. This work developed a high performance liquid chromatography-tandem mass spectrometric method for the determination of bornyl caffeate and caffeic acid (major metabolite and a main unit of bornyl caffeate) in vivo. Successful application of the method included identification of its metabolites and investigation on the drug pharmacokinetics. A total of 30 compounds were identified as the metabolites of bornyl caffeate in rats. We attributed these metabolites to phase I metabolic routes of reduction, oxidation, hydrolysis and phase II metabolic reactions of glucuronidation, sulfation, O-methylation and glycine. Glucuronidation, sulfation, O-methylation and reduction were the main metabolic pathways of bornyl caffeate. The method presented a linear range of 1–4000 ng mL⁻¹. The pharmacokinetic profile of bornyl caffeate was found to be a three compartment open model, while caffeic acid fitted to a two compartment open model when it was administered alone or served as the main metabolite of bornyl caffeate. The time to peak concentration (T_max) and the maximum plasma concentration (C_max) of bornyl caffeate were 0.53 h and 409.33 ng mL⁻¹. Compared with original caffeic acid, the compound displayed an increased half-life of elimination (T_1/2β), area under the concentration time curve from 0 to t (AUC_0–t) and area under the concentration time curve from 0 to ∞ (AUC_0–∞), a decreased half-life of absorption (T_1/2α) and an identical C_max. Taking together, we concluded that bornyl caffeate is able to rapidly initiate therapeutic effect and last for a relatively long time in rats; metabolic pathways of O-methylation and reduction is key to interpret the mechanism and toxicity of bornyl caffeate.

We revealed the metabolic profile of bornyl caffeate by HPLC-Q-TOF/MS, and then simultaneously examined the pharmacokinetics of bornyl caffeate and CA after administration of a single dose of bornyl caffeate by HPLC ion trap MS.

β-Cyclodextrin Does not Alter the Bioaccessibility and the Uptake by Caco-2 Cells of Olive By-Product Phenolic Compounds

Alperujo—a two-phase olive mill waste that is composed of olive vegetation water and solid skin, pulp, and seed fragments - is a highly valuable olive by-product due to its high content in phenolic compounds. In this study, we assessed whether β-cyclodextrin (β-CD), which is used to extract and protect alpejuro phenolic compounds (hydroxytyrosol-O-glucoside, tyrosol, caffeic, and p-coumaric acids) could impact on their bioaccessibility (i.e., the percentage of molecule found in the aqueous phase of the digesta) and uptake by intestinal cells, by using an in vitro digestion model and Caco-2 TC7 cells in culture, respectively. Our results showed that β-CD did not change the bioaccessibility of the selected phenols. Hydroxytyrosol-O-glucoside and caffeic did not cross Caco-2 cell monolayers. Conversely ferulic acid, identified as the main caffeic acid intestinal metabolite, was absorbed through intestinal cell monolayers (~20%). Interestingly, β-CD moderately but significantly improved the local absorption of tyrosol and p-coumaric acid (2.3 + 1.4% and 8.5 ± 4.2%, respectively, p < 0.05), even if their final bioavailability (expressed as bioaccessibility × absorption by Caco-2 cells) was not modified (16.2 ± 0.6% vs. 16.8 ± 0.5% for tyrosol and 32.0 ± 3.2% vs. 37.2 ± 3.2% for p-coumaric acid, from pure alperujo and alperujo complexed with β-CD, respectively). Overall, our results show that β-CD is an interesting extraction and storage agent for phenolic compounds that does not alter their in vitro bioavailability.

In-vitro and in-vivo antimalarial activity of caffeic acid and some of its derivatives

Objectives

To explore the in-vitro and in-vivo antimalarial potential of caffeic acid and derivatives.

Methods

Two common phenolic acids (caffeic acid and chlorogenic acid) were evaluated for in-vitro and in-vivo antiplasmodial activity in comparison with some semi-synthetic derivatives that were synthesized. An in-vitro assay based on plasmodial lactate dehydrogenase activity, and the classical in-vivo 5-day suppressive test from Peters on an artemisinin-resistant Plasmodium berghei strain was used. Parasitic stage sensitivity to ethyl caffeate was determined in this work.

Key findings

Phenolic acid esters derivatives showed better antiplasmodial activity than corresponding phenolic acids. The derivative with the highest in-vitro activity being caffeic acid ethyl ester, exhibiting an IC50 = 21.9 ± 9.4 μm. Ethyl caffeate and methyl caffeate were then evaluated for antimalarial activity in vivo and ethyl caffeate showed a growth inhibition of 55% at 100 mg/kg. Finally, it seems that ethyl caffeate blocks the growth of young parasitic forms.

Conclusions

Our study provides evidence for an antimalarial potential of caffeic acid derivatives which are common in several medicinal plants traditionally used against malaria. It also demonstrates the possibility to use such derivatives in the treatment of malaria.

Development and Validation of a HPLC Method for Determination of Isochlorogenic Acid A in Rat Plasma and Application to Pharmacokinetic Study

A simple, optimized and sensitive high-performance liquid chromatograph method with ultraviolet (UV) detection (HPLC/UV) was developed and validated for determination of isochlorogenic acid A in rat plasma. The analytes were successfully separated on a Shodex C18 column (5 μm particle size, 250 mm × 4.6 mm, i.d.), the mobile phase contained 0.1% phosphoric acid aqueous solution (solvent A) and methanol (solvent B) (50:50, v/v) at a flow rate of 1.0 mL/min. The wavelength for UV detection was set at 300 nm and the column temperature was maintained in 30°C. Calibration curve for isochlorogenic acid A was found to be good linear over the range of 0.04-40 μg/mL (r = 0.9998). The intra- and inter-day precisions (relative standard deviation) were within 7.63% and the assay accuracy (RE) ranged from -1.41 to 3.25%. The limit of detection and the lower limit of quantification were 0.012 and 0.04 μg/mL, respectively. The validated method was successfully applied to pharmacokinetic study of isochlorogenic acid A in rats for the first time. The pharmacokinetic parameters were evaluated after the rats were administered intravenously and intragastrically isochlorogenic acid A at the single dose of 18 mg/kg, respectively. The absolute bioavailability was calculated to be 22.6%.

Pharmacokinetics of isochlorgenic acid C in rats by HPLC-MS: Absolute bioavailability and dose proportionality

ETHNOPHARMACOLOGICAL RELEVANCE

Isochlorgenic acid C (IAC), one of the bioactive compounds of Lonicera japonica, exhibited diverse pharmacological effects. However, its pharmacokinetic properties and bioavailability remained unresolved.

AIM OF THE STUDY

To determine the absolute bioavailability in rats and the dose proportionality on the pharmacokinetics of single oral dose of IAC.

MATERIALS AND METHODS

A validated HPLC-MS method was developed for the determination of IAC in rat plasma. Plasma concentration versus time data were generated following oral and intravenous dosing. The pharmacokinetic analysis was performed using DAS 3.0 software analysis. Absolute bioavailability in rats was determined by comparing pharmacokinetic data after administration of single oral (5, 10 and 25mgkg(-1)) and intravenous (5mgkg(-1)) doses of IAC. The dose proportionality of AUC(0-∞) and Cmax were analyzed by linear regression.

RESULTS

Experimental data showed that absolute oral bioavailability of IAC in rats across the doses ranged between 14.4% and 16.9%. The regression analysis of AUC(0-∞) and Cmax at the three doses (5, 10 and 25mgkg(-1)) indicated that the equations were y=35.23x+117.20 (r=0.998) and y=121.03x+255.74 (r=0.995), respectively.

CONCLUSIONS

A new HPLC-MS method was developed to determine the bioavailability and the dose proportionality of IAC. Bioavailability of IAC in rats was poor and both Cmax and AUC(0-∞) of IAC had a positive correlation with dose. Evaluation of the pharmacokinetics of IAC will be useful in assessing concentration-effect relationships for the potential therapeutic applications of IAC.

Modification of Caffeic Acid with Pyrrolidine Enhances Antioxidant Ability by Activating AKT/HO-1 Pathway in Heart

Overproduction of free radicals during ischemia/reperfusion (I/R) injury leads to an interest in using antioxidant therapy. Activating an endogenous antioxidant signaling pathway is more important due to the fact that the free radical scavenging behavior in vitro does not always correlate with a cytoprotection effect in vivo. Caffeic acid (CA), an antioxidant, is a major phenolic constituent in nature. Pyrrolidinyl caffeamide (PLCA), a derivative of CA, was compared with CA for their antioxidant and cytoprotective effects. Our results indicate that CA and PLCA exert the same ability to scavenge DPPH in vitro. In response to myocardial I/R stress, PLCA was shown to attenuate lipid peroxydation and troponin release more than CA. These responses were accompanied with a prominent elevation in AKT and HO-1 expression and a preservation of mnSOD expression and catalase activity. PLCA also improved cell viability and alleviated the intracellular ROS level more than CA in cardiomyocytes exposed to H₂O₂. When inhibiting the AKT or HO-1 pathways, PLCA lost its ability to recover mnSOD expression and catalase activity to counteract with oxidative stress, suggesting AKT/HO-1 pathway activation by PLCA plays an important role. In addition, inhibition of AKT signaling further abolished HO-1 activity, while inhibition of HO-1 signaling attenuated AKT expression, indicating cross-talk between the AKT and HO-1 pathways. These protective effects may contribute to the cardiac function improvement by PLCA. These findings provide new insight into therapeutic approaches using a modified natural compound against oxidative stress from myocardial injuries.