Effects of caffeine and caffeic acid on selected biochemical parameters in L-NAME-induced hypertensive rats

Therapeutic potential of natural arginase modulators: mechanisms, challenges, and future directions

Arginase (Arg) plays a pivotal role in numerous pathological processes, with its dysregulated expression being intricately associated with tumor progression and immune evasion. This review comprehensively examines the diversity, mechanisms, and clinical potential of natural Arg modulators, encompassing polyphenols, flavonoids, and terpenoids. These bioactive compounds exert their modulatory effects on Arg activity through multiple mechanisms, including direct enzyme interaction, regulation of signaling pathways, and modulation of cellular metabolism. The therapeutic potential of these metabolites spans across various medical domains, notably in cardiovascular diseases, oncology, neurological disorders, and inflammatory conditions. Specifically, polyphenol metabolites such as resveratrol and curcumin have demonstrated significant benefits in cardiovascular health and neuroprotection, while flavonoids including rutin and quercetin have shown promising effects on intracellular inflammatory factors and tumor cell proliferation. Similarly, terpenoids like perillyl alcohol and triptolide have been found to influence cell polarization processes. However, despite their substantial therapeutic potential demonstrated in experimental studies, the development of natural Arg modulators faces several significant challenges. These include complexities in drug design attributed to the intricate structure and multiple isoforms of Arg, difficulties in elucidating precise mechanisms due to Arg's multifaceted roles in various metabolic pathways, and limitations in current drug delivery systems. To overcome these challenges, future research should focus on continuous optimization of experimental design paradigms, enhancement of experimental models and data quality, thorough evaluation of therapeutic efficacy, and strategic integration of natural Arg modulators with precision medicine approaches.

The Role of Xenobiotic Caffeine on Cardiovascular Health: Promises and Challenges

Cardiovascular diseases (CVDs) represent a leading cause of premature mortality and disability worldwide, with their incidence expected to rise, potentially reaching 24 million deaths per year by 2030. These multifactorial diseases, including hypertension, coronary artery disease, arrhythmia, and heart failure, are often linked to metabolic disturbances such as diabetes, oxidative stress, endothelial dysfunction, and inflammation. Natural compounds, such as caffeine, have been explored for their potential therapeutic effects on CVDs. Caffeine, found in coffee, tea, cocoa, and various energy drinks, is a widely consumed psychoactive compound with noted analgesic and anti-inflammatory properties. Despite its long history of use, caffeine's impact on cardiovascular health remains controversial, with both beneficial and harmful effects reported. This review examines the current literature on the effects of caffeine on cardiovascular diseases (CVDs), with an emphasis on preclinical and clinical studies, its pharmacokinetic properties, and the molecular mechanisms it modulates. There is evidence that moderate caffeine intake can be beneficial for some CVDs, such as hypertension, while for other CVDs, such as dyslipidemia, the evidence collected so far suggests that caffeine intake could be detrimental since it increases total cholesterol levels. But variability in dosage, intake patterns, and individual factors (such as genetics and diet) complicates the reliability of results. Additionally, challenges related to dose standardization and the absence of consistent clinical trial designs hinder the full utilization of caffeine in CVD treatment. Nonetheless, caffeine appears to be safe for individuals without significant cardiovascular conditions. Future research should aim for well-designed studies with precise patient cohorts and standardized methodologies to better assess caffeine's role in CVD management.

Unrevealing the mechanisms behind the cardioprotective effect of wheat polyphenolics

Cardiovascular diseases pose a major threat to both life expectancy and quality of life worldwide, and a concerning level of disease burden has been attained, particularly in middle- and low-income nations. Several drugs presently in use lead to multiple adverse events. Thus, it is urgently needed to develop safe, affordable, and effective management of cardiovascular diseases. Emerging evidence reveals a positive association between polyphenol consumption and cardioprotection. Whole wheat grain and allied products are good sources of polyphenolic compounds bearing enormous cardioprotective potential. Polyphenolic extract of the entire wheat grain contains different phenolic compounds viz. ferulic acid, caffeic acid, chlorogenic acid, p-coumaric acid, sinapic acid, syringic acid, vanillic acid, apigenin, quercetin, luteolin, etc. which exert cardioprotection by reducing oxidative stress and interfering with different toxicological processes. The antioxidant capacity has been thought to exert the cardioprotective mechanism of wheat grain polyphenolics, which predominantly suppresses oxidative stress, inflammation and fibrosis by downregulating several pathogenic signaling events. However, the combined effect of polyphenolics appears to be more prominent than that of a single molecule, which might be attained due to the synergy resulting in multimodal cardioprotective benefits from multiple phenolics. The current article covers the bioaccessibility and possible effects of wheat-derived polyphenolics in protecting against several cardiovascular disorders. This review discusses the mechanistic pharmacology of individual wheat polyphenols on the cardiovascular system. It also highlights the comparative superiority of polyphenolic extracts over a single phenolic.

Caffeic acid and its derivative caffeic acid phenethyl ester as potential therapeutic compounds for cardiovascular diseases: A systematic review

Cardiovascular diseases (CVDs) contribute to major public health issues. Some studies have found that caffeic acid (CA) and caffeic acid phenethyl ester (CAPE) may effectively prevent or treat CVDs. However, there is a major need to sum up our current understanding of the possible beneficial or detrimental effects of CA and CAPE on CVDs and related mechanisms. Therefore, this study aimed to summarize the data on this topic. A methodical search was carried out on key databases, including Pubmed, Google Scholar, Scopus, and Web of Science, from the beginning to June 2024. Studies were then assessed for eligibility based on inclusion and exclusion criteria. Treatment with CA and CAPE significantly and positively affected cardiovascular health in various aspects, including atherosclerotic diseases, myocardial infarction, hypertension, cardiac arrhythmias, and hypercoagulation state. Several mechanisms were proposed to mediate these effects, including transcription factors and signaling pathways associated with antioxidant, cytostatic, and anti-inflammatory processes. CA and CAPE were found to have several beneficial effects via multiple mechanisms during the prevention and treatment of various CVDs. However, these promising effects were only reported through in vitro and animal studies, which reinforces the need for further evaluation of these effects via human clinical investigations.

Decoding coffee cardiometabolic potential: Chemical composition, nutritional, and health relationships

Coffee is one of the most consumed beverages worldwide, recognized for its unique taste and aroma and for its social and health impacts. Coffee contains a plethora of nutritional and bioactive components, whose content can vary depending on their origin, processing, and extraction methods. Gathered evidence in literature shows that the regular coffee consumption containing functional compounds (e.g., polysaccharides, phenolic compounds, and melanoidins) can have potential beneficial effects on cardiometabolic risk factors such as abdominal adiposity, hyperglycemia, and lipogenesis. On the other hand, coffee compounds, such as caffeine, diterpenes, and advanced glycation end products, may be considered a risk for cardiometabolic health. The present comprehensive review provides up-to-date knowledge on the structure-function relationships between different chemical compounds present in coffee, one of the most prevalent beverages present in human diet, and cardiometabolic health.

Cardiomodulatory and Antioxidative Potentials of Almond-Citrus Peel Fortified Shortbread in High Fat Diet/L-NAME-Induced Hyperlipidemic-Hypertensive Rats

In folk medicine, the almond nut (Terminalia catappa) and orange peel (Citrus sinensis) are cost-effective sources of nutraceutical utilized in the treatment of degenerative diseases. Hyperlipidemia and hypertension are two pathological conditions implicated in cardiovascular disorders. This study sought to evaluate the cardiomodulatory effect of almond-citrus peel fortified shortbread in hyperlipidemic-hypertensive rats induced by high fat diet and Nω-nitro-l-arginine methyl ester. The experimental animals were divided into eight groups. The experimental rats were fed with shortbread supplemented with almond and citrus peel at varying inclusions of 0.2% citrus, 50% almond, and almond (50%)- citrus (0.2%) for 21 days. The mean arterial blood pressure (MABP), systolic blood pressure (SBP), and lipid profile of the experimental rats were measured. Thereafter, the activities of angiotensin-1-converting enzyme (ACE), arginase, malondialdehyde (MDA), phosphodiesterase-5, nitric oxide (NO), and antioxidant indices were evaluated. The result showed significant elevation in SBP, MABP, blood cholesterol, triglyceride, ACE, arginase, activities, and MDA levels in the heart tissue of the untreated rats. In contrast, the antioxidant status and NO level were significantly decreased in the untreated groups. Remarkably, the treatment with almond-citrus peel fortified shortbread and the individual effect of almond (50%) and citrus peel (0.2%) all reversed these trends in the hyperlipidemic-hypertensive rats. Intriguingly, the blend of almond (50%)-citrus peel (0.2%) fortified shortbread showed the best antioxidative and cardioprotective effect. The results suggest that almond and citrus peel offer potentials as therapeutic agent in the prevention and management of hyperlipidemia and hypertension.

Effect of Caffeine Consumption on Cardiovascular Disease: An Updated Review

The incidence of cardiovascular diseases has significantly increased with the expansion of the industrialization of societies, which is notably linked to lifestyle changes and an unhealthy diet. Hence, determining the healthiest diet habits and supplements seems to be an appropriate way to decrease the global burden of cardiovascular diseases. Currently, caffeine, one of the most widely consumed compounds in the world, has emerged with some promising results in the treatment of numerous pathophysiological conditions of cardiovascular diseases. A literature search was conducted in PubMed, Scopus, Science Direct, Google Scholar, and Web of Science databases for the relevant articles regarding the pharmacology, preclinical, and clinical studies on the potential effects of caffeine on cardiovascular diseases. While caffeine could improve cardiovascular outcomes through several mechanisms of action, the literature review revealed controversial clinical effects of caffeine on blood pressure, cardiac arrhythmias, acute coronary syndrome, stable angina, and heart failure. In the case of dyslipidemia, coffee consumption increased total cholesterol, triglyceride, and low-density lipoprotein. Taken together, the existence of multiple confounding factors in the caffeine studies has resulted in inconclusive data interpretation. Further well-designed studies with adequate control of the confounding factors are warranted to draw a clear conclusion on the cardiovascular efficacy and safety of caffeine.

A comprehensive insight into the effects of caffeic acid (CA) on pepsin: Multi-spectroscopy and MD simulations methods

The interaction between caffeic acid (CA) and pepsin was investigated using multi-spectroscopy approaches and molecular dynamic simulations (MDS). The effects of CA on the structure, stability, and activity of pepsin were studied. Fluorescence emission spectra and UV-vis absorption peaks all represented the static quenching mechanism of pepsin by CA. Moreover, the fluorescence spectra displayed that the interaction of CA exposed the tryptophan chromophores of pepsin to a more hydrophilic micro-environment. Consistent with the simulation results, thermodynamic parameters revealed that CA was bound to pepsin with a high binding affinity. The Van der Waals force and Hydrogen bond interaction were the dominant driving forces during the binding process. The circular dichroism (CD) spectroscopy analysis showed that the CA binding to pepsin decreased the contents of α-Helix and Random Coil but increased the content of β-sheet in the pepsin structure. Accordingly, MD simulations confirmed all the experimental results. As a result, CA is considered an inhibitor with adverse effects on pepsin activity.

Extract of Pinus densiflora needles suppresses acute inflammation by regulating inflammatory mediators in RAW264.7 macrophages and mice

CONTEXT

Pinus densiflora Siebold & Zucc. (Pinaceae) needle extracts ameliorate oxidative stress, but research into their anti-inflammatory effects is limited.

OBJECTIVE

To investigate antioxidant and anti-inflammatory effects of a Pinus densiflora needles (PINE) ethanol extract in vitro and in vivo.

MATERIALS AND METHODS

We measured levels of reactive oxygen species (ROS), superoxide dismutase (SOD) and inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW264.7 cells at various PINE concentrations (25, 50 and 100 μg/mL; but 6.25, 12.5 and 25 μg/mL for interleukin-1β and prostaglandin E₂ (PGE₂)). Thirty ICR mice were randomized to six groups: vehicle, control, PINE pre-treatment (0.1, 0.3 and 1 mg/left ear for 10 min followed by arachidonic acid treatment for 30 min) and dexamethasone. The posttreatment ear thickness and myeloperoxidase (MPO) activity were measured.

RESULTS

PINE 100 μg/mL significantly decreased ROS (IC₅₀, 70.93 μg/mL, p < 0.01), SOD (IC₅₀, 30.99 μg/mL, p < 0.05), malondialdehyde (p < 0.01), nitric oxide (NO) (IC₅₀, 27.44 μg/mL, p < 0.01) and tumour necrosis factor-alpha (p < 0.05) levels. Interleukin-1β (p < 0.05) and PGE₂ (p < 0.01) release decreased significantly with 25 μg/mL PINE. PINE 1 mg/ear inhibited LPS-stimulated expression of cyclooxygenase-2 and inducible NO synthase in RAW264.7 macrophages and significantly inhibited ear oedema (36.73-15.04% compared to the control, p < 0.01) and MPO activity (167.94-105.59%, p < 0.05).

DISCUSSION AND CONCLUSIONS

PINE exerts antioxidant and anti-inflammatory effects by inhibiting the production of inflammatory mediators. Identified flavonoids such as taxifolin and quercetin glucoside can be attributed to effect of PINE.

Comparable Benefits of Stingless Bee Honey and Caffeic Acid in Mitigating the Negative Effects of Metabolic Syndrome on the Brain

There is mounting evidence that metabolic syndrome (MetS) contributes to the development of neurodegenerative disorders such as Alzheimer’s disease. Honey, which has been used for generations, is high in antioxidants and has been demonstrated to benefit the brain and mental health by reducing oxidative stress and boosting cognitive outcomes. Honey from the stingless bees of Heterotrigona itama has been found to have higher phenolic content compared to other types of honeys. The aim of this study is to investigate the effects of stingless bee honey (SBH) supplementation and to compare it with a pure form of antioxidant, caffeic acid (CA), on MetS parameters and inflammatory markers in the brains of MetS-induced rats. A total of 32 male Wistar rats were divided equally into groups of control, high-carbohydrate high-fructose (HCHF) diet (MetS), HCHF + SBH supplemented (1 g/kg) (SBH), and HCHF + CA supplemented (10 mg/kg) (CA) groups. The total duration for SBH and CA supplementation was eight weeks. The HCHF diet was found to promote hypertension, hyperglycemia, and hypertriglyceridemia, and to increase brain TNF-α levels. Supplementation with SBH and CA significantly reversed (p < 0.05) the hyperglycemic and hypertensive effects of the HCHF diet. Although both supplemented groups showed no significant changes to serum HDL or TG, SBH significantly reduced (p < 0.05) brain TNF-α levels and increased (p < 0.05) brain BDNF levels. Immunohistochemistry investigations of neurogenesis (EdU) and apoptosis (TUNEL) on the cornu Ammonis 1 (CA1) and dentate gyrus (DG) areas of the hippocampus showed no changes with SBH and CA supplementation compared to the control. These findings suggest that SBH and CA have the potential to mitigate HCHF-induced MetS effects and possess neuroprotective abilities.

Caffeic Acid on Metabolic Syndrome: A Review

Metabolic syndrome (MetS) is a constellation of risk factors that may lead to a more sinister disease. Raised blood pressure, dyslipidemia in the form of elevated triglycerides and lowered high-density lipoprotein cholesterol, raised fasting glucose, and central obesity are the risk factors that could lead to full-blown diabetes, heart disease, and many others. With increasing sedentary lifestyles, coupled with the current COVID-19 pandemic, the numbers of people affected with MetS will be expected to grow in the coming years. While keeping these factors checked with the polypharmacy available currently, there is no single strategy that can halt or minimize the effect of MetS to patients. This opens the door for a more natural way of controlling the disease. Caffeic acid (CA) is a phytonutrient belonging to the flavonoids that can be found in abundance in plants, fruits, and vegetables. CA possesses a wide range of beneficial properties from antioxidant, immunomodulatory, antimicrobial, neuroprotective, antianxiolytic, antiproliferative, and anti-inflammatory activities. This review discusses the current discovery of the effect of CA against MetS.

Caffeic acid and its derivatives as potential modulators of oncogenic molecular pathways: New hope in the fight against cancer

As a phenolic acid compound, caffeic acid (CA) can be isolated from different sources such as tea, wine and coffee. Caffeic acid phenethyl ester (CAPE) is naturally occurring derivative of CA isolated from propolis. This medicinal plant is well-known due to its significant therapeutic impact including its effectiveness as hepatoprotective, neuroprotective and anti-diabetic agent. Among them, anti-tumor activity of CA has attracted much attention, and this potential has been confirmed both in vitro and in vivo. CA can induce apoptosis in cancer cells via enhancing ROS levels and impairing mitochondrial function. Molecular pathways such as PI3K/Akt and AMPK with role in cancer progression, are affected by CA and its derivatives in cancer therapy. CA is advantageous in reducing aggressive behavior of tumors via suppressing metastasis by inhibiting epithelial-to-mesenchymal transition mechanism. Noteworthy, CA and CAPE can promote response of cancer cells to chemotherapy, and sensitize them to chemotherapy-mediated cell death. In order to improve capacity of CA and CAPE in cancer suppression, it has been co-administered with other anti-tumor compounds such as gallic acid and p-coumaric acid. Due to its poor bioavailability, nanocarriers have been developed for enhancing its ability in cancer suppression. These issues have been discussed in the present review with a focus on molecular pathways to pave the way for rapid translation of CA for clinical use.