Search Results (1,935)

This study aimed to systematically investigate the chemical constituents and bioactivities of the traditional wild tea plant Camellia kwangsiensis Chang. An HPLC method was first established to simultaneously quantify five major components. Subsequently, extensive isolation was performed using chromatographic techniques, and the structures of isolated compounds were elucidated by spectroscopic methods. Their biological potential was evaluated through antioxidant (DPPH and ABTS⁺ radical scavenging), α-glucosidase inhibitory, and anti-inflammatory (inhibition of nitric oxide production) assays. The LC-MS/MS analyses confirmed the absence of caffeine, theophylline, and theobromine. A total of 19 phenolic compounds were first isolated and identified, including one new proanthocyanidin, namely kwangsienin A (1), and 18 known phenolic components with six proanthocyanidins (2–7), one catechin (8), six flavonol glycosides (9–14), and five simple phenols (15–19). Notably, the proanthocyanidins displayed stronger or comparable antioxidant and α-glucosidase suppressive activity than the positive controls. In conclusion, C. kwangsiensis, rich in proanthocyanidins and naturally caffeine-free, represents a promising plant resource for developing decaffeinated functional tea beverages with antioxidant and hypoglycemic potential. Full article

This study evaluates the bioadsorption efficiency of sugarcane bagasse (SCB) for removing pharmaceuticals and illicit drugs—such as acetaminophen, atenolol, caffeine, carbamazepine, diclofenac, orphenadrine, losartan, enalapril, citalopram, cocaine, and benzoylecgonine—from wastewater effluents. In Brazil, where 46% of the population lacks access to sewage systems, and over 5.3 billion pharmaceutical packages are consumed annually, untreated discharges contribute significantly to aquatic contamination. Results show that applying SCB biochar at a 1% (m/v) ratio removes up to 99.8% of these compounds at total concentrations of 140 ng mL⁻¹, reducing the ecological risk from high to low for caffeine and losartan. SCB offers several advantages as a bioadsorbent: it is abundant, non-toxic, inexpensive, easy to handle, and exhibits high adsorption capacity and rapid kinetics across a wide range of chemical polarities. These findings highlight SCB’s potential as a sustainable and efficient material for wastewater treatment applications. Full article

Coffee cascara is a byproduct of coffee production traditionally used for infusions and animal feed. In this study, aqueous extracts of cascara from three different sources (Cas1–Cas3) were analyzed for their polyphenol and flavonoid content, as well as the concentrations of key individual bioactive compounds including caffeine, trigonelline, chlorogenic acid, and protocatechuic acid. Among the tested samples, Cas1 exhibited the highest total polyphenol (802.2 mg GAE/L) and flavonoid (134.7 mg QE/L) contents. The antibacterial activity of these extracts and an artificial mixture of the four compounds were evaluated against ESKAPE pathogens. Cas1 exhibited the most promising antibacterial effect, with minimal bactericidal concentration (MBC) values as low as 0.03 mg/mL for S. aureus and A. baumannii, and 0.26 mg/mL for P. aeruginosa. The artificial mixture, despite containing higher concentrations of the major compounds, exhibited reduced efficacy (MBC of 0.04 mg/mL for S. aureus and 0.15 mg/mL for A. baumannii, respectively), highlighting the superior activity of the native extracts. These results indicate that cascara extracts possess strong antibacterial activity, which correlates with their content of bioactive compounds, mainly polyphenols and alkaloids. The pronounced efficacy of the native extracts compared to the artificial mixture suggests that minor constituents in cascara may synergistically contribute to antibacterial effects. The present study highlights the potential of cascara aqueous extracts as natural multi-component antimicrobial agents, particularly against clinically relevant pathogens such as A. baumannii. Full article

Background: Caffeine (CAF), whether extracted from plants or synthesised as a chemical compound, is considered the safest among other xanthine alkaloids. Novel nano-cream formulations have been successfully developed and evaluated to increase the potential of caffeine as a skin cosmeceutical, targeting the minimisation of cellulite appearance. Methods: Nano-cream formulations were prepared through a process of hot-temperature emulsification, in a variety of homogeniser combinations. Results: When chemical penetration enhancers (CPEs) (lanolin, transcutol, and propylene glycol), either alone or in combination, were incorporated into the nano-cream formulations, the permeation of CAF through skin increased. All nano-cream formulations achieved sustained delivery of CAF into and through the skin over 8 h (IVPT). Quantification of CAF from skin tissues was achieved using high-performance liquid chromatography (HPLC). The nano-cream formulation containing lanolin (LAN) showed the highest CAF permeation (8.829 ± 1.472 µg/cm²/h) through the skin compared to CAF in an aqueous solution (2.533 ± 0.480 µg/cm²/h) and a commercial CAF cellulite product with the same CAF concentration (2.827 ± 0.555 µg/cm²/h). Therefore, 2% CAF nano-cream formulation containing LAN was chosen for clinical testing. A double-blind, randomised, placebo-controlled paired trial was conducted, in which each volunteer applied active and placebo creams to the upper thighs twice daily for 12 weeks. The effect of the cream on skin appearance was monitored over 12 weeks. The primary outcome measures were reduced cellulite scores from 3.96 (95% CI: 3.16–4.76) to 2.50 (95% CI: 1.70–3.30) (active) compared with placebo from 3.88 (95% CI: 3.08–4.67) to 2.83 (95% CI: 2.03–3.63). The effect sizes (E.S.) indicated a moderate effect for the active CAF nano-cream formulation (E.S. = 0.475), while the placebo (E.S. = 0.286) had a small effect. Conclusion: We concluded that our optimised 2% CAF nano-cream formulation containing LAN offered an effective formulation strategy for enhancing skin penetration in the IVPT study. The LAN nano-cream formulation demonstrated efficacy and tolerability, both objectively and subjectively, in a human clinical trial. Full article

Background: Caffeine, dairy products and other food items may influence retinal microcirculation. Retinal microvascular indices provide quantitative biomarkers of systemic microvascular health and are increasingly used in clinical and research settings. The aim of this study was to elucidate the possible effects of these food products on structural and functional indices of the retinal microcirculation. Methods: Based on a registered protocol, we identified eligible interventional/observational studies examining the association of these factors with retinal biomarkers, including central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), arteriolar-to-venular diameter ratio (AVR), retinal vascular tortuosity, vessel diameter index (VDI) and retinal vessel flicker light-induced dilation (FID). Results: Fourteen studies were included addressing caffeine (4), dairy products (2) and other food (9) consumption. Acutely, caffeine intake was dose-dependently associated with narrowed CRAE, CRVE, decreased VDI and increased AVR and FID. Long-term, caffeine consumption was associated with larger CRVE and lower AVR, while decaffeinated coffee with larger CRAE and AVR and narrower CRVE. Low-fat dairy products, fish and fiber were associated with larger CRAE, smaller CRVE, and increased AVR, while red meat consumption was associated with narrower CRAE and lower AVR. Increased salt intake was associated with increased venular tortuosity, while almond consumption was associated with larger CRVE. Owing to substantial study heterogeneity, a meta-analysis was not feasible. Conclusions: Potentially clinically meaningful associations between food groups and retinal indices were identified. These associations should be considered when evaluating retinal microcirculation and assessing CVD risk since modification of these factors may be beneficial for the cardiovascular system. Full article

Tea production in Europe represents an emerging segment of the specialty tea market, but a structured comparative analysis remains unexplored. This study employs a standardized approach to systematically characterize hot brews from black and green teas across five European gardens. Antioxidant capacity, total polyphenolic content (TPC), total flavonoid content (TFC), and metabolomic profiling by ultra-high performance liquid chromatography–mass spectrometry were evaluated, and for the first time, sensory profiling of these teas was conducted. Green teas consistently exhibited higher TPC, TFC, and antioxidant capacity compared to black teas, confirming the influence of processing methods. Metabolomic analysis revealed variability in caffeine linked to geographical origin and propagation method (cuttings vs. seeds). Importantly, sensory evaluation suggested a negative correlation between high TPC and overall consumer appreciation. The two most highly appreciated teas often showed lower TPC. These reliable findings advance knowledge in European tea research, providing valuable data for growers to enhance cultivar selection and marketing strategies in alignment with consumer preferences. Full article

The gut microbiome is a modifiable factor in cancer survivorship. Diet represents the most practical intervention for modulating the gut microbiome. However, diet–microbiome relationships in prostate-cancer survivors remain poorly characterized. We conducted a comprehensive analysis of diet–microbiome associations in 79 prostate-cancer survivors (ages 62–81) enrolled in a randomized exercise intervention trial, 59.5% of whom still have active metastatic disease. Dietary intake was assessed using the Diet History Questionnaire (201 variables) and analyzed using three validated dietary pattern scores: Mediterranean Diet Adherence Score (MEDAS), Healthy Eating Index-2015 (HEI-2015), and the Mediterranean-Dash Intervention for Neurodegenerative Delay (MIND) diet score. Gut microbiome composition was characterized via 16S rRNA sequencing. Dimensionality reduction strategies, including theory-driven diet scores and data-driven machine learning (Random Forest, and Least Absolute Shrinkage and Selection Operator (LASSO)), were used. Statistical analyses included beta regression for alpha diversity, Permutational Multivariate Analysis of Variance (PERMANOVA) for beta diversity (both Bray–Curtis and Sørensen metrics), and Microbiome Multivariable Associations with Linear Models (MaAsLin2) with negative binomial regression for taxa-level associations. All models tested interactions with exercise intervention, APOLIPOPROTEIN E (APOE) genotype, and testosterone levels. There was an interaction between MEDAS and exercise type on gut alpha diversity (Shannon: p = 0.0022), with stronger diet–diversity associations in strength training and Tai Chi groups than flexibility controls. All three diet-quality scores predicted beta diversity (HEI p = 0.002; MIND p = 0.025; MEDAS p = 0.034) but not Bray–Curtis (abundance-weighted) distance, suggesting diet shapes community membership rather than relative abundances. Taxa-level analysis revealed 129 genera with diet associations or diet × host factor interactions. Among 297 dietary variables tested for cognitive outcomes, only caffeine significantly predicted Montreal Cognitive Assessment (MoCA) scores after False Discovery Rate (FDR) correction (p = 0.0009, q = 0.014) through direct pathways beneficial to cognitive performance without notable gut microbiome modulation. In cancer survivors, dietary recommendations should be tailored to exercise habits, genetic background, and hormonal status. Full article

Pesticides remain among the most significant threats to biodiversity and natural ecosystems. Non-invasive methods, such as the analysis of bird faeces, have shown great potential for detecting pesticide exposure. In this study with a new approach, we analysed faecal sacs from nestlings of Blue tits (Cyanistes caeruleus) and Great tits (Parus major) to gain deeper insights into pesticide contamination during the breeding period. Samples were collected from three distinct sites near Münster, Germany. In total, we detected 65 substances from 57 different pesticides, as well as caffeine, with pesticides present in 16.07% of the 168 samples. Concentrations varied between species and sites and were higher for fungicides and insecticides in nests located closer to agricultural fields. While no direct effects on reproductive success were found, our results underscore the potential of faecal sac analysis as a valuable tool for spatially resolved pesticide monitoring. The novel, non-invasive approach to pesticide monitoring offers crucial exposure data on juvenile birds during their sensitive breeding period. Full article

Background: Caffeine is a well-established ergogenic aid, yet most experimental evidence is based on isolated caffeine, whereas habitual intake in both the general and physically active populations occurs mainly through coffee. This gap between experimental models and everyday practice complicates the interpretation of existing findings. Objective: This review compares coffee and isolated caffeine as ergogenic aids, focusing on biological mechanisms, methodological differences, tolerability, and context-dependent use in sport and exercise. Methods: A narrative review of human studies examining the effects of coffee and isolated caffeine on exercise performance, fatigue, and post-exercise recovery was conducted, with attention being paid to dosing accuracy, bioavailability, inter-individual variability, and the influence of the coffee matrix. Results: Isolated caffeine consistently improves performance under controlled conditions. Coffee can produce similar ergogenic effects, particularly in endurance exercise, although responses are more variable due to differences in caffeine content and individual sensitivity. Emerging evidence suggests that coffee, especially when consumed with carbohydrates, may support post-exercise glycogen resynthesis. Coffee also appears to be better tolerated by many individuals and provides additional bioactive compounds with antioxidant and anti-inflammatory properties. Conclusions: Coffee and isolated caffeine should not be viewed as interchangeable ergogenic strategies. While isolated caffeine remains useful in experimental settings, coffee represents a more ecologically relevant and potentially safer source of caffeine in applied practice. Further direct comparative studies are needed to clarify their context-specific roles. Full article

Background: Deceptive caffeine ingestion has shown inconsistent effects as an ergogenic aid for short-term exercises. Objective: Therefore, the aim of this study was to evaluate the potential placebo effect of deceptive caffeine ingestion on short-term performance during countermovement and repeated-jump tests, as well as bench press throw and bench press-to-failure assessments, and to document any associated side effects. Methods: A repeated, randomized, and counterbalanced design was implemented to compare the effects of ingesting a placebo claimed to be caffeine with a control condition in which no substance was consumed. Twenty-five physically active young adults (17 men and 8 women) completed a countermovement jump (CMJ) test, a 15 s repeated-jump test, bench press throws at 25%, 50%, and 75% of 1RM, and a bench press-to-failure test at 75% of 1RM and also completed a questionnaire regarding potential side effects. Results: Performance was similar between the placebo and control in the CMJ (38.1 ± 6.8 vs. 37.5 ± 6.8 cm; p = 0.225; d = 0.25) and in the 15 s repeated-jump test (p > 0.05; trivial–small effects). In the bench press throw, propulsive mean velocity did not differ at 25% 1RM (p = 0.296; d = 0.23) or 50% 1RM (p = 0.626; d = 0.10). However, deceptive caffeine ingestion increased propulsive mean velocity at 75% 1RM (0.500 ± 0.131 vs. 0.480 ± 0.131 m/s; p = 0.024; d = 0.48) and increased repetitions to failure at the same load (11.9 ± 3.7 vs. 11.0 ± 3.1; p = 0.047; d = 0.42). Mean velocity during the first 3 repetitions tended to be higher with the placebo (p = 0.064; d = 0.39), while final repetitions were similar (p = 0.469; d = 0.15). The most common side effects were increased activeness (34.8%) and nervousness (17.4%). Conclusions: In summary, deceptive caffeine ingestion had minimal impact on jump and ballistic bench press performance in physically active individuals. However, repetitions to failure were improved by ≈1 repetition (+8.2%). These findings suggest that the placebo effect of caffeine is unlikely to serve as a reliable strategy for enhancing short-term exercise performance. Full article

Background/Objectives: Caffeine is a well-established ergogenic aid in many strength- and endurance-based sports, but its efficacy in sport climbing remains underexplored despite the sport’s unique physical demands on grip strength, power, and muscular endurance. Therefore, this study examined the acute impact of a low caffeine dose (3 mg/kg) on climbing-specific performance, including pull-up and grip tests, in intermediate-advanced climbers. Methods: In a triple-blind, randomized, crossover design, thirteen male climbers (age: 28.2 ± 8.6 years) completed two experimental trials (caffeine vs. placebo). Performance was assessed via a pull-up one-repetition maximum (1RM) and power test at various loads, a pull-up muscular endurance test, and grip tests including maximum dead-hang time, maximum dead-hang strength, and rate of force development (RFD). Results: Caffeine did not significantly enhance performance in any measured variable. While a non-significant increase in peak power was observed at 80% 1RM (+8.0%, 95% CI: −0.232 to 0.304, p > 0.05, g = 0.348), effects at other loads and on pull-up endurance were trivial based on effect size (e.g., repetitions: +3.3%, 95% CI: −3.30 to 4.37, p = 0.292, g = 0.061). For grip metrics, caffeine was associated with a modest reduction in endurance time (+7.4%, p = 0.162, g = 0.171) and a slight increase in maximum strength (+2.4%, p = 0.060, g = 0.120). RFD was unaffected (p > 0.169, g < 0.13). Despite the lack of objective improvement, participants reported significantly greater subjective feelings of strength, energy, and alertness with caffeine (p < 0.05). Conclusions: A 3 mg/kg dose of caffeine, while altering psycho-physiological state, did not elicit statistically or practically meaningful ergogenic effects on pull-up or grip performance in climbers. Higher doses or sport-specific performance tests should be investigated in future research. Full article

Hawk tea (Litsea coreana Levl. var. lanuginosa), a naturally caffeine-free herbal beverage widely consumed in Southwest China, is characterized by a pronounced camphoraceous note that often deters first-time consumers. In this study, hawk tea leaves were subjected to solid-state fermentation with four microbial strains—Monascus purpureus, Aspergillus cristatus, Bacillus subtilis, and Blastobotrys adeninivorans. The volatile compounds of unfermented and fermented hawk teas were identified by ultra-fast gas chromatography electronic nose (ultra-fast GC e-nose), gas chromatography–mass spectrometry (GC-MS) and gas chromatography–ion mobility spectrometry (GC-IMS) analyses, respectively. Furthermore, the calculation of odor activity values (OAVs) and relative odor activity value (ROAV) revealed that 6 and 25 volatile chemicals, including perillaldehyde (OAV 3.692) and linalool (ROAV 100), were the main contributors to the floral, fruity, and woody aroma of fermented hawk tea. Sensory evaluation confirmed that fermentation generally enhanced woody notes while significantly reducing the characteristic camphoraceous and oil oxidation odors. Notably, the Blastobotrys adeninivorans-fermented sample exhibited the most pronounced floral and fruity nuances, accompanied by significantly elevated aroma complexity and acceptability. Consequently, Blastobotrys adeninivorans represents a promising starter culture for the improvement of hawk tea flavor. Full article

Ergogenic aids have long attracted scientific interest for their potential to enhance neuromuscular performance, with caffeine being among the most extensively studied. While traditionally attributed to peripheral actions on skeletal muscle, accumulating evidence indicates that, at physiological doses, caffeine’s ergogenic effects are predominantly mediated by antagonism of central adenosine receptors. This antagonism leads to increased arousal, reduced inhibitory neuromodulation, enhanced corticospinal excitability, and altered motor unit recruitment and firing behavior. Importantly, the concentrations required to elicit direct effects on excitation–contraction coupling via ryanodine receptors exceed those compatible with human safety, rendering such mechanisms unlikely in vivo. This narrative review synthesizes contemporary neurophysiological evidence to propose that caffeine acts primarily by “tuning” motor system gain through central neurotransmitter modulation, rather than by directly augmenting muscle contractile properties. Additionally, we highlight unresolved questions regarding persistent inward currents, sex-dependent neuromodulatory influences—including the potential role of estrogen in regulating adenosine receptor expression—and the implications of repeated caffeine use during training for neural adaptation and motor control. Finally, we outline key methodological and conceptual directions for future research aimed at refining our understanding of caffeine’s neuromuscular effects in both acute and chronic contexts. Full article

The quality of different coffee varieties varies, and the corresponding bioactive value of coffee processing byproducts is often overlooked. For that, we employed HPLC, GC-MS, and electronic sensory analyses to evaluate the key bioactive components, antioxidant potential, and flavor traits of green coffee bean and coffee processing byproducts of seven coffee varieties. The results showed that green coffee beans (Oe+Ie) and exocarp (Ep) possessed strong antioxidant activity and high total phenolic content (TPC), caffeine and trigonelline content. Among the varieties, DR390 contained higher levels of total phenols, caffeine, and trigonelline, whereas DR402 was rich in caffeine and chlorogenic acid. In addition, RY3 exhibited higher TPC, total flavonoid content (TFC), caffeine, and chlorogenic acid. The parchment (Pc) layer was rich in soluble sugars (1.83–5.43%), while the silverskin (Sk) contained relatively high levels of chlorogenic acid (3.58–4.69 mg/g). Flavor analysis identified eleven classes of volatile compounds in green coffee bean (Oe+Ie) and byproducts (Ep, Pc, Sk), with esters, ketones, alcohols, and aldehydes being the most prevalent. Seven key aroma compounds, including methyl salicylate, phenethyl alcohol, nonanal, and benzaldehyde, were identified across the various structural tissues of coffee fruit. Distinct flavor profiles were observed among the coffee fruit parts: green coffee bean (Oe+Ie) was nutty; the Ep showed fruity and cocoa-like aromas; the Pc and Sk exhibited papery and nutty aromas, respectively. Varieties DR397, DR402, and RY3 exhibited pronounced aroma profiles. Comprehensive analysis showed that DR402 and RY3 had higher overall scores for bioactive and flavor components than other varieties in their groups. In summary, green coffee bean (Oe+Ie) exhibited strong antioxidant activity and high levels of bioactive compounds. Coffee byproducts, such as the Ep, hold potential for extracting natural antioxidants and bioactive compounds to develop specialty products or for other high-value utilization. Full article

Background/Objectives: Caffeine citrate represents the standard pharmacological intervention for apnea of prematurity (AOP) and episodes of intermittent hypoxia (IH). Despite its widespread use, consensus regarding the necessity of routine serum monitoring, optimal dosing protocols, and precise clinical indications remains elusive. The primary objective of this investigation was to evaluate the longitudinal trajectory of serum caffeine concentrations in preterm infants and to analyze their correlation with the incidence of AOP and IH episodes. Furthermore, we sought to determine whether blood caffeine concentrations varied significantly across gestational ages throughout the postnatal period. Methods: This multicenter, prospective observational study enrolled preterm infants with a gestational age of ≤30 weeks. Participants were administered a standard loading dose of caffeine citrate within the first 24 h of life, followed by a standardized maintenance regimen. Serum caffeine levels were quantified on a weekly basis. The cohort was stratified into two distinct groups based on gestational age: Group 1 (23–27 weeks) and Group 2 (28–30 weeks). Results: The study yielded 588 serum caffeine measurements from a cohort of 104 preterm infants, characterized by a median gestational age of 28 weeks (range: 23–30 weeks) and a mean birth weight of 1034 ± 296 g. Statistical analysis revealed no significant disparities in serum caffeine concentrations across gestational age groups (p > 0.05). Notably, during the third week of life, infants with apneic episodes demonstrated significantly lower caffeine levels than those without apnea (p = 0.016). Furthermore, a significant negative correlation was identified between serum caffeine concentrations and the frequency of IH episodes during the third, fourth, and fifth weeks of life across multiple oxygen saturation thresholds. Conclusions: While serum caffeine concentrations in preterm infants did not vary significantly with gestational age, lower levels were associated with a higher incidence of AOP and IH episodes. These results suggest that while routine monitoring or dose adjustment based solely on gestational age may not be warranted, maintaining adequate serum levels is critical for symptom management. Future research should prioritize randomized controlled trials with expanded sample sizes, extended follow-up periods, and a rigorous analysis of adverse effects. Full article