Anti-obesity potential of natural methylxanthines

The Therapeutic Potential of Theobromine in Obesity: A Comprehensive Review

Obesity, characterized by chronic low-grade inflammation, is a significant health concern. Phytochemicals found in plants are being explored for therapeutic use, particularly in combating obesity. Among these, theobromine, commonly found in cocoa and chocolate, shows promise. Although not as extensively studied as caffeine, theobromine exhibits positive effects on human health. It improves lipid profiles, aids in asthma treatment, lowers blood pressure, regulates gut microbiota, reduces tumor formation, moderates blood glucose levels, and acts as a neuroprotective agent. Studies demonstrate its anti-obesity effects through mechanisms such as browning of white adipose tissue, activation of brown adipose tissue, anti-inflammatory properties, and reduction of oxidative stress. This study aims to suggest theobromine as a potential therapeutic agent against obesity-related complications.

Non-invasive caffeinated-nanovesicles as adipocytes-targeted therapy for cellulite and localized fats

Caffeine (CAF) is a non-selective adenosine A1 receptor antagonist which predominates in fat cells. When CAF binds to adenosine receptors, it increases cyclic adenosine monophosphate; inhibiting adipogenesis and inducing fat lipolysis. Resveratrol (RSV) is an antioxidant polyphenol possessing different anti-obesity mechanisms. Topical application of both hydrophilic CAF and lipophilic RSV is limited. This study aimed to develop novel caffeinated-resveratrol bilosomes (CRB) and caffeine-bilosomes (CB) that could non-invasively target and deposit in fat cells. RSV bilosomes (RB) were prepared as a non-targeted system for comparison. CRB showed nanosize (364.1 nm ±6.5 nm) and high entrapment for both active compounds. Rats treated topically with CRB revealed a significant decrease (P = 0.039) in body weight. Histological analysis of the excised skin demonstrated a reduction in the subcutaneous fatty layer thickness and a decrease in the size of connective tissue-imbedded fat cells. Kidney histological examination of RB-treated rats showed subcapsular tubular epithelial cells with cytoplasmic vacuolation. This reflects a systemic effect of RSV from the non-targeted RB compared to CRB, which had a targeting effect on the adipose tissue. In conclusion, CAF in CRB significantly enhanced RSV deposition in adipose tissue and assisted its local-acting effect for managing obesity and cellulite.

Genotoxic and mutagenic potential of 7-methylxanthine: an investigational drug molecule for the treatment of myopia

7-Methylxanthine (7-MX, CAS No. 552-62-5, purity 99.46%) is the first orally administered drug candidate, which showed anti-myopic activity in different pre-clinical studies. In the present study, we investigated the in-vivo genotoxic and mutagenic toxicity of 7-MX in Wistar rats using comet/single-cell gel electrophoresis, chromosomal aberration and micronucleus assays after oral administration. For the single-dose study (72 h), two doses of 7-MX 300 and 2000 mg/kg body weight were selected. For a repeated dose 28 d study, three doses (250, 500, and 1000 mg/kg) of 7-MX were selected. The doses were administered via oral gavage in the suspension form. Blood and major vital organs such as bone marrow, lung and liver were used to perform comet/single cell gel electrophoresis, chromosomal aberration, and micronucleus assays. The in-vitro Ames test was performed on TA98 and TA100 strains. In the chromosomal aberration study, a non-significant increase in deformities such as stickiness, ring chromosome, and endoreduplication was observed in bone marrow cells of 7-MX treated groups. These chromosomal alterations were observed upon treatment with doses of 2000 mg/kg single dose for 72 h and 1000 mg/kg repeated dose for 28 d. At a dose of 500 mg/kg, DNA damage in terms of tail length, tail moment, % tail DNA and the olive tail moment was also found to be non-significant in 7-MX treated groups. The Ames test showed the non-mutagenic nature of 7-MX in both strains of TA98 and TA100 of Salmonella typhimurium with or without metabolic activation. Thus, the present work is interesting in view of the non- genotoxicity and non-mutagenicity of repeated doses of 7-MX.

Current therapeutic targets and multifaceted physiological impacts of caffeine

Caffeine, which shares consubstantial structural similarity with purine adenosine, has been demonstrated as a nonselective adenosine receptor antagonist for eliciting most of the biological functions at physiologically relevant dosages. Accumulating evidence supports caffeine's beneficial effects against different disorders, such as total cardiovascular diseases and type 2 diabetes. Conversely, paradoxical effects are also linked to caffeine ingestion in humans including hypertension-hypotension and tachycardia-bradycardia. These observations suggest the association of caffeine action with its ingested concentration and/or concurrent interaction with preferential molecular targets to direct explicit events in the human body. Thus, a coherent analysis of the functional targets of caffeine, relevant to normal physiology, and disease pathophysiology, is required to understand the pharmacology of caffeine. This review provides a broad overview of the experimentally validated targets of caffeine, particularly those of therapeutic interest, and the impacts of caffeine on organ-specific physiology and pathophysiology. Overall, the available empirical and epidemiological evidence supports the dose-dependent functional activities of caffeine and advocates for further studies to get insights into the caffeine-induced changes under specific conditions, such as asthma, DNA repair, and cancer, in view of its therapeutic applications.

Multimodal Strategies to Fight Obesity: Research on Tailored Therapies Based on Natural and Synthetic Compounds for Prevention, Management and Treatment

In the past 50 years, the global prevalence of obesity and overweight has tripled, reaching pandemic proportions and blatantly representing an urgent problem for public health [...].

The efficacy of topical aminophylline in local fat reduction: A systematic review

Background and aims

Some studies have reported that the topical forms with aminophylline as the active ingredient appear to be relatively effective on local fat burning while having no/minimal side effects. This systematic review accumulates all of the data on the local fat-burning potency of aminophylline topical formulation.

Methods

Documents were retrieved from PubMed, Web of Science, and Scopus databases until Aug 2022. Data were extracted from clinical trials reporting the reduction in thigh or waist circumference as a result of using topical forms containing aminophylline. Screening of included studies was performed independently by two authors and the quality assessment of included studies was performed based on the Cochrane Collaboration's approach.

Results

Of the 802 initial studies, 5 studies were included in the systematic review. Several concentrations of aminophylline were used in different studies. Most studies administred the topical formulation on participants' one thigh, and the other thigh was considered to be the control for comparing the fat reduction amount. Except for one study, all other studies reported that all participants lost more fat on the treated area than the control groups. The amount of fat reduction differed in studies regarding their different aminophylline concentrations and administration routines. In the case of side effects, except for some studies reporting skin rashes, other studies reported no significant side effects at all.

Conclusions

Aminophylline topical formulation offers a safe, effective, and much less invasive alternative to cosmetic surgery for localized fat reduction. It seems that the 0.5% concentration, administered five times a week for five weeks is the most potent concentration. However, more high-quality clinical trials are needed to verify this conclusion.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022353578.

Green Extraction Techniques for the Determination of Active Ingredients in Tea: Current State, Challenges, and Future Perspectives

In recent years, the scientific community has turned its attention to the further study and application of green chemistry as well as to sustainable development in reducing the consumption of raw materials, solvents, and energy. The application of green chemistry aims to ensure the protection of the environment and to also, consequently, improve the quality of human life. It offers several benefits, both socially and economically. In the last few decades, new alternative non-conventional green extraction methodologies have been developed for the purposes of the extraction of active ingredient compounds from various raw products. The main objective of this literature review is to present the current knowledge and future perspectives regarding the green extraction of tea species in respect of the isolation of safe active biomolecules, which can be used as commercially available products—both as dietary supplements and pharmaceutical formulations. More specifically, in this literature review, the intention is to investigate several different extraction techniques, such as ultrasonic-assisted extraction, ultrasonic-assisted extraction with DESs, the microwave assisted-extraction method, and the reflux method. These are presented in respect of their role in the isolation of bioactive molecules regarding different tea species. Furthermore, following the literature review conducted in this study, the commonly used green extraction methods were found to be the ultrasound-assisted method and the microwave-assisted method. In addition to these, the use of a green solvent, in regard to its role in the maximum extraction yield of active ingredients in various species of tea, was emphasized. Catechins, alkaloids (such as caffeine), gallic acid, and flavonoids were the main extracted bioactive molecules that were isolated from the several tea species. From this literature review, it can be demonstrated that green tea has been widely studied at a rate of 52% in respect of the included research studies, followed by black tea at 26%, as well as white tea and oolong tea at 11% each. Regarding the determination of the bioactive molecules, the most utilized analytical method was found in the combination of high-performance liquid chromatography (HPLC) with a photodiode array detector (PDA) and mass spectrophotometry (MS) at a usage rate of about 80%. This method was followed by the utilization of UPLC and GC at 12% and 8%, respectively. In the future, it will be necessary to study the combination of green extraction techniques with other industry strategies, such as an encapsulation at the micro and nano scale, for the purposes of preparing stable final products with antioxidant properties where, finally, they can be safely consumed by humans.

Inhibition of Mitochondrial Uncoupling Proteins Arrests Human Spermatozoa Motility without Compromising Viability

Mitochondrial uncoupling proteins (UCPs) are central in the regulation of mitochondrial activity and reactive oxygen species (ROS) production. High oxidative stress is a major cause of male infertility; however, UCPs expression and function in human spermatozoa are still unknown. Herein, we aimed to assess the expression and function of the different homologs (UCP1-6) in human spermatozoa. For this purpose, we screened for the mRNA expression of all UCP homologs. Protein expression and immunolocalization of UCP1, UCP2, and UCP3 were also assessed. Highly motile spermatozoa were isolated from human normozoospermic seminal samples (n = 16) and incubated with genipin, an inhibitor of UCPs (0, 0.5, 5, and 50 µM) for 3 h at 37 °C. Viability and total motility were assessed. Mitochondrial membrane potential and ROS production were evaluated. Media were collected and the metabolic profile and antioxidant potential were analyzed by ¹H-NMR and FRAP, respectively. The expression of all UCP homologs (UCP1-6) mRNA by human spermatozoa is herein reported for the first time. UCP1-3 are predominant at the head equatorial segment, whereas UCP1 and UCP2 are also expressed at the spermatozoa midpiece, where mitochondria are located. The inhibition of UCPs by 50 µM genipin, resulting in the UCP3 inhibition, did not compromise sperm cell viability but resulted in irreversible total motility loss that persisted despite washing or incubation with theophylline, a cAMP activator. These effects were associated with decreased mitochondrial membrane potential and lactate production. No differences concerning UCP3 expression, however, were observed in spermatozoa from normozoospermic versus asthenozoospermic men (n = 6). The inhibition of UCPs did not increase ROS production, possibly due to the decreased mitochondrial activity and genipin antioxidant properties. In sum, UCPs are major regulators of human spermatozoa motility and metabolism. The discovery and characterization of UCPs' role in human spermatozoa can shed new light on spermatozoa ROS-related pathways and bioenergetics physiology.

Paraxanthine safety and comparison to caffeine

Introduction: Caffeine, one of the most ubiquitous ingredients found in beverages and other ingested food products, has a long history of safe use. As a member of the methylxanthine class of stimulants, caffeine is not devoid of unwanted side effects at any serving level. Caffeine safety has been the subject of a safety workshop by FDA and the Institute of Medicine in the past decade. Thus, investigation into an alternate stimulant with similar pharmacology but improved safety is warranted. Paraxanthine (1,7-dimethylxanthine) is the predominant metabolite of caffeine in humans with similar stimulant properties. The few toxicity studies that are available for paraxanthine suggest that the molecule is relatively safe, although thorough characterization of its safety is required prior to widespread incorporation into foods/beverages. Methods: The aim of this study was to evaluate the toxicity of paraxanthine (Rarebird, Inc.) relative to caffeine through a battery of toxicological studies conducted in accordance with international guidelines. These studies evaluated the potential mutagenicity (bacterial reverse mutation, in vitro mammalian chromosomal aberration), genetic toxicity (in vitro mammalian cell gene mutation) and acute, sub-acute and sub-chronic oral toxicity of paraxanthine in Sprague Dawley rats. Results/Discussion: There was no evidence of genetic toxicity or mutagenicity in the in vitro studies. An acute oral LD₅₀ of 829.20 mg/kg body weight (bw) was established. There was no mortality or treatment-related adverse effects in the 14-day repeat dose oral toxicity study, wherein rats received low, mid, or high doses of paraxanthine (50, 100, or 150 mg/kg bw, n = 5 rats/sex/group). The same findings were observed in the subchronic repeat-dose 90-day oral toxicity study at daily doses of paraxanthine of 100, 150, or 185 mg/kg bw which were compared to caffeine at 150 or 185 mg/kg bw (n = 10 animals/sex/group). However, mortality was reported in two animals in the high dose caffeine-treated animals. Therefore, the no observed adverse effect level (NOAEL) from the 90-day study was determined to be 150 mg/kg bw for caffeine and 185 mg/kg bw for paraxanthine for both male and female Sprague Dawley rats. These findings may suggest that paraxanthine could be a safer alternative to caffeine in humans.

Nutraceuticals and the Network of Obesity Modulators

Obesity is considered an increasingly widespread disease in the world population, regardless of age and gender. Genetic but also lifestyle-dependent causes have been identified. Nutrition and physical exercise play an important role, especially in non-genetic obesity. In a three-compartment model, the body is divided into fat mass, fat-free mass and water, and obesity can be considered a condition in which the percentage of total fat mass is in excess. People with a high BMI index or overweight use self-medications, such as food supplements or teas, with the aim to prevent or treat their problem. Unfortunately, there are several obesity modulators that act both on the pathways that promote adipogenesis and those that inhibit lipolysis. Moreover, these pathways involve different tissues and organs, so it is very difficult to identify anti-obesity substances. A network of factors and cells contributes to the accumulation of fat in completely different body districts. The identification of natural anti-obesity agents should consider this network, which we would like to call "obesosome". The nutrigenomic, nutrigenetic and epigenetic contribute to making the identification of active compounds very difficult. This narrative review aims to highlight nutraceuticals that, in vitro or in vivo, showed an anti-obesity activity or were found to be useful in the control of dysfunctions which are secondary to obesity. The results suggest that it is not possible to use a single compound to treat obesity, but that the studies have to be addressed towards the identification of mixtures of nutraceuticals.

Preliminary Evidence of the Potent and Selective Adenosine A2B Receptor Antagonist PSB-603 in Reducing Obesity and Some of Its Associated Metabolic Disorders in Mice

The adenosine A2A and A2B receptors are promising therapeutic targets in the treatment of obesity and diabetes since the agonists and antagonists of these receptors have the potential to positively affect metabolic disorders. The present study investigated the link between body weight reduction, glucose homeostasis, and anti-inflammatory activity induced by a highly potent and specific adenosine A2B receptor antagonist, compound PSB-603. Mice were fed a high-fat diet for 14 weeks, and after 12 weeks, they were treated for 14 days intraperitoneally with the test compound. The A1/A2A/A2B receptor antagonist theophylline was used as a reference. Following two weeks of treatment, different biochemical parameters were determined, including total cholesterol, triglycerides, glucose, TNF-α, and IL-6 blood levels, as well as glucose and insulin tolerance. To avoid false positive results, mouse locomotor and spontaneous activities were assessed. Both theophylline and PSB-603 significantly reduced body weight in obese mice. Both compounds had no effects on glucose levels in the obese state; however, PSB-603, contrary to theophylline, significantly reduced triglycerides and total cholesterol blood levels. Thus, our observations showed that selective A2B adenosine receptor blockade has a more favourable effect on the lipid profile than nonselective inhibition.

Antihyperlipidemic effect and increased antioxidant enzyme levels of aqueous extracts from Liupao tea and green tea in vivo

Liupao tea (fermented dark tea) may improve the active function of hyperlipidemia. Utilizing a hyperlipidemia Sprague-Dawley model and UPLC-MS/MS metabolomics, we examined how the effect of Liupao and green tea extracts on hyperlipidemia and antoxidant enzyme levels and compared their constituents. The results showed that the two types of tea could reduce the levels of total cholesterol (TC), total triglyceride, and low-density lipoprotein cholesterol (LDL-C); increase the contents of bile acids and cholesterol in feces; and improve catalase and glutathione peroxidase (GSH-Px) activities. Compared with the model control group, Liupao tea effectively reduced TC and LDL-C levels by 39.53% and 58.55% and increased GSH-Px activity in the liver by 67.07%, which was better than the effect of green tea. A total of 93 compounds were identified from two samples; the amounts of alkaloids and fatty acids increased compared with green tea, and ellagic acid, hypoxanthine, and theophylline with relatively high contents in Liupao tea had a significantly positive correlation with antihyperlipidemic and antioxidant effects. Therefore, Liupao tea had better antihyperlipidemic and antioxidant activities in vivo than green tea, which might be related to the relatively high content of some active substances.

Chemometric Classification of Colombian Cacao Crops: Effects of Different Genotypes and Origins in Different Years of Harvest on Levels of Flavonoid and Methylxanthine Metabolites in Raw Cacao Beans

The aim of this study was to evaluate the levels of chemical markers in raw cacao beans in two clones (introduced and regional) in Colombia over several years. Multivariate statistical methods were used to analyze the flavanol monomers (epicatechin and catechin), flavanol oligomers (procyanidins) and methylxanthine alkaloids (caffeine and theobromine) of cocoa samples. The results identified genotype as the main factor contributing to cacao chemistry, although significant differences were not observed between universal and regional clones in PCA. The univariate analysis allowed us to establish that EET-96 had the highest contents of both flavanol monomers (13.12 ± 2.30 mg/g) and procyanidins (7.56 ± 4.59 mg/g). In addition, the geographic origin, the harvest conditions of each region and the year of harvest may contribute to major discrepancies between results. Turbo cocoa samples are notable for their higher flavanol monomer content, Chigorodó cocoa samples for the presence of both types of polyphenol (monomer and procyanidin contents) and the Northeast cocoa samples for the higher methylxanthine content. We hope that knowledge of the heterogeneity of the metabolites of interest in each clone will contribute to the generation of added value in the cocoa production chain and its sustainability.

The association of coffee consumption rate with serum 25-hydroxyvitamin D, non-HDL levels, and TC/HDL ratio in females with vitamin D deficiency

OBJECTIVES

The purpose of this study was to evaluate the association of coffee consumption rate with serum 25-hydroxyvitamin D, non-high-density lipoprotein cholesterol levels, and total cholesterol to high-density lipoprotein cholesterol ratio in females with vitamin D deficiency.

METHODS

This retrospective cross-sectional study was carried out by studying the records of 270 Jordanian females aged 18-65 years with varying degrees of vitamin D deficiency. Following completion of the questionnaire regarding their anthropometric characteristics and coffee consumption rate during the preceding 3 months, the participants were required to provide blood samples for analysis to measure 25-hydroxyvitamin D and lipid profile levels including non-high-density lipoprotein cholesterol and total cholesterol to high-density lipoprotein cholesterol ratio.

RESULTS

The current study demonstrated that coffee consumption rate and vitamin D deficiency were significantly positively connected with the total cholesterol to high-density lipoprotein cholesterol ratio (p = .003) in women with vitamin D deficiency. In addition, vitamin D deficiency alone correlated positively with non-high-density lipoprotein cholesterol levels and the total cholesterol to high-density lipoprotein cholesterol ratio (p = .010) and (p = .002), respectively.

CONCLUSION

Higher coffee consumption rate among women with vitamin D deficiency significantly elevated total cholesterol to high-density lipoprotein cholesterol ratio that may increase woman's risk of hyperlipidemia.

Chemical and Skincare Property Characterization of the Main Cocoa Byproducts: Extraction Optimization by RSM Approach for Development of Sustainable Ingredients

Methylxanthines and polyphenols from cocoa byproducts should be considered for their application in the development of functional ingredients for food, cosmetic and pharmaceutical formulations. Different cocoa byproducts were analyzed for their chemical contents, and skincare properties were measured by antioxidant assays and anti-skin aging activity. Musty cocoa beans (MC) and second-quality cocoa beans (SQ) extracts showed the highest polyphenol contents and antioxidant capacities. In the collagenase and elastase inhibition study, the highest effect was observed for the SQ extract with 86 inhibition and 36% inhibition, respectively. Among cocoa byproducts, the contents of catechin and epicatechin were higher in the SQ extract, with 18.15 mg/100 g of sample and 229.8 mg/100 g of sample, respectively. Cocoa bean shells (BS) constitute the main byproduct due to their methylxanthine content (1085 mg of theobromine and 267 mg of caffeine/100 g of sample). Using BS, various influencing factors in the extraction process were investigated by response surface methodology (RSM), before scaling up separations. The extraction process developed under optimized conditions allows us to obtain almost 2 g/min and 0.2 g/min of total methylxanthines and epicatechin, respectively. In this way, this work contributes to the sustainability and valorization of the cocoa production chain.

Natural Dietary and Medicinal Plants with Anti-Obesity Therapeutics Activities for Treatment and Prevention of Obesity during Lock Down and in Post-COVID-19 Era

Overweight and obesity have become global epidemics, especially during the lockdown due to the COVID-19 pandemic. The potential of medicinal plants as a better and safe option in treating obesity and overweight has gained attention in recent years. Obesity and overweight has become a major public health concern, and its incidence rising at an alarming rate. Obesity is one of the major types of metabolic syndrome, resulting in various types of problems such as hypertension, diabetes, dyslipidemia, and excess fat accumulation. The current searching was done by the keywords in main indexing systems including Scopus, PubMed/MEDLINE, the search engine of Google Scholar, and Institute for Scientific Web of Science. The keywords were traditional medicine, health benefits, pharmaceutical science, pomegranate, punicalin, punicalagin, and ellagitannins. Google Scholar was searched manually for possible missing manuscripts, and there was no language restriction in the search. This review was carried out to highlight the importance of medicinal plants which are common in traditional medicinal sciences of different countries, especially Asia to prevent and treatment of obesity and overweight during the global pandemic and the post-COVID-19 era.

Chemical and biological properties of cocoa beans affected by processing: a review

Cocoa (Theobroma cacao L.) is widely cultivated in tropical countries. The cocoa beans are a popular ingredient of confectionery. Cocoa beans contain various chemicals that contribute to their bioactivity and nutritional properties. There has been increasing interest in developing cocoa beans for "healthy" food products. Cocoa beans have special combination of nutrients such as lipids, carbohydrates, proteins and other compounds of biological activities. The bioactive phytochemicals include methylxanthines, polyphenols, biogenic amines, melanoidins, isoprostanoids and oxalates. These phytochemicals of cocoa are related to various in vivo and in vitro biological activities such as antioxidation, anti-cancer, anti-microbial, anti-inflammation, anti-diabetes, cardiovascular protection, physical improvement, anti-photoaging, anti-depression and blood glucose regulation. The potential of bioactive compounds in cocoa remains to be maximized for food and nutritional applications. The current processing technology promotes the degradation of beneficial bioactive compounds, while maximizing the flavors and its precursors. It is not optimized for the utilization of cocoa beans for "healthy" product formulations. Modifications of the current processing line and non-conventional processing are needed to better preserve and utilize the beneficial bioactive compounds in cocoa beans.

Sub-chronic and chronic toxicity evaluation of 7-methylxanthine: a new molecule for the treatment of myopia

Myopia (nearsightedness) is a vision disorder with a blurring of far objects, affect millions worldwide. 7-methylxanthine (7-MX) is a molecule that is presently under clinical investigation for the treatment of myopia. In the present study, we have investigated sub-chronic and chronic toxicity of 7-MX in comparison to other clinically used methylxanthines i.e., caffeine and theobromine as per OECD guidelines 408 and 452. 7-MX was administered orally for 90 days at three different doses of 250, 500, and 1000 mg/kg for sub-chronic toxicity evaluation, and at a limit dose of 1000 mg/kg in 180 days chronic toxicity evaluation in rats. In sub-chronic treatment, 7-MX showed no mortality and signs for toxicity in any group, whereas 10% and 40% mortality with signs for toxicity were observed in caffeine and theobromine treated groups, respectively. A similar, safety profile was observed with 7-MX in 180 days of chronic toxicity study. Further, to confirm any morphological changes in organs; ultrasound and X-rays analysis were performed and no changes in the size of organs, cyst formation, fluid retention, or crystal formation was observed. Thus, the repeated dose study of 7-MX for 180 days may augment the possibility of using 7-MX clinically for the safe and effective treatment of myopia.

Acrolein-Trapping Mechanism of Theophylline in Green Tea, Coffee, and Cocoa: Speedy and Successful

Increasing evidence has identified the unsaturated aldehyde acrolein (ACR) as the potential factor that causes deoxyribonucleic acid cross-linking and the development of chronic diseases. The objective of this study was to investigate the mechanism by which theophylline (TP) scavenges ACR for the first time. TP efficiently scavenged ACR through forming adducts, which was demonstrated in a system in which TP was incubated with ACR at different ratios for different times for liquid chromatography with tandem mass spectrometry. Then, the mono- and di-ACR-TP adducts were purified, and their structures were elucidated by high-resolution mass spectrometry and nuclear magnetic resonance analysis. We found that the ACR residue on mono-ACR-TP further trapped one more ACR and formed di-ACR-TP adducts. Furthermore, mono- and di-ACR-TP had similar time-dependent ACR-scavenging activity to TP. Finally, we demonstrated that green tea, coffee, and cocoa inhibited ACR by trapping ACR to form mono- and di-ACR-TP adducts during the incubation of green tea, coffee, and cocoa with ACR.

KD-64-A new selective A2A adenosine receptor antagonist has anti-inflammatory activity but contrary to the non-selective antagonist-Caffeine does not reduce diet-induced obesity in mice

The A2 adenosine receptors play an important role, among others, in the regulation of inflammatory process and glucose homeostasis in diabetes and obesity. Thus, the presented project evaluated of influence of the selective antagonist of A2A adenosine receptor-KD-64 as compared to the known non-selective antagonist-caffeine on these two particular processes. Two different inflammation models were induced namely local and systemic inflammation. Obesity was induced in mice by high-fat diet and the tested compounds (KD-64 and caffeine) were administrated for 21 days. KD-64 showed anti-inflammatory effect in both tested inflammation models and administered at the same dose as ketoprofen exerted stronger effect than this reference compound. Elevated levels of IL-6 and TNF-α observed in obese control mice were significantly lowered by the administration of KD-64 and were similar to the values observed in control non-obese mice. Interestingly, caffeine increased the levels of these parameters. In contrast to caffeine which had no influence on AlaT activity, KD-64 administration significantly lowered AlaT activity in the obese mice. Although, contrary to caffeine, KD-64 did not reduce diet-induced obesity in mice, it improved glucose tolerance. Thus, the activity of the selective adenosine A2A receptor antagonist was quite different from that of the non-selective.

Modified graphene-silica as a sorbent for in-tube solid-phase microextraction coupled to liquid chromatography-tandem mass spectrometry. Determination of xanthines in coffee beverages

Given the increasing need for analyzing natural or contaminating compounds in complex food matrices in a simple and automated way, coupling miniaturized sample preparation techniques with chromatographic systems have become a growing field of research. In this regard, given the low extraction efficiency of conventional sorbent phases, the development of materials with enhanced extraction capabilities is of particular interest. Here we present several synthesized graphene-based materials supported on aminopropyl silica as sorbents for the extraction of xanthines. The synthesized materials were characterized by infrared spectroscopy and scanning electron microscopy. Aminopropyl silica coated with graphene oxide and functionalized with octadecylsilane/end-capped (SiGOC18ecap) showed the best performance for xanthines extraction. Hence, this material was employed as an in-tube solid phase microextraction (in-tube SPME) device coupled online with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and applied for the analysis of xanthines in roasted coffee samples. Extraction parameters and detection conditions were optimized. The method showed low limits of quantification (0.3-1.0 µg L^-1), precision as relative standard deviation (RSD) values lower than 10%, recoveries between 73 and 109%, and pre-concentration factors from 5.6 to 7.2. Caffeine was determined in all ground roasted and instant coffee samples, in a wide range (0.9 to 36.8 mg g^-1), and small amounts of theobromine and theophylline were also detected in some samples. This work demonstrated that functionalized graphene-based materials represent a promising new sorbent class for in-tube SPME, showing improved extraction capacity. The method was efficient, simple, and fast for the analysis of xanthines, demonstrating an excellent potential to be applied in other matrices.

Anti-obesity potential of rare sugar d-psicose by regulating lipid metabolism in rats

d-Psicose is a new-generation sugar substitute with a low calorie count and can still offer the desirable sweetness. The objective of this study was to investigate the antiobesity potential of d-psicose and the possible mechanism using Wistar rats as the animal model. The animals were divided into five groups and supplemented with diets containing 5% of different carbohydrates, such as glucose, fructose, cellulose, d-psicose, and a control diet, for 4 weeks. After sacrifice, blood lipid profile, tissue morphology, and related genes participating in lipid metabolism were analyzed. The results indicated that the supplementation by d-psicose leads to minimum fat accumulation in rats when compared with the other carbohydrates. The blood lipid profile and antioxidative activity of the rat were also improved. d-Psicose can regulate lipid metabolism by increasing the lipid-metabolism-related enzymes such as SDH in serum and liver and HL in the liver. d-Psicose can prevent fat accumulation by suppressing the expression of lipogenesis-related gene ACCα and hepatic fatty acid uptake gene (FAS and SREBP-1c), while stimulating the expression for fatty-acid-oxidation-related gene including AMPK2α, HSL, and PPARα. In conclusion, d-psicose can be considered to be a healthy alternative to traditional sweeteners.

Mechanisms of action of coffee bioactive components on lipid metabolism

Coffee consumption is associated with reduced risk of metabolic syndrome, obesity and diabetes, which may be related to the effects of coffee and its bioactive components on lipid metabolism. Coffee contains caffeine, a known neuromodulator that acts as an adenosine receptor antagonist, as well as other components, such as chlorogenic acids, trigonelline, cafestol and kahweol. Thus, this review discusses the up-to-date knowledge of mechanisms of action of coffee and its bioactive compounds on lipid metabolism. Although there is evidence that coffee and/or its bioactive compounds regulate transcription factors (e.g. peroxisome proliferator-activated receptors and sterol regulatory element binding proteins) and enzymes (e.g. AMP-activated protein kinase) involved in lipogenesis, lipid uptake, transport, fatty acid β-oxidation and/or lipolysis, needs for the understanding of coffee and its effects on lipid metabolism in humans remain to be answered.

Obesity and male hypogonadism: Tales of a vicious cycle

Obesity prevalence, particularly in children and young adults, is perilously increasing worldwide foreseeing serious negative health impacts in the future to come. Obesity is linked to impaired male gonadal function and is currently a major cause of hypogonadism. Besides signs and symptoms directly derived from decreased circulating testosterone levels, males with obesity also present poor fertility outcomes, further evidencing the parallelism between obesity and male reproductive function. In addition, males with androgen deficiency also exhibit increased fat accumulation and reduced muscle and mineral bone mass. Thus, compelling evidence highlights a vicious cycle where male hypogonadism can lead to increased adiposity, while obesity can be a cause for male hypogonadism. On the opposite direction, sustained weight loss can attain amelioration of male gonadal function. In this scenario, a thorough evaluation of gonadal function in men with obesity is crucial to dissect the causes from the consequences in order to target clinical interventions towards maximized improvement of reproductive health. This review will address the causes and consequences of the bidirectional relationship between obesity and hypogonadism, highlighting the implicit male reproductive repercussions.