Reinforcing effects of caffeine and theobromine as found in chocolate

Rationale  

Although in a previous study we showed that caffeine and theobromine were the main psychopharmacologically active constituents in a 50-g bar of chocolate, mere activity does not guarantee a role in our liking for the food.     

Caffeine markedly sensitizes human mesothelioma cell lines to pemetrexed

Pemetrexed is a new generation antifolate approved for the treatment of mesothelioma and non-small cell lung cancer. Caffeine is known to augment radiation or chemotherapeutic drug-induced cell killing. The current study addresses the impact of caffeine on the activity of pemetrexed in mesothelioma cell lines. Caffeine enhanced pemetrexed activity in all four mesothelioma cell lines tested (H2052, H2373, H28 and MSTO-211H). Caffeine sensitized H2052 cells in a dose- and schedule-dependent manner, and was associated with a markedly decreased clonogenic survival. Caffeine sensitization occurred only in cells subjected to pulse, but not continuous, exposure to pemetrexed. Similar pemetrexed sensitization was also observed with the clinically better tolerated caffeine analog, theobromine. Pemetrexed sensitization by caffeine was associated with an increase in pemetrexed-induced phosphorylation of ataxia-telangiectasia-mutated (ATM) and Chk1. These data indicate that caffeine and its analog, theobromine, may be a useful approach to enhance pemetrexed-based chemotherapy.     

Analysis of group I intron splicing in the presence of naturally occurring methylxanthines

BackgroundRecent advances in the understanding of RNA structure–function, intricate folding and its affinity to bind small molecules have led to the proposal that RNA can be a fastidious target for drug design. The revelation that RNA can act as enzymes as in group I intron and that has been recognized by small molecule ligands targeting the catalytic activity has necessitated our focus on group I intron as target for RNA binders.MethodsWe studied the group I intron splicing of Tetrahymena in the presence of naturally occurring methylxanthines (theophylline, theobromine and caffeine) at 5–200 μmol/l concentration, and analyzed the spliced out products. For the first time the interference of splicing was ascertained on the basis of pre-rRNA accumulation.ResultsThe gel mobility shift showed the binding of methylxanthines with group I intron RNA in a dose dependent manner. The densitometric analysis of pre-rRNA accumulation showed 50% of splicing interference at 200 μmol/l of theophylline and theobromine, whereas the structurally similar molecule caffeine does not alter splicing.ConclusionThe splicing interference measured from the accumulation of pre-rRNA in group I intron splicing is considered to be an uncomplicated or simple denominator for calculating the splicing interference or relative splicing activity in the presence of above RNA binders or splicing modulators.     

New HPTLC methods for analysis of major bioactive compounds in mate (Ilex paraguariensis) tea

New HPTLC (high-performance thin-layer chromatography) methods to evaluate major bioactive compounds in mate (Ilex paraguariensis) tea were developed. Identification of compounds was based on HPTLC-MS (high-performance thin-layer chromatography–mass spectrometry), parallel to other techniques. Quantitative evaluation of the main methylxanthines and phenolic compounds in this species was accomplished by two HPTLC methods which can be performed consecutively on one single plate. A solvent system for the separation of the identified saponins is also described for qualitative evaluations. The methods for quantification were validated in terms of: robustness; LOD and LOQ (limits of detection and quantification); repeatability; intra-day and inter-day variation; ruggedness; and accuracy. The methods have proven to be suitable for evaluation of mate tea aqueous and methanolic extracts, with the advantages of: high-throughput; reduced need of plates and application procedures; and high sensitivity – low LODs and LOQs were achieved. Aqueous extracts of nineteen mate teas of different type, geographical origin and age were evaluated in terms of methylxanthines, phenolic compounds and pH. By means of principal component analysis, distinctive characteristics between mate teas could be observed.     

Methylxanthines are the psycho-pharmacologically active constituents of chocolate

Rationale Liking, cravings and addiction for chocolate (chocoholism) are often explained through the presence of pharmacologically active compounds. However, mere presence does not guarantee psycho-activity.Objectives Two double-blind, placebo-controlled studies measured the effects on cognitive performance and mood of the amounts of cocoa powder and methylxanthines found in a 50 g bar of dark chocolate.Methods In study 1, participants (n=20) completed a test battery once before and twice after treatment administration. Treatments included 11.6 g cocoa powder and a caffeine and theobromine combination (19 and 250 mg, respectively). Study 2 (n=22) comprised three post-treatment test batteries and investigated the effects of milk and dark chocolate levels of these methylxanthines. The test battery consisted of a long duration simple reaction time task, a rapid visual information processing task, and a mood questionnaire.Results Identical improvements on the mood construct energetic arousal and cognitive function were found for cocoa powder and the caffeine+theobromine combination versus placebo. In chocolate, both milk chocolate and dark chocolate methylxanthine doses improved cognitive function compared with white chocolate. The effects of white chocolate did not differ significantly from those of water.Conclusions A normal portion of chocolate exhibits psychopharmacological activity. The identical profile of effects exerted by cocoa powder and its methylxanthine constituents shows this activity to be confined to the combination of caffeine and theobromine. Methylxanthines may contribute to the popularity of chocolate; however, other attributes are probably much more important in determining chocolates special appeal and in explaining related self-reports of chocolate cravings and chocoholism.     

Theobromine mitigates IL-1β-induced oxidative stress,inflammatory response,and degradation of type II collagen in human chondrocytes

Osteoarthritis is one of the major causes of disability in elderly adults. Chondrocytes are responsible for the formation and remodeling of articular cartilage in joint tissue. The dysfunction of chondrocytes is a significant factor in the development of osteoarthritis. In the current study, we found that theobromine, a constituent of the cacao plant, possesses a preventive effect against interleukin (IL)-1β-induced chondrocyte dysfunction. Theobromine ameliorates IL-1β-induced production of cellular reactive oxygen species (ROS) and inflammatory mediators including cyclooxygenase-2 (COX-2) and prostaglandin E₂ (PGE₂). The presence of theobromine suppresses IL-1β-induced inducible nitro oxide synthase (iNOS) expression and cellular nitro oxide (NO) production. Theobromine also suppresses IL-1β-induced production of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1), as well as matrix metalloproteinases (MMP)-3 and MMP-13. Additionally, theobromine mitigates IL-1β-induced type II collagen degradation. Mechanistically, we show that theobromine inhibits IL-1β-induced IκBα activation, nuclear factor-κB (NF-κB) protein p65 accumulation, and transfected NF-κB promoter activity, indicating that theobromine suppresses the NF-κB pathway in chondrocytes. Collectively, our study demonstrates that the natural molecule theobromine has a protective effect to counter cytokine-induced chondrocyte dysfunction, implying its beneficial effect in the prevention of osteoarthritis.     

Effects of Methylxanthine Derivatives on Adriamycin Concentration and Antitumor Activity

We studied the mechanism whereby caffeine acts as a biochemical modulator of adriamycin, and examined various methylxanthine derivatives to determine whether they would be of value as biochemical modulators. In an in vitro study of adriamycin efflux in Ehrlich ascites carcinoma cells, theophylline, pentoxifylline, and theobromine inhibited this efflux, while caffeine metabolites did not. The effects of several methylxanthine derivatives on the antitumor activity of adriamycin and on adriamycin concentration in tissue were also examined in CDF₁ tumor-bearing mice. Theobromine, which inhibited adriamycin efflux in vitro , increased the antitumor activity of adriamycin and the concentration of adriamycin in tumors. The caffeine metabolites, which had no effect on the adriamycin efflux, did not increase antitumor activity. These results suggest that the metabolism of caffeine may weaken its effect as a biochemical modulator, and that pentoxifylline and theobromine would be of value as biochemical modulators of adriamycin.     

分光光度法测定柯柯豆碱的含量

利用分光光度法测定柯柯豆碱的含量，在２７２．５ｎｍ滤长处有最大吸收峰，浓度在２．２￣１５．３μｇ／ｍｌ（ｒ＝０．９９９３）呈良好线性关系，Ｅ＾１％１ｃｍ＝５４．７．１，ＲＳＤ＝０．９８％（ｎ＝３２）。重现性、精密度、稳定性良好。     

咖啡因可可碱和茶碱的电喷雾质谱

对嘌呤生物碱的咖啡因、可可碱和茶碱的电喷雾质谱进行了研究。CONE电压较低时,3个生物碱不发生裂解,其各自的[M+H]~+峰为基峰,可获得分子量信息。CONE电压升高后,3个生物碱均发生主要裂解,其中咖啡因和茶碱较可可碱易发生裂解,这些裂解方式可用于结构分析。