| In vitro: |
| Med Sci Monit. 2003 Sep;9(9):BR325-30. | | Antioxidant and prooxidant properties of caffeine, theobromine and xanthine.[Pubmed: 12960921] | Caffeine, along with its catabolic products Theobromine and xanthine, is a key component of tea and coffee. These compounds are structurally similar to uric acid, a known antioxidant which is present in blood at relatively high concentrations, but also shows prooxidant activity.
In view of the structural similarity between uric acid and caffeine and its metabolites, we studied the antioxidant and prooxidant properties of these compounds.
METHODS AND RESULTS:
Antioxidant activity was determined by measuring the quenching effect of the compounds on oxidative DNA degradation by a hydroxyl radical generating system. Prooxidant activity was studied by measuring the ability of the compounds to oxidatively degrade DNA in the presence of copper ions. Caffeine, Theobromine and xanthine have a quenching effect on the production of hydroxyl radicals, as well as on oxidative DNA breakage by hydroxyl radicals. Consistent with previous observations that many known antioxidants of plant origin are also capable of prooxidant action, the purine alkaloids also show oxidative DNA breakage in the presence of transition metal ions.
CONCLUSIONS:
The alkaloid caffeine and its catabolic products Theobromine and xanthine exhibit both antioxidant and prooxidant properties.
The results lead to the observation that caffeine and its metabolites may also contribute to the overall antioxidant and chemopreventive properties of caffeine-bearing beverages, such as tea. |
|
| In vivo: |
| FASEB J. 2005 Feb;19(2):231-3. | | Theobromine inhibits sensory nerve activation and cough.[Pubmed: 15548587 ] | Cough is a common and protective reflex, but persistent coughing is debilitating and impairs quality of life. Antitussive treatment using opioids is limited by unacceptable side effects, and there is a great need for more effective remedies.
METHODS AND RESULTS:
The present study demonstrates that theobromine, a methylxanthine derivative present in cocoa, effectively inhibits citric acid-induced cough in guinea-pigs in vivo. Furthermore, in a randomized, double-blind, placebo-controlled study in man, theobromine suppresses capsaicin-induced cough with no adverse effects. We also demonstrate that theobromine directly inhibits capsaicin-induced sensory nerve depolarization of guinea-pig and human vagus nerve suggestive of an inhibitory effect on afferent nerve activation.
CONCLUSIONS:
These data indicate the actions of theobromine appear to be peripherally mediated. We conclude theobromine is a novel and promising treatment, which may form the basis for a new class of antitussive drugs. | | Am J Clin Nutr. 2013 Jun;97(6):1201-9. | | Effect of cocoa and theobromine consumption on serum HDL-cholesterol concentrations: a randomized controlled trial.[Pubmed: 23595874] | Evidence from clinical studies has suggested that cocoa may increase high-density lipoprotein (HDL)-cholesterol concentrations. However, it is unclear whether this effect is attributable to flavonoids or Theobromine, both of which are major cocoa components.
METHODS AND RESULTS:
We investigated whether pure Theobromine increases serum HDL cholesterol and whether there is an interaction effect between Theobromine and cocoa. DESIGN: The study had a 2-center, double-blind, randomized, placebo-controlled, full factorial parallel design. After a 2-wk run-in period, 152 healthy men and women (aged 40-70 y) were randomly allocated to consume one 200-mL drink/d for 4 wk that contained 1) cocoa, which naturally provided 150 mg Theobromine and 325 mg flavonoids [cocoa intervention (CC)], 2) 850 mg pure Theobromine [Theobromine intervention (TB)], 3) cocoa and added Theobromine, which provided 1000 mg Theobromine and 325 mg flavonoids [Theobromine and cocoa intervention (TB+CC)], or 4) neither cocoa nor Theobromine (placebo). Blood lipids and apolipoproteins were measured at the start and end of interventions. RESULTS: In a 2-factor analysis, there was a significant main effect of the TB (P < 0.0001) but not CC (P = 0.1288) on HDL cholesterol but no significant interaction (P = 0.3735). The TB increased HDL-cholesterol concentrations by 0.16 mmol/L (P < 0.0001). Furthermore, there was a significant main effect of the TB on increasing apolipoprotein A-I (P < 0.0001) and decreasing apolipoprotein B and LDL-cholesterol concentrations (P < 0.02).
CONCLUSIONS:
Theobromine independently increased serum HDL-cholesterol concentrations by 0.16 mmol/L. The lack of significant cocoa and interaction effects suggested that Theobromine may be the main ingredient responsible for the HDL cholesterol-raising effect. |
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