ABSTRACT
Title
Anti-inflammatory properties of clovamide and Theobroma cacao phenolic extracts in human monocytes: evaluation of respiratory burst, cytokine release, NF-κ B activation and PPARγ
Authors
C. Bardelli1, HW. Zeng1,2#,,M. Locatelli2, A. Amoruso1, JD. Coisson2, F. Travaglia2, M. Arlorio2,§ and S. Brunelleschi1,3,§
1Dept of Scienze Mediche, University of Piemonte Orientale “A. Avogadro”, Novara, Italy;
2Dept of Chemical, Food, Pharmaceutical and Pharmacological Sciences (DiSCAFF);
§ Drug & Food Biotechnology (DFB) Centre, University of Piemonte Orientale “A. Avogadro”, Novara, Italy;
3 Interdisciplinary Research Centre on Autoimmune Diseases (IRCAD), Novara, Italy;
# Present address: Second Military Medical University, Shangai, 200081, People’s Republic of China.
1Dept of Scienze Mediche, University of Piemonte Orientale “A. Avogadro”, Novara, Italy;
2Dept of Chemical, Food, Pharmaceutical and Pharmacological Sciences (DiSCAFF);
§ Drug & Food Biotechnology (DFB) Centre, University of Piemonte Orientale “A. Avogadro”, Novara, Italy;
3 Interdisciplinary Research Centre on Autoimmune Diseases (IRCAD), Novara, Italy;
# Present address: Second Military Medical University, Shangai, 200081, People’s Republic of China.
Abstract
Cocoa beans are rich in polyphenols (especially catechins and procyanidins), total poliphenol content being 6-8% by weight of the dry bean (1). There is a great interest in the potential health benefits of biologically active phenolic compounds in cocoa and dark chocolate.Cocoa polyphenols have been demonstrated to decrease LDL oxidation and platelet activation, to lower blood pression and to promote endothelium-dependent relaxation (2-5) . Since human monocytes play a key role in inflammation and chronic diseases, they represent an interesting model to evaluate the effects of potential anti-inflammatory drugs. We therefore investigated the effects of clovamide, an N-phenylpropenoyl-L-amino acid amide present in cocoa beans,and of two phenolic extracts (from unroasted and roasted cocoa beans) in human monocytes, in comparison with rosmarinic acid, a well-known natural antioxidant.
In the present study, we investigated the effects of these compounds on PMA (phorbol 12-myristate 13-acetate)-stimulated human monocytes, evaluating the superoxide anion (O2-) production, cytokine release and NF-kB signalling. Clovamide, synthesized in order to provide the pure compound, and rosmarinic acid inhibited PMA-induced O2- production, with a bell-shaped curve and maximal inhibition (80% and 43%, respectively) at 10-100 nM, while the two cocoa extracts were less active.All the compounds significantly inhibited the release of pro-inflammatory cytokines, TNF-abeing reduced by about 50% in monocytes treated with clovamide. Even morerelevant effects are documented by measuring PMA-induced IL-6 release; in this case, an 80%inhibition is observed with clovamide, possibly due to the lower quantitative release of IL-6,as compared to TNF-a.Clovamide and rosmarinic acid dose-dependently inhibited PMA-induced NF-kB activation, with a major involvement of p65 subunit; in this case, too, clovamide was significantly more effective than rosmarinic acid and cocoa extracts. Moreover, at micromolar concentrations, clovamide enhanced Peroxisome Proliferator-Activated Receptor (PPAR)-gactivity, as evidenced by EMSA.
Altogether, these findings indicate that clovamide, besides increasing PPARgactivity, exerts greater effects than rosmarinic acid and cocoa extracts on three anti-inflammatory mechanisms (inhibition of the respiratory burst, inhibition of NF-kB activation and inhibition of pro-inflammatory cytokine release), so resulting a potent regulator of human monocyte activity. Although clovamide is present in low amounts in cocoa powder, adding it to cocoa-derived products could evidence its nutraceutical value and its possible beneficial effects for the treatment of cardiovascular inflammatory disorders. Therefore, we suggest clovamide as a novel bioactive compound endowed with anti-inflammatory properties.
(1)Wollgast J. et al. (2000). Food Res Int. 33: 423-447
(2) Baba S. et al. (2007). J. Nutr. 137: 1436–1441
(3) Hermann F.et al. (2006). Heart 92: 119–120
(4) Heiss C.et al. (2005). J. Am. Coll. Cardiol.46: 1276–1283
(5) Taubert D.et al. (2007). J. Am. Med. Assoc. 298: 49–60.
In the present study, we investigated the effects of these compounds on PMA (phorbol 12-myristate 13-acetate)-stimulated human monocytes, evaluating the superoxide anion (O2-) production, cytokine release and NF-kB signalling. Clovamide, synthesized in order to provide the pure compound, and rosmarinic acid inhibited PMA-induced O2- production, with a bell-shaped curve and maximal inhibition (80% and 43%, respectively) at 10-100 nM, while the two cocoa extracts were less active.All the compounds significantly inhibited the release of pro-inflammatory cytokines, TNF-abeing reduced by about 50% in monocytes treated with clovamide. Even morerelevant effects are documented by measuring PMA-induced IL-6 release; in this case, an 80%inhibition is observed with clovamide, possibly due to the lower quantitative release of IL-6,as compared to TNF-a.Clovamide and rosmarinic acid dose-dependently inhibited PMA-induced NF-kB activation, with a major involvement of p65 subunit; in this case, too, clovamide was significantly more effective than rosmarinic acid and cocoa extracts. Moreover, at micromolar concentrations, clovamide enhanced Peroxisome Proliferator-Activated Receptor (PPAR)-gactivity, as evidenced by EMSA.
Altogether, these findings indicate that clovamide, besides increasing PPARgactivity, exerts greater effects than rosmarinic acid and cocoa extracts on three anti-inflammatory mechanisms (inhibition of the respiratory burst, inhibition of NF-kB activation and inhibition of pro-inflammatory cytokine release), so resulting a potent regulator of human monocyte activity. Although clovamide is present in low amounts in cocoa powder, adding it to cocoa-derived products could evidence its nutraceutical value and its possible beneficial effects for the treatment of cardiovascular inflammatory disorders. Therefore, we suggest clovamide as a novel bioactive compound endowed with anti-inflammatory properties.
(1)Wollgast J. et al. (2000). Food Res Int. 33: 423-447
(2) Baba S. et al. (2007). J. Nutr. 137: 1436–1441
(3) Hermann F.et al. (2006). Heart 92: 119–120
(4) Heiss C.et al. (2005). J. Am. Coll. Cardiol.46: 1276–1283
(5) Taubert D.et al. (2007). J. Am. Med. Assoc. 298: 49–60.