Anti-inflammatory activity of Theobroma cacao L. stem bark ethanol extract and its fractions in experimental models

Ethnopharmacological relevance: The stem bark of Theobroma cacao L. have been used for the treatment of inflammation, toothache, measles and malaria in ethnomedicine. However, the anti-inflammatory activity of Theobroma cacao stem bark has not been fully elucidated. Aim: The anti-inflammatory activity of Theobroma cacao stem bark ethanol extract and its fractions was investigated in this study. Materials and Methods: The anti-inflammatory effect of ethanol extract of Theobroma cacao stem bark (EETc) and its dichloromethane (DCMF), ethylacetate (EAF) and aqueous (AQF) fractions was investigated in erythrocytes membrane stabilizing assay and carrageenan-induced paw oedema. The anti-inflammatory activity of the EAF and EETc was investigated in carrageenan induced-granuloma air pouch models. Results: The extract and fractions showed significant membrane stabilizing action on rat erythrocytes cell membrane. The oral administration of DCMF, EAF and AQF (250 mg/kg) significantly inhibited paw oedema induced by carrageenan (41.3%, 55.0% and 45.0%, respectively) compared to control group. The EAF (62.5, 125 and 250 mg/kg) and EETc (250 mg/kg) significantly inhibited exudates formation in carrageenan air pouch by (63.8, 71.5, 74.5, 64.3%) at 24 h and by (69.4%, 75.7%, 77.1% and 68.4%) at 72 h respectively. The EETc and EAF significantly reduced neutrophil counts, protein, nitrite, Tumor necrosis factor (TNF-alpha) and malondialdehyde (MDA) but increased reduced glutathione (GSH) levels compared to control in pouch exudates. The HPLC fingerprint of EAF revealed presence of caffeic acid, rutin, ferulic acid and morin. Conclusion: Ethanol extract of Theobroma cacao and its ethylacetate fraction demonstrated anti-inflammatory activity partly by reducing neutrophil migration and inflammatory mediator production.