Optimization of the Extraction of Procyanidin B-2 Rich Extract from Unfermented Cocoa Using Response Surface Methodology and Interaction of Procyanidin B-2 Rich Cocoa Extract with Collagenase and Elastase as Biomarkers of Skin Aging

Abstract

Skin ageing is a natural process accelerated by environmental exposure that generate reactive oxygen species and activates enzymes that degrade the integrity of the dermis. Cocoa powder (Theobroma cacao) is a good source of polyphenols, particularly procyanidins and flavan-3-ols, with potential enzyme inhibitory activities. In this study we determined whether cocoa extraction standardized to its procyanidin B-2 content has a potential application as anti-ageing bioactive compound. Oil-bath-assisted extraction (OBAE) and microwave-assisted extraction (MAE) were optimized for procyanidin B-2 rich extract using response surface methodology and water as solvent. Methanol (70% in water) extraction was the control to which other extraction methods were compared. The molecular masses distributions of the extracts were evaluated using MALDI-TOF-MS. The best extraction method was compared to methanol extraction through the extract inhibitory effect on collagenase and elastase. OBAE optimal conditions were 1:16 cocoa:water ratio, 48 min, and 115°C; while, MAE optimal conditions were 1:16 cocoa:water ratio, 13 min, and 115°C. The procyanidin B-2 content from OBAE (8.90 mg/g cocoa) was significantly (P < 0.05) greater than MAE (7.64 mg/g cocoa) or methanol (7.07 mg/g cocoa) extract. Methanol extract showed more compounds peak distribution than OBAE or MAE. Most of the compounds extracted were below 1000 Da regardless of the method of extraction. Methanol extraction was more effective in inhibiting collagenase or elastase activities than OBAE than epigallocatechin gallate, a well-known natural inhibitor of these two enzymes. Regardless of the method of extraction, this study has shown promising results for the use of cocoa extract as an active ingredient for the cosmetic industry.