Black Bean (Phaseolus vulgaris L.) Phenolic Extract Exhibits Antioxidant and Anti-Aging Potential

OBJECTIVES: The objective of this work was to evaluate the potential of common bean phenolic extract to exert anti-aging and antioxidant effect by inhibiting the collagenase, elastase, tyrosinase enzymes and free radicals. METHODS: 18 varieties of common bean (Phaseolus vulgaris L.) from Chiapas, Mexico, were analyzed for total phenolic content (TPC) and total anthocyanin content (ACN). Supercritical fluid (SCF) and leaching extractions were used for phenolic compounds extraction. Antioxidant capacity was evaluated using DPPH and ABTS scavenging assay. The inhibitory potential of the extract was evaluated for tyrosinase from mushroom, collagenase type-1 from Clostridium histolycum and elastase from porcine pancreas enzymes. RESULTS: The TPC ranged from 3.8–34.33 mg GAE/g coat and ACN ranged from 0.04–9.41 mg C3GE/g coat among the 18 common bean varieties (P < 0.05). The cultivar selected for this study was black bean with a TPC of 27.45 ± 0.7 mg GAE/g coat and ACN of 5.3 ± 0.1 mg C3GE/g coat. The best extraction conditions for the obtention of phenolic compounds and anthocyanins were SCF water-ethanol 50% as cosolvent, obtaining 66.60 ± 7.4 mg GAE/g coat (TPC) and 7.3 ± 0.6 mg C3GE/g coat (ACN). TPC and ACN content between each extraction process were statistically different (P < 0.05). For DPPH scavenging assay the IC50 for the black bean extract was 0.32 ± 0.01 mg GAE/g coat, and 0.40 ± 0.03 mg GAE/g coat for ABTS assay. Finally, the IC50 for the enzymatic inhibition assays of tyrosinase, collagenase and elastase were 10.44 ± 1.32, 8.33 ± 0.65 and 0.11 ± 0.02 mg GAE/g coat, respectively. CONCLUSIONS: Black bean (Phaseolus vulgaris L.) extract presents high antioxidant capacity and inhibitory potential for tyrosinase and metalloproteinases such as collagenase and elastase. Black bean phenolic extracts could be used in cosmeceutical products related to preventing oxidative stress and aging. FUNDING SOURCES: Author David Fonseca Hernández was supported by a scholarship from Consejo Nacional de Ciencia y Tecnología CONACyT-México, number 901,000. CONACYT-FORDECYT GRANT.