Black and pinto beans (Phaseolus vulgaris L.) unique mexican varieties exhibit antioxidant and anti-inflammatory potential.

ABSTRACT

Oxidative stress and inflammation play a key role in diverse pathological conditions such as cancer and metabolic disorders. The objective of this study was to determine the antioxidant and anti-inflammatory potentials of crude extract (CE) and phenolic-enriched extract (PHE) obtained from the seed coats (SCs) of black bean (BB) and pinto bean (PB) varieties. Delphinidin-3-O-glucoside (46 mg/g SC), malvidin-3-O-glucoside (29.9 mg/g SC), and petunidin-3-O-glucoside (7.5 mg/g SC) were found in major concentrations in the PHE-BB. Pelargonidin (0.53 mg/g SC) was only identified in the PHE-PB. PHE from both varieties showed antioxidant and radical scavenging capacities, with strong correlations associated with total phenolic content (TPC). Polyphenolics, including catechin, myricetin, kaempferol, quercetin, and isorhamnetin glucosides, were identified in the extracts. In terms of the anti-inflammatory potentials, PHE-PB had an IC50 of 10.5 µg dry extract/mL (µg DE/mL) for cyclooxygenase-2 (COX-2) inhibition. The inhibition values for cyclooxygenase-1 (COX-1) ranged from 118.1 to 162.7 µg DE/mL. Regarding inducible nitric oxide synthase (iNOS) inhibition, PHE-BB had an IC50 of 62.6 µg DE/mL. As determined via in silico analysis, pelargonidin showed binding affinities of -7.8 and -8.5 kcal/mol for COX-1 and iNOS, respectively, and catechin had a value of -8.3 kcal/mol for COX-2. Phenolic-enriched extracts from seed coats of black and pinto beans showed good antioxidant and anti-inflammatory potential that warrants in vitro and in vivo studies.