Phenolic-rich extract from the Costa Rican guava (Psidium friedrichsthalianum) pulp with antioxidant and anti-inflammatory activity. Potential for COPD therapy

Abstract The potential therapeutic effects of Costa Rican guava ( Psidium friedrichsthalianum ) extracts for chronic obstructive pulmonary disease were examined. The ethyl acetate fraction displayed the highest antioxidant activity, as compared to the hexane, chloroform, and n -butanol fractions, as well as the crude extract. This fraction was evaluated for its anti-inflammatory activity response relationship against interleukin-8 (IL-8) and inhibition of matrix metalloproteinase-1 (MMP-1) expression before and after treatment with cigarette smoke. The ethyl acetate fraction exhibited inhibitory activity against IL-8 production and MMP-1 expression, showing the most potent inhibitory activities in both assays at 100 μg/mL, and nine compounds ( 1 – 9 ) were found. Phenolic compounds 1- O - trans -cinnamoyl- β - d -glucopyranose ( 2 ), ellagic acid ( 3 ), myricetin ( 4 ), quercitrin ( 7 ), and quercetin ( 9 ) were identified using standard compounds or literature reports from related species. Compounds 1 , 5 , 6 , and 8 were tentatively identified as 1,5-dimethyl citrate ( 1 ), sinapic aldehyde 4- O - β - d -glucopyranose ( 5 ), 3,3′,4-tri- O -methylellagic acid-4′- O - d -glucopyranoside ( 6 ), and 1,3- O -diferuloylglycerol ( 8 ), All nine compounds are reported for the first time in Costa Rican guava.