Flavonoid/Polyphenol Ratio in Mauritia flexuosa and Theobroma grandiflorum as an Indicator of Effective Antioxidant Action

Abstract

Studies on polyphenols and flavonoids in natural products reveal benefits in the prevention of multiple diseases. Proper extraction, treatment of extracts, and quantification of polyphenols and flavonoids demand attention from the scientific community in order to report more specific biological action. Total polyphenol content (TPC) and total flavonoid content (TFC) (measured at three different times) of ethanol, methanol and acetone extracts of Mauritia flexuosa (aguaje) and Theobroma grandiflorum (copoazú) fresh pulp, from the Colombian Amazon region, were evaluated with the purpose of focusing in the polyphenol/flavonoid proportion and its effective antioxidant activity. This objective could help to explain specific flavonoid biological action based on higher flavonoid proportion rather than higher total polyphenol content. Differences in extracting solvents resulted in statistically significant different yields; the highest TPC was observed with acetone 70% in Mauritia flexuosa and ethanol 80% for T. grandiflorum. The best flavonoid/polyphenol ratio in M. flexuosa was about 1:2.4 and 1:12.8 in T. grandiflorum and the antioxidant efficacy was proportionally higher for flavonoids extracted from T. grandiflorum. HPLC analysis revealed 54 µg/g of the flavonoid kaempferol in M. Flexuosa and 29 µg/g in T. grandiflorum. Further studies evaluating this proportionality, in seeds or peel of fruits, as well as, other specific biological activities, could help to understand the detailed flavonoid action without focusing on the high total polyphenol content.

Antioxidant Activity of Polyphenols, from Mauritia flexuosa (Aguaje), Based on Controlled Dehydration

“…All samples were refrigerated before laboratory analyses. The extraction of total polyphenol compounds was performed following a previous method from this research group [ 2 , 51 ]. Different amounts of fresh and dehydrated pulp and seeds of M. flexuosa were placed in ethanol (80% w/v ) at proportions of 1:5 per volume, stirred for 15 min at 500 rpm, homogenized, and stored at room temperature, in the dark, for 24 h without stirring.…”

“…The DPPH compound is a stable free radical in methanol. The DPPH assay was performed following previous work from this research group [ 2 ]. Volumes of 1900 μL of DPPH (100 μM) prepared in pure methanol were mixed with 100 μL of each diluted (1:5) extract and left to react in the dark at room temperature for 30 min.…”

“…The antioxidant benefit of fruit consumption is mainly connected to the polyphenol content; these types of phytochemicals display several other functions [ 1 , 2 ]. Multiple publications have reported improved lipid metabolism in overweight and obese humans due to a regular diet inclusion of plant polyphenols [ 3 , 4 , 5 ].…”

“…Commonly known as buriti plant, Mauritia flexuosa (Arecaceae) is a palm broadly cultivated in Colombia, Venezuela, the Guianas, Trinidad, Ecuador, Peru, Brazil, and Bolivia [ 2 , 14 ]. The fresh form of M. flexuosa fruits ( Figure 1 ) has an orange, soft, water-soluble, and edible pulp and numerous small circular dark red and brown flat seeds.…”

“…The mesocarp oil is used to treat respiratory symptoms, pneumonia, influenza, snake bites, and heart problems [ 20 ]. In Colombia, M. flexuosa is also named “aguaje” [ 2 ].…”